In space, nobody can hear you scream — or meow, for that matter. This was as true for Félicette — the stray Parisian tuxedo cat who safely completed the world's first (and only) suborbital feline flight, in 1963 — as it is for the gargantuan Cat's Head Nebula, which is featured in stunning new images from the Hubble and James Webb space telescopes.

Rising from the cloudy Carina Nebula some 7,500 light-years from Earth, the Cat's Head Nebula is a column of star-sculpted gas and dust that vaguely resembles a feline sitting with its back to us, coyly turning its head to show off a single red eye. That eye is a young star that's embedded deep within the dust and possibly transforming it before our eyes.

Nebulas like these occur when the radiation from active young stars lights up and erodes the material around them. They are beautiful and easy to find; if this cosmic cat gets bored staring at us, it can just waltz over to the other side of the Carina Nebula and crawl into a similar globule of gas that looks exactly like a box with an open lid. (Cats will be cats, after all.)

In honor of Halloween, the European Space Agency (ESA) shared three competing views of the Cat's Head Nebula — one from the Hubble Space Telescope, which captures optical light, and two from the infrared instruments aboard the James Webb Space Telescope (JWST). The three views, shown below, reveal different features of the nebula in different wavelengths of light, getting progressively spookier as more color drains out of the scene.Take a look at all three images — and cast your vote for the spookiest in the poll at the end.

Hubble's view

Observing the nebula in the same visible wavelength range that you could see through a strong backyard telescope, Hubble highlights the dark pillar of dust that has survived the ultraviolet assault of nearby stars. The wispy edges at the right of the column show where starlight is evaporating the gas around it, slowly whittling it away to nothing.

The glow of blue, yellow, orange and red light around the dust pillar mark where starlight is interacting with different gas molecules, including oxygen, hydrogen and sulfur, according to ESA. The process is similar to how different molecules in Earth's atmosphere produce different-colored auroras when excited by solar radiation — just on a much grander scale.

JWST's near-infrared view

Switching to light human eyes cannot see, JWST's Near-Infrared Camera cuts through the wispier outer layers of dust to show the densest material at the column's center. Countless additional stars and galaxies appear in the field of view as their infrared glow penetrates the surrounding material.

Here we see a more complex, turbulent column, showing how stellar radiation is carving up the inside of the cat's head as well as its edges. JWST's view also illuminates a disembodied, hand-like structure to the left of the cat, reaching out as if to pet its cosmic companion.

JWST's mid-infrared view

The final view, taken with JWST's Mid-Infrared Instrument, cuts to the ghostly core of the nebula, showing little more than smoky, bluish light. According to ESA, these are the emissions of molecules called polycyclic aromatic hydrocarbons — typically colorless molecules of carbon and hydrogen related to combustion.

While most starlight disappears in this view, a strange new bright spot emerges to the right of the cat's head. This orange speck is a true mystery, according to ESA, and its relationship to the rest of the nebula is unknown.

The mysterious force that cleared the cosmic fog at the dawn of the universe may not be what we thought, a new study suggests. The results hint that astronomers may need to rethink a major aspect of cosmological evolution, which led to the universe we clearly see today.

Around 400,000 years after the Big Bang, the fledgling universe finally cooled enough to form atoms — mostly hydrogen. But these neutral, non-electrically charged hydrogen atoms shrouded the cosmos in a fog that made it opaque to ultraviolet (UV) light.

Then, after the first stars flickered to life and gathered into galaxies, bursts of radiation ionized the neutral hydrogen. This turned the impenetrable fog of atoms into electrically charged protons and electrons, allowing light to pass through interstellar space unimpeded and, eventually, reach our observatories. This cosmic curtain parting is known as the Epoch of Reionization, or what a team of researchers studying it call the "last major phase transition in the universe."

"We don't know exactly what objects caused reionization or how it evolved," Cody Carr, an astronomer who focuses on galaxy evolution at the University of Michigan and first author of a new study of the epoch, said in a statement. "We know that it took place, but we don't have complete answers to those questions."

Astrophysicists previously thought that this fog-clearing effect depended on supernovas, the violently explosive deaths of stars around eight to 50 times the mass of the sun.

But in the new study, published Oct. 15 in the journal Nature Astronomy, Carr and colleagues presented evidence that supernovas exerted the opposite effect, trapping the so-called Lyman continuum (LyC) photons of ionizing UV radiation that dispelled the celestial fog instead of scattering them.

