Gravitational lensing occurs when things with mass create ripples and dents in the fabric of spacetime, and light has to follow along those lines, which sometimes create a magnifying glass effect. This both sounds and looks like something wild from science fiction, but it’s actually a very important tool in astronomy. The James Webb Space Telescope has been in the news a lot recently for just this: watching how light bends around massive galaxy clusters in space, revealing fainter, further away old galaxies behind them. 

Now, Slava Turyshev, a scientist at NASA’s Jet Propulsion Lab, is trying to harness one of these gravitational lenses closer to home, using our sun. In a new paper posted to the pre-print server arXiv, Turyshev computes all the detailed math and physics needed to show that it is actually possible to harness our sun’s gravity in this way, with some pretty neat uses. A so-called “solar gravitational lens” (SGL) could help us beam light messages into the stars for interstellar communication or investigate the surfaces of distant exoplanets.

“By harnessing the gravitational lensing effect of our star, astronomy would experience a revolutionary leap in observing capability,” says Nick Tusay, a Penn State astronomer not involved in the new work. “Light works both ways, so it could also boost our transmitting capability as well, if we had anyone out there to communicate with.”

When it comes to telescopes here on Earth, bigger is definitely better. To collect enough light to spot really faint far away objects, you need a huge mirror or lens to focus the light—but we can really only build them so big. This is where the SGL comes in, as an alternative to building bigger telescopes, instead relying on spacetime bent by the sun’s gravity to do the focusing for us. 

“Using the SGL removes the need to build larger telescopes and instead raises the problem of how to get a telescope out to the focal distance of the Sun (and how to keep it there),” explains Macy Huston, a Berkeley astronomer not involved in the new research. “And there’s a lot of work ongoing to try to solve this,” they add.

Turyshev is actively working on a mission design to send a one-meter telescope (less than half the size of the famous Hubble) out to the focus of the sun’s gravitational well. It’s quite a trek—this focal point is located about 650 AU out from our star, almost five times out from humanity’s current distance record holder, Voyager 1. To get out to such a huge distance in less than a lifetime, the team is relying on cutting-edge solar sail technology to move faster than ever before.

Currently, the James Webb Space Telescope is investigating the atmospheres of planets around other stars, and the future Habitable Worlds Observatory in the 2040s will hopefully be able to see enough detail in exoplanetary atmospheres to find hints of life. Turyshev’s mission would be the next big step towards confirming life on other worlds, hopefully launching around 2035. Once JWST and HWO identify possibly interesting worlds, the SGL telescope will then actually map the surface of an exoplanet in detail. Turyshev claims it would be able to see a planet blown up to 700 by 700 pixels—a huge improvement on direct imaging’s current 2 or 3 pixels. “If there is a swamp on that exoplanet, emitting methane, we’ll know that’s what is positioned on this continent on this island, for example,” he explains.

Looking further into the sci-fi future, this same SGL technology could be used not only “as a telescope we could use from the solar system to view other planetary systems in great detail” but also as an “interstellar communication network (for intentional communications),” says Huston. A laser positioned at the sun’s gravitational focus could send messages to other stars without losing as much signal as our current Earth-bound beacon tech.

“If we were to ever become an interstellar civilization, this [SGL] could potentially be the most effective means of communication between star systems,” says Tusay. Our radio transmissions, leaking out of Earth’s atmosphere since the early 1900s, rapidly become fainter the further away from our planet. Turyshev’s mathematical calculations show that signals sent from the SGL could be easily noticed at the distances of nearby stars, even when accounting for the noisy background of the real world. Transmission via the SGL is “not prohibited, it’s really encouraged by physics,” says Turyshev.

This tech wouldn’t solve all our interstellar roadblocks, though. We might be able to send messages, but we still don’t have a way of sending ourselves out amongst the stars to travel. There’d also be a huge delay in our galactic calls—more like sending a cross-country letter by horseback than FaceTiming with your friends. “Light still has a maximum speed,” reminds Tusay. As a result, sending a message to a star four light-years away would take four years to get there, and another four for the response to reach us. Still, the solar gravitational lens is one big step towards making our science fiction futures a reality.

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NASA’s Juno spacecraft has been exploring Jupiter since it arrived at the planet in 2016. In recent years, the mission has turned its attention to the gas giant’s many moons, including the hellish volcanic world Io and the ice ball Europa. Now, in research published in Nature Astronomy, the Juno team revealed new photos of Jupiter’s largest moon, Ganymede, which show evidence of salts and organic compounds. These materials are likely the residue of salty sea water from an underground ocean that bubbled up to the frozen surface of Ganymede. And, excitingly, a salty ocean indicates conditions there might be conducive to life.

Ganymede is a particularly weird place. Not only is it Jupiter’s most massive satellite, it’s the biggest moon in the whole solar system—it’s even larger than the planet Mercury. It also is the only moon to have its own magnetic field, generated from a molten metal core deep in its interior. Like other icy worlds of the outer solar system, such as Europa or possibly Pluto, Ganymede probably has an ocean lurking under its icy crust. Some studies suggest multiple seas, stacked together in a layer cake of ice sheets and oceans, hide underground.

“Because Ganymede is so big, its interior structure is more complicated” than that of smaller worlds, explains University of Arizona geologist Adeene Denton, who is not affiliated with the new work. She notes that the moon’s massive size means there’s a lot of space for interesting molecules to mix about. But that also means they’re tricky to spot, because material must cover a large distance  to get to the surface where our spacecraft can see them.

Juno finally passed close enough to Ganymede—within 650 miles, less than the distance from New York City to Chicago—to take a close look at the chemicals on its surface using its Jovian InfraRed Auroral Mapper (JIRAM). This incredible instrument tracked the composition of Ganymede’s surface in great detail, noting features as small as 1 kilometer wide. If JIRAM were looking at New York City, it would be able to map Manhattan in ten-block chunks.

[Related: Astronomers find 12 more moons orbiting Jupiter]

Importantly, material on the surface of Ganymede might tell us about the water hiding below. If there are salts above, the subsurface ocean might have that same brine. Oceans, including the ones on Earth, acquire their salt from chemical interactions where liquid water touches a rocky mantle. This kind of exchange is “one of the conditions necessary for habitability,” says lead author Federico Tosi, research scientist at the National Institute for Astrophysics in Rome, Italy.

However, other current research suggests that Ganymede doesn’t have a liquid water layer directly touching its mantle. Instead, icy crusts separate the ocean from the rock. But because the team did see these salts in the JIRAM data, it suggests they were touching at one point in the past, if not now. “This testifies to an era when the ocean must have been in direct contact with the rocky mantle,” explains Tosi.

As for the organic chemicals that Juno detected, the team still isn’t completely  sure what flavor of compound they are. They’re leaning towards aliphatic aldehydes, a type of molecule found elsewhere in the solar system that’s known as an intermediate step necessary to build more complex amino acids. These usually indicate liquid water and a rocky mantle are interacting. This definitely isn’t a detection of life, but it’s interesting for the possibility of life lurking in Ganymede’s hidden oceans. “The presence of organic compounds does not imply the presence of life forms,” says Tosi. “But the opposite is true: life requires the presence of some categories of organic compounds.”

[Related: Why a 3,000-mile-long jet stream on Jupiter surprised NASA scientists]

Unfortunately, Juno won’t have a chance to swing by Ganymede again to search for more salty shores—instead, it’s headed toward the explosive Io. The probe’s most recent survey of these minerals was a “a unique opportunity to take a close look at this satellite,” Tosi says. We won’t have to wait too much longer, though, for a second visit. In about ten years, he adds, we’ll get another chance to explore these salty waters with the ESA JUICE mission, “which is expected to achieve complete and unprecedented coverage of Ganymede.”

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In the summer, astronomers spotted an airplane-sized asteroid—large enough to potentially destroy a city—on an almost-collision course with Earth. But no one saw the space rock until two days after it had zoomed past our planet. 

This asteroid, named 2023 NT1, passed by us at only one-fourth of the distance from Earth to the moon. That’s far too close for comfort. Astronomers weren’t going to let this incident go without a post-mortem. They’ve recently dissected what went wrong and how we can better prepare to defend our planet from future impacts, in a new paper recently posted to the preprint server arXiv.

We know from history that asteroids can cause world-shattering events and extinctions—just look at what happened to the dinosaurs. The study team estimated that, if NT1 hit Earth, it could have the energy of anywhere from 4 to 80 intercontinental ballistic missiles. “2023 NT1 would have been much worse than the Chelyabinsk airburst,” says University of California, Santa Barbara astronomer Philip Lubin, a co-author on the new work, referring to the meteor that exploded over a Russian city in 2013. As devastating as that would be, it’s “not an existential threat like the 10-kilometer hit that killed our previous tenants,” he adds.

The asteroid-monitoring system ATLAS, the “Asteroid Terrestrial-impact Last Alert System”—four telescopes in Hawaii, Chile, and South Africa—discovered NT1 after the rock flew by. ATLAS’s entire purpose is to scour the skies for space rocks that might threaten Earth. So with this set of eyes on the sky, how did we miss it? 

It turns out that Earth has what Brin Bailey, UC Santa Barbara astronomer and lead author on the paper, calls a “blindspot.” Any asteroid coming from the direction of the sun gets lost in the glare of our nearest star.” There’s another way for asteroids to sneak up on us, too: the smaller the asteroid, the harder it is for our telescopes to spot them, even when the rocks come from parts in the sky away from the sun.

[Related: NASA’s first asteroid-return sample is a goldmine of life-sustaining materials]

“Currently, there is no planetary defense system which can mitigate short-warning threats,” Bailey says. “While NT1 has no chance of intercepting Earth in the future, it serves as a reminder that we do not have complete situational awareness of all potential threats in the solar system,” they add. That leads to Lesson #1: We simply need better detection methods for planetary defense. 

If we can manage to detect an asteroid with a few years’ warning, we might be able to redirect it with the technology recently tested by NASA’s Double-Asteroid Redirection Test (DART) mission.For a case with very little warning, such as NT1, though, we’d need a different approach—that’s Lesson #2. Bailey and colleagues propose a method they call “Pulverize It” (PI). 

PI’s plan is exactly what it sounds like: break the asteroid into tiny pieces, small enough to burn up in the atmosphere or fall to the ground as much less dangerous little rocks. They’d do this by launching one or multiple rockets to send arrays of small impactors to space. The impactors—six-foot-long, six-inch-thick rods—would smash into the asteroid like buckshot, efficiently dismantling it. “Had we intercepted it [NT1] even one day prior to impact, we could have prevented any significant damage,” claims Lubin.

It sounds simple enough, but some astronomers aren’t quite convinced. “I think the PI method is impractical even though it does not violate the laws of physics,” says University of California, Los Angeles astronomer Ned Wright, who was not involved in the new work. “When a building is demolished by implosion using explosive charges, a weeks-long testing and planning phase is needed in order to place the charges in the right locations and set up the proper timing. The PI method seeks to do this measuring, planning, and placing the explosives all within a period of 1 minute or so just before the spacecraft hits the asteroid.”

[Related: NASA’s first attempt to smack an asteroid was picture perfect]

Lubin points out that unlike a careful demolition on Earth, the goal is a sudden, bomb-like explosion—an event that needs less prep to pull off. But whether we use PI or another line of defense, it’s clear that we need to plan ahead. Not only is there the hazy threat of an asteroid coming out of nowhere, there are two specific, extremely risky events headed our way: asteroid Apophis’ near flyby in 2029, and close approaches from the even larger Bennu (recently sampled by NASA’s OSIRIS-REx mission) in 2054, 2060, and 2135.

“Humanity now possesses the technology to robustly detect and defend the planet if we choose to do so,” says Lubin. “And a variety of people are working hard to ensure we can.”

This story has been updated: An earlier version indicated that the asteroid-destroying impactors would be filled with explosives. While that may be an option, most forms of the “Pulverize It” method use non-explosive metal rods.

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Humans have been changing the atmosphere from Earth’s surface for nearly two centuries—but now in the Space Age, we’re altering it from outer space, too. Atmospheric scientists recently found traces of unexpected metals in the stratosphere, the second-lowest layer of the atmosphere where ozone resides and meteors burn up into shooting stars. The researchers determined that this pollution came from spacecraft as they reenter Earth’s atmosphere, in research published last week in the journal Proceedings of the National Academy of Sciences. 

This study is “the first observational evidence that space activities are a very significant source of particulate pollution to the stratosphere” says Slimane Bekki, an atmospheric scientist at LATMOS not involved in the new work. “More importantly, nobody knows the impacts of these particles on the ozone layer,” he adds, pointing out the importance of this molecule in shielding humans from dangerous UV radiation.

Usually, mission planners’ main concern is to ensure that space debris doesn’t hit the ground, where it could hurt people or structures—but, as this research points out, what evaporates in the stratosphere could still be making an impact, even if it’s not a literal one. That material has to exist somewhere, and it looks like it’s lingering in the stratosphere. “We are finding this human-made material in what we consider a pristine area of the atmosphere. And if something is changing in the stratosphere—this stable region of the atmosphere—that deserves a closer look,” said co-author and Purdue atmospheric scientist Dan Cziczo in a press release. 

[Related on PopSci+: Rocket fuel might be polluting the Earth’s upper atmosphere]

The research team flew through the stratosphere across the continental US in aircraft specially designed to fly at high altitudes, equipped with air-analyzing instruments in their nose cones. These unique planes— NASA’s ER-2 and WB-57—cruise at around 65,000 feet, almost double the altitude of typical passenger jets. Flying as high as 70,000 feet, the research craft can go above 99 percent of the mass of Earth’s atmosphere.

Within the stratosphere, the collecting equipment on these planes recorded traces of the heavy metals niobium and hafnium. These elements aren’t found naturally in the atmosphere, but they are typically used in rockets and spacecraft shells. The team also measured higher-than-expected concentrations of over 20 metals, including copper, lithium, aluminum, and lead. All told, about 10 percent of aerosol particles in the stratosphere contain metals. 

Atmospheric scientists aren’t sure exactly how these changes will affect Earth. The stratosphere contains tiny blobs of sulfuric acid, which are now infused with the metals from old spacecraft. The presence of those metals could change the chemistry of the stratosphere, including how big the sulfuric acid drops grow. Even small tweaks high up could affect the way light bends, the transfer of heat, or how crystals of ice grow. 

The big question is how these changes will affect human life on the surface. Unfortunately, there’s no clear answer to that, but in the past small stratospheric changes have led to big impacts—like adding CFCs that ate away at the ozone layer. Eventually, there may need to be additional environmental precautions for spaceflight to prevent harm to the stratosphere.

[Related: This beautiful map of Earth’s atmosphere shows a world on fire]

“The only way for these particles not to appear in the upper atmosphere is for the satellites not to be launched in the first place,” explains University of Exeter atmospheric scientist Jamie Shutler, who was not part of the research team. “The possible ways forward are to launch less, make the satellites last for longer (so we need to launch less), or encourage industry to make the constituents of satellites public knowledge (so we can guide manufacturers as to the potential harmful effects).” He adds that this new finding “confirms our concern” about stratospheric contamination.

But before we can solve this problem, “the concept that reentry can affect the stratosphere has to be thought about,” says lead author Daniel Murphy, atmospheric scientist at NOAA. He emphasized that this idea is still incredibly new and will require much more research to understand the scale and potential consequences of this pollution.

Potential impacts are expected only to grow as the rate of spacecraft launches and reentries accelerate. In the last five years, space agencies and private companies have launched more than 5,000 satellites, noted Martin Ross, co-author on the work and climate scientist at The Aerospace Corporation, in a press release. “Most of them will come back in the next five, and we need to know how that might further affect stratospheric aerosols,” he said. The team expects that the proportion of particles containing metal could grow from 10 to more than 50 percent in the next few decades, especially thanks to upcoming plans to reduce space debris by hurling it back into the atmosphere.

Those efforts and upcoming launches, though, need to be aware of the possible effects on Earth—and researchers need to do more work to determine the extent of those effects. “Understanding our planet is one of the most urgent research priorities there is,” said Cziczo.

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Last Friday, NASA launched the Psyche spacecraft toward an asteroid of the same name. Psyche is blazing a trail as the first mission to a metal asteroid, and it’s also about to blaze a literal blue trail. The source of its bright wake—the probe’s remarkable propulsive system—will switch on within the first 100 days of the mission.

A mechanism known as a Hall thruster will propel the Psyche through space. This thruster glows blue as it ionizes xenon, a noble gas also used in headlights and plasma televisions, to move the spacecraft forward. This is the first time this tech, which has only been available for NASA spaceflight since 2015, has been used to travel beyond the moon—but what makes it so special, and why is Psyche using it?

When planning a space mission, engineers are focused on efficiency. Carrying chemical fuel along for the massive interplanetary journey would be like trying to drive around the entire world while having to keep all the gasoline you need in the trunk, because there are no rest stops along the way—it’s just not feasible. To get to its destination, Psyche would need thousands and thousands of pounds of chemical propellant.

[Related: How tiny spacecraft could ‘sail’ to Mars surprisingly quickly]

To get around this problem, engineers turned to electric thrusters. These come in many flavors: “There are many different types of electric thrusters, almost as many as there are different makers of cars,” explained NASA’s Psyche chief engineer Dan Goebel in a blog post. But space travel uses two kinds in particular, known as ion thrusters and Hall thrusters. “They can probably be considered the Tesla versions of space propulsion,” Goebel wrote. Rather than burning fuel, electric thrusters rip off the electrons from the propellant’s atoms in a process known as ionization. Then they chuck those ions out at some 80,000 miles per hour. This generates a higher specific impulse—which Goebel says is “equivalent to miles per gallon in your car,” but for spacecraft—than chemical fuels, enabling a thruster-powered spacecraft to go farther on less propellant.

Ion thrusters use high electric voltages to make a plasma (the fourth state of matter) and spew ions into space. NASA’s Dawn mission used these to get to dwarf planet Ceres, but they’re not the fastest—according to NASA, it would take the spacecraft four days to go from 0 to 60 miles per hour. Definitely not race car material! 

[Related: Want to learn about something in space? Crash into it.]

Hall thrusters, on the other hand, use a magnetic field to swirl electrons in a circle, producing a beam of ions. They don’t get quite as good “mileage” as ion thrusters, but they pack a bigger punch. The Psyche team picked this system because it allowed them to make a smaller, and therefore more cost-efficient, spacecraft. 

For the thrusters to work, the spacecraft needs power—which it gets from the sun, via solar panels—and something to ionize. For Psyche, that’s xenon gas. “Xenon is the propellant of choice because it’s inert (it doesn’t react with the rest of the spacecraft) and is easy to ionize,” explained Goebel. It also gives the thrusters their remarkable blue shine. Psyche carries about 150 gallons of the stuff, and gets about 10 million miles per gallon. 

Now that the mission has launched, the team will spend the next 100 days checking out all the spacecraft’s systems to ensure they’re ready for the journey. At some point in this period, those glimmering blue thrusters will turn on.

If Psyche proves to be a success, Hall thrusters will be likely to make an appearance on future space missions. They offer “the right mix of cost savings, efficiency, and power, and could play an important role in supporting future science missions to Mars and beyond,” said Steven Scott, program manager for the Psyche mission at the company Maxar, which built the thrusters, in a press release. Thanks to these propulsive devices, Psyche should reach its destination in the asteroid belt in just 3.5 years—and we can’t wait to see what lies at the end of its electric blue trail.

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The universe is expanding—but astronomers can’t agree how fast. And NASA’s superstar observatory, the James Webb Space Telescope, just confirmed there’s a problem in our understanding of the stretching cosmos. JWST’s new measurements are the most precise of their kind, but they don’t clear up a baffling mismatch in the two methods scientists track this growth. 

In 1929, astronomer Edwin Hubble discovered that all the galaxies we can see are moving away from us. The relationship between the distance to a galaxy and how fast it’s moving is now known as Hubble’s law. This law uses the also-eponymous Hubble constant to describe the rate at which the universe is expanding. It also tells us the age of the universe: Astronomers can use the Hubble constant to “rewind” time to when the universe would be a single point in space—the big bang.

There are two main ways to measure this fundamental number. One is by tracing tiny fluctuations in the cosmic microwave background from the beginning of the universe. The other is to watch flickering stars known as Cepheids. But those two methods disagree. This baffling mismatch is known as the Hubble tension, and it’s unclear if it’s a problem with our models of the universe or our measurements.

If it’s our measurements, the error might result from the way we survey Cepheid stars. Astronomers consider these objects to be a type of “standard candle,” a thing in space whose intrinsic brightness is known. We can observe how bright one of these stars looks in the sky. If it’s faint, it’s farther away. Brighter is closer. 

Researchers use the luminosity of these stars like a yardstick to measure distance. Then, with methods such as spectroscopy, they can gauge the motion of far-off galaxies. Putting those observations together tells us how fast the universe is expanding.

[Related: NASA releases Hubble images of cotton candy-colored clouds in Orion Nebula]

“When we use Cepheids like this, we need to be very, very sure we’re measuring their brightnesses correctly, otherwise our distance measurements will be off. However, Cepheids can be in crowded parts of their galaxies and if our telescopes aren’t sensitive enough, we can’t clearly distinguish a Cepheid from the stars around it,” explains astronomer Tarini Konchady, a program officer at the National Academies of Sciences, Engineering, and Medicine. 

Before JWST, the Hubble Space Telescope (HST) took the best measurements of Cepheid stars. HST couldn’t distinguish individual Cepheids where they were bunched in crowded regions, but JWST can—and it just did. JWST peered into two distant galaxies, and made measurements of the Hubble constant 2.5 times better than HST could. 

“Webb’s measurements have dramatically cut the noise in the Cepheid measurements,” said project lead Adam Riess, an astronomer at Johns Hopkins University in a NASA press release. “This kind of improvement is the stuff astronomers dream of!”

One of JWST’s major advantages is its ability to look at the cosmos in infrared light, which helps cut through dust between our telescopes and the Cepheids. “Sharp infrared vision is one of the James Webb Space Telescope’s superpowers,” Riess said.

[Related: How old is the universe? Our answer keeps getting more precise.]

However, the new measurements matched up with those from HST, just with smaller error bars—so we can’t confidently pin the mystery on those old numbers.

The new results from Riess and team are just the beginning, though, and they still have many more galaxies to observe with JWST. “I think the jury is still out on whether the JWST has completely eliminated crowding as a solution to the Hubble tension,” says University of Chicago astronomer Abigail Lee. “Analyzing the data for the rest of the 42 galaxies [that JWST plans to observe] will illuminate whether the Hubble tension is alive and real or if there are indeed just errors in the Cepheid measurements.”

The fate of the universe, or at least the Hubble tension, doesn’t just hinge on JWST. Many other facilities will come online in the next few years, providing more evidence for this investigation. The Vera Rubin Observatory, for example, is going to scan the whole Southern sky every few nights when it opens next year, and will likely discover many more Cepheid stars.

“We’re at a point where astronomers are going to be deluged by the most sensitive and wide-reaching data yet,” says Konchady. There might not be a clear answer yet, but astronomers are surely on the case to figure out this mystery.

This post has been updated to include additional details about astronomical methods for measuring the expansion rate.

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Trillions of particles from distant stars and galaxies are streaming through your body every second—you just can’t feel them. These ghost-like particles are called neutrinos. Although the universe spits them out constantly, these objects barely interact with matter—they can even slip through humanity’s toughest barriers, such as steel or lead walls. 

Some neutrinos come from supernovae, the extravagant deaths of the biggest stars; they’re also produced by radioactive decay in Earth’s rocks, reactions in the sun, and even our planet’s aurorae. These hard-to-see particles are all over the place and crucial to multiple areas of science, but we’re still in need of better ways of finding them. Now, a new observatory under construction in China’s Guangdong province—the Jiangmen Underground Neutrino Observatory, or JUNO—plans to hunt these elusive particles with better sensitivity than ever before. 

Like most neutrino detectors, it’s a huge vat filled with liquid for the neutrinos to interact with—the bigger the net, the more fish you’re likely to catch. “When it is completed, JUNO will be 20 times larger than the largest existing detector of the same type,” says Yufeng Li, a researcher and member of the JUNO collaboration at the Institute of High Energy Physics (IHEP) in Beijing. Currently under construction and expected to start operation in 2024, this detector will not only be bigger, but also more sensitive to slight variations in neutrinos’ energies than any of its predecessors. Li adds, it’s going to be “a unique and important observatory in the community.”

[Related: The Milky Way’s ghostly neutrinos have finally been found]

The observatory’s most ambitious goal is to preemptively spot neutrinos from stars that are dying but haven’t exploded yet. That way, telescopes can catch these stars in their final destructive act. “Neutrinos are expected to reach Earth hours earlier than photons because of their weakly-interacting nature,” explains Irene Tamborra, a physicist at the Niels Bohr Institute in Denmark not affiliated with the project. 

Astronomers still don’t know the finer details of how a star explodes, but observing the supernova as it starts might help give some clues. “The early detection of neutrinos will be crucial to point the telescopes in the direction of the supernova and catch its electromagnetic emission early on,” adds Tamborra. JUNO should be able to alert astronomers hours to days before a star is slated to explode, giving them time to prep and point their telescopes. It might even be able to measure the faint background of neutrinos coming from distant supernovae, all across the galaxy, which is of great interest to cosmologists trying to put together a picture of the whole universe. 

In addition to supernovae, the observatory will be searching for neutrinos from much closer to home: nuclear reactors. The nearby Yangjiang and Taishan nuclear power plants produce neutrinos, and physicists are hoping to get a taste of those neutrinos’ flavors with JUNO. Neutrinos come in three flavors (yes, they’re really called that!), known as the electron, tau, and muon neutrinos. They can flip between their different states in so-called oscillations. Scientists can calculate the number of neutrinos of each kind they expect from the power plant, and compare to what they actually observe with JUNO to better understand these flips.

[Related: This ghostly particle may be why dark matter keeps eluding us]

“It is also very likely that there will be surprise discoveries, as that often happens when powerful new experiments are deployed,” says Ohio State University astrophysicist John Beacom.

JUNO isn’t the only big observatory after neutrinos. The current largest liquid neutrino detector is Super-Kamiokande in Japan, and researchers there are planning a huge upgrade to make it the Hyper-Kamiokande. The United States is getting in the game too, currently using a detector at the Fermi National Accelerator Lab and planning its own multi-billion-dollar next-gen observatory, called the Deep Underground Neutrino Experiment. These projects are a few years away, though, so IHEP president Yifang Wang told Science that he gives JUNO “3-to-1 odds to get there first” to figure out some fundamental properties of neutrinos.

No matter who wins the race, this observatory is opening up one of our windows to the universe a bit wider. “JUNO is a huge step forward for neutrino physics and astrophysics,” Beacom says, “and I’m very excited to see what it will do.”

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Every year or two, the solar system lines up just right, with the moon casting a shadow over part of Earth’s surface and blocking out the sun—a solar eclipse. In 2017, people across the United States flocked to see the “Great American Total Eclipse”, which was the first one visible in the continental states since 1979. Now, eclipse chasers and citizen scientists across North America are getting ready for the next big events: an annular eclipse on October 14, 2023 and a total eclipse on April 8, 2024. This will be the last eclipse visible in the continental US until August 2045, more than two decades away. 