"The most interesting thing about our paper is the observation that the strongest LyC emitters do not have fast galactic winds," Carr told Live Science via email. "This challenges the notion that galaxies require fast supernova-driven winds to enable LyC escape."

Which way the winds blow

The researchers used the Hubble Space Telescope to observe an analogue of the ancient universe in the local cosmos: six star-forming, wind-launching galaxies around 3.5 billion light-years away.

These compact starburst galaxies are generally smaller than 6,500 light-years in diameter and form around 10 solar masses' worth of stars per year. That star-birthing rate is several times higher than that of the Milky Way, which is up to 20 times larger.

The galaxies' spectra, or light-based fingerprints, revealed the origin, chemical composition, speed and direction of their stellar winds, which were whipped up by the radiation from their newly formed stars.

The researchers also described how these processes changed as the massive young stars evolved and died in energetic supernovas several billion years later, with the resultant galactic winds overpowering the stellar winds.

These nearby galaxies highlighted a counterintuitive two-phase process.

In the initial phase, which occurred during the first 3 million years of star formation, the newly formed massive stars' stellar winds carved through their galaxies' neutral gas and dust at nearly 2,000 miles per second (3,000 kilometers per second). This allowed LyC light to escape the galaxy and ionize the neutral gas and dust in intergalactic space.

The second phase, which emerged around 3 million years after star formation, seemed to reverse this process. As O-type stars — the hottest, bluest and most massive stars in the cosmos — lived fast and died young, their expelled stellar guts added to the opaque galactic gas and dust, churning it and loading it with mass, which created a trap for LyC light.

The oldest galaxies in this study ‪—‬ and, therefore, the ones with the fastest supernova-generated galactic winds ‪—‬ allowed the least amount of ionizing radiation to escape their environs.

"In general, our results are in disagreement with most cosmological simulations, which typically show the LyC escape fraction peaking after the launch of supernova-driven winds," Carr explained via email. In other words, supernovas didn't drive the Epoch of Reionization, but they may have dampened it. The intense light of newborn stars now seems like the most viable source of reionization.

Future research could aim to obtain additional galactic samples and higher-resolution observations across other wavelengths.

When the sun inevitably dies, not even the outer solar system will be safe from the resulting chaos, new research hints.Scientists have long thought the outer solar system ‪—‬ which comprises the four giant planets Jupiter, Saturn, Uranus and Neptune — would mostly retain its present-day appearance for hundreds of billions of years to come. But a new study suggests that the outer giants may develop weirdly shaped orbits as the sun runs out of fuel, causing the planets to cross paths and destroy themselves through collisions within three billion years of the sun's transformation into a red giant.

The findings, published Sept. 21 in The Astrophysical Journal Letters, could change our understanding of what kinds of exoplanets orbit certain stars.

In about 5 billion years, the sun will balloon outward as a red giant after exhausting all of the hydrogen in its core. During this red giant phase, our star will swell to 100 times its present-day size, gobbling up Mercury, Venus and possibly even Earth in the process, Nathan Kaib, a planetary scientist at the University of Oklahoma who wasn't involved in the new research, told Live Science in an email. Following this violent swelling, the sun will crumple into a collapsed core called a white dwarf.

Until now, scientists thought the four outer planets would escape this phase relatively unscathed. A 1998 simulation-based study suggested that the gas the sun spews from its outer layers will push this planetary quartet outward, doubling the radius of each planet's orbit. Only the gravitational impact of a runaway star could destabilize this new order, and such events are thought to occur only once every billion billion years.

Solar recoil

These predictions hinged on the assumption that the sun will eject its outer layers smoothly. However, recent observations of stars suggest a jerkier loss of mass, with gas clouds lofted by plumes of plasma in the sun — as though our star were spitting out mass blobs. "They're kind of like coronal mass ejections, except much larger," Jim Fuller, a professor of theoretical astrophysics at Caltech and co-author of the new study, told Live Science in an email.

Each "blob" pushes the star backward, similar to how a fired bullet causes a gun to recoil. Although every push is small, moving the sun just a few feet per second, many pushes can, over time, impart the equivalent of an enormous kick that alters the sun's speed by several hundred feet per second. In fact, astronomers have already seen white dwarfs suffer such kicks in other star systems.

When Fuller, who studied these kicks, described them to Konstantin Batygin, a professor of planetary science at Caltech and the study's first author, Batygin "realized this would have important consequences for the evolution of our own solar system," Fuller said. That's because the kicks change the sun's gravitational pulls on everything around it.