People love eclipses for the novelty—how cool it is to see the sun disappear in the day. But these phenomena are both showstoppers and opportunities: a group of radio astronomers and citizen scientists called Radio JOVE is aiming to capitalize on the upcoming eclipses for science, part of NASA’s “Helio Big Year.”

Radio JOVE “initially started as an education and outreach project to help students, teachers, and the general public get involved in science,” explains project co-founder Chuck Higgins, an astronomer at Middle Tennessee State University. The project has been running since the late 1990s, when it began at NASA’s Goddard Space Flight Center. “We now focus on science and try to inspire people to become citizen scientists.” 

As its name suggests, Radio JOVE originally focused on the Jovian planet, Jupiter. “Serendipitously, it turns out that the same radio wavelengths we use for observing Jupiter are also useful for observing the sun,” says Thomas Ashcraft, a citizen scientist from New Mexico who has been observing with Radio JOVE since 2001. After the 2017 Great American Eclipse, its members became more involved with heliophysics, the study of the sun.

[Related: Total eclipses aren’t that rare—and you’ve probably missed a bunch of them]

As energy spews from the sun and travels to Earth, it interacts with our planet’s atmosphere; in particular, the sun’s rays create a layer of ionized particles, known as the ionosphere. Any radio waves coming from the sun have to pass through these particles above us. Communication technology takes advantage of this layer, bouncing radio waves off it to travel long distances.

The ionosphere’s plasma changes a lot between day and night. When the sun shines on this layer, particles break into ions. When the sun is absent, those ions calm down. During eclipses, when most of the sun’s light is blocked, similar changes happen in the short term change. By measuring those fluctuations precisely with a fleet of amateur observers, Radio JOVE hopes to improve our understanding of the ionosphere.

To do so, Radio JOVE is equipping citizen scientists across the country with small radio receivers and training them to observe radio waves from Earth’s ionosphere. The project offers some-assembly-required starter kits for around $200, and a whole team of experts and experienced observers are around to support new volunteers. 

[Related: The best US parks for eclipse chasers to see October’s annularity]

Right now, they’re prepping participants for a full day of observing during the October annular eclipse. Project members are already gathering data to have a baseline of the sun’s influence on a normal day, which they’ll compare to the upcoming eclipse data. And this is only a small taste before the big event: next year’s total eclipse. “The 2023 annular eclipse will be used as a training, learning, and testing experience in an effort to achieve the highest quality data for the 2024 total eclipse,” Higgins wrote in a summary for an American Geophysical Union conference.

Citizen science projects such as Radio JOVE not only collect valuable data, but they also involve a new crowd in NASA’s scientific community. Anyone interested in science can join in, and if Radio JOVE doesn’t suit your interests, NASA has a long list of other opportunities. For example, if you’re a ham radio operator, you can get involved with HamSCI, which also plans to observe the upcoming eclipse.

“NASA’s Radio JOVE Citizen Science Project allows me to further explore my lifelong interest in astronomy,” said John Cox, a Radio JOVE citizen scientist from South Carolina, in a NASA press release. “A whole new portion of the electromagnetic spectrum is now open to me.”

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Our understanding of the solar system is a work in progress. Pluto’s demotion to a dwarf planet was just one of many revisions—in recent decades astronomers have cataloged new dwarfs, like far-off Eris, and spotted more moons around our gas giant neighbors. And now some researchers think there’s evidence for a new planet hiding beyond Neptune.

Two astronomers in Japan, Patryk Sofia Lykawka and Takashi Ito, claim there is a planet a little larger than Earth lurking in the Kuiper belt, the ring of icy debris where Pluto also resides, as they published last week in The Astronomical Journal. The pair hasn’t seen this world directly, but their computer models show that such a planet could explain the wonky observed orbits of other Kuiper belt objects.

The disturbance in this belt “predicts the existence” of an undiscovered planet with 1.5 to 3 times the mass of Earth, says lead author Lykawka, an astronomer at Japan’s Kindai University. “The solar system would officially have nine planets again.”

[Related: There might be an ice giant planet hiding in our solar system]

The Kuiper belt is somewhat similar to the asteroid belt: It contains small bits of rock and ice, all leftovers from the violent process of making planets. A few objects there have strange orbits, where their paths around the sun are extremely tilted or elongated (more egg-shaped than circular like Earth’s orbit). These weird orbits suggest that something massive must be pushing them around, tugged by  its gravity—something as big as an  undiscovered planet.

“It may be that this planet will be uncovered even in the next few years, if it exists on a relatively nearby orbit,” says Yale astronomer Malena Rice, who wasn’t involved in the new work.

Lykawka and Ito’s simulations show that a planet could explain the oddities in the Kuiper belt. The world, which they referred to as the Kuiper Belt Planet (KBP), would be located about 6 to 12 times further from the sun than even distant Neptune. The KBP’s orbit would also have to be tilted from the plane of the solar system by about 30 degrees, which is pretty weird. Dwarf planet Pluto sticks out because it’s off-kilter compared to the eight major planets—and its orbit is only tilted by about 17 degrees.

This bizarre and distant Earth-like planet, though, isn’t the first hidden world to be proposed. In 2016, astronomers from Caltech claimed to have evidence for a super-Earth, referred to as Planet 9 or Planet X, even farther out in the solar system. Those researchers also proposed Planet 9 as a way to explain the quirks of the Kuiper Belt; it caused quite a stir among scientists, who debated for years whether those idiosyncrasies were real or just the result of flawed observations.

Lykawka claims that the KBP hypothesis is superior to Planet 9 because it relies on other observations that haven’t caused as much dispute. “We demonstrated that a hypothetical Earth-like planet located in the far outer solar system could explain several properties of the distant Kuiper Belt and be compatible with observations simultaneously,” he says. “The Planet 9 model has yet to demonstrate that.” 

Yet other researchers don’t think the KBP is necessary. Konstantin Batygin, an astronomer at Caltech who was part of the initial Planet 9 research, agrees that there are oddities in the Kuiper belt that have to be explained by some sort of additional object beyond Neptune. “However, all of this has been understood for quite some time within the framework of the Planet 9 model,” he says, questioning the need for this new work, whose predictions for a hidden planet overlap substantially with the existing Planet 9 hypothesis. 

[Related: What will we name the solar system’s next planet?]

Batygin’s model suggests Planet 9 is somewhat bigger and farther: about five to six times the mass of Earth at 500 astronomical units (AU) away from the sun. Meanwhile, the KBP would be between 200 and 500 AU from the sun. (These are extreme distances—1 AU is equal to the gap between Earth and the sun.) Planet 9 would have an odd tilt to its orbit, to, of 20 degrees.

But we won’t know for sure if there’s a hidden planet, whether it looks like Planet 9 or the KBP, until astronomers actually pinpoint it in the night sky. Astronomers have been looking for Planet 9 for years, and that hunt includes some regions where the newly-proposed planet could be. “Those searches are still ongoing,” Rice says. “It’s incredible just how much parameter space remains to be searched in the outer solar system where hidden planets could be lurking.”

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Since Russia invaded Ukraine in February 2022, the earth has been shaking—not from natural earthquakes, but from bombings and other wartime explosions. By harnessing seismic data from sensors within Ukraine, international scientists have used the ground-rocking tremors after explosions to track the events of the war. 

This is the first time such data have been used to monitor explosions in an active combat zone in almost real-time. The results, published in the journal Nature, show far more explosions than previously reported: more than 1,200 explosions in the war’s first nine months, throughout Kyiv, Zhytomyr, and Chernihiv.

“Seismic data provide an objective data source, which is important for understanding what is happening in the war, for providing potential evidence where there are claims of breaches of international law, or for verifying individual attacks,” explains lead author Ben Dando, a seismologist at the Norwegian Seismic Array (NORSAR).

[Related: Ukraine claims it built a battle drone called SkyKnight that can carry a bomb]

Dando and his colleagues’ data comes from an array of 23 seismic sensors outside of Kyiv. From the signals recorded by these seismometers, the researchers were able to pinpoint the time, location, and intensity of each explosion. Smaller disruptions, like the blast that accompanies a gunshot, are too weak for these sensors to detect; what they can observe are almost certainly large impacts, such as those from missiles and bombs.

Such detections can bring clarity to the confusion of armed conflict. It’s especially vital in Ukraine, which has been flooded with disinformation and propaganda. Accurate and timely information on the events of a battle are key for other countries and watchdog organizations to intervene—especially if it seems like international laws are being broken. Marco Bohnhoff, a seismologist at the GFZ Potsdam German Research Center who was not involved in the study, told German magazine SPIEGEL that this kind of seismic monitoring could be used to confirm events and expose deliberate misinformation in war reporting.

Seismic data “can provide insight into how certain locations are being targeted and at what intensity,” Dando says. For example, the Nova Kakhovka dam in Ukraine was destroyed in June 2023, causing widespread flooding and a humanitarian crisis. Ukrainian officials claimed the damage was due to Russian bombing. If true, the destruction of civilian infrastructure would be considered a war crime under several international protocols. The hope is that seismic monitoring, like that done by Dando and colleagues, will provide further insight into situations like these and enable international responses.

[Related: The terrible history behind cluster munitions]

This is not the first time that scientific Earth-monitoring technology has overlapped with a conflict. Other techniques, namely satellite imaging, have also been used for this kind of surveillance in recent history, including during the Russia-Ukraine war. Satellites have captured images of destroyed infrastructure and large-scale movement of war materiel. A space-based NASA project intended to track human-made light sources at night, known as Black Marble, has even identified war-related power outages in Ukraine. Such satellite data “proves invaluable in identifying vulnerable populations deserving of immediate assistance,” says Ranjay Shrestha, a remote sensing expert involved with the Black Marble project at NASA Goddard Space Flight Center.

Remote sensing techniques have their limitations. They work best when coupled with on-the-ground information and context to produce accurate interpretations. “Consider, for example, instances in Ukraine where residents intentionally turned off their lights to reduce the risk of aerial attacks,” says Shrestha. “Without corroborating ground truth information, we might misinterpret the situation as a power outage resulting from infrastructure damage.”

Dando’s organization, NORSAR, was founded on the principle of using seismic data to study nuclear explosions as part of the Comprehensive Nuclear Test Ban Treaty. The 23 sensors outside Kyiv that powered this study are part of that system, which had been used to detect nuclear tests across the world that violate international law. Usually, though, there aren’t suitable high-quality seismic sensors so close to an active military conflict. “We’re now seeing that with the right sensors in the right place,” Dando says, “there is significant value that seismic and acoustic data can provide for active conflict monitoring.”   

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Outer space is a rough place for the human body. The effects of space travel on our health pose substantial challenges to our future in the cosmos. Beyond Earth, astronauts literally lose bone and muscle while being exposed to potentially cancer-causing radiation. As they plan to go on longer trips—like to the moon and Mars, such as in NASA’s Artemis program—biologists need to prepare to keep these explorers safe on these extended voyages. 

Part of that is understanding exactly how space changes our bodies, from the macroscopic scale of our organs all the way down to our microscopic cells. To that end, Swedish biologists used an experiment here on Earth to simulate what happens to a human’s immune system in microgravity, the “weightlessness” experienced by space travelers. In a new research paper, published last week in Science Advances, the study authors report significant genetic changes to these guardian cells. 

The immune system is a crucial system in the human body, protecting us from a barrage of bacteria and viruses that dwell on our lively planet. If an astronaut’s immune system is damaged by the conditions of outer space, they may not be able to fight off infections when they return to Earth, and viruses that were lingering dormant in their system might even come back with a vengeance. 

[Related: Most of us have viruses sleeping inside us, and spaceflight wakes them up]

To study this on Earth, volunteer test subjects lived in space-like conditions for 21 days, essentially floating on what are called “dry immersion” beds. Researchers analyzed the participants’ blood and found that the genes in their T cells, a type of germ-fighting white blood cell, had altered in ways that might make them less effective at protecting against pathogens.

“T cells significantly changed their gene expression—that is to say, which genes were active and which were not—after seven and 14 days of weightlessness,” says co-author Lisa Westerberg, an immunologist from Sweden’s Karolinska Institute. “T cells began to resemble more so-called naïve T cells, which have not yet encountered any intruders. This could mean that they become less effective at fighting tumor cells and infections.” 

But there’s some good news. After a return to usual gravity, some of the cells’ changes reverted back to normal, Westerberg and her colleagues observed. This suggests human bodies have the potential to re-adapt once they’re back on Earth—at least, based on this research, for 21-day trips. It’s still unclear how longer-term spaceflight, like the perilous possibly years-long journey to and from Mars, would affect astronauts, their genes, and their immune systems.

[Related: Space stations could wage war on hitchhiking bacteria with self-cleaning tech]

This isn’t the first time that scientists have noticed changes in DNA due to space travel. NASA’s famous “Twins Study”, in which astronaut Scott Kelly lived aboard the International Space Station while his twin brother Mark Kelly remained on Earth, revealed that a year in space does affect and sometimes damage genes. We also know that space can harm blood cells and bone marrow, destroying them to the point that astronauts could experience so-called “space anemia.” (Although new research shows there might be a way to combat that, using fat cells.)

The truly novel bit of this new research is how it ties cellular changes to the human body’s broader functions, allowing researchers to brainstorm fixes to the problem at a cellular level. Several clinical trials are underway for new drugs and therapies to treat similar cell-related issues on Earth, including certain cancers, allergies, and autoimmune disorders. “We therefore think this study can pave the way for new treatments that reverse these changes to the immune cells’ genetic program,” says Westerberg.

Prepping for Mars or beyond, then, has the potential to help both Earth-bound patients and spacefaring travelers, providing a better understanding of the human body no matter where it is in the universe.

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This post has been updated. It was originally published on August 22.

On August 23, the Indian Space Research Organization (ISRO) successfully landed on the moon on with the Chandrayaan-3 mission. India is now only the fourth country to successfully place a probe on the moon, and the first to land at the lunar south pole. Previous moon missions touched down on the moon’s equator. Scientists now hope to deploy a rover to send images and data back to Earth.

“India’s successful moon mission is not just India’s alone,” said Prime Minister Narendra Modi. He added that the mission is based on a “human-centric” approach and its success belongs to all of humanity.

This has been a record week for space exploration—despite the obliterating crash of Russia’s lunar spacecraft on Sunday. The first Soviet and American soft landings on the moon happened all the way back in the 1960s, at the dawn of the Space Race. But it’s not easy to deposit a lunar lander—since those early successes, China has been the sole country to join Russia and the US in this feat.

“Very few countries have landed on anything. It’s just really hard, and everything has to work just about perfectly,” says Dave Williams, a planetary scientist who archives data of the moon at NASA’s Goddard Space Flight Center.

To start, spaceflight is a huge engineering challenge, and the moon is a particularly tricky target. Unlike Earth or Mars, our satellite has no atmosphere, so there’s nothing natural to slow down a spacecraft—no air for parachutes or gliders to use. The only way to get to the surface without crashing is a controlled descent, in which rockets lower the probe all the way down. Plus, the rocket engines must shut off at a precise moment so the craft doesn’t bounce back up off the lunar surface.

[Related: 10 incredible lunar missions that paved the way for Artemis]

Making matters worse, although the moon doesn’t have oceans or cities, it still has plenty of hazards—namely, rocks and craters. Spacecraft have to navigate this terrain mostly on their own. The moon is far away enough from Earth command centers that a lander must be pre-programmed to do what it needs to for a safe landing.

This isn’t India’s first visit to the moon. The country’s lunar program began back in 2008, with a lunar orbiter and impactor in the Chandrayaan-1 mission. Chandrayaan-1 “played a vital role in raising awareness of space science among the general public,” says University of Florida astronomer Pranav Satheesh. “Many students, including myself, were inspired to pursue careers in space science and astronomy upon witnessing the success of ISRO’s programs.”

India made its first attempt at a soft landing with the Chandrayaan-2 mission in 2019. Unfortunately, that lander, named Vikram after the pioneering physicist Vikram Sarabhai, failed in the very last stages of its descent, crashing into the lunar surface. NASA’s Lunar Reconnaissance Orbiter later spotted debris from Vikram’s crash as bits of metal strewn across the lunar landscape. The Chandrayaan-2 orbiter remained operational, however, and it continues to collect data in support of the current lunar landing attempt.

[Related: Why do all these countries want to go to the moon right now?]

Chandrayaan-3’s journey so far has been right on track. “Excitement about this mission is definitely palpable across Indian news media, WhatsApp chats, and even in everyday conversations for a lot of folks there,” says Pratik Gandhi, an astronomer at the University of California, Davis. 

It entered lunar orbit on August 5, separated from its propulsion system on August 17, and even snapped a few teaser pics of the moon on August 18. As the lander descends to the moon in the coming days, the most dangerous moment is likely the landing’s second-to-last step: the fine braking phase. “The lander must kill all of its velocity and enter a hover state at about a kilometer above the lunar surface, at which point it must also decide in 12 seconds if it’s above its desired landing region or not and proceed with the touchdown accordingly,” explains science journalist Jatan Mehta. Russia’s Luna-25 probe, on the other hand, failed much earlier in its journey—which may be a sign of poor manufacturing or a lack of testing.

When the Indian lander touched down, it should have only been moving at about 4 miles per hour. But only the slightest deviations separate a crash landing from a controlled one. “The moon’s gravity, even though it is only about one-sixth of Earth’s, is still more than enough to destroy a spacecraft if it isn’t slowed down,” says Williams. 

Some exciting science investigations are now in store for the spacecraft. Unlike any lander to come before, Chandrayaan-3 is targeting the moon’s south pole, where astronomers think there are deposits of water. Water is a crucial resource for future longer-term space exploration, both for astronauts to drink and for use as rocket fuel. 

Chandryaan-3’s lander, also called Vikram, is carrying a small rover named Pragyan. Pragyan is only about 50 pounds—the weight of a medium-sized Goldendoodle—and will roam the lunar surface for about two weeks. It’s equipped with two spectrometers, which can measure the composition of rocks and soil, providing scientists with crucial information about this never-before-explored region of the moon.

The lunar southlands are also a key target for future installments in NASA’s Artemis program, paving the way for semi-permanent human habitation on our nearest celestial neighbor. In June 2023, India signed on to the Artemis Accords, an agreement for cooperation between countries in space exploration. Japan, another signatory of the accords, even has a rover in the works with India, with the goal of drilling into the lunar south pole in search of more water. All of these plans will have a better chance at fruition if India successfully lands on the moon.

“That India is one of the few countries to be able to build lunar landers means Chandrayaan-3’s success will be a critical part of being able to truly sustain the current global momentum for a return to the moon,” says Mehta. As more nations try to land on the moon, lessons from success—and failures—should help improve each next attempt.

Correction: A previous version of this article described the fine breaking phase as the last step of the landing. It is the penultimate step.

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The idea of gravity as we know it has been around for a long time. More than 300 years ago, Isaac Newton first shared his theory of gravitation, describing how massive objects are attracted to each other. Then, around a hundred years ago, Albert Einstein refined and expanded upon Newton’s ideas to create the theory of relativity—explaining gravity as the way objects, especially at the extremes across the universe, warp the fabric of space around them.

But there are still a few mysteries in the cosmos that even the well-tested ideas of relativity can’t explain. The biggest one? Dark matter, the most notorious problem in astronomy today. Many scientists think dark matter is some kind of yet-unknown particle that obeys traditional laws of gravity. Others think the issue is actually gravity itself. In that view, perhaps we need a modified theory of gravity—also known as MOND, for MOdified Newtonian Dynamics—where, at the largest and smallest scales, gravity acts differently from the usual Newton or Einstein theories.

MOND is often met with significant skepticism, because Newton and Einstein’s ideas of gravity have had so much success. But new observations recently published in The Astrophysical Journal claim to provide evidence for modified gravity by taking a detailed look at the ways binary stars move around each other. 

“The new results provide direct evidence that Newton’s theory simply breaks down” at certain scales, explains Kyu-Hyun Chae, astronomer at Sejong University in Seoul, South Korea and author of the new paper claiming evidence for MOND. Chae used data from the European Gaia satellite, which has been measuring the positions and motions of stars with unprecedented precision over the past decade. In particular, he looked at binary stars with particularly wide, far-apart orbits to measure their accelerations, for which MOND and traditional theories predict different values. 

[Related: Have we been measuring gravity wrong this whole time?]

These spaced-out stars move pretty slowly, enabling tests of gravity where there are tiny accelerations. These small accelerations are where the two theories of gravity diverge, and modified gravity predicts the stars will move 30 to 40 percent faster than they would under “normal” gravity—precisely what Chae claims to have seen in the data. At the small scales of binary stars, too, according to Chae, dark matter can’t really have an effect, so it can’t explain the observed differences from the predictions of traditional gravity.

Xavier Hernandez, an astronomer at the National Autonomous University of Mexico who first proposed the idea of testing gravity with wide binary systems but wasn’t involved in the new work, has confidence in these new results, especially since they complement his past work. “Two largely independent and complementary approaches have been shown to yield the same result,” he says, emphasizing that this a clear example of the scientific process.

The best explanation for Chae’s observations is a particular flavor of modified gravity theories, called AQUAL MOND. But just because gravity might not be a perfect match to one theory, doesn’t mean we need to throw out everything we have. “There are many versions of modified gravity because it can be anything that goes beyond Einstein’s theory of general relativity,” said physicist Sergei Ketov in a news release from the University of Tokyo Kavli Institute. “Modified gravity does not rule out Einstein’s theory, but it shows its boundaries.”

[Related: Gravity could be bringing you down with IBS]

Not all in the scientific community are convinced this is actually a “smoking-gun” for MOND, though. “The quick answer is that this result is a confluence of three things: good science, bad science, and the ugly state of science news,” wrote science communicator Ethan Siegel on Friday in his column Starts with a Bang. Siegel and other scientists have expressed concerns about the reliability of the observations used in Chae’s study—with some even publishing contradictory research—and discontent with news articles creating the impression that this work is a decisive victory for modified gravity. Depending on what stars scientists include in their analysis, the results vary, and these scientists currently disagree on what assumptions are the correct ones to make.

“If anyone is truly skeptical, he/she should try to disprove my results,” counters Chae. However, he empathizes with the motivation for some of the disbelief. The analyses at odds with this research, he adds, failed to include an important self-calibration step. Current modified gravity theories are “like the Bohr model of atoms without quantum physics developed yet. But, we need to remember that quantum physics was eventually developed,” he adds. (The Bohr model is the classic elementary-school science view of an atom, with electrons orbiting a nucleus, which was later replaced by the much fuzzier and probabilistic view of quantum mechanics.)

Only time and many other tests will be able to determine which theory will come out on top, and if dark matter is a particle or just a tweak to gravity. “We have these binary stars orbiting each other in front of us, and not doing what Newton said they should be doing,” says Hernandez. “Not considering modified gravity is no longer an option.”

This post has been updated with additional comments from Chae.

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Reality is stranger than fiction, especially in space, where astronomers just spotted two tiny stars orbiting so close together that the whole system could fit inside our sun. In a new article submitted to the Open Journal of Astrophysics, researchers present the discovery of ZTF J2020+5033, a not-quite-a-star object called a brown dwarf that’s circling a small, low-mass star.

This is what’s known as a binary system, where two stars are bound to each other in a sort of gravitational dance—think the iconic twin suns in the sky above Tatooine, the Star Wars planet. What’s wild about this particular new—and very real—binary is just how small it is. “This system shouldn’t exist,” says Mark Popinchalk, an astronomer at the American Museum of Natural History not involved in the new research. 

The brown dwarf completes one lap of its parent star in just under two hours, about the time it takes Popinchalk to commute from Brooklyn to his Manhattan office and back. “I would have been skeptical of the system,” he adds, but the authors have collected “an impressive amount of data” using multiple telescopes and techniques to support this discovery.

[Related: Your guide to the types of stars, from their dusty births to violent deaths]

“The orbit is much tighter (i.e., smaller, with a shorter orbital period) than any previously discovered brown dwarf binaries,” says lead author Kareem El-Badry, an astronomer at Caltech. “Until now it seemed like these kinds of binaries were unable to reach such short periods, but this system shows that is not the case.”

Binary systems are an important tool for astronomers to understand stars more generally. Thanks to the gravitational interactions between the two components, researchers can measure mass, radius, and temperature and other key properties more reliably and accurately for binaries than they can when observing lone stars. These measurements are needed to test our models and understanding of how stars change over time.

The center of this binary system is a low-mass star—something smaller than our sun—with a brown dwarf orbiting around it. Brown dwarfs are sometimes called “failed stars” because they’re not quite big enough to be a star but too big to be a planet. “Failed stars” may be a misnomer, though, since astronomers are still trying to figure out if brown dwarfs and stars are born the same way.

This particular newly discovered brown dwarf, which is about 80 times the mass of Jupiter, is on the cusp of being massive enough to be a star. Studying it in particular can help astronomers unravel how these intermediate objects came to be. “The way brown dwarfs form still has several big question marks around it, and each brown dwarf/low-mass star binary system is an important laboratory to answer these questions,” says Popinchalk. ZTF J2020+5033 is such a large example of a brown dwarf that someday, if any of its partner star’s material transfers onto it, that addition might push the brown dwarf into star territory—“like a cosmic gift, some mass passed on to an old friend to help them over the line and into the category of full fledged star,” says Popinchalk.

[Related: Dust clumps around a young star could one day form planets]

Plus, this new binary’s tight orbit poses a puzzle for researchers. Stars are puffier when they’re young—so much so that if these stars weren’t old, they couldn’t orbit so close and would be touching. “A majority of known brown dwarfs are young and inflated,” says El-Badry. “So it lets us test models for how brown dwarfs should cool as they age.” Their youthful puffiness also means they couldn’t have possibly been in this orbit their whole lives, and instead the orbit somehow shrunk with the stars by a factor of five over their lifetimes.

The authors propose the shrinking orbit could be caused by magnetic braking, where energetic particles from a star are funneled through its magnetic field, robbing the star of energy. Existing models assume that magnetic braking doesn’t work for small stars, but it looks like it must be operating here. If small stars decelerate more than previously thought, this could have big impacts for the evolution of other types of binary stars too—X-ray binaries that have a neutron star and a low-mass star, or cataclysmic variables with a low-mass star and a white dwarf.

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If you’re part of the 83 percent of Americans who live in an urban area, you probably can’t see many stars from your home. Cities are overwhelmed with lights, shining from lamps in skyscrapers, the streets, and the ones in bedroom windows. All of this light from the ground drowns out the stars in a phenomenon called light pollution.

Thankfully, a few organizations including the National Park Service (NPS) and the International Dark Sky Association (IDA) are fighting to preserve stargazing spots across the country and the world. Their goals are to ensure that people can access the majesty of the cosmos and safeguard eons-old cultures tied into the night sky. The IDA designates certain areas as “dark sky parks”—or even “dark sky sanctuaries” for the most remote, precious locations.

Of the US’s many dark sky sites, we’re highlighting seven of the most spectacular stargazing spots in the continental states. These might not be the country’s absolute darkest places, but they’re where you can see some incredible natural views and the beauty of the night sky at the same time.

Crater Lake National Park, Oregon

Crater Lake, Oregon’s only national park, is a showstopper, as seen in the top photo. The 6,000-plus foot elevation atop the volcanic caldera makes for pristine skywatching, since at this height there’s just less atmospheric stuff to get in the way between you and the stars. The website Space Tourism Guide recommends the Scenic Rim Drive, the path that circles the lake, as a popular spot. The starlight is supposedly so bright that flashlights are optional.