Chaos at the edge of town

To determine how the sun's mass loss would influence the giant planets, Batygin created computer-based simulations of the sun and the outer planets. The researchers considered three scenarios: if the sun lost its mass smoothly, if it spit out distinct mass blobs during its entire time evolving as a red giant, and if the sun spewed the blobs only during its last stages. The researchers also varied each ejected blob's mass.

The first scenario produced results similar to those of previous studies, with the outer solar system retaining almost all of its features for billions of years. In contrast, the other two cases had drastically different results. Using 672 simulations, the researchers found that if the sun lost mass in blobs, the giant planets would be thrown into chaos, switching places, developing weirdly oval-shaped orbits, and even getting ejected out of the solar system entirely. Most dramatically, in 96% of the simulations with the heaviest ejected mass packets, the planets get destroyed as they crashed into each other.

These developments also happened much more rapidly — less than a few hundred million years after the sun transformed into a white dwarf, or even during the red giant phase, in the most extreme scenarios.

The study's findings hint that analogues of the present-day outer solar system around white dwarf stars are less likely to exist than previously thought. Kaib noted that the study's results suggest that planets with oval-shaped orbits should dominate instead. It's thought that habitable planets could exist around white dwarfs, but this study's findings show that our understanding of those distant star systems may be incomplete, and that such worlds may, in reality, be unstable.

See how well you know our planetary neighborhood with our solar system quiz!

The Vera C. Rubin Observatory has found what might be a tiny new world in the far reaches of our solar system, hidden beyond the orbit of Neptune — and it is among the largest and brightest objects ever discovered beyond Neptune.

If confirmed, the miniature world would increase the number of officially recognized solar system dwarf planets to six. Upper estimates of the object's size place it at more than half the diameter of Pluto, the largest known dwarf planet.

"My first reaction was one of excited disbelief," Matthew Holman, an astrophysicist at the Smithsonian Astrophysical Observatory and member of the Rubin team who wrote the code that helped discover the prospective dwarf planet, said in a statement. "Objects like this are very rare, so I immediately started checking whether I or the code had done something wrong."

Hidden among stars

The potential dwarf planet, designated 2026 ED138, orbits the sun at roughly 46 times the distance between Earth and the sun. The potential new planetoid has been hiding behind galactic camouflage; with its orbit tilted at a 25-degree angle from the solar system plane, it's at just the right angle to get lost in the light from the inner Milky Way, the researchers said.

Many telescopes struggle to see past the millions of stars making up our galaxy's bulge. The Vera C. Rubin Observatory, however, images the entire southern sky every few nights with the largest digital camera ever built, sending out millions of nightly alerts for every object that has changed brightness or position. This makes it exceptional at identifying anything that moves, from solar system objects to transient events like supernova explosions.

The observatory had only just begun its 10-year mission of scanning the sky in July, and ED138 stood out in the data.

Holman works on the software algorithms that process the extreme amounts of data the observatory collects. The code he developed with his colleague, Kevin Napier, compares billions of observations to determine which ones are detections of the same moving object. Running data from Rubin through the code revealed the unusually large object.

By looking at past data from Rubin and archival images from the Dark Energy Camera mounted on the Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (both in Chile), the team was able to map out ED138's orbit over the past 10 years.

Going beyond Neptune

The Kuiper Belt is a region of the solar system beyond Neptune that is a wild frontier of small, mostly icy bodies made from frozen methane, ammonia, water and rock. It ranges from roughly 30 to 50 times the distance between Earth and the sun, and is home to most of the known dwarf planets, including Pluto. Thousands of Kuiper Belt objects have already been discovered. These space rocks can be frozen time capsules that hold clues about the early solar system's formation.

Dwarf planets are the largest Kuiper Belt objects that we know of. Bigger than asteroids but not quite planets, dwarf planets are big enough to be rounded under the force of their own gravity but too small to clear their orbits like planets do. While the International Astronomical Union (IAU) has officially confirmed five dwarf planets — Pluto, Ceres, Eris, Haumea and Makemake — astronomers studying dwarf planets often recognize at least nine, with several more candidates whose properties are still unknown.

Depending on which astronomer you ask, there could be anywhere from a handful to hundreds of dwarf planets in this part of the solar system. Identifying which Kuiper Belt objects are dwarf planets is tricky because they are often very dim and move very slowly from Earth's perspective, since their orbits are so large and distant. The likeliest candidates have high albedo (surface reflectivity) and diameters greater than roughly 370 to 500 miles (600 to 800 km).