Rainbow Bridge National Monument, Utah

The Rainbow Bridge National Monument in Utah, which the IDA recently designated as a dark sky sanctuary, is a magnificent rock formation and one of the world’s largest natural bridges. It is a sacred site to the Hopi, Navajo, Zuni, and other Indigenous nations of the Southwest. Getting there isn’t easy: It is only accessible by boat or a lengthy 14-plus mile backpacking trip. If you are looking for a reverent experience of the night sky, this may be the place. As the National Park Service says on its website, “Please visit Rainbow Bridge in a spirit that honors and respects the cultures to whom it is sacred.”

Chaco Culture National Historical Park, New Mexico

Designated as a dark sky park in 2013, Chaco Culture NHP in New Mexico bears the marks of millenia of human astronomical activities. In this canyon, Ancestral Puebloan people built massive structures that reflected their observations of the night sky, such as the solar cycles. They also created astronomical rock art that still stands today. The park even offers night sky programs to carry on this long tradition, including public stargazing nights and a yearly astronomy festival.

[Related: The 10 most underrated national parks in the US]

Cherry Springs State Park, Pennsylvania

Cherry Springs Dark Sky Park in rural Pennsylvania is a contender for the absolute best stargazing in the United States—and unlike so many of the national parks, which are located in the southwest, this one’s an easy drive for urban New Englanders. Plus, it’s a personal favorite; my college’s astronomy group took yearly camping trips here, driving out of the glare of New York City and into this idyllic preserve. The park has a designated overnight astronomy observation field, complete with restrooms and telescope domes.

Big Bend National Park, Texas

Big Bend officially takes the title of having the darkest skies in a national park, at least in the lower 48 states. This Texas gem boasts over 150 miles of trails, drawing over half a million visitors per year. The National Park Service offers three campgrounds for stargazers, plus backcountry camping for the more adventurous wilderness enthusiasts. (Just don’t forget your permit!) It’s a great place to see the splendor of the Milky Way.

Stephen C. Foster State Park, Georgia

The terrain in Georgia’s Stephen C. Foster State Park is a bit different from the other deserts and forests on this list. It’s home to the Okefenokee Swamp, the largest wetland in the Southern US, which is bursting with biodiversity from alligators and black bears to storks and ibis. Plus, Foster State Park is the only gold-tier dark sky part in the Southeast, scoring the highest rating for a dark sky park from the IDA. It’s the best bet for folks living in Georgia, Florida, and other nearby states. You can even go for a late night paddle on the swamp and enjoy the stars from the water.

Katahdin Woods & Waters National Monument, Maine

Although it’s better known as the northern terminus of the Appalachian Trail, this forested region in Maine also hosts a stellar stargazing site. Katahdin Woods and Waters National Monument is a reserve that sprawls over 87,000 acres. The NPS claims this monument has “some of the darkest night skies east of the Mississippi River.” Just be sure to visit in a warmer season, since Katahdin freezes into a snowmobiler’s paradise in the winter.

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Before a spacecraft lands on Mars, or futuristic cargo planes soar above our cities, they have to be designed and rigorously tested in wind tunnels. Even passenger airliners, such as Boeing’s 747 jets used by major airlines, are subject to such tests. These facilities allow engineers to “fly” aircraft and spacecraft just a few feet off the ground. NASA, which has a 100-year history of using the machines, is finally building a new one, updated for the 21st century—the agency’s first new wind tunnel in over 40 years.

The NASA Flight Dynamic Research Facility (FDRF), slated to open in 2025 at the Langley Research Center in Virginia, will be over 100 feet tall. NASA leaders think it’s going to be key for creating the spacecraft of the future. The agency plans to use the new wind tunnel to prepare for human spaceflight to the Moon and Mars, plus robotic missions to two solar system worlds with thick atmospheres: Venus and Titan, Saturn’s methane-rich moon. It will also be key for the next generation of Earth-bound aircraft, which NASA hopes to make more sustainable, in line with its goal of net-zero emissions by 2050. 

“What we’re going to do with this facility is literally change the world,” said Clayton Turner, director of NASA Langley Research Center, in a press release from the facility’s groundbreaking ceremony. “The humble spirit of our researchers and this effort will allow us to reach for new heights, to reveal the unknown, for the betterment of humankind.” 

Wind tunnels push air past a stationary object, usually using huge fans, to simulate the motion of air around, over, and under flying craft. This allows engineers to tweak their designs based on what they see in the experiment, making vehicles more stable and aerodynamic. The wind tunnel is a safe place to try out new technologies, and a key step in testing the safety of any craft before a human jumps aboard. It’s also key for rockets and spacecraft, where engineers must ensure the vehicle can safely traverse a planet’s atmosphere. (Biologists have even used wind tunnels—though not NASA’s—to observe flying geese.)

Langley’s most recently built wind tunnel is the National Transonic Facility, constructed in 1980. That will remain in operation, but the FDRF will replace two existing wind tunnels, both near 80 years old: the 12-foot Low-Speed Spin Tunnel from 1939, and the 20-foot Vertical Spin Tunnel from 1940. The flying machines tested in the new facility will be beyond what the original builders could have dreamed. “We haven’t tested anything with a propeller on it in decades,” joked NASA Langley chief engineer Charles “Mike” Fremaux at a recent community lecture about the project.

[Related: How to build a massive wind farm]

The first NASA wind tunnel (which was the US government’s first wind tunnel) was built all the way back in 1921 at Langley. It was basically a glorified box with some powerful fans. Since then, the agency has built more than 40 wind tunnels, many with specialized purposes. Some are tiny, meant only for miniature models, and some are large enough to fit a whole jet. Each produces a different temperature, pressure, and speed of wind, meant to simulate the different conditions a craft might encounter in the real world. Some wind tunnels can move air at over 4,000 miles per hour, significantly quicker than a 747’s usual cruising speed of around 600 mph.

Many famous missions have started their journeys in a wind tunnel. The Curiosity rover’s parachute, for example, was first tested in the National Full-Scale Aerodynamics Complex at NASA Ames in California, long before it ballooned open in the Red Planet’s atmosphere. In the past few years, key parts of NASA’s Artemis missions, which aim to return Americans to the moon, including the Orion crew capsule and the SLS rocket, were tested in wind tunnels.

The new wind tunnel at the FDRF will be more efficient than past facilities, cutting down on costs. Plus, it’ll be safer for the staff running the wind tunnel tests, who used to run the risk of getting sucked into the machine as they deployed models. “Just like we do now…a very skilled technician is going to launch the models by hand. That’s not a joke,” said Fremaux in his presentation. In the past, there have only been some minor injuries, and most accidents just damage the facility itself. But, now there will be more fail-safes to minimize the risks.

It really might even pave the way for flying cars, too, by testing the tech for vertical takeoff, as demonstrated by Back to the Future’s hover cars or a classic Jetsons’-style flying car. Those are far-out ideas, but they’d never be able to take off without the help of the time-tested wind tunnel.

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In the series I Made a Big Mistake, PopSci explores mishaps and misunderstandings, in all their shame and glory.

Astronomers can’t help but be enchanted with fast radio bursts, or FRBs, thanks to their mysterious nature. These humongous pulses of radio waves blast toward Earth from outer space, often from beyond the Milky Way. But these bursts were almost thrown aside as noise almost 10 years ago, all because of a lunchtime blunder. FRBs are real signals from space, but a very similar radio wave, known as a peryton, originates from an Earthly mistake. 

When the first FRB was discovered in 2006, researchers knew they’d found something unexpected—but they didn’t know what it was. West Virginia University astronomers Duncan Lorimer and Maura MacLaughlin were trawling through old troves of radio telescope observations, hunting for signals from pulsars, the rapidly spinning husks of dead stars. Pulsars pulse because they have bright jets that sweep across Earth, like an interstellar lighthouse. One day, a student working on this project came in with a bizarre finding: a pulse more than a hundred times brighter than expected. 

The team’s first thought was that it could be interference from Earth-based radio transmissions, but this burst had all the usual fingerprints of something coming from space—it was definitely something new and strange the universe had produced. They published this detection in the prestigious journal Science in 2007, and this first FRB discovery became known as the “Lorimer burst.”

The Lorimer burst spurred more searches, with teams of astronomers scouring radio data to see whether they missed any FRBs in past observations. FRBs were elusive. Years went by without discovering new ones. 

Astronomers did, however, find another type of signal in 2007: the peryton. No one knew exactly what it was, but it showed up in radio telescope data for decades, looked kind of like an FRB, and was clearly coming from Earth—not space, like the Lorimer burst had claimed to be.

These perytons “basically cast doubt on the original event,” says Lorimer. Even its name evokes this doubt—the mythological peryton, created by Argentine writer Jorge Luis Borges, is an elk-bird creature that casts a misleading human shadow. “Many people just moved on.”

But not everyone. At the time, a graduate student in Australia named Emily Petroff was writing her PhD thesis on FRBs. Her advisor, though, was so concerned about perytons that he asked her to get to the bottom of the mystery. “The line between the two [perytons and FRBs] was blurry enough to be concerning,” she says. During her PhD work, she’d present new results to her research group, only to be met with the same question, she recalls: “That’s great, but have we figured out the perytons yet?”

[Related: Astronomers spot repeating radio burst patterns from deep space]

Petroff and her collaborators collected all the hints about perytons observed at their local facility, Parkes Observatory. Perytons only showed up when the telescope was pointed in particular directions, so the scientists deduced it had to be something at the observatory. Their monitoring systems showed a spike in energy at the same time a peryton was observed around 2.5 gigahertz, a common frequency that WiFi, Bluetooth, kitchen appliances, and other electronics employ. Looking through old data revealed these spikes had happened since 1998, so the cause had to be decades-old technology. And most damning—they happened much more often around lunchtime. 

All signs pointed to microwaves, which were in the two buildings where perytons appeared to come from. But what exactly about the microwaves made this signal? The observatory staff tried everything: microwaving water, microwaving different foods, using different settings, and more. As they experimented, one engineer would stand by the microwave, communicating on a walkie-talkie to another engineer at the telescope. Eventually, they tried breaking the major rule of microwaves—opening the door while it’s still running. 

And voila, the peryton appeared. 

[Related: Two bizarre stars might have beamed a unique radio signal to Earth]

The mystery was solved with a clear-cut, satisfying answer. Response to the result, published in the journal Monthly Notices of the Royal Astronomical Society in 2015, was electric. “I’ve heard from university teachers, high school teachers, that they teach this paper as how science works,” adds Petroff, who now works as support staff at the Perimeter Institute in Canada. “I don’t think I’ve ever had as satisfying of a moment in my research.”

With the peryton mystery solved, astronomers could devote more time to the puzzle of FRBs. They finally detected a second batch of FRBs in 2013, six years after the initial Lorimer burst, and their count reached almost a dozen by 2015. The momentum shows no signs of stopping, either, as the Canadian CHIME instrument discovers multiple FRBs daily. Radio astronomers have a plethora of other telescopes on the case, too: the Green Bank Telescope in West Virginia, precursors to the Square Kilometer Array in South Africa, the Deep Synoptic Array in California, and ASKAP in Australia. “Ten years from now, we’ll have probably well over 50,000 FRBs,” Lorimer says.

Astronomers also finally have a clue to what these things actually are. The leading theory traces FRBs to magnetars, spinning dead stars (similar to pulsars) with extremely strong magnetic fields. “When you’re spinning around on a carousel, you have some rotational energy due to the fact that you’re spinning,” explains Alice Curtin, astronomy graduate student at McGill University. But magnetars also store energy in their magnetic fields. “We think that it’s something having to do with the possible release of energy from their magnetic fields that could be powering FRBs.”

FRBs have also proven to be an extraordinary resource for exploring the universe. “FRBs are encoded with information about all the stuff between us and them,” adds Curtin. Armed with their newly-expanded catalog of FRBs, astronomers can track hard-to-see dust and gas filling the spaces between the stars. When the FRB travels through matter in space, parts of it are slowed down, smearing out the FRB across frequencies. By looking at the amount of smear, scientists can approximate the amount of stuff. Just earlier this year, a team used FRBs to explore the Milky Way, finding our galaxy actually has less matter than expected.

Perytons are a thing of the past: Radio observatories now have stricter rules for using microwaves. But other sources of radio interference are ramping up, threatening astronomers’ ability to observe the night sky. SpaceX’s infamous Starlink satellites, for example, are ruining so-called radio-quiet zones around major telescopes. The future looks shaky for some ground-based astronomy, and it won’t be as easy to solve as turning off a microwave.

But, for now, the tale of the peryton-producing microwave is a great example of a mistake with a satisfying scientific conclusion—and a fun story. “When I talk to people about FRBs, or even just radio astronomy,” Petroff says, “someone will almost always mention microwave ovens.” 

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Everyone loves a good Uranus crack—the mere mention of its name can draw snickers in a serious science class. But the sideways planet has a surprisingly respectable backstory that few people know. 

How did Uranus get its name?

Uranus (officially pronounced yur-un-us) was the god of the sky in ancient Greece, but actually was not the first choice for the seventh planet’s name. The ice giant was discovered by British astronomer William Herschel in 1781, and finally recognized as a planet at that time. It had been seen in the night sky for millennia, but people simply assumed it was another star. “There were many observations of the position of Uranus before its discovery as a planet,” says Bonnie Buratti, planetary scientist at NASA’s Jet Propulsion Laboratory.

Herschel thought his new celestial trophy should be called Georgium after King George III, the reigning king of England at the time. Astronomers from other countries weren’t too happy with this choice, though, so they proposed a number of alternatives. A year later, German astronomer Johann Bode suggested the winning name, Uranus, the Latin word for the Greek god Ouranos. He made quite a persuasive argument with two main points. First, King George would stand out in a very strange way from the other planetary names, all based on ancient gods. Second, Saturn is the father of Jupiter in mythology, and Uranus’s Roman counterpart (Caelus) is the father of Saturn, making a neat hierarchy in the order of the planets. The element uranium was named in 1789 in support of Bode’s proposed title for the planet.

[Related: How old is Earth?]

It is a bit strange, however, that Uranus is the only Greek god amongst a planetary neighborhood full of Romans. It’s unclear if this was a mistake—maybe Bode didn’t know the Roman equivalent of Ouranos was actually Caelus—or if 18th-century astronomers simply preferred the Greek version of the name.

Such mistakes don’t really happen nowadays, as the International Astronomical Union (IAU) meticulously oversees the naming of celestial discoveries (and has done so since its founding in 1919), from whole new objects to detailed features on planets’ surfaces. 

“The IAU is the sole authority for official names for solar system objects,” says Tenielle Gaither, database manager for the U.S. Geological Survey Gazetteer of Planetary Nomenclature. Chuck Wood, Wheeling University scientist and member of the IAU Working Group on Planetary Nomenclature, adds, “the IAU is the only international body that is concerned with astronomy, and every professional astronomer and nation accepts their authority.”

How do astronomers choose names today?

When a new body in space needs a label, the IAU committee for that kind of object gets to work. Planetary scientists can suggest names, but the ultimate authority still rests with the IAU, which has specific themes for each planetary system and kind of feature. Exoplanets, for example, are named after the star they orbit or the telescope that found them (like 51 Pegasi b or Kepler-16b), followed by a lowercase letter assigned in order of discovery. Meanwhile, comets are named after their discoverers plus a standardized number, like 1P/Halley. Asteroids, on the other hand, are named by their discoverers (not after their discoverers), and can be a reference to anyone or anything as long as it’s not inappropriate. “An asteroid [363115 Chuckwood] is named after me, so I passed the bar,” says Wood. 

The IAU also maintains a list of categories for every planet and its moons in the solar system. The six largest known rocks that orbit Uranus are borrowed from works of Shakespeare and Alexander Pope: Puck, Miranda, Ariel, Umbriel, Titania, and Oberon. The features on these satellites have even more individualized naming conventions. For example, all the cracks, crevasses, and craters on Puck must be named after mischievous Puck-like spirits. On Miranda, names come from characters and places in Shakespeare plays. 

Just like in Herschel’s time, some proposals can stir up debate and drama. “You might think that deciding on names would be a dry, humdrum activity,” says Wood. “But it has often been contentious, starting with the US and Soviet naming of lunar features in the early [space race].” He’s been cursed at by other scientists, threatened with appeals to the president of the United States, and more, simply for insisting that names adhere to the IAU’s established rules.

There is a lot of beauty in planetary naming, too. “While IAU nomenclature is first and foremost a tool for scientists to discuss surface features clearly and unambiguously in the literature, some names certainly have personal significance,” says Gaither, whose favorite planetary feature name is Morrison crater on Mercury, which she helped propose. “I read most of Toni Morrison’s novels in my late teens and early 20s, and they were pivotal in developing my understanding of the tragedy of Black women’s lived experiences of racism, sexism, and poverty,” she adds.

[Related: How long does it take to get to Mars?]

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Today, a humongous team of astronomers called the NANOGrav Collaboration announced something remarkable: the first evidence for a background hum of gravitational waves that permeates our universe. The research group, based in the US and Canada, used dead stars across the galaxy as a Milky-Way-sized measurement device to find these distorting undulations.

“We’ve been on a mission for the last 15 years” to find this background, said Stephen Taylor, Chair of NANOGrav and Vanderbilt University astronomy, in a press briefing. “And we’re very happy to announce that our hard work has paid off.” These waves can reveal the kinds of black holes scattered across the cosmos, which will help astronomers figure out how galaxies grow and change.

Gravitational waves are ripples in the fabric of space-time itself. Just like telescopes are specialized for different parts of the electromagnetic spectrum, gravitational wave experiments are sensitive to different wavelengths, too. The LIGO experiment, which found the first gravitational waves in 2016, can detect shorter waves, like those made when two star-sized black holes smash together. But it can’t feel longer, lower frequency waves, which some astronomers think are key to unlocking the universe’s history. 

“If we want to observe the largest black holes to further understand galaxy evolution, as well as test theories at the frontiers of modern physics, we need to be able to observe low-frequency gravitational waves,” says Vanderbilt University astronomer William Lamb, who is part of the NANOGrav team.

[Related: Astronomers recorded a whopping 35 gravitational wave events in just 5 months]

Such waves come from the most massive black holes, which should be merging all across the universe to create background noise, like cosmic TV static. For a while, astronomers worried these monster black holes could never get close enough to combine into one galactic center, which would be a big problem for our understanding of galaxies’ evolution—and would result in a quieter gravitational wave background. Since NANOGrav has heard the signal, now astronomers know these black holes do collide, and they can figure out the details of how galaxies merge. Gravitational waves from right after the Big Bang might also contribute to this background, offering one way to probe the first seconds of the universe.

To detect such a low-frequency signal, astronomers needed an experiment larger than the entire Earth—possibly something the size of the whole galaxy. Luckily, nature provided just the tool: pulsars. Pulsars are the dead cores of the heaviest stars, which spew out jets of light and spin unbelievably fast. Like watching the beams from a lighthouse, we see them pulse brighter when their jet spins toward us—and somehow nature is the best lighthouse keeper, since pulsars are as predictable in their timing as atomic clocks.

When these pulsars ride the swell of a gravitational wave, though, the space-time ripple distorts this precision. Pulsar timing arrays (PTAs), collections of radio telescopes that record pulsars across the galaxy and can measure these minute deviations in pulsars’ otherwise super-accurate clocks. Together, the many tiny shifts in pulsars’ periods paint a picture of how a long, low-frequency gravitational wave propagates throughout the galaxy. To make these measurements, NANOGrav used telescopes across North America: Puerto Rico’s famed Arecibo Telescope (which has since collapsed), the Green Bank Telescope in West Virginia, the Very Large Array in New Mexico, and the CHIME experiment in Canada.

Pulsar timing “is fundamentally different from how LIGO detects gravitational waves,” says University of Mississippi astronomer Sumeet Kulkarni, who was not involved in the new work. “What I find particularly amazing about this discovery is the coordination involved” between the numerous telescopes and contributors, he adds.

This new result uses 15 years of data from NANOGrav’s PTAs, but it isn’t quite robust enough for the team to call it an official detection. Instead, the researchers are using the term “strong evidence.” But because the signal builds up with time, they’re confident that they’ll have a clear-cut detection in a few years. “We’ll be able to produce better and better maps of the gravitational wave sky,” said Luke Kelley, a University of California, Berkeley astronomer and NANOGrav team member, in a press briefing.

[Related: Gravitational waves just showed us something even cooler than black holes]

Full implications of this detection are yet to be understood, but studies of these low-frequency waves are only beginning. Members of the International Pulsar Timing Array have similar data from across the world, including Australia, China, and India. These measurements will be even more powerful when astronomers bring them all together, possibly within the next year. 

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You probably learned growing up there are nine planets around the sun—or eight, after Pluto’s infamous demotion. But what if another world lurked in the distant outer reaches of our solar system? 

There may be more than just comets at the solar system’s extreme edges, astronomers show in a new paper accepted to the journal MNRAS Letters. In fact, they calculate  a 7 percent chance that Earth has another neighboring planet hiding in the Oort cloud, the spherical region of icy chunks and rocks where comets reside. The Oort cloud is mind-bogglingly large and far away: Its edge is tens of thousands of times farther from the sun than Earth is from our star. Around one in every 200 to 3,000 other stars likely has one of these far-out planets, too, according to the researchers’ computer simulations.

“It’s completely plausible for our solar system to have captured such an Oort cloud planet,” says Nathan Kaib, a co-author on the new work and an astronomer at the Planetary Science Institute. These hidden strangers are “a class of planets that should definitely exist but have received relatively little attention” until now, he adds.

If there’s a planet in this cloud, it’d almost definitely be an ice giant. When large planets like Jupiter, Saturn, Uranus, or Neptune form, they’re born as twins. The problem is that these hefty worlds have quite the gravitational pull, and, like quarreling siblings, often knock each other around. The nudges destabilize the young solar system, and sometimes a planet gets shoved out—either kicked out of the system entirely, or maybe exiled to the outer reaches with a few odd orbital quirks that mark its journey.

[Related: Planet Nine might not be a planet at all]

“The survivor planets have eccentric orbits, which are like the scars from their violent pasts,” says lead author Sean Raymond, researcher at the University of Bordeaux’s Astrophysics Laboratory. This means that not only would the exiled Oort cloud planet be really far from its star, its orbit would also be elongated, like a comet’s ellipse and unlike the near-perfect circle Earth follows around the sun. The immense distance is also precisely why we haven’t actually seen such a planet. If it does exist, it would be incredibly faint. “It would be extremely hard to detect,” adds Raymond.

“If a Neptune-sized planet existed in our own Oort cloud, there’s a good chance that we wouldn’t have found it yet,” agrees Malena Rice, an astronomer at MIT not involved in this work. “Amazingly, it can sometimes be easier to spot planets hundreds of light-years away than those right in our own backyard!” 

Despite the difficulty, astronomers have been searching the Oort cloud (and the nearer Kuiper Belt) for decades, in the hopes of finding the elusive “hypothetical Planet X.” Planet X, also known as Planet Nine—to the chagrin of Pluto’s loyal supporters—is a Neptune-sized planet thought to orbit 60 billion miles from the sun. Caltech astronomers Mike Brown and Konstantin Batygin used observations of objects in the Kuiper Belt to infer that something as massive as a Planet X must be shepherding them into the arrangements we see, but this theory has yet to be confirmed.

[Related: This alien world could help us find Planet Nine in our own solar system]

Unfortunately, the Oort cloud planet from Raymond and team couldn’t be the same Planet X that Brown and Batygin have been hunting. Although this supposed Oort cloud planet would be far away and have a stretched-out, eccentric orbit, that’s where the similarities end. “The Oort cloud planets in our simulations would be much more distant than the proposed Planet Nine orbit—at least 10 times further away,” explains Kaib. “Our simulations cannot place planets on Planet-Nine-like orbits.”

So not one but two planets might be waiting for us to discover them in the outer solar system, plus countless others around different stars. “These results highlight just how much remains to be discovered not only in exoplanet systems, but even in our own solar system,” says Rice.

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Earth’s atmosphere is absolutely crucial for life on our blue marble, so it’s no wonder astronomers are eager to peer into the clouds of exoplanets around other stars. One popular far-flung world—TRAPPIST-1c—was so appealing to researchers because it was previously thought to be shrouded in a thick layer of carbon dioxide. But new observations from the James Webb Space Telescope (JWST), however, have revealed that it is more likely to be a barren rock, with no atmosphere in sight. 

When astronomers try to get a handle on how many planets out in space could support life, the first place to look is a rocky world like Earth, where the planet has a sturdy surface for biology to take root. “Small planets are abundant in the galaxy,” says Sebastian Zieba, exoplanet researcher at the Max Planck Institute for Astronomy and Leiden Observatory and the lead author of a study published in Nature on the new TRAPPIST-1c observations. “At least 20 to 50 percent of stars host a planet similar in size to the Earth.” Astronomers still don’t know much about these rocky planets’ atmospheres, or whether they have one at all. It’s also an open question whether M dwarf stars, the abundant kind of star TRAPPIST-1c orbits, might destroy those planets’ atmospheres, rendering them uninhabitable. 

JWST is quickly changing that reality. “There is no other observatory right now which can give us precise measurements like these,” Zieba adds—studying infrared light is where the telescope excels. The fingerprints of many molecules important for life show up in those infrared wavelengths, but these are challenging to detect. To make these measurements, JWST has to be far beyond freezing, a meager 7 kelvin (equivalent to -500°F).

“For many years, scientists have been modeling the atmospheres of these worlds,” says Daria Pidhorodetska, an astronomer at the University of California, Riverside not involved in the new research. “To finally get to see the real data come from JWST feels like a dream come true.”

[Related: A whopping seven Earth-size planets were just found orbiting a nearby star]

Observers have focused so much attention on TRAPPIST-1c for a good reason: it’s by far the best target to study rocky, Earth-sized planets in detail, since it’s nearby (about 40 light years away) and easy to see with current tech. “You would obviously start with the lowest-hanging fruit,” says Zieba. TRAPPIST-1c orbits the star TRAPPIST-1, which hosts a family of seven Earth-sized planets. Three of them might be in the star’s habitable zone. 

That solar system offers a unique chance for astronomers to look at Earth-like planets at different temperatures, getting a glimpse at a spectrum of possibilities for rocky worlds. By determining what molecules surround these worlds, “we may be able to infer whether they could indeed support life,” says University of California, Los Angeles astronomer Judah Van Zandt, who was not involved in the paper. 

[Related: What Earth looks like to far-out celestial bodies]

TRAPPIST-1 isn’t like our sun, though. It’s a small red star called an M dwarf, which happens to be the most common star type in the galaxy. One of the big questions in astronomy right now is: Can planets around M dwarfs keep their atmospheres, or do the brutal flares of these powerful little stars burn the skies away? If astronomers find that most planets around M dwarfs are bare rocks, maybe sun-like stars are necessary for life after all. So far, there are two strikes against M dwarfs—not only does TRAPPIST-1c lack an atmosphere, but a publication from earlier this year showed that TRAPPIST-1b is also barren. 

We will soon find out whether TRAPPIST-1c’s neighbors follow this pattern—or upend it. All seven TRAPPIST-1 planets will be observed with JWST within the year, and it’s yet to be seen if others may have kept their clouds. And even if they don’t, as Zieba says, “this is obviously just one M-type star.” Astronomers will have to observe many more planets to truly judge whether M dwarfs are fit to support life.

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The hunt for aliens isn’t as sensational or speculative as you might think. In fact, astronomers are constantly inventing practical ways to search for intelligent life in our universe. Research recently published in the Astronomical Journal describes a pioneering method to look for radio beacons at the center of the Milky Way—a new idea for how extraterrestrials might send us signals. (Spoiler: the study authors didn’t find any beacons…yet!)

Astronomers have been scanning the sky with radio telescopes since the dawn of the Search for Extraterrestrial Intelligence, or SETI, in the 1960s, when they began listening for technological messages from the stars. In particular, they’ve been looking for so-called narrowband signals—blips of radio waves that occur over a very small range of frequencies, which couldn’t be produced by nature. Narrowband messages generally have to target a specific star, whereas a centralized radio beacon could cast a wide net, sweeping across the galaxy.

“This paper is hugely important for the Search for Extraterrestrial Intelligence because it contains the first large survey for radio technosignatures that are periodic,” says SETI Institute astronomer Sofia Sheikh, a co-author on the new work. Periodic means these signals would be “flashing over time like a lighthouse,” she says, “instead of assuming that the signal has to be on continuously like a streetlight.”

[Related: Alien civilizations could send us messages by 2029]

Sheikh and other collaborators, including Cornell University astronomer Akshay Suresh, propose these repeating pulses of radio emission could originate from some sort of rotating beacon. If situated at the center of the galaxy, such a beacon could be a particularly efficient way of communicating across vast distances. The signals from this kind of beacon may also be easier to find while sifting through radio data, which is often contaminated with the omnipresent buzzing of Earth’s technology.

These beacons would be more energy efficient compared to the continuous narrowband signals astronomers previously looked for. What’s more, “their regularly flashing nature makes them easy to detect with algorithms, differentiable from human-based radio interference, and generally obvious as something weird,” Sheikh explains. Looking toward the galactic center is also a great way to increase the odds of spotting something, since the concentration of stars is higher in the middle of the Milky Way. More stars means more planets and more chances for life to arise.

“It’s a logical technique for searching for events or transmissions that we can’t otherwise predict,” agrees Penn State astronomer Macy Huston, who is not affiliated with the findings. But, there’s a catch— although the center of the galaxy is dense with stars, many astronomers predict the radiation there makes it too dangerous for life to arise, putting it outside the so-called Galactic Habitable Zone.

[Related: Why astronomers are blasting Earth’s location to potential intelligent aliens]

That didn’t deter Sheikh, Suresh, and their teammates, who used the world’s largest steerable radio dish, the Green Bank Telescope in West Virginia, to test out their probe for galactic beacons. After looking at the central 600,000 stars in the Milky Way for five hours, nothing extraordinary jumped out of the data. This amount of searching, though, is like exploring  a single drop of water plucked from an entire swimming pool; just because nothing showed up in this first search, it doesn’t mean the theory of galactic beacons is bust. Suresh is particularly excited that the algorithm developed for this search will allow astronomers to easily “explore their data for pulsating signals” in future scans.

“The jury is still out on the general prevalence of technological life in the universe,” says Sheikh. Although the progress may be slow, steadily sifting through the whole pool of stars in the galaxy is the only way “that we’ll ever be able to say anything conclusive about the prevalence of technological life, and this paper brings us one step closer.”

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NASA’s upcoming Psyche mission will send a small probe to a unique metal asteroid—a curious object that may be the exposed heart of a former planet. But to prepare for the 280-million-mile journey, engineers have had to attend to a million little details over the course of years of planning and construction. Working those out took more time than anticipated: NASA delayed Psyche’s launch last year, prompting concerns about the mission’s future and triggering an investigation into what caused the set back. On Monday, NASA announced that Psyche is thriving and on track for a new launch date in October 2023.

“The 2023 launch date is credible, and the probability of mission success is high,” said A. Thomas Young, chair of the independent review board that assessed Psyche’s missteps, at a news conference. NASA Jet Propulsion Lab (JPL) Director Laurie Leshin confirmed the fall blast-off: Psyche is “green across the board, and on track for October launch.” Of the 18 weeks to go until launch, seven are buffer time—a pretty impressive margin for such an intense engineering project.

Psyche, announced in 2017, was first delayed in June 2022 when issues with its flight software arose during testing. NASA commissioned the review board soon after, which delivered its findings last fall. The review cited issues across the entire laboratory—understaffing, a lack of experienced managerial oversight, budget strain, and the COVID-19 pandemic—as factors contributing to the mission’s woes. JPL’s reckoning with this review had ripple effects, including the controversial indefinite pause of the VERITAS mission to Venus.

[Related: 5 ways we know DART crushed that asteroid (but not literally)]

Now, in May 2023, the review board has reassessed JPL’s readiness. The Psyche debacle may have raised questions about the ability of JPL to juggle building more than a dozen spacecraft, but NASA officials emphasized the concerns plaguing the center’s operations has been addressed. The progress made at JPL is “not only outstanding, but world-class as determined by our review board,” said Nicola Fox, associate administrator for NASA’s Science Mission Directorate.

JPL’s changes include hiring more experienced staff (including luring back talent that left JPL for commercial spaceflight companies), reorganizing the engineering teams to focus on high-priority work, and updating their hybrid work policy to bring more people back in-person to the lab. “We’ve overcome our workforce issues, our missions are staffed,” said Leshin.

[Related: The asteroid that created Earth’s largest crater may have been way bigger than we thought]

If Psyche leaves Earth as scheduled in the fall, it will arrive at the asteroid 16 Psyche in 2029. The mission will hopefully reveal information about how planets form, and will confirm if 16 Psyche is the leftover metal core of a failed planet as hypothesized. Some companies even see the Psyche mission as a potential first step toward mining asteroids for precious metals, as the space rock contains approximately 10 quintillion dollars worth of materials. 

And things are looking up for other missions, too—especially since JPL recently delivered the NISAR Earth-radar satellite on schedule and is making good progress for next year’s launch of Europa Clipper. The laboratory’s strong progress is a good sign for the hopeful restart of VERITAS, which would be a huge win for planetary scientists and a monumental return to our sister planet.

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When you look up at the clouds, what do you see? A blob, a wisp, perhaps an elephant-shaped clump. It’s fun to get creative with the descriptions, but scientists have a formal classification system that can be useful to the everyday cloud watcher, too. We’ve made a field guide to types of clouds, so next time you’re enjoying a day outside, you can put your newfound knowledge of the skies to work.

What’s in clouds and their names?

Clouds are made up of droplets of water or tiny ice crystals floating in the planet’s atmosphere. They hold clues about the weather—like if it’s going to rain, snow, or worse—and the interesting physical and chemical cycles churning through the air.

“They are such an amazing feature of Earth that are simply fun to look at and study,” says Vanessa Maciel, an atmospheric scientist at the University of California, Los Angeles. Clouds are shaped by the many changing characteristics of the atmosphere: temperature, moisture, winds, and more. 

[Related: Make your own weather station with recycled materials]

Just like animal species, climate scientists have a system for naming clouds with genera, plus smaller subdivisions of species and varieties. These designations are based on their shape, appearance, and how high they are in the atmosphere. Each genus of clouds can be described as one of four main shapes, first categorized in 1803: cirro-form, cumulo-form, strato-form, and nimbo-form. Cirro-type clouds are the thin wisps; cumulo-type clouds are huge and fluffy; strato-type clouds are wide and flat layers; and nimbo-type clouds are the quintessential gray rain clouds. 

The astonishing diversity of clouds might seem overwhelming to a beginning cloud-gazer, but Maciel has advice on where to start. “A great way to narrow down the type of cloud you are seeing is to first try to estimate whether it is in the lower, middle, or high atmosphere,” she says.

High clouds

The highest clouds are the wispiest: cirrus, cirrocumulus, and cirrostratus. They generally form above 20,000 feet, and typically indicate a coming change in the winds or weather. In certain regions of the tropics, they can even indicate that hurricanes are on the way. Generally, the air gets colder higher up in Earth’s atmosphere, so cirrus and friends are made up of ice crystals that are stretched and spread by the winds, giving them their thin, strand-like shapes.

Cirrus are the thinnest wisps, whereas cirrocumulus appear more like a thin, rippled white sheet. Cirrostratus are a more homogenous sheer veil. If you see a bright halo forming around the sun, that might be the cirrostratus. When cirrus clouds stack together like ridges, almost like a rack of ribs, the variety is called vertebratus.

Maciel’s favorite cloud looks a bit like a cirrus cloud, but is actually something quite different. Nacreous clouds, also known as mother-of-pearl or ice polar stratospheric clouds, are made of very cold ice. When the sun goes down they catch the light and reflect brilliant colors. “These colors occur only during sunrise and sunset, and are created by the interaction between sunlight and the cloud’s ice crystals, which are smaller than that of a standard ice cloud,” says Maciel. “They are also pretty rare as they only occur at high atmospheric altitudes and high latitudes.” Your best bet of seeing them is near the planet’s poles.

Mid-level clouds

In the middle of the atmosphere, we start to see more clumps: altostratus and altocumulus. They can be found 6,500 to 20,000 feet up, and tell very different tales when it comes to weather—altocumulus often mean you’ve got a pleasant day ahead, but altostratus indicate a long bout of rain or snow. 

Altostratus appear as large, flat sheets that aren’t quite thick enough to block out the sun entirely. Altocumulus, on the other hand, look like a horde of little cotton balls scattered in the sky. You’ve likely seen a few different species and varieties of altostratus and altocumulus before, particularly cavum. This variety is a continuous sheet of cloud with a big chunk missing. Stratiformis is another common species of altocumulus, where high clouds appear like a patchy, ridged sheet. Similarly, if there are layers of cloud that cover the sun entirely, they may be a variety known as opacus.

Low clouds

Many kinds of clouds start close to the ground—6,500 feet or below—and extend high into the atmosphere. These clouds are called nimbostratus, stratus, stratocumulus, cumulus, and cumulonimbus. These clouds are made up of water droplets from the surrounding warm air, creating their quintessential fluffy look.

Nimbostratus are the gray gloomy clouds that indicate rain. Stratus clouds also create gloomy days as they cover the sky in a low sheet of dingy white. Stratocumulus are somewhat similar to altocumulus, but they have a darker shadow and don’t appear quite as bright white as their higher altitude counterparts. 

Cumulus and cumulonimbus clouds are the behemoths of the bunch. Cumulus are huge white clouds reaching high up into the sky—the classic cotton balls. Cumulonimbus, on the other hand, are imposing and a bit foreboding, with a high, flat top and a promise of rain storms.

[Related on PopSci+: Cloudy with a chance of cooling the planet]

Low clouds come with some of the oddest and most interesting varieties and features. This is where tubes or vortexes appear from clouds, called tuba. They can also show—for a brief moment, anyway—a feature that looks like a set of perfect crashing waves, known as fluctus. Although the fluctus pattern looks almost too good to be true, it’s a somewhat common consequence of the physics of fluid motions. Stratocumulus clouds can also put on a cow costume: That is, they can grow little nubs on their undersides that almost look like udders, known as mamma. Cumulus clouds can even put on a hat, an accessory cloud called pileus that pops up at the top of one of these huge cloud formations.

What clouds to look for now

This summer, you can expect all the fair weather clouds, plus some of the weirder ones that pop up with summer storms like pileus. “Summer usually has clear skies, unlike the overcasts typical of winter,” adds Maciel. “But as summer also has a lot of convection due to the warm surface temperature, you can expect to see cumulus clouds, which are your iconic fluffy and bright white clouds.”

Clouds are just as complex as their classifications, and they’re changing not just with the seasons, but also with the climate. As Earth’s temperature warms, the varieties we see might change, too. “In spite of their ubiquity, there is still a lot about clouds that we don’t know,” says Maciel. For now, though, see how many you can spot—and enjoy the beautiful views provided by our planet’s magnificent atmosphere.

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Our solar system has a suite of eight planets—rocky Mars and Earth, the ice giants, and massive gas planets—but other stars often have a much smaller group. Some suns have just one exoplanet orbiting around them. These loner worlds are often one specific type: A huge gas giant that orbits very close to its star, known as a hot Jupiter.

A newly discovered exoplanet, however, has challenged this view, showing that maybe not all hot Jupiters go solo. Last week, astronomers announced that a hot Jupiter orbiting a star 400 light years away has a pal: It shares its solar system with WASP-84c, a rocky planet so large it’s known as a super-Earth. This discovery was made public as a preprint, a research paper that has yet to undergo peer review, and submitted to the journal Monthly Notices of the Royal Astronomical Society for official publication.

Hot Jupiters are a weird kind of planet. We don’t have any in our own solar system. Until the first was spotted, astronomers never expected them to exist. Gas giants like Jupiter usually only form far away from their stars, where things are cool enough for gas to stay safe from blazing solar heat. If a Jupiter-like planet has to be born at a distance, then, how can it get so close to its star? 

Astronomers have three main theories for how this happens. Two are gentle, and one is catastrophic. First, a hot Jupiter could move inward from its birthplace due to little gravitational nudges from the protoplanetary disk, a collection of dust and gas used to form planets in a star’s youth. Second, maybe we’re wrong about the theory that Jupiter-like planets must form far from stars. Instead, these planets are simply born where we see them. Both of these scenarios would allow hot Jupiters to have smaller friend planets hanging out nearby.

[Related: Ridiculously hot gas giant exoplanet is about to be swallowed by its dying sun]

But the third option is the most dynamic. Jupiters could form far out, but then encounter other planets that change the gas giants’ orbits. The gravity of the other planets would force a hot Jupiter into a stretched out, elliptical path, and then the gravity of the star would pull the gas giant in close, resulting in a circular, super-short orbit. In this violent dance, any low mass planets would be destroyed—creating the lonely hot Jupiter.

The best theory for the origin of this particular hot Jupiter, named WASP-84b, is the first—that a disk helped shepherd the planet through the solar system. Previous observations showed that the gas giant’s spin is aligned with the star’s, a sign that the large planet migrated within the protoplanetary disk instead of pinballing around with other planets. The discovery of super-Earth WASP-84c now adds more evidence to the case that this hot Jupiter formed with a nudge, not a planet-destroying bang—and that scenario may be more common than previously thought.

WASP-84c joins a growing list of smaller planetary buddies to hot Jupiters: WASP-47 b, Kepler 730 b, and WASP-132 b, to name a few. “The discovery of low-mass planetary companions like WASP-84c suggests that not all hot Jupiter systems formed under violent scenarios, as previously thought,” says lead author Gracjan Maciejewski from the Institute of Astronomy of the Nicolaus Copernicus University in Torun, Poland.

Maciejewski and his colleagues used NASA’s Transiting Exoplanet Survey Satellite (TESS) to spot WASP-84c. TESS hunts for exoplanets using the transit method, where a telescope watches a star for teensy dips in its brightness, caused by a dark planet passing in front. 

[Related: A deep-space telescope spied an exoplanet so hot it can vaporize iron]

WASP-84c “was too small in radius to have been discovered by the original WASP survey, who discovered the hot Jupiter,” according to Caltech astronomer Juliette Becker, who is not affiliated with the new discovery. “It’s a great example of what TESS can do,” she adds.

With the transit method, astronomers can figure out a planet’s dimensions. However, to find out how much it weighs, they need different data, from another exoplanet-detecting technique known as the radial velocity method. When WASP-84c’s discoverers gathered this extra data, they determined that the planet has about 15 times the mass of Earth. Like our Blue Marble, it’s probably made of iron and rocks, too.

Jonathan Brande, a University of Kansas astronomer not involved in the discovery, thinks such discoveries will become even more common as the James Webb Space Telescope brings in new exoplanet data, deepening our understanding of how these planet pairs came to be. “I would not be surprised if we see further results on this system in the near future,” he says.

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A team of more than 1,000 astronomers and college students just took a step closer to solving one of the long-lasting mysteries of astronomy: Why is the sun’s outer layer, known as the corona, so ridiculously hot? The solar surface is 10,000°F, but a thousand miles up, the sun’s corona flares hundreds of times hotter. It’s like walking across the room to escape an overzealous space heater, but you feel warmer far away from the source instead of cooler, totally contrary to expectations.

The research team used hundreds of observations of solar flares—huge ejections of hot plasma from our star’s surface—to determine what’s heating up the sun’s corona, in results published May 9 in The Astrophysical Journal. What’s really striking about this result, though, is how they did it: with the help of hundreds of undergrads taking physics classes at the University of Colorado, totaling a whopping 56,000 hours of work over multiple years.

Lead author James Paul Mason, research scientist and engineer at the Johns Hopkins Applied Physics Laboratory, calls this a “win-win-win scenario.” He adds, “We were able to harness a ton of brainpower and apply it to a real scientific challenge, the students got to learn firsthand what the scientific process looks like.”

[Related: Volunteer astronomers bring wonders of the universe into prisons]

The classroom project began in 2020, when University of Colorado physics professor Heather Lewandowski found herself teaching a class on experimental physics, which suddenly had to pivot online due to the COVID-19 pandemic—quite the challenge, especially for a hands-on science course. Luckily, Mason had an idea for a solar flare project that needed a lot of hands, and Lewandowski, who usually researches a totally different topic in quantum mechanics, saw that as an opportunity for her students. 

“The question of why the sun’s corona is so much hotter than the ‘surface’ of the sun is one of the main outstanding questions in solar physics,” says Lewandowski. There are two leading explanations for this dilemma, known as the coronal heating problem. One theory suggests that waves in the sun’s mega-sized magnetic field push heat into the corona. The other claims that small, unseen solar flares called nanoflares heat it up, like using a thousand matches instead of one big blow torch. 

Nanoflares are too small for our telescopes to spot, but by studying the sizes of other larger flares, scientists can estimate the prevalence of these little radiation bursts. And, although artificial intelligence is improving every day, automated programs can’t yet do the kind of analysis that Mason and Lewandowski needed. Groups of students in Lewandowski’s class each used data on a different solar flare, getting into nitty-gritty detail to measure how much energy each one dumped into the corona. Together, their results suggest nanoflares might not be powerful enough to heat up the corona to the wild temperatures we see.

[Related: Small ‘sparks’ on the sun could be key to forecasting dramatic solar weather]

The scientific result is only half of the news, though. Lewandowski and Mason pioneered a new way to bring real research into the classroom, giving students a way to not only learn about science, but do it themselves. This type of large-scale student research effort is more common in biology and chemistry, but was pretty much unheard of in physics—until now. “The students participated in all aspects of the research from literature review, meetings with the principal investigator, a proposal phase, data analysis, and peer review of their analysis,” says Lewandowski. The involvement of many students, and their work in groups, is also a reminder that “science is inherently a collaborative endeavor,” she adds.

“I hope that we inspire some professors out there to try this with their classes,” says Mason. “I’m excited to see what kinds of results they’re able to achieve.”

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Our asteroid belt is home to more than a million space rocks, varying in size from a dwarf planet to dust particles, which float between Jupiter and Mars. Astronomers have just discovered another such belt—but this one circles a different star, not our sun.

NASA’s James Webb Space Telescope (JWST) detected this asteroid belt around the star Fomalhaut, only 25 light-years away. For years, scientists have studied Fomalhaut’s debris disk, a collection of rocky, icy, dusty bits from all the collisions that happen while planets are being created. This new data, published today in Nature Astronomy, shows the system in unprecedented detail, uncovering fingerprints of hidden worlds and evidence for planets smashing together.

Many telescopes have pointed to Fomalhaut over the years: the Spitzer Space Telescope, the Atacama Large Millimeter Array (ALMA) in the high desert of Chile, and even the Hubble Space Telescope. Fomalhaut, which is much younger than our sun, may be a good likeness of our solar system near birth; since astronomers can’t time travel back to our sun’s formation, they instead observe other young stars, using these still-forming planetary systems as examples of what the process of making planets can look like.

Fomalhaut is an appealing choice to astronomers because it’s nearby, meaning it’s easier for astronomers to notice fine details. “This system was definitely one of the first we wanted to observe with JWST,” says co-author Marie Ygouf, research scientist at NASA’s Jet Propulsion Lab.

Before JWST, other observations revealed that Fomalhaut is surrounded by a ring of dust analogous to our own solar system’s Kuiper Belt, which contains all the little bits of ice and rock beyond Neptune. The new data from NASA’s superlative space telescope spot not only this outer ring, but also an inner ring more analogous to the asteroid belt. There’s a third feature, too—a giant clump of dust, lovingly referred to as the Great Dust Cloud. 

[Related: These 6 galaxies are so huge, they’ve been nicknamed ‘universe breakers’]

Between Fomalhaut’s outer Kuiper-Belt-like ring and its inner asteroid-belt-like ring is a gap. “The new gap that we see hints at the presence of an ice-giant mass planet, which would be an analog of what we see in the solar system,” like Neptune or Uranus, says lead author András Gáspár, astronomer at the University of Arizona. This unseen planet could be “carving out the gaps” via gravity, explains fellow Arizona astronomer and co-author Schuyler Wolff.

Fomalhaut’s asteroid belt has a curious tilt, appearing at a different angle from the outer ring, as though something knocked it off kilter. A knock, in fact, might explain the misalignment, the researchers say—a major collision could have tilted the asteroid belt, creating the massive dust cloud, too. 

All signs in Fomalhaut “point to a solar system that is alive and active, full of rocky bodies smashing into each other,” says co-author Jonathan Aguilar, staff scientist at Space Telescope Science Institute, home of JWST’s mission control.

JWST was uniquely suited to take these photos of Fomalhaut’s dust. The dust glows brightest in the mid-infrared, at long wavelengths unreachable by most other observatories. A particularly powerful telescope is necessary, too, to resolve enough details—and JWST is the only scope with both these features. The space telescope’s Mid-Infrared Instrument (MIRI) also has a coronagraph, a small dot to block out a bright star and reveal the surrounding dust.

“Mid-infrared wavelengths are so important for debris disk observations because that’s where you observe dust emission, and the distribution of dust tells you a lot about what’s going on,” says Aguilar. The new view of Fomalhaut “showcases the scientific power of JWST and MIRI even just a year into operations,” he adds.

[Related: NASA sampled a ‘fluffy’ asteroid that could hold clues to our existence]

It’s certainly interesting to see what our solar system may have looked like in its infancy—but Fomalhaut isn’t an exact clone. Fomalhaut’s Kuiper Belt and asteroid belt doppelgangers are more spread out and contain more material than those features in our solar system. Although Fomalhaut has more movement and smashing than our solar system does now, our planets had a similar phase in the distant past, known as the Late Heavy Bombardment. Astronomers hope debris disks seen by JWST will help them figure out the details of how solar systems are born, and how they grow up to look like our own set of planets.

“We are at this frontier of unexplored territory, and I’m especially excited to see what JWST finds towards planet-forming disks,” says University of Michigan astronomer Jenny Calahan, who was not involved in the new findings. “Looking at these JWST images I was reminded of the moment that I got glasses for the first time,” adds Calahan. “It just changes your whole perspective when the world (or a debris disk) comes into focus at a level that you aren’t used to.”

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Our Earth has siblings—the seven other planets in our solar system—but it doesn’t have a twin with which to share its ring of space. Earth sails through its orbit all alone. Other solar systems, though, might have zanier families that chase each other around a sun: twins, triplets, or even quattuorvigintuplets (that’s 24 Earth-sized planets in a single orbit!). 

Computer simulations by an international team of astronomers illustrated how two dozen planets can share the same orbit, in research published this spring in the Monthly Notices of the Royal Astronomical Society. These wacky configurations can be stable for billions of years, even outliving the stars they’re around. It’s pretty unlikely that nature would create packed planetary orbits, though, which is why researchers suggest a detection of such a system could be a sign of intelligent alien life—possibly even an interstellar message that could exist for eons.

“Our paper explores one additional branch of possible planetary systems that could potentially exist,” says lead author Sean Raymond, CNRS Researcher at the Laboratoire d’Astrophysique de Bordeaux. “I love that it’s so unexpected and weird, and that so many planets can end up sharing the same orbit.”

Multiple planet systems, like our solar system, are often referred to as peas in a pod. But these co-orbiting planets could be “pearls on a necklace,” says University of Kansas astronomer Jonathan Brande, who was not affiliated with the new research.

Nobody had proposed observing two planets in the same orbit, though, until an article posted to the preprint server arXiv last week—but most exoplanet astronomers are skeptical, especially since the signal wasn’t seen in data from other major exoplanet-hunting telescopes like TESS. This paper was written by a group of amateur astronomers who captured observations with small, commercially-available telescopes. “I don’t think it’s the sort of thing you’d be able to pull off in your backyard,” says Brande, regarding the supposed detection. 

[Related: These 6 exoplanets somehow orbit their star in perfect rhythm]

There are a few known examples of co-orbits that involve smaller objects. Our solar system actually has a few such strange orbits, known as horseshoe or tadpole orbits, depending on their shapes. Jupiter’s Trojan asteroids—soon to be visited for the first time by the spacecraft Lucy—share the gas giant’s orbital path as tadpoles, oscillating around points before and after Jupiter in its track around the sun. Two of Saturn’s moons, Janus and Epimethus, orbit the ringed planet together in a horseshoe, periodically swapping places. 

Since objects in our solar system share orbits, it seems reasonable that there might be exoplanets out there that share paths as well. “There are plenty of exoplanet systems in which the planets seem to fill every available niche of stable real estate,” says Raymond. This new research pushes this concept to the extreme, seeing how many planets can cram into the same orbit and remain stable. 

The research team’s simulations also reveal that such co-orbiting planets would have distinct signals for astronomers here on Earth to observe. The Kepler Space Telescope and other space observatories can reveal so-called transit timing variations (TTVs), where the gravitational tug between nearby planets ever-so-slightly changes when a planet passes in front of its star. The TTVs from a system of 24 planets with the mass of Earth sharing an orbit would be large enough for astronomers to see, but it would take months to years of regular monitoring to notice the effect, according to NASA Jet Propulsion Lab astronomer Rob Zellem.

Although academics haven’t been persuaded by the latest observation of supposed co-orbiting planets, there is certainly an important role for amateur astronomers in exoplanet science, Zellem adds.“Given the capability of the observers..we could definitely use their expertise,” he says, especially through citizen science projects such as NASA’s Exoplanet Watch. 

[Related: This alien world could help us find Planet Nine in our own solar system]

A robust detection of co-orbiting planets could be truly exciting, though—not only an observation of nature’s extreme diversity, but possibly even a sign of alien life. “Something like an engineered co-orbiting planetary might not be unambiguously artificial, but would be weird enough to prompt intensive further study,” says Brande.

The study authors think these odd orbits would actually be a perfect technosignature, or sign of intelligent life beyond Earth. Co-author David Kipping, an astronomer at Columbia University, explains that once an advanced civilization constructs an unnatural ring of co-orbiting planets, it wouldn’t require any power to maintain and would be visible for billions of years—a perfect combo for an interstellar message. “The likelihood of this happening really comes down to whether anyone is out there with the capability and will to do this,” he says. “We have no idea. But if we don’t look, we’ll never know.”

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On April 19, 2021, a little more than a century after the Wright Brothers’ first test flight on Earth, humans managed to zoom a helicopter around on another planet. The four-pound aircraft, known as Ingenuity, is part of NASA’s Mars2020 exploration program, along with the Perseverance rover.