What makes ED138 special is its size, inferred from its brightness, albedo and distance from the sun. It's estimated to have a diameter between 370 to 930 miles (600 to 1,500 km). For comparison, Pluto — the largest dwarf planet recognized by the IAU — is 1,477 miles (2,377 km) in diameter. Ceres, the smallest IAU-recognized dwarf planet, is 595 miles (958 km) in diameter. Future observations of ED138 will give researchers a more accurate idea of its diameter and density to determine if it's round enough to join the dwarf planet club.

"If confirmed as a dwarf planet, ED138 would join a very small family of worlds," Holman said in the statement. "Rubin will image the whole southern sky again and again for ten years, so any others hiding in the places earlier surveys skipped are now within reach."

Scientists are getting a new glimpse of how the first galaxies came to be. In a stunning new simulation, researchers charted the aftermath of the universe's "dark age," including the appearance of the first galaxies that began to shine about 380,000 years after the Big Bang.

Lumina, the program behind the simulation, catalogs 2 billion years of cosmic time and represents a decent chunk of the 13.8 billion-year-old history of our universe. The results were published Monday (Oct. 26) in the journal Monthly Notices of the Royal Astronomical Society.

"Other simulations cannot zoom in as far as this," study co-author Mark Vogelsberger, a professor of physics at MIT, said in a statement. "The difference between the smallest and largest scales that we simulate is larger than in any other simulation."

A video published alongside the paper shows what the scientists saw. The team zoomed in on an area roughly 1.6 billion light-years wide to learn more about how the ingredients of space create galaxies.

Lighting up the Cosmic Dark Age

In the earliest years of our universe, a fog of neutral hydrogen atoms gradually built up, blocking out the light of the first stars. The hydrogen served as a "shroud" and didn't make light visible until galaxies began to form. This ancient, enshrouded period is known as the Cosmic Dark Age.

The video begins in the middle of this epoch, at roughly 45 million years after the Big Bang. Zooming in on one small part of the simulated universe, it slowly reveals a gassy halo giving way to young galaxies shining brightly within it. Included in the calculations are dark matter, stars, gas and radiation — all contributing to the reemergence of cosmic light.

"We see this is where the first galaxies form," first author Oliver Zier, a former postdoctoral researcher and computational astrophysicist at MIT who is now at Harvard University, said in the statement. "And the first stars form in those first galaxies. Those stars then create radiation. The simulation then tracks that radiation, and we can zoom way out to see how that radiation travels out from stars, through the universe, until at some point it ionizes some neutral hydrogen."

Lumina aims to show off two phenomena key to the young universe's history: hydrogen reionization and helium reionization — a first for a program of its kind. Reionization describes how the intergalactic medium, or the area between galaxies, changed from neutral hydrogen to negatively charged ions.

Hydrogen reionization took place when ultraviolet light from young stars and galaxies hit the hydrogen, removing negatively charged electrons from the hydrogen molecules — a process that also allowed light to shine through the fog. Helium reionization happened when supermassive black holes, which have a lot of energy, broke apart neutral helium molecules.

The team said the simulation could eventually be used to validate telescope observations of the early universe, especially those focused on mapping many galaxies at the same time.

A new U.S. intelligence agency report has seemingly released the first clear photograph of China's mysterious "dragon" space plane in orbit around Earth. The surprise snap reveals that the top-secret vehicle is very similar to its American counterpart and provides new clues about its capabilities.

The image is widely believed to show China's secretive Shenlong, or "divine dragon," space plane, which has been in action for just over six years. During this time, the reusable winged spacecraft has repeatedly made headlines after deploying various unidentified objects in low Earth orbit (LEO). As a result, government officials, private companies and individual researchers have closely monitored the vehicle using tools such as ground-based radar.

Until now, the only direct images of the space plane have been blurry snaps of light reflecting off the uncrewed vehicle toward Earth's surface — offering no clear clues to its specific design, capabilities or intended purpose. China has also never publicly shared any photos of the vehicle or revealed any key information about its design.

On Monday (Oct. 26), the Defense Intelligence Agency (DIA) released the latest version of its "Challenges to Security in Space" report, which assesses the various factors that pose a risk to American space assets. Deep within the 130-page document (on page 53), the authors included a previously unseen image of a "PRC [People's Republic of China] Spaceplane." The image's brief caption revealed that the photo had been taken in 2024 by a satellite belonging to the private space company Maxar Technologies, now known as Vantor.