The dynamic duo made history again this month, as Ingenuity celebrated its landmark 50th flight. The small aircraft was built to fly only five times—as a demonstration of avionics customized for the thin Mars air, not a key part of the science mission—but it has surpassed that goal 10 times over with no signs of slowing down.

[Related: InSight says goodbye with what may be its last wistful image of Mars]

“Ingenuity has changed the way that we think about Mars exploration,” says Håvard Grip, NASA engineer and former chief pilot of Ingenuity. Although the helicopter started as a tech demo, proving that humans could make an aircraft capable of navigating the thin Martian atmosphere, it has become a useful partner to Percy. Ingenuity can zip up to 39 feet into the sky, scout the landscape, and inform the rover’s next moves through the Red Planet’s rocky terrain.

In the past months, Perseverance has been wrapping up its main science mission in Jezero Crater, a dried-up delta that could give astronomers insight on Mars’ possibly watery past and ancient microbial life. Ingenuity has been leap-frogging along with the rover, taking aerial shots of its robotic bestie and getting glimpses into the path ahead. This recon helps scientists determine their priorities for exploration, and helps NASA’s planning team prepare for unexpected hazards and terrain.

Unfortunately, the narrow channels in the delta are causing difficulties for the helicopter’s communications with the rover, forcing them to stay close together for fear of being irreparably separated. Ingenuity also can’t fall behind the rover, because its limited stamina (up to 3-minute-long flights at time) means it might not be able to catch up. Over the past month, the team shepherded the pair through a particularly treacherous stretch of the drive, though, and they’re still going strong—even setting flight speed and frequency records at the same time. Meanwhile, Percy has been investigating some crater walls and funky-colored rocks, of which scientists are trying to figure out the origins.

Ingenuity has certainly proven the value of helicopters in planetary exploration, and each flight adds to the pile of data engineers have at their disposal for planning the next generation of aerial robots. “When we look ahead to potential future missions, helicopters are an inevitable part of the equation,” says Grip.

What exactly comes next for Ingenuity itself, though, is anyone’s guess. “Every sol [Martian day] that Ingenuity survives on Mars is one step further into uncharted territory,” Grip adds. And while the team will certainly feel a loss when the helicopter finally goes out, they’ve already completed their main mission of demonstrating that the avionics can work. All the extra scouting and data collection is a reward for building something so sturdy. 

[Related: Two NASA missions combined forces to analyze a new kind of marsquake]

They’re now continuing to push the craft to its limits, testing out how far they can take this technology. For those at home who want to follow along, the mission actually provides flight previews on Ingenuity’s status updates page. 

“It may all be over tomorrow,” says Grip. “But one thing we’ve learned over the last two years is not to underestimate Ingenuity’s ability to hang on.” 

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Humans have used radio waves to communicate across Earth for more than 100 years. Those waves also leak out into space, a fingerprint of our presence propagating through the cosmos. In more recent years, humans have also sent out a stronger signal beyond our planet: communications with our most distant probes, like the famous Voyager spacecraft.

Scientists recently traced the paths of these powerful radio transmissions from Earth to multiple far-away spacecraft and determined which stars—along with any planets with possible alien life around them—are best positioned to intercept those messages. 

The research team created a list of stars that will encounter Earth’s signals within the next century and found that alien civilizations (if they’re out there) could send a return message as soon as 2029. Their results were published on March 20 in the journal Publications of the Astronomical Society of the Pacific.

“This is a famous idea from Carl Sagan, who used it as a plot theme in the movie Contact,” explains Howard Isaacson, a University of California, Berkeley astronomer and co-author of the new work. 

[Related: UFO research is stigmatized. NASA wants to change that.]

However, it’s worth taking any study involving extraterrestrial life with a grain of salt. Kaitlin Rasmussen, an astrobiologist at the University of Washington not affiliated with the paper, calls this study “an interesting exercise, but unlikely to yield results.” The results, in this case, would be aliens contacting Earth within a certain timeframe.

As radio signals travel through space, they spread out and become weaker and harder to detect. Aliens parked around a nearby star probably won’t notice the faint leakage from TVs and other small devices. However, the commands we send to trailblazing probes at the edge of the solar system—Voyager 1, Voyager 2, Pioneer 10, Pioneer 11, and New Horizons—require a much more focused and powerful broadcast from NASA’s Deep Space Network (DSN), a global array of radio dishes designed for space communications.

The DSN signals don’t magically stop at the spacecraft they’re targeting: They continue into interstellar space where they eventually reach other stars. But electromagnetic waves like radio transmissions and light can only travel so fast—that’s why we use light-years to measure distances across the universe. The researchers used this law of physics to estimate how long it will take for DSN signals to reach nearby stars, and for alien life to return the message. 

The process revealed several insights. For example, according to their calculations, a signal sent to Pioneer 10 reached a dead star known as a white dwarf around 27 light-years away in 2002. The study team estimates a return message from any alien life near this dead star could reach us as soon as 2029, but no earlier. 

[Related: Nothing can break the speed of light]

More opportunities for return messages will pop up in the next decade. Signals sent to Voyager 2 around 1980 and 1983 reached two stars in 2007: one that’s 26 light-years away and a brown dwarf that’s 24 light-years away, respectively. If aliens sent a message right back from either, it could reach Earth in the early 2030s.

This work “gives Search for Extraterrestrial Intelligence researchers a more narrow group of stars to focus on,” says lead author Reilly Derrick, a University of California, Los Angeles engineering student.  

Derrick and Isaacson propose that radio astronomers could use their star lists to listen for return messages at predetermined times. For example, in 2029 they may want to point some of Earth’s major radio telescopes towards the white dwarf that received Pioneer 10’s message.

But other astronomers are skeptical. “If a response were to be sent, our ability to detect it would depend on many factors,” says Macy Huston, an astronomer at Penn State not involved in the new study. These factors include “how long or often we monitor the star for a response, and how long or often the return signal is transmitted.”

There are still many unknowns when considering alien life. In particular, astronomers aren’t certain the stars in this study even have planets—although based on other exoplanet studies, it’s likely that at least a fraction of them do. The signals from the DSN are also still incredibly weak at such large distances, so it’s unclear how plausible it is for other stars to detect our transmissions.

“Our puny and infrequent transmissions are unlikely to yield a detection of humanity by extraterrestrials,” says Jean-Luc Margot, a University of California, Los Angeles radio astronomer who was not involved in the recent paper. He explains that our radio transmissions have only reached one-millionth of the volume of the Milky Way. 

“The probability that another civilization resides in this tiny bubble is extraordinarily small unless there are millions of civilizations in the Milky Way,” he says. But if they’re out there, there might be a time and place to capture the evidence.

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Since 1995 scientists have found more than 5,000 exoplanets—other worlds beyond our solar system. But while space researchers have gotten very good at discovering big planets, smaller ones have evaded detection.

However, a novel astronomy detection technique known as microlensing is starting to fill in the gaps. Experts who are a part of the Korea Microlensing Telescope Network (KMTNet) recently used this method to locate three new exoplanets about the same sizes as Jupiter and Saturn. They announced these findings in the journal Astronomy & Astrophysics on April 11. 

How does microlensing work?

Most exoplanets have been found through the transit method. This is when scientists use observatories like the Kepler Space Telescope and the James Webb Space Telescope to look at dips in the amount of light coming from a star. 

Meanwhile, gravitational microlensing (usually just called microlensing) involves searching for increases in brightness in deep space. These brilliant flashes are from a planet and its star bending the light of a more distant star, magnifying it according to Einstein’s rules for relativity. You may have heard of gravitational lensing for galaxies, which pretty much relies on the same physics, but on a much bigger scale.

The new discoveries were particularly unique because they were found in partial data, where astronomers only observed half the event.

“Microlensing events are sort of like supernovae in that we only get one chance to observe them,” says Samson Johnson, an astronomer at the NASA Jet Propulsion Lab who was not affiliated with the study. 

Because astronomers only have one chance and don’t always know when events will happen, they sometimes miss parts of the show. “This is sort of like making a cake with only half of the recipe,” adds Johnson.

[Related: Sorry, Star Trek fans, the real planet Vulcan doesn’t exist]

The three new planets have long serial-number-like strings of letters and numbers for names: KMT-2021-BLG-2010Lb, KMT-2022-BLG-0371Lb, and KMT-2022-BLG-1013Lb. Each of these worlds revolves around a different star. They weigh as much as Jupiter, Saturn, and a little less than Saturn, respectively. 

Even though the researchers only observed part of the microlensing events for each of these planets, they were able to rule out other scenarios that could confidently explain the signals. This work “does show that even with incomplete data, we can learn interesting things about these planets,” says Scott Gaudi, an Ohio State University astronomer who was not involved in the published paper.

The exoplanet search continues

Microlensing is “highly complementary” to other exoplanet-hunting techniques, says Jennifer Yee, a co-author of the new study and researcher at The Center for Astrophysics | Harvard & Smithsonian. It can scope out planets that current technologies can’t, including worlds as small as Jupiter’s moon Ganymede or even a few times the mass of Earth’s moon, according to Gaudi.

The strength of microlensing is that “it’s a demographics machine, so you can detect lots of planets,” says Gaudi. This ability to detect planets of all sizes is crucial for astronomers as they complete their sweeping exoplanet census to determine the most common type of planet and the uniqueness of our own solar system. 

Astronomers are honing their microlensing skills with new exoplanet discoveries like those from KTMNet, ensuring that they know how to handle this kind of data before new space telescopes come online in the next few years. For example, microlensing will be a large part of the Roman Space Telescope’s planned mission when it launches mid-decade. 

“We’ll increase the number of planets we know by several thousand with Roman, maybe even more,” says Gaudi. “We went from Kepler being the star of the show to TESS [NASA’s Transiting Exoplanet Survey Satellite] being the star of the show … For its time period, Roman [and microlensing] will be the star of the show.”

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On Wednesday and Thursday, a particularly strange “hybrid” eclipse is coming to Australia, Indonesia, and some other parts of Southeast Asia, but you don’t have to be there to watch. Don’t miss it—the next one won’t happen for nearly another decade.

How to see the April 20 solar eclipse in person

The exact time of the eclipse will vary depending on your location, so you’ll need to check when it will be visible for you. Timeanddate.com has a particularly handy tool for figuring this out. To use it, click Path Map at the top of the page and see if you’re going to be under any part of the eclipse’s path. If so, zoom in to pinpoint where you are and click on the map to bring up an information box that shows when the event will be visible in local time.

Even if you’re in the partial eclipse zone, it’s worth stepping outside to take a peek at this celestial happening. “We are going to get coffee and freak out about the sky. It’s going to be fun,” says University of Melbourne astronomer Benji Metha about his eclipse plans. The moon will cover only about 10 percent of the sun where he is in southeastern Australia.

[Related: April 2023 stargazing guide]

If you’re in the eclipse’s path, be sure to come prepared. Never look directly at the sun. Eclipse glasses are readily available online, but make sure the ones you’re buying aren’t fake. Too late to buy? You can make your own eclipse projector instead. Unlike almost every other astronomical event, solar eclipses happen in the daytime, so you won’t really be able to spot other stars or deep sky objects at the same time. The sun and moon will be the only ones on stage.

Timeanddate is also hosting an eclipse livestream in collaboration with Perth Observatory in western Australia, where roughly 70 percent of the sun will be covered. Like Exmouth, Perth is 12 hours ahead of New York City, so live video will start at 10 p.m. ET on April 19 and continue until the partial eclipse ends around 12:46 a.m. ET on April 20.

Tune in, and you’ll be joining solar scientists around the world who are particularly interested in this event and the data they can gather from it. “I look forward to this eclipse, because it is a long-anticipated party,” says Berkeley heliophysicist Jia Huang. “A hybrid eclipse is very rare.”

When is the next eclipse?

If you miss the show, there are sure to be some incredible photos posted from the event, and you will be able to watch recordings online afterward. But if you want to see an eclipse in person, a few are coming to the States soon enough.

First, an annular solar eclipse will travel from Oregon to Texas on October 14, 2023, followed several months later by the next North American total solar eclipse from Texas up through Maine on April 8, 2024.

What to know about the four types of solar eclipses

Solar eclipses happen whenever Earth’s moon gets between us and the sun, aligning to block out the sunlight and cause an eerie daytime darkness. Eclipses are predictable, thanks to centuries of observational astronomy across many cultures, and “we can now forecast these events with incredible accuracy,” Metha says. It’s a good thing we know when they’re coming so we’re not surprised. “Imagine how many car accidents a sudden solar eclipse would cause if people were not expecting it,” he adds.

These celestial events come in a few flavors: total, partial, annular, and hybrid. In a total eclipse, the moon fully blocks out the sun. For a partial eclipse, the sun and moon aren’t quite lined up, so only a chunk of the sun is covered. Similarly, for an annular eclipse, some of the sun remains exposed—but this type happens when the moon is at its farthest point from Earth and appears smaller, creating a ring of light when it lines up with the sun. Hybrid eclipses, like the one happening this week, shift between total and annular due to the curvature of Earth.

Solar eclipses trace paths along Earth’s surface, with a path of totality—where you can see a total eclipse—in the center, surrounded by various shades of partial eclipse. The upcoming April 20 eclipse path of totality clips the northwestern corner of Australia and passes through the islands of Timor, Indonesia, and Papua New Guinea. The entirety of Australia, the Philippines, Malaysia, and parts of other Southeast Asian countries will experience at least a partial eclipse.

[Related: How worried should we be about solar flares and space weather?]

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Few places in the solar system get hotter than the surface of the sun. But contrary to expectations, the tenuous tendrils of plasma in the outermost layer of its atmosphere—known as the corona—are way more searing than its surface.

“It is very confusing why the solar corona is farther away from the sun’s core, but is so much hotter,” says University of California, Berkeley space sciences researcher Jia Huang. 

The solar surface lingers around 10,000 degrees Fahrenheit, while the thin corona can get as hot as 2 million degrees. This conundrum is known as the coronal heating problem, and astronomers have been working on solving it since the mid-1800s.

“Simply speaking, solving this problem could help us understand our sun better,” says Huang. A better understanding of solar physics is also “crucial for predicting space weather to protect humans,” he adds. Plus, the sun is the only star we can send probes to—the others are simply too far away. “Thus, knowing our sun could help understand other stars in the universe.”

A brief history of the coronal heating problem

During the 1869 total solar eclipse—an alignment of the sun, moon, and Earth that blocks out the bulk of the sun’s light—scientists were able to observe the faint corona. Their observations revealed a feature in the corona that they took as evidence of presence of a new element: coronium. Improved theories of quantum mechanics over 60 years later revealed the “new element” to be plain old iron, but heated to a temperature that was higher than the sun’s surface.

[Related: We still don’t really know what’s inside the sun—but that could change very soon]

This new explanation for the puzzling 1869 measurement was the first evidence of the corona’s extreme temperature, and kicked off decades of study to understand just how the plasma got so hot. Another way of phrasing this question is, where is the energy in the corona coming from, and how is it getting there? 

“We know for sure that this problem hasn’t yet been resolved, though we have many theories, and the whole [astronomy] community is still enthusiastically working on it,” says Huang. There are currently two main hypotheses for how energy from the sun heats the corona: the motion of waves and an explosive phenomenon called nanoflares.

Theory 1: Alfvén waves

The surface of the sun roils and bubbles like a pot of boiling water. As the plasma convects—with hotter material rising and cooler material sinking down—it generates the sun’s immense magnetic field. This magnetic field can move and wiggle in a specific kind of wave, known as Alfvén waves, which then push around protons and electrons above the sun’s surface. Alfvén waves are a known phenomenon—plasma physicists have even seen them in experiments on Earth. Astronomers think the charged particles stirred up by the phenomenon might carry energy into the corona, heating it up to shocking temperatures.

Theory 2: Nanoflares

The other possible explanation is a bit more dramatic, and is kind of like the sun snapping a giant rubber-band. As the sun’s plasma tumbles and circulates in its upper layer, it twists the star’s magnetic field lines into knotted, messy shapes. Eventually, the lines can’t take that stress anymore; once they’ve been twisted too far, they snap in an explosive event called magnetic reconnection. This sends charged particles flying around and heats them up, a happening referred to as a nanoflare, carrying energy to the corona. Astronomers have observed a few examples of nanoflares with modern space telescopes and satellites.

The coronal heating mystery continues

As is usually the case with nature, it seems that the sun isn’t simply launching Alfvén waves or creating nanoflares—it’s more than likely doing both. Astronomers just don’t know how often either of these events happen.

[Related: Hold onto your satellites: The sun is about to get a lot stormier]

But they might get some straightforward answers soon. The Parker Solar Probe, launched in 2018, is on a mission to touch the sun, dipping closer to our star than ever before. It’s currently flying through some outer parts of the corona, providing the first up-close look at the movements of particles that may be responsible for the extreme temperatures. The mission has already passed through the solar atmosphere once, and will keep swinging around for a few more years—providing key information to help scientists settle the coronal heating problem once and for all.

“I would be very confident that we could make big progress in the upcoming decade,” says Huang.

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Astronomers recently detected an explosion so large they dubbed it the BOAT—the brightest of all time. This explosion—known now as GRB 221009A—was a gamma-ray burst (GRB), a flash of extremely high-energy light that resulted from the death of a colossal star.

This detonation is the brightest burst at X-ray and gamma-ray energies since human civilization began. It is 70 times brighter than any observed before. Papers describing this result and others related to the burst were published in a focus issue of The Astrophysical Journal Letters in March.

“A burst this bright arrives at Earth only once every 10,000 years,” says Eric Burns, a Louisiana State assistant professor and astronomer involved in the detection. 

[Related: Black hole collisions could possibly send waves cresting through space-time]

So-called long GRBs—gamma-ray bursts that last longer than two seconds—materialize when a massive star runs out of fuel and collapses into a black hole. This catastrophic collapse causes powerful jets of material to stream out, collide with gas around the former star, and produce high-energy gamma rays. We can see this explosion from Earth if the jet is pointed directly at our planet. 

Astronomers are constantly monitoring the sky for GRBs and other bright, short-lived bursts of light—and that’s how they found the BOAT. The research team that works with NASA’s Neil Gehrels Swift Observatory, is notified each time a certain camera, known as the Burst Alert Telescope (BAT), spots a new GRB.

“This one was bright enough to trigger BAT twice,” says Maia Williams, a Penn State astronomer and lead author of one of the GRB 221009A papers. 

The initial detection of the burst was based on data gathered from the Ultraviolet/Optical Telescope onboard SWIFT and NASA’s Fermi Gamma-ray Space Telescope. After “it was seen by instruments on more than two dozen satellites,” explains Burns. These include the NICER x-ray telescope on the International Space Station, NASA’s NuSTAR x-ray telescope, NASA’s new Imaging X-ray Polarimetry Explorer (IXPE) satellite, and even one of the Voyager spacecraft.

With this vast trove of information on the BOAT, astronomers realized it was a “more-complicated-than-usual GRB,” says Huei Sears, a Northwestern University astronomer and graduate student not involved in the discovery.

Why was the BOAT so bright? First, it’s nearby (in cosmic terms, about 1.9 billion light-years away), which adds to its extreme shine—just like a light bulb appears brighter to your eyes closer up than across a room. But its brightness isn’t just a quirk of its proximity. It’s also “intrinsically the most energetic burst ever seen,” says Burns. 

Astronomers suspect the jets blasted out of the black hole that created the BOAT were narrower  than usual. Imagine the jet setting on a garden hose—and by lucky coincidence this particular hose was aimed directly at Earth. However, why these jets behaved like this is not understood. 

“Scientifically, the BOAT has proven most of our existing models for these events to be incomplete,” says Burns.

[Related: Astronomers now know how supermassive black holes blast us with energy]

Gamma-ray bursts are at their brightest in their first moments but continue with an afterglow for much longer—possibly several years in the case of the BOAT. Williams and her team plan to continue observing the BOAT once a week with SWIFT as long as they can. They’ll also use NASA’s powerhouse James Webb and Hubble space telescopes to get a look at other wavelengths, capturing as much as they can from this rare happening.

“The BOAT is so important because it is one of those events that breaks what we know,” says Sarah Dalessi, a University of Alabama astrophysicist and graduate student involved in the detection. “This is truly a once-in-a-lifetime event.”

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I’ve always loved learning about the planets and stars, but it sure takes a lot to get me outside on a cold, dark night to see them with my own eyes. This week, though, there’s a celestial lineup I don’t want to miss—and you shouldn’t either!

What’s the big deal here?

Although there have been some wild theories about strange happenings during planetary alignments—like an increase in natural disasters—those have generally been debunked. Instead, the reason a planetary alignment is a big deal is that it’s simply cool to see. “You get to see pretty much the whole solar system in one night,” says Rory Bentley, UCLA astronomer and avid stargazer.

Usually, the planets are spread across the sky, visible at different times of the night (even into the early morning). They’re technically always in some version of a line—all our solar system’s planets appear on the ecliptic, an invisible arc across the sky tracing the plane where everything orbits the sun. If the planets are close enough together, though, they appear to be in an almost straight line. 

[Related: Astronomers just mapped the ‘bubble’ that envelopes our planet]

That’s precisely what’s happening on March 28. The five planets will come within 50 degrees of each other, a tight bunch compared to their usual spread, giving stargazers of all ages an opportunity to meet our planetary neighbors.

How to see the March 28 alignment

The time to spot this planetary parade is right after sunset on the March 28—no more than about 45 minutes after sundown, since Jupiter and Mercury will both disappear below the horizon fairly quickly. You’ll want to make sure you have a clear view of the western horizon, where the sun sets and Jupiter and Mercury will follow close behind. 

Jupiter will be closest to the horizon, easy to spot even in the lingering sunlight of dusk since it’s so bright. Mercury will be nearby—possibly visible to the naked eye, and definitely visible with binoculars. A bit higher up in the sky you’ll find Venus, shining intensely from its ultra-reflective thick clouds. It’s accompanied by Uranus, just a bit above—and for this one, you’ll definitely need those binoculars. Bringing up the tail end of the parade is Mars, up even higher in the sky near the crescent moon. (Bonus: you can see the moon, too, while you’re at it.)

If you’re not completely sure how to tell what’s a planet, know that the planets you see with your naked eye will generally be brighter than everything around them, and if you look really closely they won’t twinkle quite like stars.

You should be able to spot at least three of the parade participants (Jupiter, Venus, and Mars)—possibly even a fourth (Mercury)—with just your eyes if you’ve got good eyesight and/or a clear sky. Grab some binoculars or a telescope, and you can collect all five planets. Venus and Uranus will be visible until they dip below the horizon about three hours after sunset, and Mars stays out past midnight.

Another benefit to using a decently sized pair of binoculars or a telescope is that you’ll get to see a slew of neat planetary features as the alignment glides by. You should be able to spot Saturn’s famous rings, and possibly even some of the colorful cloud bands of Jupiter. Although you won’t notice any surface features on Venus, you will be able to determine what phase it’s in, since Venus has phases (crescent, full, etc.) similar to our moon. Keep in mind that it’s easier to see details when you have clear, still skies, and are looking overhead. The closer your target gets to the horizon, the more of Earth’s atmosphere you end up looking through, making viewing more difficult.

The Pleiades, a star cluster known across many cultures as the seven sisters, also shines between Venus and Mars. You may recognize this particular arrangement of stars from the logo on Subaru automobiles—it’s no coincidence, because Subaru is actually the Japanese name for this cluster. You’ll likely be able to see this one with just your eyes, even in a big city like Los Angeles.

[Related: Why we turn stars into constellations]

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Since its discovery in 2017, the interstellar object ‘Oumuamua has been a point of fascination—and sometimes obsession—for astronomy fans. As the first object we’ve seen from another solar system, it’s naturally drawn a lot of interest, with its strange tube-like shape and surprisingly small size. It even accelerated at one point in its orbit, which happens regularly with comets—but ‘Oumuamua didn’t have the usual gassy tail, leading some to even propose it may be an alien ship.

A new hypothesis, published on March 22 in the journal Nature, proposes a different explanation for ‘Oumuamua’s anomalous orbit. Astronomers Jennifer Bergner and Darryl Seligman say the half-mile-long object is just a comet after all, but that its time in interstellar space changed its chemistry. Instead of water causing the extra propulsion, ‘Oumuamua released nearly invisible hydrogen.

“It’s exciting that we can explain the strange behavior of ‘Oumuamua without needing to resort to any exotic physics,” says Bergner, an astrochemist at the University of California, Berkeley and lead author on the new paper.

“Hopefully this discovery will put to rest any outlandish ideas about ‘Oumuamua being an alien probe,” adds University of Washington astrobiologist Kaitlin Rasmussen, author of the upcoming book Life in Seven Numbers: The Drake Equation Revealed.

Comets are chunks of ice and debris left over from the process of planet formation, lurking at the edge of our solar system. On their extremely long and stretched out orbits, they occasionally dive in towards the sun. There, the sun’s bright rays vaporize some of the comet’s ice and dust to make the fuzzy coma and the sweeping tails we see. 

[Related: Scientists finally solve the mystery of why comets glow green]

‘Oumuamua may have begun its life as a typical comet around another star—rich with water ice—before being thrust out into open space by the chaos of a young solar system. (Our solar system likely spewed out similar chunks of detritus in its early days.) On its voyage between the stars, Bergner and Seligman propose that ‘Oumuamua was bombarded with energetic particles known as cosmic rays. These high-energy particles broke the bonds between hydrogen and oxygen in water molecules, creating molecular hydrogen (H₂) trapped in the crystalline structure of the ice.

Once ‘Oumuamua swung by the sun, the heat rearranged the crystals of its ice, releasing the molecular hydrogen to propel the interstellar interloper and cause its observed acceleration, almost like a rocket booster. “It’s more plausible than the other ideas,” says UCLA astronomer David Jewitt, “including those relying on carbon monoxide (which was not detected), nitrogen ice (which is relatively hard to find), and, of course, the spaceship idea.”

“I think the authors have a very interesting hypothesis,” agrees Caltech planetary scientist Qicheng Zhang, who is not affiliated with the research team. The real significance of this result, though, will come with further observations, he adds. 

‘Oumuamua was only invisible for a short time when it passed within 15 million miles of Earth in 2017; now on Pluto’s fringes, it’s far beyond the reach of even our largest telescopes. As an alternative to direct data, Bergner and Seligman suggest studying a similar effect on ‘Oumuamua-sized comets from our own solar system. But there’s one catch—we haven’t spotted any solar system comets that small yet. Astronomers hope the next generation of telescopes, including NASA’s recently launched James Webb Space Telescope, will spot the first of those objects.

[Related: The Milky Way could have dozens of alien civilizations capable of contacting us]

Casey Lisse, an astronomer at Johns Hopkins Applied Physics Lab, also suggests that a comet’s H₂ may be observable if it splits apart into two hydrogen atoms under the influence of the sun’s ultraviolet rays. The signal on a ‘Oumuamua look-alike could be picked up by certain satellites like SOHO, NASA’s long-running solar space telescope, “which are known to measure bright comets,” he says.

Astronomers also expect to root out many more interstellar objects in the coming years; they recorded the second one, known as comet 2I/Borisov, in 2019. “There’s approximately one similar object in the inner solar system at any given time,” says Seligman, Cornell astronomer and co-author on the Nature study. “When we get the Rubin Observatory and the NEO [Near-Earth Object] Surveyor going, we’ll be discovering way more.”