The surprise inclusion of the photo was spotted and shared on the social platform X by journalist Andrew Jones, who specializes in China's space program and has previously shared crucial information about other ongoing missions.

Neither the caption nor the related section of the report made any mention of the photo being the first of its kind or explained why it was previously classified, raising questions about whether the authors realized its significance.

There is one small caveat. The report notes that China has two active space plane designs — Shenlong and Tengyun, meaning "cloud rider" — and the image's caption does not specify which design we are looking at, according to The Aviationist.

However, there have been no confirmed launches of Tengyun to date. Existing photos of a potential prototype also hint that this vehicle's design looks markedly different from what we can see in the new photo. Therefore, most experts agree that the spacecraft in the image is most likely Shenlong.

What does the new photo tell us?

Until now, all we really knew about Shenlong is that it operates similarly to NASA's iconic space shuttles: It gets launched into space by a rocket and circles Earth before eventually gliding down to the planet's surface, where it can then be refueled and relaunched into LEO.

It is not the world's only active space plane. The U.S. Space Force has its own, the X-37B, which has already completed seven orbital missions since its first launch in 2010 and is currently in LEO experimenting with quantum navigation. Based on the new photos, Shenlong shares many similarities with its American counterpart.

"The Chinese spaceplane has delta wings, payload bay doors, a dark heat shield, and a rear-mounted service module with power-generating solar arrays," technology news site ArsTechnica reported. "In other words, the design of the winged ship is, to a great degree, a copy of the X-37B spaceplane flown by the U.S. Space Force."

However, the two spacecraft are not exactly the same: "The overall arrangement resembles the American vehicle, although differences in wing geometry show that the two spacecraft are not externally identical," according to specialist news site Global Defense News.

It is still unclear how large Shenlong is. The X-37B is 29 feet (8.8 meters) long and has a wingspan of 15 feet (4.5 m), according to Popular Science.

The new image also indicates that Shenlong is most likely not a military asset, Global Defense News reported, noting that "the image does not establish a weapons role."

However, China likely has other space-based weapons, similar to the mysterious "in-orbit" American weapons recently confirmed by U.S. Air Force Secretary Troy E. Meink.

"China has developed and will continue to advance weapons for use against satellites in orbit to disrupt, damage, and destroy other nations' space capabilities," DIA representatives wrote in a separate section of the new report. "Beijing aims to become the preeminent leader in space," they added.

The Shenlong story so far

Since first launching into space on an initial two-day mission in September 2020, Shenlong has completed two feature-length missions: an eight-month stint in LEO between August 2022 and May 2023, and a nine-month spaceflight between December 2023 and September 2024. (The new image was taken during the latter mission).

The space plane is currently on its fourth mission, which launched Feb. 7 on board a Long March 2F rocket from China's Jiuquan Satellite Launch Center, Live Science's sister site Space.com previously reported. In total, Shenlong has racked up more than 800 days in orbit. However, it is unclear whether the same space plane was used on all four missions or if China has more than one space plane in use.

So far, Shelong has released at least nine unidentified payloads around Earth. These objects are most likely small satellites, known as cubesats, but their purpose remains unclear.

The most recent object was deployed in June this year, although astronomer Jonathan McDowell, who specializes in tracking spacecraft in LEO, has since suggested that the spacecraft retrieved the object, potentially with a robotic arm, and rereleased it in late August.

The new report also mentions that the space plane "appeared to maneuver with a companion satellite" during its second mission in November 2022, coming within 330 feet (100 m) of the smaller spacecraft and potentially even capturing and re-releasing it.

This may support an existing theory that the main goal of Shenlong is to "conduct rendezvous and proximity operations" with other spacecraft, and that its payloads may be targets for it to practice flyby maneuvers in orbit.

Editor's note: This article was updated on Oct. 29 to correct a typo. A previous version of the article abbreviated the People's Republic of China as "PCR" rather than "PRC". This has been corrected.

Astronomers using the James Webb Space Telescope (JWST) have discovered a galaxy with a glowing ring of newborn stars shining in the early universe. The galaxy, which the researchers observed as it appeared just 2.1 billion years after the Big Bang, is the most distant ring galaxy ever found.

The ring galaxy, known as GS18660, may be the result of a collision between two galaxies, the researchers reported in their study, published Sept. 8 in the journal Astronomy & Astrophysics.

It's rare to find the possible snapshot of a merger like this, given the timescales involved in these systems, Christopher Conselice, a professor of extragalactic astronomy at the University of Manchester in the U.K. who was not involved in the study, told Live Science. Although interactions between galaxies may have been common in the early universe, the creation of ringed systems like this is thought to be unusual.

"In this sense, the galaxy system is quite unique and may give us important information about early galaxy formation," Conselice said in an email.

A surprising discovery

Scientists selected GS18660 for observation because it looked stretched out in older Hubble Space Telescope images.

"We therefore did not target GS18660 specifically as a ring galaxy," Michele Perna, a postdoctoral researcher at the Spanish Astrobiology Center and the first author of the study, told Live Science in an email. "When we observed it with JWST [Near-Infrared Spectrograph instrument], the much more detailed data revealed the prominent ring structure and allowed us to investigate the galaxy in three dimensions."

Using JWST, the team looked at the galaxy's unique shape, tracked the motions of its hot gas, analyzed the gas's chemical properties, and studied the galaxy's star formation history.

Intruder-driven rings

When a small galaxy plunges through the center of a larger galaxy, the impact creates a wave of dense gas that ripples outward, similar to how water moves when a stone is dropped into a pond. As a result, a collisional galaxy is formed. Gas piles up along the wave and forms stars, producing a ring. These galaxies are rare in the local universe, and the few candidates found in the distant universe have been hard to confirm.

Several clues support the case for GS18660 as a collisional ring galaxy. For one, the researchers spotted a small companion galaxy, moving away from GS18660 at about 264 miles per second (425 kilometers per second). They also detected a bridge of gas linking the two, and the velocity along it changed, Perna noted. The change in velocity along this bridge-like structure indicates that the companion and GS18660 may be interacting.

Its position is also important, Perna added ‪—‬ the companion is located roughly along the main galaxy's minor axis, consistent with where an intruder would be expected to appear after a head-on plunge through the galaxy's disk.

Backed by stars

Using the companion's speed and distance, the team estimated a rough timeline for the impact. It revealed that the collision happened about 17 million to 42 million years earlier in the galaxy's history. This time scale seems reasonable, Conselice said.

He explained that it is difficult to determine the age of a past interaction directly, but that if one did occur, it must have happened around the time a rapid star-formation episode began and its age should be consistent with the average ages of the star clusters.

Looking at star formation rates with different instruments, the team estimates that 10% to 20% of the stellar mass in the ring formed in the past few tens of millions of years. This suggests that the collision and the ring's burst of new stars might have happened at the same time, so they were most likely caused by the same event, Perna explained.

"It is not, by itself, definitive proof of a collision, but together with the bridge and the ring morphology, it strengthens the case for a recent impact," Perna noted.

The discovery may also shed light on how common these kinds of collisions used to be. Whereas earlier estimates suggested that collisional rings in the early universe might be about as rare as they are today ‪—‬ around 1 in 10,000 galaxies ‪—‬ the new findings hint that head-on collisions that form ring galaxies may be more common in the early universe.

"If GS18660 is confirmed as a collisional ring, it would therefore suggest that we need to revisit our estimates of how frequently these systems occur in the distant universe," Perna said

Another explanation?

The team expressed caution about how much the data can prove. "It is really the combination of several pieces of evidence rather than one single observation," Perna said. "So we regard the collisional interpretation as our preferred scenario rather than a definitive conclusion."

Conselice thinks the evidence presented in the paper is consistent with a genuine collisional origin for the ring. "It looks to me like the merger hypothesis is more likely, given the nearby galaxy intruder and the stability of the intruder galaxy and the main galaxy itself," Conselice said. “Overall, it is convincing evidence that a past interaction and/or merger has occurred for this galaxy system based on the light distribution."

The other competing explanation involves a stellar bar. It proposes that the ring was not made by an intruder at all. GS18660 also shows a bar-like structure running north to south, and bars can funnel gas and stars into rings at specific distances from the center. Perna said the team cannot yet tell whether this is a true stellar bar or a result of the interaction.

A bar would be an exciting finding, too. JWST has already discovered barred galaxies in the early universe, including CEERS-2112. But researchers have not yet found a clear example of a bar-driven ring so early in the universe.

"Whether the ring was triggered by another galaxy or by the internal dynamics of GS18660," Perna said, "the result would tell us something important about how galaxies were already becoming structurally organised when the universe was only a few billion years old."

Editor's note: This article was updated on Oct. 29 to correct a typo. In the image caption, the lead researcher's surname was mistakenly written as "Pera," rather than "Perna." This has been corrected.