Astronomers think of these interstellar objects as a window into other solar systems: the closest peek we’ll get at the building blocks of other planets. “Any object of interstellar origin is incredibly valuable to us because it’s bringing clues about the processes going on beyond our solar system,” says Bergner.

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Water is key for life here on Earth, and it will be key for humans to travel around the solar system as well. It’s a heavy resource to lug aboard a spacecraft, so it’s best to get it from your destination when possible. Thankfully, there’s already some water on the moon—and astronomers just got a better look at where it is exactly.

New observations from the SOFIA airborne observatory (which completed its final flight in September 2022) produced a detailed map of water molecules near the moon’s South Pole. These results, recently accepted to the Planetary Science Journal and presented at the annual Lunar and Planetary Science Conference last week, are answering a critical question for both geology and future human exploration: Where can we find water on the moon?

“We don’t really know the basics of where [the water] is, how much, or how it got there,” says Paul Hayne, a planetary scientist at the University of Colorado not affiliated with the new research.

[Related: Mysterious bright spots fuel debate over whether Mars holds liquid water]

NASA’s 2010 LCROSS mission first sparked interest in the southern end of the moon when its radar revealed frozen water stored in places where the sun’s light can’t reach, like the bottoms of craters. A slew of follow-up observations by India’s Chandrayaan probes added further evidence for lunar water, but there was a catch—what astronomers identified as possible water molecules (H₂O) could have been a different arrangement of hydrogen and oxygen called hydroxyl (OH). SOFIA, however, had the power to search for a wider range of molecular signatures, meaning it could scan for a surefire sign of water instead of something that could be confused for hydroxyl. 

“These observations with SOFIA are important because they definitively map the water molecules on the sunlit surface of the moon,” says NASA Lunar scientist Casey Honniball, co-author on the new study. An accurate map of the icy areas can help planetary scientists distinguish between different ways water moves across the lunar surface, and learn how the life-giving compound got there in the first place. 

“We see more water in shady places, where the surface temperature is colder,” says William T. Reach, director of SOFIA and lead author on the paper. This is similar to how ski slopes facing away from the sun retain more of their snow here on Earth.

Researchers are considering two main scenarios to explain the origins of lunar water: evaporating water from comets that crashed into the moon, or water trapped in volcanic minerals created long ago. The SOFIA data hasn’t helped them to narrow down the source yet. “These are observations, and they don’t come labeled with a nice, tidy explanation,” adds Reach.

Although his team is still figuring out the provenance of the observed water, detecting it at all could be a boon for future human space exploration. A confident claim of water on the south pole of the moon explains “why we are targeting these regions so intently for the next phase of human and robotic lunar exploration,” says UCLA planetary scientist Tyler Horvath, who was not involved in the project.

Unfortunately, SOFIA can’t continue mapping the moon’s water—the modified Boeing 747 and telescope are now retired to the Pima Air & Space Museum in Tucson, Arizona. “I hope these results help pave the way for another one of these airborne observatories to be developed in the near future,” says Horvath.

[Related: Saying goodbye to SOFIA, NASA’s 747 with a telescope]

Despite the project’s untimely end, SOFIA managed to complete a large number of observations of the moon—among other celestial targets—in its final flights. In fact, it produced so much data that scientists are still sorting through it all. SOFIA’s discoveries “will continue for years to come,” says Honniball, and could prepare teams for future missions, all tackling questions about H₂O. Some prime examples include CalTech’s Lunar Trailblazer orbiter launching later this year, NASA’s water-hunting Volatiles Investigating Polar Exploration Rover (VIPER), and of course, the US Artemis program, which aims to land humans on the satellite’s southern regions as early as 2025.

These upcoming projects also promise the tantalizing prospect of delivering lunar soil samples back to Earth, something that hasn’t happened (for Americans, at least) since the Apollo program. “In the lab, even a single grain is like a world of its own revealing stories about the history and evolution of the material on the moon,” says Reach. Actually working with samples of lunar ice in a hands-on experiment could finally determine what form water takes on the moon.

Until then, planetary scientists will keep working through SOFIA’s moon maps, squeezing out every last drop of information they can.

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The universe has a dark side—it’s filled with dark matter and dark energy. Dark matter is the unseen mass floating around galaxies, which physicists have searched for using giant vats of ice, particle colliders, and other sophisticated techniques. But what about dark matter’s stranger sibling, dark energy? 

Dark energy is the term given to something that is causing the universe to expand faster and faster as time goes on. The great puzzle facing cosmologists today is figuring out the identity of that “something.”

“We can tell you a lot about the properties of dark energy and how it behaves,” says astrophysicist Tamara Davis, a professor at the University of Queensland in Australia. “However, we still don’t know what it is. That’s the big question.”

How do we know dark energy exists?

Astronomers have long known that the universe is expanding. In the early 1900s,  Edwin Hubble observed galaxies in motion and created Hubble’s Law, which relates a galaxy’s velocity to its distance from us. At the end of the 20th century, though, new detections of supernovae in far-off galaxies revealed a conundrum: The expansion of the universe isn’t constant, but is instead speeding up.

“The fact that the universe is accelerating caught us all by surprise,” says University of Texas at Austin astrophysicist Katherine Freese. Unlike the attractive force of gravity, dark energy must create “some sort of repulsive behavior, driving things apart from one another more and more quickly,” adds Freese.

Many observations since the 1990s have confirmed that the universe is accelerating. Exploding stars in distant galaxies appear fainter than they should have been in a steadily-expanding universe. Even the cosmic microwave background—the remnant light from the first clear moments in the universe’s history—shows fingerprints of dark energy’s effects. To explain the observed universe, dark energy is a necessary component of our mathematical models of cosmology.

[Related: Dark matter has never killed anyone, and scientists want to know why]

The term dark energy was coined in 1998 by astrophysicist Michael Turner to match the nomenclature of dark matter. It also conveys that the universe’s accelerating expansion was a crucial, unsolved problem. Many scientists at the time thought that Albert Einstein’s cosmological constant—a “fudge factor” he included in general relativity to make the math work out, also known as lambda—was the perfect explanation for dark energy, since it fit nicely into their models. 

“It was my belief that it was not that simple,” says Turner, now a visiting professor at UCLA. He views the accelerating universe as “the most profound problem” and “the biggest mystery in all of science.” 

Why does dark energy matter?

The Lambda-CDM model, which says we live in a universe that consists of only 5 percent normal matter—everything you’ve ever seen or touched—plus 27 percent dark matter and a whopping 68 percent dark energy, is “the current paradigm in cosmology, says Yale astrophysicist Will Tyndall. It “rather ambitiously seeks to incorporate (and explain) all of cosmic history,” he says. But it still leaves a lot unexplained, including the nature of dark energy. “After all, how can we have so little understanding of something that supposedly constitutes 68 percent of the universe we live in?” adds Tyndall. 

Dark energy is also a major deciding factor in our universe’s ultimate fate. Will the universe be torn apart in a Big Rip, in which everything is shredded apart atom by atom?  Or will it end in a whimper? 

These scenarios depend on whether dark energy changes with time. If dark energy is just the cosmological constant, with no variation, our universe will expand eternally into a very lonely place; in this scenario, all the stars beyond our local cluster of galaxies would be invisible to us, too red to be detected.

If dark energy gets stronger, it might lead to the  event known as the Big Rip. Maybe dark energy weakens, and our universe crunches back down, starting the cycle all over with a new big bang. Physicists won’t know which of these scenarios lies ahead until they have a better handle on the nature of dark energy.

What could dark energy actually be? 

Dark energy shows up in the mathematics of the universe as Einstein’s cosmological constant, but that doesn’t explain what physically causes the universe’s expansion to speed up. A leading theory is a funky feature of quantum mechanics known as the vacuum energy. This is created when pairs of particles and their antiparticles quickly pop into and out of existence, which happens pretty much everywhere all the time. 

It sounds like a great explanation for dark energy. But there’s one big issue: The value of the vacuum energy that scientists measure and the one they predict from theories are wildly and inexplicably different. This is known as the cosmological constant problem. Put another way, particle physicist’s models predict that what we think of as “nothing” should have some weight, Turner says. But measurements find it weighs very little, if anything at all. “Maybe nothing weighs nothing,” he says. 

[Related: An ambitious dark energy experiment just went live in Arizona]

Cosmologists have raised other explanations for dark energy over the years. One, string theory, claims that the universe is made up of tiny little string-like bits, and the value of dark energy that we see just happens to be one possibility within many different multiverses. Many physicists consider this to be pretty human-centric in its logic—we couldn’t exist in a universe with other values of the cosmological constant, so we ended up in this one, even if it’s an outlier compared to the others.

Other physicists have considered changing Einstein’s equations for general relativity altogether, but most of those attempts were ruled out by measurements from LIGO’s pioneering observations of gravitational waves. “In short, we need a brilliant new idea,” says Freese.

How might scientists solve this mystery?

New observations of the cosmos may be able to help astrophysicists measure the properties of dark energy in more detail. For example, astronomers already know the universe’s expansion is accelerating—but has that acceleration always been the same? If the answer to this question is no, then that means dark energy hasn’t been constant, and the lives of physics theorists everywhere will be upended as they scramble to find new explanations.

One project, known as the Dark Energy Spectroscopic Instrument or DESI, is already underway at Kitt Peak Observatory in Arizona. This effort searches for signs of varying acceleration in the universe by cosmic cartography. “It is like laying grid-paper over the universe and measuring how it has expanded and accelerated with time,” says Davis. 

Even more experiments are upcoming, such as the European Euclid mission launching this summer. Euclid will map galaxies as far as 10 billion light-years away—looking backward in time by 10 billion years. This is “the entire period over which dark energy played a significant role in accelerating the expansion of the universe,” as its mission website states. Radio telescopes such as CHIME will be mapping the universe in a slightly different way, tracing how hydrogen spreads across space.

New observations won’t solve everything, though. “Even if we measure the properties of dark energy to infinite precision, it doesn’t tell us what it is,” Davis adds. “The real breakthrough that is needed is a theoretical one.” Astronomers have a timeline for new experiments, which will keep marching forward, recording better and better measurements. But theoretical breakthroughs are unpredictable—it could take one, ten, or even a hundred-plus years. “In science, there are very few true puzzles. A true puzzle means you don’t really know the answer,” says Turner. “And I think dark energy is one of them.”

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Star Trek fans knew they would lose the planet Vulcan someday in a fiery implosion at the hands of the Romulans—but they probably didn’t expect it to lose the planet in real life, too. Now reality is once again following fiction: The exoplanet once considered to be the real Vulcan has been erased, based on a new analysis of old data.

The 2018 discovery of the exoplanet known as 40 Eri b, which is located around the real-life star canonically orbited by Spock’s fictional homeworld, has turned out to be a false alarm. In a new research paper accepted for publication in the Astronomical Journal, astronomers used years of observations to re-analyze many previous exoplanet detections, including that of 40 Eri b. Unfortunately, astronomers hadn’t actually found Vulcan after all.

“As we continue to study objects with better and more precise instruments, reevaluating things we thought we already knew can lead to new conclusions about what’s really going on,” says Ohio State University astronomer Katherine Laliotis, lead author on the new work. In the case of 40 Eri b, the signal previously thought to be a planet turned out to be activity on the star’s surface. This work, she adds, is “a reminder that re-studying and reproducing already published results is a very valuable use of time.”

40 Eri b was originally detected using the radial velocity method, in which astronomers analyze the different wavelengths of light coming from a star. As a planet orbits a star, it’ll tug on its sun ever so slightly. When this tug pushes the star away from Earth, the star appears redder—thanks to the Doppler effect—and if it moves toward us, it appears bluer. With this method, astronomers believed they found 40 Eri b: A Neptune-sized planet 16 light-years away, so close to its star that a year would last only 42 days. This wouldn’t have been a particularly pleasant or habitable planet, but it made waves thanks to its sci-fi ties.

[Related: Newly discovered exoplanet may be a ‘Super Earth’ covered in water]

Some astronomers, such as NASA astronomer Eric Mamajek, immediately expressed doubts about the supposed detection. That’s because the time it took for this planet to complete one orbit was suspiciously close to the time the star takes to rotate. His suspicions were right. By tracing a feature of the light spectrum known to be part of the star, Laliotis and collaborators confirmed the star’s rotation rate, marking the end of the possible planet 40 Eri b. 

They didn’t specifically set out on a mission to kill Vulcan, though. This work was part of a bigger analysis, looking into all of NASA’s top picks for future exoplanet exploration—and 40 Eridani just happened to be on the list. Astronomers are always collecting new data, observing different stars, but “​​many planetary systems haven’t been officially updated since they were published in the early 2000s,” according to Laliotis.

Astronomers are already starting preparation for the next big space telescope, known as the Habitable Worlds Observatory. This future NASA mission aims to take photos of Earth-like planets around sun-like stars, allowing scientists to directly look into these exoplanets’ atmospheres for oxygen and other signs of life. Laliotis’s work fits right into this plan—she says this study aimed to figure out “what [planetary] systems we already understand well, what systems we have a misunderstanding of, and what systems need to be observed a lot more in the coming years.” This review will help make sure the future telescope’s precious observing time is used wisely.

“NASA is planning to spend billions of dollars on future missions to fly telescopes to study planets,” says Jessie Christiansen, project scientist at NASA’s Exoplanet Archive. “Imagine if this had been one of the targets! It’s not real!”

Although astronomers are, of course, glad to see rigorous scientific work being done, they’ll also admit that they are a bit sad about losing an exoplanet with such a cool sci-fi crossover. “I’m sad whenever any planet gets disproven, but this one hit especially hard because I’ve been using it for a few years now as a provocative, intriguing tie between the real worlds we’re discovering and the fictional worlds we know and love,” says Christiansen, who also started a lively Twitter conversation on the topic.

[Related: In a first, James Webb Space Telescope reveals distant gassy atmosphere is filled with carbon dioxide]

This doesn’t completely rule out a real-world equivalent of Vulcan, though. The Neptune-sized planet discovered in 2018 isn’t there, but it’s possible a smaller planet—one we haven’t seen yet—still exists around the star 40 Eridani. With current technology and observations, astronomers simply can’t detect any planet smaller than 12 times Earth’s mass on an orbit similar to Earth’s. “This means there’s still a chance that Vulcan exists. In fact, there’s even a chance that Vulcan could be in the habitable zone for the star,” says Laliotis.

Even if Vulcan is gone for now, Trekkie astronomers will still find ways to have fun with sci-fi and outer space. “There are still many other planets in the Star Trek universe that haven’t been disproven,” adds Louisiana State University astronomer Alison Crisp. One potential planet orbiting Wolf 359, for example, could still exist—the site of a major Star Trek battle. 

UCLA astronomer Isabella Trierweiler actually sees a way this saga fits into Star Trek canon. “Until 2063, Vulcans are just observing Earth and waiting for us to develop warp capabilities,” Trierweiler says. “Maybe they were able to adjust our observations to hide the planet, maybe they found super strong cloaking devices, or maybe Vulcan was briefly one of those planets that phases in and out of dimensions!” Whatever Vulcan’s fate, humanity has a few more years of technological development ahead of us until we reach these sci-fi dreams. And perhaps those lofty goals will help us find a real planet around 40 Eridani.

The post Sorry, Star Trek fans, the real planet Vulcan doesn’t exist appeared first on Popular Science.

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The fabric of space and time is wrinkly and warped. Gravity tugs on this fabric, causing indents and wiggles—some of which are observable to humans as gravitational waves. When two black holes, neutron stars, or other extremely massive objects smash into each other, they emit these waves, which were first heard by the revolutionary LIGO experiment in 2016.

After that first detection seven years ago, physicists thought their mathematical models described the data well enough. Now, physicists have just determined that gravitational waves released from collisions between two black holes are more complex than previously thought. Two new studies from Caltech and Johns Hopkins—concurrently published on February 22 in Physical Review Letters with matching results—use computer models to reveal so-called nonlinear effects in black hole collisions, in which gravitational ripples influence each other like waves on a shore.

“Nonlinear effects are what happens when waves on the beach crest and crash,” said Keefe Mitman, Caltech astronomer and lead author on one of the studies, in a press release. “The waves interact and influence each other rather than ride along by themselves. With something as violent as a black hole merger, we expected these effects but had not seen them in our models until now.”

[Related: ‘Rogue black holes’ might be neither ‘rogue’ nor ‘black holes’]

These new studies investigate a particular part of the black hole-black hole merger, known as ringdown because it resembles the vibrations of a struck bell. When black holes collide, they temporarily form one lumpy and unstable large black hole that needs to settle down into a simple, round shape. This settling and shifting releases the gravitational waves that make up the ringdown. Since the mathematics describing this process is unwieldy, prior work assumed gravitational waves don’t interact with each other. 

But this new work tackles those complicated events and discovered the waves in fact influence each other. In computer simulations, the Caltech group modeled what happens when two black holes collide in orbits that aren’t perfect circles, and the Johns Hopkins team smashed two black holes together head-on at almost the speed of light. Both these scenarios are particularly energetic, leading to the nonlinearities they expect to see. 

To explain why energetic collisions have this result, Mitman likens this to two people on a trampoline. Two jumpers who gently hop up and down shouldn’t affect each other that much, as he points out in the press release. “But if one person starts bouncing with more energy, then the trampoline will distort, and the other person will start to feel their influence,” Mitman said. “This is what we mean by nonlinear: the two people on the trampoline experience new oscillations because of the presence and influence of the other person.”

Without accounting for nonlinear effects, physicists may be wrong about the size and other properties of the black holes they detect—of which there have been many with LIGO over the past few years. Plus, these details are key for making sure our understanding of the laws of physics are fully correct, such as checking the intricacies of Albert Einstein’s theory of general relativity.

[Related: We’re still in the dark about a key black hole paradox]

“Black hole ringdowns offer a great playground to test Einstein’s theory of relativity,” says Sumeet Kulkarni, a University of Mississippi astronomer not affiliated with the study. “But to use ringdowns as a test, one must understand them completely. This study takes us a step closer to this understanding.”

For now, however, nonlinearities are only seen in the realm of supercomputers. Humanity’s best black hole detectors aren’t sensitive enough to spot these small effects. Future detector projects are already in the works, though, and researchers are already starting to plan for the future. 

“An obvious next step is to gauge whether these effects will be detectable in LIGO or next generation detectors,” says Mark Ho-Yeuk Cheung, physicist and lead author of the Johns Hopkins study. The Cosmic Explorer and the Einstein Telescopes are two upcoming gravitational wave experiments that may be able to do the job. “While the prospects are promising,” Cheung adds, “we still need to quantify more precisely how and when they will be detected.”

Not only do the pair of simulations shed new light on the mysteries of black holes, they also illustrate the beauty of the scientific process: two teams of scientists producing independent results, complementing and supporting the others’ findings. As Mitman tells Popular Science, “I’m just charmed that we have yet another beautiful example of theorists and numerical relativists coming together to discover something fascinating about the way black holes work.”

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In our solar system neighborhood, there’s one planetary family that we haven’t met properly: the ice giants, Uranus and Neptune. Thanks to Voyager mission flybys, we’ve said hello and we know their faces—but we’ve never stopped over for a visit. Now, planetary scientists have decided to make long-overdue plans to walk over and ring the doorbell for a house tour.

The 2022 Planetary Science Decadal Survey, an influential document for planning future missions run by the National Academies of Science, Engineering, and Medicine, recommended NASA prioritize sending an orbiter and probe to Uranus in the coming decades. Past decrees from this process have launched some of the most exciting projects of the 2020s, including the Mars Sample Return and the upcoming Europa Clipper mission.

With eight planets and countless smaller rocks to explore in our solar system, how could planners possibly settle on a single destination—especially when that decision involves millions, or billions, of dollars and affects hundreds of careers? In a recent commentary for Science, Johns Hopkins Applied Physics Lab planetary scientist Kathleen Mandt argues why Uranus is the right choice—and other researchers seem to agree.

“We’ve sent missions to every other planet, to comets, to asteroids, and to trans-Neptunian objects. We’ve sent missions out of the solar system and to the surface of the sun…. Uranus and Neptune are the enigmas of the solar system,” says Will Saunders, an astronomer at Boston University who studies Uranus’s atmosphere.

Humanity’s last up-close glimpse of Uranus, and its sibling ice giant, Neptune, was back in the 1980s with the Voyager probes. Although Neptune would be nearly equally scientifically interesting—its captured Kuiper Belt Object moon, Triton, is of particular curiosity due to its icy volcanoes and more—the extra billion miles to that planet was the dealbreaker.

“The main reason that we chose Uranus first is because it is easier to get to,” Mandt tells Popular Science. “And we have already waited more than three decades for a mission to these planets. Going to Uranus first means less risk and a mission that can arrive at the planet sooner.”

For a planetary mission, “soon” means within the next few decades—the trip to Uranus takes 10 to 15 years, and engineers still need to design and build the spacecraft. As of now, the plan is to launch by 2032, hopefully reaching Uranus by the mid-2040s. The mission would have two parts: an orbiter, which would circle the planet for at least five years, and a probe to dive into the clouds and collect information about the Uranian atmosphere. 

Some key measurements that astronomers have for Jupiter and Saturn are still missing for Uranus, such as the amount of noble gases and the ratio of different types of nitrogen. The probe will measure these chemical markers because they’re fingerprints of how and when the planet formed. “The formation of the four giant planets and the way they moved to new locations had a major impact on the whole solar system,” says Mandt. This planetary rearrangement “may be how we got water on Earth,” she adds, and that motion launched many of the objects in the Kuiper Belt and Oort Cloud to their current positions.

[Related: Expect NASA to probe Uranus within the next 10 years]

Plus, Uranus is the only planet fully knocked on its side: It’s tilted 98 degrees, which is wild compared to Earth’s 23-degree angle. That causes some quirks in its atmosphere. Planetary scientists are puzzled by the resulting patterns of clouds and wind on Uranus, which they hope to resolve in this mission.

Uranus also has 27 moons, some of which may host oceans below their thick icy surfaces. Subsurface oceans are, of course, one of astrobiologists’ favorite targets for extraterrestrial life, and the satellites of Uranus are no exception. One of the major surprises from Voyager was that Uranus’s five largest moons—Miranda, Ariel, Umbriel, Titania, and Oberon—weren’t “cold dead worlds,” as Mandt describes in the article, but were instead geologically active.

“Simply put, I want another picture of Miranda before I die,” says Adeene Denton, a planetary scientist at the University of Arizona Lunar and Planetary Laboratory. “Miranda is, to me, one of the coolest and most unusual places in the solar system, covered in geologic terrains we haven’t seen anywhere else.”

The lessons from Uranus aren’t bound to our solar system, either. In the past few decades, exoplanet astronomers have found that Uranus-sized worlds may be the most common type of planet out there. An up-close study of our local example will be invaluable for astronomers trying to understand distant exoplanets—particularly helpful will be determining properties of Uranus’s core and internal structure, such as whether it’s made of rock or ice.

[Related: Uranus blasted a gas bubble 22,000 times bigger than Earth]

“We have not seen Uranus up close since before I was born. That was before we knew about the existence of exoplanets,” says University of Bristol astronomer Hannah Wakeford. “This mission to Uranus is going to change our understanding of our solar system, and planets across our galaxy.”

The upcoming Uranus orbiter and probe mission has the potential to be a revolutionary event in science, bringing our understanding of the ice giants up to par—doing what Cassini did for Saturn and Juno for Jupiter. “An orbiter is really what we need to do profound science that characterizes the entirety of the Uranian system,” says Denton. “There is so much to see and do, and committing to an orbiter is really truly worth it.” 

Plus, it will return incredible images of the edges of our solar system, certain to excite and inspire future scientists and space fans. Whenever NASA comes knocking, it always packs cameras, and this meet-and-greet is no exception.

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Astronomy outreach programs in states, which usually consist of visits to K-12 schools or public lectures, are expanding their reach into prisons, such as at Princeton’s Prison Teaching Initiative and the University of Washington eSTEAM (Education in Science, Technology, Engineering, Astrobiology/Art, and Math) program.

Access to education is a key issue in the mass incarceration epidemic facing America. As of 2010, statistics from the Prison Policy Initiative show at least 25 percent of incarcerated people haven’t finished high school, compared to 13 percent of Americans as a whole. Similarly, far fewer incarcerated individuals have done any post-secondary education before their time in prison—and, to make the situation worse, they lack access to such education once inside. 

Prison college courses in the US are often under-funded (particularly due to a 1994 law barring incarcerated students from Pell Grants), or even entirely absent, leaving millions with no opportunities for educational progress during their sentences. Youth under 18 are required to have some access to education, but these programs are often inadequate and inconsistent as well. Yet, prison education is well-known to have incredibly positive effects—it reduces long-term costs of incarceration, reduces recidivism, and reduces violence within prisons. “If you don’t have a degree, the likelihood that you’ll return to prison in the first year is 70 percent. And if you do have a degree it’s like 13 percent,” explains Erin Flowers, Princeton astronomy PhD candidate and Prison Teaching Initiative Fellow.

Prison education also significantly improves outcomes for incarcerated individuals, such as lower unemployment rates, higher incomes, better health, and increased opportunities for their kids and families. And importantly, education reconnects incarcerated people with the fundamental human rights of knowledge and curiosity, including the ability to know about space. Astronomy courses, in particular, are key to promoting science literacy—an important part of any education in today’s tech-driven world.

[Related: On surviving—and leaving—prison during a pandemic]

Princeton’s Prison Teaching Initiative (PTI) started in 2005 with astronomy faculty and postdoc researchers teaching math classes to incarcerated students, and has now grown into a large program offering coursework across multiple disciplines towards Associate’s and Bachelor’s degrees from partner institutions to local adult prison populations. More than 350 students have earned their degrees across multiple institutions within the New Jersey Department of Corrections. It incorporates full 15-week introduction to astronomy courses and lab-based physics courses through Raritan Valley Community College, which fulfill students’ general science requirements. Flowers explains that her incarcerated students take these courses to further their education and post-education goals as active learners in the program, and many have expressed that they “appreciate having [the program] as an outlet, and they appreciate having something to set their minds to.” 

University of Washington’s eSTEAM program, on the other hand, is only a few years old, and builds off the legacy of other programs such as PTI and NASA’s Astrobiology for the Incarcerated by bringing prison education to the Seattle community. eSTEAM uniquely focuses on tutoring and teaching imprisoned dozens of kids under the age of 18. The program currently helps with astronomy, physics, and any other subjects that the youth need support in. Their goal is to keep students on track with their education, filling in the gaps of their primary classes and supporting them with one-on-one attention and tutoring. The teaching team is also currently designing experiments in astrobiology, the study of life beyond Earth, to bring to the facilities, given that the kids generally don’t get much exposure to fun topics beyond the standard curriculum. One of their working ideas is to have students make a Winogradsky column, a sort of test tube environment that shows how chemistry, physics, and biology intertwine to enable life.

Both programs face significant challenges, as teaching in a prison environment is far different from the usual classroom. With the New Jersey Department of Corrections, instructors must follow facility guidelines regarding dress, behavior, and materials, says Flowers. “For a lab-based class, there’s been a lot of MacGyvering and trial and error trying to adapt those lessons” for use inside the prison, she continues. “Many items we take for granted in a traditional physics classroom are prohibited for safety reasons, and thus suitable alternatives must be found that still maintain the intellectual rigor required for the course.”