A pioneering NASA space telescope is no more. In sad news for Swifties everywhere, the Neil Gehrels Swift Observatory has officially ended its mission after more than 20 years of tracking the most powerful explosions in the universe since the Big Bang.

According to a NASA announcement, the Swift team shut down the telescope's science operations Tuesday (Oct. 20) after the observatory fell too low in its orbit to continue taking reliable measurements of the cosmos. In the coming weeks, Swift will drop even further, eventually passing a point of no return and taking a fiery plunge through Earth's atmosphere.

The observatory is the latest victim of intense solar activity, which increases the drag on satellites in Earth orbit and makes it harder for spacecraft to stay aloft. Swift has been losing altitude for a while, but the final straw came in August, when a costly mission to boost Swift's orbit with a private spacecraft failed, ending with the would-be rescue craft burning up in the atmosphere after a series of hardware malfunctions.

Swift is now beyond saving and, orbiting at just 171 miles (275 kilometers) above Earth, can no longer take reliable observations of space. NASA expects the spacecraft to break up upon reentry "in the next few weeks."

NASA knew Swift was in trouble when it went in; soon, it'll be lying on the cold hard ground. However, the Swift mission surpassed its goals by decades. According to NASA, the satellite launched in November 2004 on a primary mission intended to last just two years. In the end, Swift survived for 22 years, surpassing its intended lifespan by more than 10 times.

In that time, Swift made thousands of observations of exploding supernovas, intense gamma-ray bursts, and black-hole-related episodes of stellar destruction, contributing data to about 7,000 scientific papers, according to NASA.

Designed as a multiwavelength observatory, Swift watched the sky in optical, ultraviolet and X-ray light that made it well suited to track the aftermath of powerful energy bursts. Its greatest asset, perhaps, was its rapid response time; if an explosion flashed somewhere in the sky, engineers could swivel Swift to study it within minutes, NASA said.

"Swift was designed as a satellite dedicated to studying gamma-ray bursts, outbursts that came and went so quickly that no one could target them with large telescopes to learn more," S. Bradley Cenko, the mission's principal investigator at NASA's Goddard Space Flight Center, said in the statement.

Swift's fast-acting observations "played a major role in advancing our understanding of the changing universe and was part of a revolution in astrophysics," added Shawn Domagal-Goldman, director of the Astrophysics Division at NASA headquarters.

When a seagull stares you down, scientists recommend that you stare right back at it to keep your dignity (and your french fries) intact.

Two years ago, astronomers at the Vera C. Rubin Observatory put this idea — and their brand-new telescope — to a test of cosmic proportions, aiming an experimental 144-megapixel camera at the menacing blue eye of the Seagull Nebula (IC 2177).

Located about 3,700 light-years from Earth, the Seagull Nebula is a conglomeration of three giant, billowing clouds of irradiated gas. The "head" of the bird, featured in Rubin's image above, is a cloud called Sharpless 2-292. Its pink plumage is made of hydrogen gas, which glows brightly as ionizing radiation flies forth from the young stars at the cloud's center. The bird's blue "feathers" are clouds of dust reflecting the light from young, blue stars nesting elsewhere in the region.

It's unclear who won this stellar stare-down. If the bird appeared to blink, that's only because its eye is really the triple-star system HD 53367, a flickering trio of very young and energetic stars actively shaping the cloud around them.

The Rubin Observatory, meanwhile, had to avert its gaze quickly; this image is just one of about 16,000 exposures taken of the night sky between Oct. 24 and Dec. 11, 2024, according to the National Science Foundation, which co-manages Rubin along with the U.S. Department of Energy. Taken with the aforementioned Commissioning Camera (ComCam), the deep-space photos served as an early test of the observatory's hardware, software and image-processing capabilities.

ComCam's test image is remarkably crisp — but what's even more impressive is that Rubin has since upgraded to a camera with more than 20 times the field of view. The Legacy Survey of Space and Time Camera currently mounted on the observatory's Simonyi Survey Telescope takes 3,200-megapixel images of the night sky every 30 seconds, completing a full scan of the entire southern sky every few nights, Tony Tyson, Rubin's chief scientist, previously told Live Science.

Now that the Legacy Survey of Space and Time has officially begun, Rubin will spend the next 10 years photographing the sky night after night, creating a time-lapse movie of the universe that is expected to reveal millions of cosmic wonders, from exploding supernovas to newfound comets and exoplanets. Perhaps it will even spot another bird.