Internet access within facilities is also often limited, preventing students from doing their own research outside class or looking into possible careers. Samantha Gilbert, a University of Washington astrobiology graduate student and eSTEAM volunteer, considers a key part of her role as “being that connection to the outside world” for the incarcerated individuals she works with.

She goes on to describe widespread challenges beyond logistics—particularly, how the prison system is designed to punish those incarcerated, even if the supposed goal is rehabilitation. She says the system tends to consider their outreach work “rewarding the students, rather than the basic things that any kid should have access to, regardless of the mistakes they’ve made in their life.”

Although many teachers and volunteers inside prisons want what’s best for the students, there are still many who treat them as lesser due to their status. Gilbert recalls a particularly heartbreaking scene, where she was “watching a child grab all of the work that they had been doing out of the trash, because apparently a security guard got really mad and threw it all away.”

Both Flowers and Gilbert see their astronomy and education outreach as crucial to building a future where prisons are no longer a place to discard people from society. Instead, they dream of a future where prison is more rehabilitative, or even abolished entirely in favor of other community-based solutions.

Gilbert says her work in juvenile facilities makes “you feel even more strongly that they should be allowed to turn their lives around.” She continues to say that this is true of the adult population as well, even if they tend to garner less instinctual sympathy from many people. She urges community members to build connections with their local incarcerated populations in whatever way they can.

[Related: A Palestinian brings stargazing to his homeland, and finds wonder alongside heartbreak]

Educational outreach provides new hope and possibilities for incarcerated people, and re-opens the door to science for many who have been denied it previously—especially groups who are disproportionately affected by policing. “The problem isn’t that marginalized people aren’t excited about science early on. The problem is the way marginalized people are systemically pushed out of science,” says Gilbert.

The factors impacting participation in astronomy and other sciences stretch far beyond traditional school systems, and outreach programs are finally expanding their efforts to match. “By using the knowledge that we have and the resources that we have,” says Gilbert, they’re opening prisons up to the planets, stars, and all the space that lies between.

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ChatGPT’s cousin was just hired by NASA. On February 1, NASA and IBM announced a new partnership between the two major organizations, aimed at applying artificial intelligence (AI) tools to climate science, scanning research literature for quick answers and identifying features in Earth science data.

This is far from NASA’s first foray into artificial intelligence, or even the agency’s first collaboration with IBM. In 2014, NASA collaborated with the tech giant to infer measurements of the sun’s extreme radiation when a sensor failed on the Solar Dynamics Observatory. A year later, NASA started a summer bootcamp to bring scientists together with Silicon Valley engineers, known as the Frontier Development Lab. 

Plus, since the dawn of machine-learning techniques, scientists across NASA’s domains have been using these tools in their own projects, from looking at the sun to designing autonomous data-gathering robots. As AI has grown in power and complexity, though, it has become harder for individual researchers to harness the full potential of these tools. Each time they start a new project, many NASA engineers and scientists build a bespoke model for each dataset. To solve that problem, in 2020, NASA hosted a workshop on AI. It sought answers to large-scale, extra-challenging problems, dreaming bigger than one-off models for each problem—and IBM’s tech seemed like a perfect match for their needs.

“We have all heard and seen the magic” of widely-applicable machine learning models, especially language models like ChatGPT, said IBM lead developer Priya Nagpurkar in a press conference. “We are at this unique point where it’s time to take those advances and apply them to different domains…as well as advancing science.”

[Related: Is ChatGPT groundbreaking? These experts say no.]

This collaboration is the first time a particular kind of AI—a flexible, broadly-applicable technique known as a foundation model, which IBM is at the forefront of developing—has been applied to Earth sciences. “While NASA and IBM have discussed using AI to solve various problems for the past few years, IBM’s foundation model research was the catalyst for the current collaboration,” says IBM representative Danielle Cerasani.

As described in a recent press release, the collaboration plans to tackle two main projects: answering questions based on scientific literature, and analyzing large datasets of Earth to identify patterns and trends. NASA is providing access to its vast collection of Earth-observing data and its scientists, while IBM is adding AI development expertise and their existing research into this tech.

The literature search is based on technology similar to ChatGPT, and NASA hopes it will serve as a sort of ultra-advanced search engine for scientists.One of its key selling points is that its answers will come with citations—direct links to the research papers it’s pulling information from—unlike other tools that act more like a mysterious black box.  Rahul Ramachandran, senior research scientist at NASA’s Marshall Space Flight Center, said in a press conference this technology could be ready as early as mid-2023. 

Still, some scientists are skeptical. “The ability of the model to summarize information and answer questions, which is the most innovative aspect especially for the broader community, is also at higher risk of bias,” says Viviana Acquaviva, physicist and AI specialist at the City University of New York. “We have seen how state-of-the-art models like ChatGPT can easily produce biased or incorrect answers, while sounding plausible and confident.” In an advertisement for Google’s new Bard chatbot, for instance, the AI incorrectly stated that the James Webb Space Telescope imaged the first exoplanet, when the European Southern Observatory’s Very Large Telescope had done so years prior.

[Related: How old is Earth? It’s a surprisingly tough question to answer.]

Meanwhile, applying AI to Earth observations is the more scientifically interesting half of the collaboration, at least to Acquaviva. NASA hosts the world’s largest archives of data on our planet—enough to fill around a million typical iPhones—and they hope to sort it more effectively with IBM’s models.

“Our archive is currently at 70 petabytes and it’s projected to grow within a few years to 250 petabytes…We support 7 billion users worldwide who access our data for research and applications,” Ramachandran told reporters. “Clearly, given the scale of the data that we have, we have a big data problem.” 

With the new AI tech, they hope to easily track weather and natural disasters across the planet—as diverse as tornado tracks to dust clouds. Ramachandran imagined a scenario where a disaster response team could quickly analyze the extent of flooding after a hurricane, enabling faster and more effective emergency aid. The team plans to first analyze a data set known as Harmonized Landsat Sentinel-2, a combination of observations from two powerful NASA satellites. This work has just started, however, with Ramachandran describing it as an “open area” of research.

The collaboration also intends to publicly release the code and other tools they develop through these projects, making them available to anyone interested in their use. “It is exciting to witness progress toward the creation of an inclusive and interdisciplinary community,” Acquaviva says, “that can make climate data and AI tools more accessible to scientists and the public.”

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Being stranded in space sounds like the makings of a dramatic science fiction movie, but reality is a bit less flashy. Real-life space travel involves rigorous preparation, massive teams of support staff, and backup plans for almost every imaginable scenario.

This intense planning is exactly why the recent coolant leak on the Russian Soyuz spacecraft isn’t as dire as it originally seemed. 

In December 2022,  a micrometeorite damaged the Soyuz MS-22 spacecraft docked on the ISS, which affected the capsule’s cooling systems that keep astronauts at safe temperatures on their descent back to Earth. Engineers determined that the craft wasn’t fit for return, except in case of an emergency. The crew originally carried up on the Soyuz was stranded. 

But they were stranded aboard the safest place in space: the International Space Station. “We have the ISS as a safe haven,” says former NASA astronaut Mike Massimino, who flew aboard the space shuttle in 2002 and 2009 to service the Hubble Space Telescope. “If you get stuck up there, you just hang out there for a while until someone comes and gets you.”

The ISS is about the size of an American football field, and made up of almost 40 different modules, as diverse as solar panels to docking ports to pressurized, habitable living areas. Construction on this orbital behemoth began in 1998, and it has been occupied by at least one astronaut since the turn of the century.

[Related: ISS astronauts are building objects that couldn’t exist on Earth]

Its modular design is not only a quirk of its assembly, but a conscious design choice. In the event of an emergency—the top three are fire, depressurization, and toxic air—the crew exits the damaged area, sealing off modules as they go to isolate the leak or other issue. Even if something were to happen aboard the ISS while the crew from Soyuz MS-22 were stuck, “the chances are you’re going to be able to isolate [the problem] until you figure out how to get other folks home,” according to Massimino.

The astronauts are also trained for risky situations. They prepare on the ground before their voyages and aboard the space station. Plus, the American astronauts have to be familiar with the Russian tech on board (and vice versa) and even learn to speak Russian so that they are able to effectively work with their international counterparts.

Yet, among the many different emergencies astronauts prepare for, a damaged return capsule doesn’t feature prominently. The mission teams are more focused on ensuring the ISS remains safe and habitable, and aren’t as concerned about the ferries between space and the ground. “The spacecraft on which astronauts and cosmonauts fly to the space station are the intended spacecraft for their return to Earth,” says NASA media representative Joshua Finch.

[Related: The ISS gets an extension to 2030 to wrap up unfinished business]

In the late 1990s to early 2000s, NASA considered a dedicated “lifeboat” for the ISS, known as the X-38. It would have been a glider, similar to the space shuttle, with the sole purpose of returning astronauts to Earth in emergency situations. Although prototypes were successfully tested, the program was canceled in 2002 due to budget constraints. Instead, astronauts learned to rely on the ever-expanding ISS.

“When we had the shuttle flights after the [Space Shuttle Columbia] accident, there was a real possibility that you might not be able to come back because of your return vehicle,” Massimino recalls. “And we weren’t worried about that because if you inspected the vehicle and you couldn’t repair it, you would just stay on the space station.” Given that people have lived aboard the ISS for as much as a year at a time, a brief layover there while waiting for your connecting spaceflight doesn’t seem so bad.

American and Russian mission support teams also immediately began coordinating their next steps after the recent leak, putting their rigorous training into action while astronauts waited onboard. Numerous plans were considered, from fitting more astronauts into the SpaceX capsule also docked on the ISS to sending up new vehicles to bring them home. “Engineers at each space agency work together to provide safe return options in the event of an emergency situation,” Finch explains, “as NASA and Roscosmos have done while creating the Soyuz 68S crew return plan.”

In early January, NASA and Roscosmos decided the best course of action was to move up the date of the next Soyuz launch, sending up an uncrewed capsule to give the astronauts a ride home. The launch will send up the Soyuz MS-23 on February 20—and until then, the astronauts will continue with business as usual and ride out their stay on the ISS, humanity’s only oasis in space beyond our home planet.

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Sci-fi storytellers love to spin tales about laser-wielding aliens who visit Earth—but in reality, we’re the ones now using sophisticated laser beams to hunt for signs of extraterrestrial life.

Geologists and engineers at the University of Maryland recently created a new piece of technology, designed to fly in space, that uses light to analyze molecules. This work, published last week in Nature Astronomy, takes a common molecule-analyzing lab instrument here on Earth, known as the Orbitrap, and shrinks it down to make it compact and light enough to fit on a NASA solar system mission. They also combine the improved Orbitrap with a laser, which can break up material from a planet’s surface to prepare it for analysis.

“I am excited to see what kind of complex molecules we would be able to detect beyond Earth,” says Grace Ni, University of Maryland geologist and co-author on the study. “The next-generation Orbitrap analyzer offers about 200 times improvements” in the detail of its measurements compared to older systems, she adds. It could fly on missions within the next decade.

The Orbitrap is a tool for mass spectrometry, a go-to technique for scientists that separates molecules by their mass and measures how much of each there is in a sample. Although these machines are found in medical, biological, and other industrial labs across the planet, they’re also huge, weighing around 400 pounds—a little heavier than a giant panda. Offworld missions are often limited in how much they can carry to their destinations. One of these behemoth Orbitraps just would not fly. The new version, though, only weighs about 17 pounds.

[Related: The Milky Way could have dozens of alien civilizations capable of contacting us]

Plus, mission teams must often choose between one big component or multiple smaller tools. Selecting instruments for a space mission is “like choosing what tools you want on your pocket Swiss army knife,” explains Zach Ulibarri, an aerospace engineer at Cornell University who was not part of the new study. “But, at the same time, the tools on a Swiss army knife are smaller and lighter than the tools you keep in your garage, just like the instruments on your spacecraft have to be smaller and lighter than the full-sized ones you keep in a laboratory.”

Before it can measure a molecule, the upgraded laser-wielding tool uses ultraviolet pulses to break up the compounds from a planet’s surface—such as rocks on Mars, the icy outer shell of Enceladus, or other interesting targets for possible life in our solar system. It then funnels them into the miniaturized Orbitrap spectrometer, where the sample’s composition is measured. 

Eddie Schweiterman, a University of California Riverside astrobiologist not involved in the new Orbitrap project, explains that this tool will take the “fingerprints” of molecules related to life, while also providing information about the surrounding geology of whatever planet or moon is being explored. Context is key for signs of life—scientists must be able to rule out non-living sources of the same life-like chemicals. This new laser-Orbitrap system would also allow scientists to do this detailed chemical analysis remotely via a straightforward robotic mission, like a lander or rover, as opposed to a sample return to Earth.

Although there is a lot of ongoing work to detect biosignatures on distant exoplanets, that’s a totally different ballgame than exploring the solar system with a probe via upgraded Orbitrap. The large organic molecules to be analyzed with missions featuring Orbitrap “cannot be easily observed remotely, particularly at interstellar distances,” Schweiterman says. Instead, exoplanets can only be observed from light-years away via our telescopes. But astronomers could send robots equipped with this tool to the surfaces of the planets nearest us.

[Related: Why astronomers are blasting Earth’s location to potential intelligent aliens]

There’s also one more catch. The large amount of data generated from the new system “could be a headache for data storage and transmission during a space mission,” according to Ni. Hopefully, as computer technology inevitably advances, engineers will come up with clever ways to deal with this problem. Even then, data storage isn’t a dream-killer for the Orbitrap—just another thing to consider when designing a spacecraft. As Ulibarri says, “each instrument has its own advantages and disadvantages. There is no perfect instrument; there are only trade-offs between different ones.” 

Building a fully functioning spacecraft is always difficult, but new instrument technologies like the improved Orbitrap expand the possibilities for future missions. “It’s always exciting to add a new tool to the potential spacecraft toolkit,” says Ulibarri. “And the Orbitrap is a particularly powerful tool.”

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The lifetime of the universe is, unfortunately, so long that we can’t just wait and watch what happens to understand how it works. It’s a movie marathon that started billions of years before our species began, and will likely continue after us, too. But what if there was a recording, and we could wind back the tape?

Astronomers are doing just that with the famed James Webb Space Telescope (JWST), using the behemoth flying observatory to rewind through our universe’s history, searching for early galaxies. As a result, astronomers have found hundreds of galaxies from 11 to 13 billion years ago that also show a remarkable diversity of shapes: disks, bulges, clumps, lumps, and more. These star groupings emerged earlier in the universe’s timeline than previously thought, according to new research recently presented at the American Astronomical Society meeting and soon to be published in The Astrophysical Journal.

“It is amazing to be able to see the structures of these distant galaxies with such clarity for the first time,” said Jeyhan Kartaltepe, Rochester Institute of Technology astronomer and lead author on the new study. “They are anything but boring.”

To estimate the ages, Kartaltepe and her team used a well-established method in astronomy. Galaxies farther away from us in space also go back further in the universe’s history, thanks to the finite speed of light. Plus, given that the universe is expanding, galaxies farther away from us appear more red than they would if they were nearer, as their light gets stretched out while traveling the vast, lengthening cosmic distances to our telescopes. This gives astronomers an easy way to mark when something existed in the universe, known as redshift. 

But, this also means targets with a higher redshift literally appear red, or even shine mostly in the infrared. So, a galaxy that looked bright blue billions of years ago may appear bright in infrared light to our cameras. This is the distinct advantage of JWST—because it sees the universe in the infrared, it can spot these distant, red galaxies. The telescope is also quite simply bigger than past space tools, and in the world of telescopes, bigger really is better.

[Related: How the James Webb Space Telescope is hunting for ‘first light’]

With previous data from the Hubble Space Telescope, which sees in the visible and near-infrared, astronomers already knew there were interesting and diverse galaxies in our universe from 11 billion years ago. To find out when the sweeping spirals and rotund bulges (like those in our own Milky Way) first formed, though, researchers needed to rewind the tape a bit further. 

“We do not know what happened in the early universe to create disks and bulges, or when it happened, or where it happened, or how it happened—and we had no way of finding this out until JWST,” says University of Melbourne astronomer Benji Metha, a researcher not affiliated with the new findings. “We can use these [galactic] observations like a fossil record, to dig back through time and see what features existed in these galaxies while the universe was still under construction.”

The team gathered images of 850 galaxies with JWST, and classified them into the typical galaxy shapes: disks (like our own spiral galaxy), clumps, irregulars, or some combination of the three. The data was all analyzed by hand, with astronomers sifting through each and every file. “One thing I love about this paper is how human it is,” says Metha. He explains how a century ago, American astronomer Edwin Hubble used the Mount Wilson Observatory in California to sort different types of nearby galaxies, creating the classification system most astronomers use today. “At its core, this paper uses the exact same method that Hubble used: Look at some pictures, and write down what you see,” Metha adds.

The international group of researchers found lots of disks, which may be precursors to galaxies like the Milky Way. They also spotted lots of irregulars, which are signs of two galaxies whose gravitational fields got a little too close and nudged each others’ stars around, or even merged completely.

“We see all sorts of structures across cosmic time less than a billion years after the Big Bang,” says Olivia Cooper, an astronomer at UT Austin. These new images, she said, “demonstrate what we are able to do with JWST and hint at a universe that hosted evolved galaxies earlier than we thought.”

The fact that there was such a variety of galaxies while the universe was still young is puzzling, and sure to keep astronomers busy as they build better models to learn how these cosmic entities formed and grew. The study also shows that to see the first galaxies, experts will need to keep rewinding that tape, and pushing the boundaries of how far back JWST can peer into the universe’s past.

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Far from our cozy home in the cosmos, stars are performing violent and extreme acts almost beyond our imagination. Neutron stars, the unbelievably dense remnants of huge stars—a teaspoon of their matter weighs as much as Mount Everest—are smashing into each other. This impact creates black holes and releases extremely energetic flashes of light known as gamma ray bursts (GRBs). 

Astronomers have been interested in GRBs since the first one was spotted in 1967. But there’s still much to understand about exactly what goes on when two neutron stars collide. New research, recently published in the journal Nature, reveals helpful signals known as quasi-periodic oscillations (QPOs) in old observations of GRBs. QPOs provide a window for scientists to explore the brief time after the neutron stars collide but before they’ve collapsed into a black hole. They’re the fingerprints of how matter is swirling and mixing together in the merger.

Since the advent of gravitational wave detection in 2016, many astronomers have been focused on exploring neutron star mergers with LIGO and similar experiments. But, those observations provide half the picture, since current detectors are only sensitive to some of the gravitational waves created by the mergers. To detect the higher-frequency waves we’re currently missing, we’d have to wait years—maybe even decades—for new projects like the Einstein Telescope to come online. 

This new research shows that existing technology, using gamma-rays, may be an alternative to probe the same physics that creates higher-frequency waves. QPOs, which are wiggles in the observed gamma-rays that repeat semi-regularly, encode information about the physics of the merger. The study authors analyzed two events that produced QPOs of uncertain origin–they may have originated within our galaxy or far beyond it.

“We’re looking at what happens in the split second between the merger of the two stars and the launch of the gamma ray burst. It is almost frustrating that these signals will only be detectable in gravitational waves some 10 to 15 years from now,” says lead author Cecilia Chirenti, a research scientist at NASA Goddard Space Flight Center and the University of Maryland. “But I am impatient and don’t want to wait! It’s exciting that we’re able to start looking for and learning from them now using gamma-rays!”

[Related: Why are big neutron stars like Tootsie Pops?]

The collision of two neutron stars is an excellent laboratory for exploring the physics of these weird, dead orbs. Their ultimate fate depends on an important unknown in high-energy physics: the equation that describes what neutron stars are made of and how that material moves, flows, and interacts with the world around it. 

“The matter in the cores of neutron stars exists in a state seen nowhere else in the universe, including in laboratories on Earth,” says Cole Miller, astronomer at the University of Maryland and co-author on the study. “Measurements of neutron star properties can give us insights into an otherwise inaccessible physical realm.”

In their search for QPOs, the research team explored archives of data from multiple NASA space telescopes: the Fermi Gamma-Ray Space Telescope, the Swift Observatory, and the Compton Gamma-Ray Observatory. Although these GRBs were identified years ago—as early as the 1990s—the enormous complexity of GRB signals has kept these QPO signals hidden from astronomers until now. “One of my colleagues wryly noted that ‘If you’ve seen one gamma-ray burst, you’ve seen one gamma-ray burst,’” says Miller. “This makes it difficult to tell whether there is some signal of oscillation, or whether that’s just GRBs being GRBs.”

[Related: Black holes can gobble up neutron stars whole]

In both events, the QPOs suggest that a mega-sized neutron star may have formed before collapsing into a black hole. Itai Linial, a Columbia and Princeton astronomer not involved with the study, says it is still unclear in general whether a black hole forms immediately or a neutron star appears for a fraction of a second before the collapse to a black hole during a GRB, but agrees these new signals “may be the result of a rapidly rotating neutron star remnant.” 

With the detection of these gamma-ray signals, astronomers now have a new tool to explore some of the weirdest and wildest phenomena in the universe. With a treasure trove of old data to explore, the team now hopes to use this tool to find more examples of these curious mergers.

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The James Webb Space Telescope, NASA’s newest and biggest off-world observatory, has been collecting jaw-dropping images of the cosmos since June. Astronomers quickly shared their results online, even before the telescope’s calibrations were finished. Some of these findings were record-breaking, including observations of the most distant galaxies yet found. Significant debate and discussion ensued among researchers—was science moving too quickly by publishing observations before peer review, forsaking rigor for the glory of being first to a new discovery?

As the dust has settled, many astronomers think the early results remain informative. But, in the rush to work with a groundbreaking new observatory and sift through its mountains of data, they report stressful working conditions. That’s a scenario they hope to improve upon in 2023 and beyond, finding a balance between quickly offering exciting results to the public and taking the time needed for rigorous, sustainable science.

“I was actually quite excited to see science happening very fast,” says Klaus Pontoppidan, JWST project scientist at the Space Telescope Science Institute. “This is the way science works … if there are issues with calibration, that gets tested by other teams, and any errors get corrected later.”

[Related: A fierce competition will decide James Webb Space Telescope’s next views of the cosmos]

Every day JWST returns around 60 gigabytes of data to Earth, about the amount of information a basic iPhone can hold. This may not seem like much, but the steady stream of data amounts to a whopping 12,000 gigabytes so far—enough to fill a roomful of laptops—with much more to come. Each bit of this valuable data will be subject to the intense scrutiny of astronomers, who are trying to glean as much information as they can about the cosmos with JWST’s new view.

Some of that analysis started almost as soon as the telescope was operational, with programs known as Early Release Science (ERS), which made JWST data publicly available this June and July. 

Hannah Wakeford, an astronomer at the University of Bristol, worked on some of these early release science programs. Although she is excited about the scientific breakthroughs, she also experienced an extremely intense work environment—she hasn’t taken a break since mid-July. She criticizes this initial period of rushed results, saying that usually “fast science results in poorer or incomplete work. This is not necessarily the scientists themselves at fault for this, but the enormous external pressure to get publications.”

On the other hand, Ryan Trainor, an astrophysicist at Franklin & Marshall College, considers this frenzy as just “part of the modern scientific process, particularly given the pressure to be first to any big discovery.” Wakeford and Trainor’s statements are not mutually exclusive—the race to publish is both an accepted part of science and a possible hazard. For those trying to make astronomy their career, publishing an idea first and getting the credit for it is a necessary evil.

As we approach the one year anniversary of JWST’s launch on Christmas Day, the debate about the speed of astronomy has resurfaced again, now in the context of observations proposed by teams of scientists. NASA reportedly planned to make all data available from the telescope immediately, removing so-called proprietary periods that allow astronomers time to work with data they planned and designed. There isn’t currently a clear deadline for this change, but it may fall in line with the White House’s call for open access science by 2026.

Those in favor of removing proprietary periods claim that public access to the data will be more equitable, allowing anyone a chance to explore the wonders of the new telescope. Many astronomers disagree, though, explaining that their field will become impossibly competitive without proprietary periods to protect scientists’ ideas. The rush to publish would undermine work-life balance, and disadvantage those who can’t work as fast: parents who have to contend with childcare, astronomers at smaller schools with fewer resources, early career students who are still learning, and others.

[Related: James Webb Space Telescope reconstructed a ‘star party,’ and you’re invited]

“JWST will produce ground-breaking, paradigm-shifting science over the next 20 years of its observing time,” says Wakeford. “Why not cut the scientists a break and give them time to make sure we can do the work with rigor, while not destroying our mental and physical health at the same time?” 

Lafayette College astronomer Stephanie Douglas agrees, explaining that “this is an equity issue. We need to protect the more vulnerable members of our community.”

The situation is not so simple for the NASA scientists in charge of the telescope, though. They have a responsibility to both scientists and the general public, whose taxpayer money funds the entire program. “I think it’s a balance,” says Pontoppidan. “You’re balancing public programs and proprietary time, and both things you need to do for equity.” The future of proprietary periods is yet undecided, but no matter the outcome it will surely affect the process of science in JWST’s second year. Astronomers are currently preparing for the second round of proposals to use JWST, due just after the holidays in January. “I’m hoping that we’ll see some really ambitious proposals,” says Pontoppidan. The first year of JWST observations explored what the observatory could do—and now astronomers can start pushing the limits of those capabilities.

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In our solar system, there are worlds of ice and worlds of fire. Jupiter’s moon Io is the best example of a world of fire, freckled with volcanoes and cracked by lava spills. 

There are many competing theories to explain the workings of this fire-orb. New research published in The Planetary Science Journal and presented at the 2022 American Geophysical Union Fall Meeting narrows down what could be going on inside the volcanic world using computer simulations, suggesting that it hosts a scorching ocean of magma beneath its surface. 

Magma oceans are thought to have been a common feature of rocky planets and moons earlier in the solar system, but are almost nonexistent now as things have cooled down over time. Io’s searing sea could be the only surviving example, giving scientists the opportunity to observe one up close.

“Whether a magma ocean exists or not essentially changes how Io operates, and it greatly affects the interpretations of various observations of Io,” says Caltech planetary scientist Yoshinori Miyazaki, lead author on the new research paper. 

On Earth, volcanoes are caused by our planet’s shifting tectonic plates. Io’s volcanoes arise from a very different mechanism, called tidal heating. In tidal heating, a large object—in this case, Jupiter—squishes and stretches another object near it through gravity, heating it up with friction. It’s sort of like mushing around clay with your hands until the substance becomes flexible and warm. Thanks to this geological phenomenon, Io has enough warmth to sustain its many volcanoes.

“At Io, tidal heating has run wild, generating one of the most volcanically active worlds in our solar system, with over 100 active volcanoes at any given time,” says James Tuttle Keane, a planetary scientist at NASA’s Jet Propulsion Laboratory who is not affiliated with the research team. “Because tidal heating is so extreme at Io, it makes it the best natural laboratory to understand this process.”

There has been long-standing debate on what resides beneath Io. Before we even saw the surface of the hellish moon, scientists speculated there may be a magma ocean raging under the rocky crust due to Io’s wild tidal heating. However, once Voyager and Galileo revealed Io’s rugged terrain, astronomers began to doubt a subterranean magma ocean could support such heavy mountains. 

Scientists then pivoted to suggest the interior is just rock with little melted bits inside. A recent hypothesis proposed the interior could be something in between pure magma and pure rock—a partially molten mass called a magmatic sponge. “Think of a magma sponge like a dish sponge or a coral sponge, where both the solids and the liquids are entirely interconnected,” explains Tuttle Keane. “This means fluids, be it soapy dishwater or magma, can flow through the sponge, but the sponge still has some structural integrity.”

[Related: We just got an up-close look at the largest lava lake in the solar system]

This new work, though, uses computer models to show the interior of Io is unlikely to be a magmatic sponge—and a magma ocean makes much more sense given the existing observations of the Galilean satellite. 

Based on reasonable assumptions about the conditions inside Io, the computer simulations predicted that a magmatic sponge would quickly separate into different layers of magma and rock, creating the magma ocean. “Melt and rock tend to separate rapidly, just like the ice and water do in a slushie if you leave it for a while,” says University of California, Santa Cruz geologist Francis Nimmo, who wasn’t involved with this study. 

Unfortunately, these models can’t definitively prove if Io does have a magma ocean. For that, we’ll need to send a probe back to the fiery little moon. 

Miyazaki is looking forward to the Juno spacecraft’s upcoming flybys of Io in December 2023 and February 2024, where astronomers will measure a property of the moon called the Love number. This number is a proxy for how rigid or squishy the interior of a planetary body is. “If the Love number is large,” explains Miyazaki, “it will confirm the existence of a subsurface magma ocean on Io.”

Even if a magma ocean is confirmed, “there are still a lot of uncertainties associated with trying to understand Io’s interior structure,” Tuttle Keane says. “We need future missions to explore Io and the Jupiter system…many questions will remain unanswered until a dedicated Io mission is flown that can explore this volcanic moon in detail.”

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An essential part of any space mission is power. If a spacecraft runs out of energy, the communications go down, the craft becomes unsteerable, and life support systems shut off—a scenario that’s the stuff of sci-fi nightmares. 

For a spacecraft, the sun is a particularly vital supplier of energy, and the recent Artemis I mission proved just how powerful it can be to harness solar energy in space. During the nearly month-long flight around the moon, NASA tested all functions of the uncrewed spacecraft, including the Orion crew capsule’s innovative solar panels. The vehicle’s solar panels exceeded expectations, proving themselves to be a key technology for the future of human space exploration.

“Initial results show that the arrays are providing significantly more power than expected,” says Philippe Berthe, an engineer who manages the Orion European Service Module Project Project at the European Space Agency (ESA).

[Related: Welcome back to Earth, Orion]

Engineers from ESA and the European company Airbus collaborated with NASA and Lockheed Martin to build the Orion spacecraft, the component that separates from the launch rockets and will ferry astronauts to their destination and back during subsequent Artemis flights. The Paris-based agency’s main contribution to Orion is the European Service Module, which houses the solar panels and other critical systems. 

Orion has four wings, each nearly the length of a British double-decker bus, that unfolded 18 minutes into its journey while still in low-Earth orbit. Each of these wings holds three gallium arsenide solar panels, a particularly efficient and durable type of solar cell made for space. Together, the four wings generate “the equivalent of two households’” worth of power, according to Berthe. 

This type of solar cell is commonly used by military and research satellites. What’s innovative about Orion’s panels is how they’re maneuvered. “Usually solar arrays have only one axis of rotation so that they can follow the sun,” says Berthe. The ones on the capsule, however, can move in two directions, folding up to withstand the pressures of spaceflight and the heat of Orion’s powerful thrusters.

During Artemis I’s 26-day mission, the combined NASA and ESA team tested all aspects of the solar panels, including their ability to rotate, unfold, and produce power. According to Berthe, the panels worked so well they provided 15 percent more power than what engineers had projected. That has consequences for future Artemis missions: “Either the size of the solar arrays could be reduced,” he says, “or they could provide more power to Orion.” Smaller solar arrays could reduce the cost of missions, but more power could allow for additional capabilities onboard the crewed spacecraft.

These nimble solar panels are also equipped with cameras on their wingtips, which Matthias Gronowski, Airbus Chief Engineer for the European Service Module, likens to a “selfie stick” for the mission. These cameras have provided incredible images of the spacecraft as it cruised between the moon and Earth, and can even help the mission engineers inspect the spacecraft for damage. Because the arrays are maneuverable, they act like robotic arms, providing a “chance to inspect the whole vehicle,” says Gronowski.

[Related: These powerful solar panels are as thin as human hair]

Artemis I is NASA’s first step in testing the technology needed to return humans to the moon, and eventually venture further to Mars using the Orion crew capsule. The new lunar program plans to carry humans beyond low-Earth orbit, where the International Space Station resides, for the first time since the 1970s, including the first woman and first person of color to set foot on the moon.

The solar panels are one part of the pioneering technology of Artemis and Orion, and this first test flight proves they are a reliable technology for distant space travel. Moveable arrays like those on Artemis I will be key for future missions that require even more powerful engines, allowing the panels to shift into a protective configuration as the spacecraft speeds up. 

“We are very proud to be part of the program,” says Gronowski. “And we are very proud to be basically bringing humans back to the moon.”

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When stars are born, more times than not, they arrive into the universe as twins. In the first step of stellar creation, a large cloud of gas and dust collapses due to gravity, often fragmenting into pieces. If each piece collapses again, multiple stars will be birthed from the same gas cloud. These infant suns are then surrounded by a halo of matter, the precursor to planets, known as a planet-forming disk. And, if these stars are close enough, the planet-forming disks around them can even swirl together, creating fantastic spiral tails.

New astronomical images published in the Monthly Notices of the Royal Astronomical Society on November 28 reveal three such interacting twin planetary disks in stunning detail. The team took these photos using the European Southern Observatory’s Very Large Telescope in Chile. Although this is not the first time these disks have been imaged, advances in astronomical technology offer a new, more comprehensive vantage of the dramatic cosmic scene.

The stars are all in the Milky Way, fairly nearby by galactic standards. Astronomers photographed these three sets of known twins in polarized light, which can help untangle the dust from each disk. Certain telescope technologies, like those used in this study, can record the specific direction, or polarization, of incoming light waves. Polarized light is a great trick for finding faint structures such as the dusty disks around bright stars. Stars aren’t expected to emit this kind of light, but starlight scattered off dust will become polarized, making the disks and their spirals easier to see. 

Polarization is also a powerful tool for astronomers—it encodes a lot of information about how the light made its way to our telescopes. As a star’s light zooms through space, if it hits small bits of dust, it will bounce off those particles in specific ways. The polarization of that light results from the precise angle of its bounce and what type of matter it hits. “There are loads of intricate processes involved,” says Universidad de Santiago de Chile astronomer Sebastián Perez, a co-author of the new study. The research team used the information provided by polarization to trace which star illuminated each part of the disks, helping them to understand the geometry of the systems.

[Related: The biggest gaseous structure in our galaxy is filled with baby star factories]

Their goal is to understand how neighboring stars influence the planet-forming disks. “A large fraction of stars probably go through such a phase,” Perez says, referring to their sibling-filled childhood, “but we know little about it.” Nearby sibling stars can orbit each other, or one star can drop by for a visit to another, known as a fly-by. These new images are a first step toward determining which scenario happened for each of the three systems.

“We expect that most stars form in dense regions of the galaxy and are surrounded by other stars forming at almost the same time,” says Philipp Weber, astronomer at Universidad de Santiago de Chile and lead author of the study. Despite this fact, astronomers “mainly treat protoplanetary discs as isolated systems,” he adds. 

[Related: NASA releases Hubble images of cotton candy-colored clouds in Orion Nebula]

The new observations by Perez and Weber, who both partake in the research group YEMS Nucleus, suggest that for many star systems, this is a bad assumption to make. Fly-bys “could have lasting effects” on the structure of these planet-forming disks, says Weber, who still has a number of outstanding questions. How common are fly-bys? How do sibling stars change the evolution of disks and their planets? These new data will no doubt keep astronomers busy refining their theories as they seek to understand how planets form.

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In the past few decades, astronomers have discovered thousands of exoplanets around other stars. Many of those worlds look nothing like the planets in our own solar system. One curious type of exoplanet is the Hot Jupiter, a planet similar in size to our own Jupiter–but, unlike our neighborhood gas giant, these are extremely close to their home stars.

A team of Japanese astronomers recently discovered one of the hottest Jupiters to date, around a star known as HD 167768, as part of their long-running Okayama Planet Search Program that began in 2001. To make the situation even weirder, this planet is around an old, dying star—a place no one would have expected a planet to survive. 

Huanyu Teng, astronomer at the Tokyo Institute of Technology and lead author of this discovery, considers this planet “a relatively lucky find” and “a rare case.”

This new planet, named HD 167768 b, is so close to its parent star that one year there is only 20 Earth days long. This planet is technically considered a warm Jupiter, since Hot Jupiters are defined as having a year shorter than 10 Earth days. But HD 167768 b is a whopping 3,000°F, about the temperature of a jet engine, which is hotter than nearly all other known Hot Jupiters, the study authors say. 

Although it takes a little longer than typical for this Hot Jupiter to complete a circle around its sun, this star has inflated, shortening the distance from its blazing surface to the planet. If most Hot Jupiters orbited stars the size of M&Ms, HD 167768 b’s star is something like a golf ball. The distance between the gas planet and its sun is one-and-a-half times the star’s diameter—for context, you could fit almost 108 of our sun’s lengths within Earth’s orbit. 

[Related: A deep-space telescope spied an exoplanet so hot it can vaporize iron]

Teng and co-authors published the discovery in November 2022 as what’s called a preprint paper, a way for scientists to share work before the expert review required for publication in a journal. In this case, the Hot Jupiter study has been accepted in the Publications of the Astronomical Society of Japan.

Astronomers previously thought the aging process of a star would be “fatal to close-orbiting exoplanets” like HD 167768 b, says University of Kansas astronomer Jonathan Brande, who wasn’t involved in the new report. As stars run out of the fuel that sustains their nuclear fusion, they puff up, expanding their outer layers and often engulfing the closest planets—or so astronomers think. There are still many outstanding questions about what happens at the end of a solar system’s life, including whether planets survive or change as their stars die.

“There have been tens of planets discovered around evolved giant stars, but almost all of these planets are at large distances from their host stars,” says Aurora Kesseli, research scientist at the NASA Exoplanet Science Institute. HD 167768 b “helps to answer some of these questions about what happens to planets when their host stars become giants.”

[Related: Newly discovered exoplanet may be a ‘Super Earth’ covered in water]

There are other curiosities about HD 167768 b, too—it’s in a strange part of the galaxy for a planet to exist. Our Milky Way is shaped like a crepe stuffed within a fluffy pancake, where the crepe is known as the thin disk and the pancake is the thick disk. The stars in the thick disk tend to be much older, and are thought to be less favorable environments for planets to grow up around. We’re in the thin disk–but HD 167768 b was found in the thicker one.

This curious world also shows signs that it’s not alone. HD 167768 b was discovered via the tried-and-true radial velocity method, where astronomers measure the movement of a star to infer hidden planets. The team noticed two more possible planet signals in the data, hinting at neighboring planets orbiting a bit further away from the star—they would have years 41 and 95 Earth-days long. To find out if these neighbors are real, astronomers will need to take a closer look at this system, such as with the Transiting Exoplanet Survey Satellite (TESS). Further observations of the new planet will allow astronomers to dig deeper into questions about old planets, now that they have this excellent specimen to analyze.

We don’t have forever to watch HD 167768 b, though. Teng and collaborators calculate that this planet will only exist for 150 million more years—an absolute blink of the eye for the timescales of the universe. (Earth, meanwhile, should stick around for at least another 5 billion years.) This is an exciting opportunity to see a planet so close to the end of its existence.

“Cosmically, this is just about the last possible time we’ll be able to study the planet,” says Brande. “As the host star is continuing to expand, eventually it will totally eat this planet for dinner.”

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NASA engineers devote lots of time and effort to make sure spacecraft are durable enough to survive the hazards of space. Sometimes, though, rockets or probes are designed to crash on purpose!

In 2022, there have been a number of notable space crashes, both planned and unplanned. While unexpected events can be dangerous, planned crashes can provide important information about our solar system—revealing features as diverse as a planet’s atmosphere or the chemicals in an asteroid’s surface. They pave the way for future space missions by testing new technologies, too. And crashing a machine into a space rock can even give data that could one day be used to protect Earth from a threatening asteroid.

The history of space exploration is rich with crashes—humanity’s early voyages to the moon relied on impacts to study the lunar surface in detail, like the Russian Luna 2 that became the first spacecraft to touch the surface of the moon in 1959, and the NASA Ranger program that returned the first close-up images of the moon in the 1960s. This decades-old tradition is carried on by modern missions, from Deep Impact smashing into a comet in 2005 to DART knocking around an asteroid in 2022. It’s very likely there will be more deliberate crashes in the future, too.

The NASA lander designed to crash

One of the riskiest parts of a mission to Mars is the landing. Many mechanical parts and software programs have to work properly to avoid such a situation—a computer glitch caused a European Mars lander to catastrophically crash in 2016. So far, NASA has dealt with this through a variety of technologies: giant bouncing airbags, parachutes designed to slow down the craft in the thin Martian atmosphere, and even their complicated sky crane system—essentially a jetpack that gently lowers a lander to the surface—that the Perseverance rover used.

As successful as these technologies are, they’re also expensive. Engineers at NASA’s Jet Propulsion Lab (JPL) are working on a new technique that may reduce costs—a device intended to crash, known as SHIELD. They call it an impact attenuator, something that’s made to absorb all the force of the crash and protect the sensitive electronics inside. It’s made of steel, with the shape of an upside-down wedding cake. When it hits the ground, it crumples, absorbing the shock of the impact just like the “crumple zone” of modern cars.

While the largest and most ambitious missions will always need traditional landing gear, they also take a long time to prepare. SHIELD’s tech allows for smaller, more frequent missions in addition to those. Lou Giersch, a mechanical engineer at JPL and leader of the SHIELD project, says this device could “increase the rate of scientific discovery” by making missions to Mars speedier and cheaper. “It’s sort of a complement to the more conventional Mars landing,” Giersch adds. 

The team tested SHIELD at full Mars-landing speed–a whopping 110 miles per hour–for the first time in August 2022, strapping a smartphone to it. The smartphone survived and remained fully functional, even after hitting a two-inch-thick steel plate, which is much harder than actual Martian dirt. 

NASA hopes this sort of tech will allow it to send more small missions to Mars, maybe even establishing a network of probes across the Red Planet. These could be like the local weather stations we use on Earth. One day, atmospheric scientists might tell you the local daily forecasts for Olympus Mons or Schiaparelli Crater. Being able to monitor the whole globe at once could reveal more about Mars’ dust, its atmosphere, and even marsquakes—and it all may happen after repeated successful crash landings.

A mysterious rocket on the moon

Astronomers puzzled over a surprise crash this year, when a piece of rocket debris smashed into the moon on March 4. NASA’s Lunar Reconnaissance Orbiter (LRO) later spotted a strange double crater created by the impact. Although some astronomers hoped this impact may be able to give them new information about the lunar surface, nothing much came of it besides a hunt for the wayward rocket’s culprit.

Astronomer Bill Gray first identified it as a SpaceX part, but later realized it was actually part of a 2014 Chinese test mission, called Chang’e 5-T1. Chinese officials deny this was their booster, though, so its origin remains somewhat of a mystery. The biggest takeaway here is how alarming it is that no one was sure exactly what this piece was, or where it came from—and that there are many other lost hunks of space debris just like it.

[Related: What happens when a rocket hits the moon? It’s not always what astronomers predict.]

Although this crash was a loss for lunar scientists, there have been intentional impacts on the moon before—notably  LCROSS, a mission to hit a permanently shadowed crater on the moon’s south pole in 2009. NASA astronomers sent one spacecraft to strike the surface, followed shortly after by a probe containing scientific instruments to measure the materials stirred up by the impact. This mission helped confirm a fact we now take for granted—the existence of water ice on the lunar surface. 

University of Hawaii planetary scientist Chiara Ferrari-Wong notes that LCROSS data is still keeping scientists busy—the materials it revealed on the moon are strikingly different from those on Mercury, which is similarly cratered. “We are working to untangle what happened in each planet’s unique history that makes them similar yet different,” she says.

Knocking around asteroids

A clear highlight of this year in space crashes comes from DART, NASA’s Double Asteroid Redirection Test, a spacecraft that smacked an asteroid to nudge its orbit. This was the first test of  planetary defense technology meant to protect Earth in the event we find an asteroid hurtling toward us.

“Thankfully, no known asteroid big enough to penetrate our atmosphere is a threat to impact Earth at any time in the next century,” says Angela Stickle, planetary scientist at Johns Hopkins Applied Physics Lab and DART team member. But if an as-yet undiscovered asteroid is on a collision course with Earth, she adds, “we want to be prepared.” 

DART targeted an asteroid known as Dimorphos, which orbits another bigger asteroid called Didymos. By measuring the change in the time it takes for Dimorphos to orbit Didymos, before and after the impact, astronomers could determine how big of a punch their impacting spacecraft packed. The spacecraft changed the asteroid’s orbital period by 32 minutes, more than 25 times the goal time NASA set for a successful mission. “This was incredibly exciting and the team is still working on the details of why and how,” Stickle says.

This mission taught scientists about Didymos itself, which is actually a loose collection of rocks known as a rubble pile, showing how diverse the population of asteroids really is. For future asteroid diversions to be successful, astronomers need to know what each asteroid is made of, so they know how big of a push it needs.

[Related: NASA’s first attempt to smack an asteroid was picture perfect]

This isn’t the first time scientists have hit an asteroid, though—the Japanese Hayabusa2 mission shot a small cannon into the asteroid Ryugu in 2019, blowing up the surface just enough to expose the lower layers of dirt and to fling debris toward the main spacecraft for sample collection. But that impact was on a much smaller scale than DART, and meant for a totally different purpose. 

Now, Hayabusa2 is beginning a new mission, one that will contribute to DART’s goals of planetary protection. It’s hurtling toward a little-studied asteroid named 2001 CC21. They won’t collide; instead, the spacecraft is going to experiment with precision navigation around a fairly unknown target, a crucial skill for an asteroid-targeting planetary defense mission.

“My ideal next mission would be a spacecraft hitting an asteroid with one spacecraft watching the whole thing happen,” Stickle said about DART’s impact. “The more times we can test this technology, the better we will get.”

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Disclaimer: The author worked with the New Horizons team as a student researcher while she was an undergraduate.

On New Year’s Day three years ago, a small spacecraft zoomed by a chunk of ice billions of miles away, and scientists on Earth cheered. That was the second time the New Horizons probe got up close and personal with an object in the far-away Kuiper Belt—after capturing images of Pluto, its first target, in unprecedented detail.

Now, New Horizons has a third chance to revolutionize how astronomers see the distant parts of our solar system. On October 1, the spacecraft began the third phase of its life: the 2nd Kuiper Belt Extended Mission, or KEM2 for short.

Every few years, each NASA mission—yes, even the 45-year-old Voyager—undergoes a formal review in which administrators decide whether the project should continue. SOFIA, NASA’s observatory-on-an-airplane, was just a victim of this process, shutting down operations on September 30, the end of the administration’s fiscal year. New Horizons, on the other hand, was successfully renewed this summer for a two-year extension to its operations as it continues flying farther out of the solar system.

In KEM2, because the probe is traveling through a uniquely far-out place in space, New Horizons is going to expand its scope beyond the planetary science of its earlier phases. “New Horizons has become this interdisciplinary observatory in the Kuiper Belt,” says Alan Stern, principal investigator of New Horizons. 

The mission is branching out into two more disciplines: astrophysics and heliophysics. New Horizons is going to measure the solar wind, particles streaming out from the sun, and the probe will eventually reach the termination shock and heliopause, two places that can be considered outer boundaries of our solar system. Although Voyagers 1 & 2 reached the heliopause and made similar measurements, they did so with far less sophisticated tech. 

[Related: NASA’s New Horizons is so far away, it’s seeing stars from new angles]

New Horizons will help heliophysicists better understand the shape of our solar system’s edges and explore the limits of our sun’s influence on space. It’s also the “ultimate dark-sky site” for astrophysicists, allowing them to measure the amount of background light in the universe, a key constraint on the history of galaxies.

Although those aims are departures from its previous goals, it will continue to explore far-off bodies of rock and ice, too. New Horizons has been incredibly successful at exploring the outer solar system, providing the first detailed images of both the dwarf planet Pluto and a smaller Kuiper Belt object (KBO) called 2014 MU69. The Kuiper Belt contains a huge number of these icy objects, which are some of the best-preserved relics of our solar system’s early days—a window for astronomers to look into the past of how our planets formed. 

The spacecraft is currently moving a whopping 32,000 miles per hour, faster than even a rocket launching off Earth. It’s about 54 astronomical units (AU) from the sun, and will move 3 AU further away each year, rapidly approaching the edges of our solar system. It’s in unexplored territory—only four other probes, from the Voyager and Pioneer missions, have made it that far out). And those craft took different paths than New Horizons, carrying the now-outdated technology of the 1970s.

“I am excited about how far out we will be going into the distant parts of the solar system,” says Kelsi Singer, project scientist on New Horizons. In two years, she adds, the probe will be at 60 AU–at an edge of the belt that’s nearly impossible for scientists to explore using Earth-based tools. 

Because Kuiper Belt objects are so extraordinarily far away, even our largest telescopes on Earth have trouble spotting the tiny, faint specks. New Horizons, however, will have a much closer view, embedded within the Kuiper Belt itself. In the first extended mission, the team spotted 36 KBOs using the spacecraft’s onboard cameras, the closest from only 0.1 AU away, and they expect similar observations in KEM2. The team also has the opportunity to use New Horizons for unique images of the ice giants, Uranus and Neptune, from an angle we can’t see here on Earth.

[Related: The New Horizons spacecraft just revealed secrets of the most distant object we’ve ever visited]

Plus, New Horizons has an instrument, the Student Dust Counter, to measure how much space dust it encounters, tracing the distribution of dust near the edges of the solar system. Although we usually think of outer space as totally empty, there’s a good amount of dust floating around there, left over from when planets were formed—again, giving astronomers key insight into the history of the solar system. 

For now, the spacecraft is still in hibernation until it awakens in March 2023. Until then, the team is preparing for the exciting science to come, working tirelessly to hunt for new KBO targets with ground-based observations. And if they’re lucky, KEM2 may be the second of many more extended missions to come.
“The spacecraft is in perfect health, and it has the fuel and the power to run through sometime in the 2040s,” Stern says. “This is not the last hurrah of New Horizons by a long shot.”

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Space agencies like NASA keep a close watch on our nearest neighbor, Mars. With almost a dozen active missions on or around the Red Planet, they can track its daily weather, just like our forecasts here on Earth, and notice even small changes on its surface. 

Today, though, astronomers revealed a much bigger change: two new large impact craters in the Martian crust, observed by both the Mars Reconnaisance Orbiter (MRO) and the InSight lander. These are the largest impact craters discovered by MRO to date and the first detection of seismic surface waves, according to two new studies published in the journal Science.

“We never thought we’d see anything this big,” said Ingrid Daubar, planetary scientist at NASA’S Jet Propulsion Lab and MRO/InSight team member, in a NASA press conference on the new findings. Quakes on Mars, like those resulting from these meteor impacts, reveal more detailed information on its contents, and how rocky planets, including Earth, came to be.

Here at home, we’ve been measuring earthquakes for centuries—but marsquakes are newer territory. The InSight mission, which landed on Mars in 2018, recorded its first marsquake less than a year into its operations and has since recorded more than 1,300 of them. The lander provides NASA and other research teams a unique opportunity to understand what’s going on under the Martian surface, and study its core, mantle, and crust in detail. To fully understand how rocky planets like Mars and Earth form, we need more information on exactly how they’re structured—information that InSight aims to provide. MRO, which has been orbiting around Mars for 16 years, provides detailed images of the surface for birds-eye-view context for observations taken on the ground.

Mars has plenty of quakes caused by its own seismic activity, but without a thick atmosphere to protect it like Earth, astronomers also expect meteors to hit the surface and cause additional waves. The first of the newly detected impacts, known as S1000a, happened in September 2021, and created a cluster of craters in an area of rocky, craggy terrain to the North of Mars known as Tempe Terra. The second impact, called S1094b, hit in December 2021, and was much closer to InSight. It impacted a flat, dusty region on Amazonis Planitia, and formed a larger crater 150 meters in diameter—a distance comparable to the height of the Washington Monument. This created an approximately magnitude 4 quake, which is fairly small by Earth’s standards, but large for our less tectonically active neighbor.

Both of these detections were true displays of teamwork between the various missions. For S1000a, InSight noticed the seismic signatures, and scientists used that to direct MRO’s search to image the crater. For S1094b, on the other hand, the MRO team independently noticed the freshly formed crater, and collaborated with InSight researchers to confirm that the two spacecraft’s seismic signatures were, in fact, from the same event. The impact was large enough that it could even be seen in MRO’s daily weather camera, MARCI, allowing its team to pinpoint the timing of the impact to within a day. From these visuals, they estimated that the meteor that struck Mars was around 5 to 12 meters across, somewhere between the length of a giraffe and a telephone pole. 

[Related: Meteoroids make little ‘bloop’ noises when crashing into Mars]

When quakes happen on a rocky planet, the waves bounce around in different ways depending on the materials they encounter. So far, all the quakes observed by InSight have been characterized as body waves that travel deep within the planet’s mantle. Any major event—volcanoes, earthquakes, landslides, etc.—sends both body waves and shallower surface waves rippling through a planet. This left astronomers wondering about Mars’ crust. 

They finally got a clue with the meteor impact last December. S1094b created large waves that traveled through the crust, making it possible for InSight to measure them. Doyeon Kim, senior research scientist at ETH Zurich and lead author of one of the new studies, says that these kinds of detections, called surface waves, “were already a part of the mission goals of InSight from the beginning.” This marks the first unambiguous detection of surface waves on any planet other than Earth, and revealed that Mars’ crust may be a bit more uneven than previously thought. 

Images of S1094b from MRO’s HiRISE also show peculiar lighter patches on the Red Planet’s surface around the new crater, which the team identified as frozen water dredged up from below the crust upon impact. We’ve known Mars has ice caps for a while, but this is the lowest latitude that ice has been observed at so far. What’s more, the combination of imaging and seismic data gave the researchers particularly precise measurements of the location of the impact and the path the seismic waves took through Mars, providing information on the properties of the rocks along those paths.

This groundbreaking combination of observations opens the door for a much more detailed understanding of Mars and other rocky planets, from the physics of meteor impacts to the structure of planetary interiors and beyond. Unfortunately, this may be InSight’s last hurrah—dust has been slowly covering its solar panels for months, and in around four to eight weeks it will no longer have enough power to operate. The team sees this as a high note to end on: Their observations could pave the way for fresh discoveries on Mars.

[Related: 5 new insights about Mars from Perseverance’s rocky roving]

“The new results on crustal structure far from the InSight landing site will improve our overall understanding of the formation and evolution of the Martian crust,” says Martin Knapmeyer, planetary scientist at the German Aerospace Center (DLR) in Berlin. “In a cooperation kindled by a common goal, international science teams of two different Mars missions joined efforts to obtain the best possible results.”

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