Like what you see? Take a look at the hidden details in the Vera C. Rubin Observatory's debut images here.

October's full "Hunter's Moon" is about to rise, and skywatchers will get two great chances to see it appear on the eastern horizon around sunset.

Although it officially turns full at 12:11 a.m. EDT on Monday (Oct. 26), the Hunter's Moon will appear almost perfectly full as it rises on both Sunday (Oct. 25) and Monday evenings, giving skywatchers two opportunities to observe it.

October's full moon is nicknamed the Hunter's Moon because it was traditionally a signal for hunters to prepare for the coming cold winter by hunting, slaughtering and preserving meat, according to Time and Date. That's an Anglo-Saxon name; Native American names for October's full moon include the Drying Rice Moon, the Falling Leaves Moon and the Freezing Moon.

The first chance to see the Hunter's Moon comes just before sunset on Sunday, when the almost-full moon will rise in the east. The second opportunity comes on Monday, when the moon — still essentially 100% illuminated — will again rise just after sunset. Because it will be in a slightly darker sky, Monday's moonrise will likely be more dramatic.

As it rises Sunday, the moon will appear in the constellation Aries, and Saturn will be to its upper right. On Monday, it will rise above the Pleiades open cluster (M45).

For the best view on either evening, find somewhere with a clear view low to the eastern horizon and be in position shortly before moonrise where you are. An elevated viewpoint, open field or coastline is ideal because buildings, trees and hills can delay the moment the moon becomes visible.

Although the full moon will look magnificent with the naked eye, a backyard telescope or good stargazing binoculars can help you zoom in on various lunar features.

The Hunter's Moon may appear unusually large thanks to the "moon illusion," which makes the moon seem bigger when it's seen beside familiar objects, such as trees and buildings, near the horizon. The illusion stems from the fallacies of how our brains use distance to perceive size.

October's Hunter's Moon isn't a supermoon, but it comes immediately before a notable sequence of four consecutive supermoons. The first will be the next full moon, the Beaver Moon, on Nov. 24, followed by full moons in December, January and February. A supermoon occurs when a full moon happens while the moon is relatively close to Earth in its slightly elliptical orbit, making it appear somewhat larger and brighter than average.

How much do you know about the moon? Test your lunar smarts with our moon quiz!

TENERIFE, Spain — The commander of NASA's Artemis II mission briefly feared that he and his crew would never return home from their trip around the moon after overshooting their turn-back point.

Commander Reid Wiseman and his three crewmates were supposed to reach 219,667 nautical miles (252,788 standard miles, or 406,823 kilometers) — farther than any humans have ever traveled from their home planet — before turning back toward Earth on the sixth day of their 10-day mission to the moon.

But the odometer on the Integrity spacecraft continued to tick upward as they shot past their intended point of return, leading the astronaut to fear that something had gone terribly wrong, he told an audience here at the Starmus VIII festival earlier this week. (This semi-annual event is held to celebrate achievements in science, exploration, and creativity.)

"Mission control in Houston had told us our maximum distance would be 219,667 nautical miles and that was the furthest we were supposed to be from Earth," Wiseman said. "I was watching this number, and I saw it hit 219,667, and I thought, 'Great, this is the farthest we will be from Earth, and the next number I will see will be 219,666 ‪—‬ we'll be going home.' But about three minutes later, I didn't see 219,666; I saw 219,668. It went up. I was like. 'Huh? That's weird.'

"And then about three minutes later, it goes to 219,669, and that was the moment that I felt real fear because I thought we had just gone too far ‪—‬ we're never going to come home ‪—‬ and so I was very scared," he added.

Then, at last, he saw the counter start to drop. Meanwhile, NASA astronauts Victor Glover and Christina Koch were at the window, doing science observations of the moon, and Canadian Space Agency astronaut Jeremy Hansen was sending reports back to mission control ‪—‬ so Wiseman's moment of terror went unnoticed.

When Wiseman saw the odometer click back to 219,668 nautical miles, he said, "We're going home," and the crew let out a cheer. "I knew there was a good chance we might make it," he added.

In an interview with Live Science's sister publication The Week Junior Science+Nature, Wiseman paid tribute to NASA's Earth-based teams for the ultimate success of the mission.

"Getting home safely is a testament to the engineering rigor and the flight control teams back here on planet Earth, who put this rocket together and then who controlled it as we went out to the moon and came back. Those are the true heroes of this mission. They have real courage."

The Artemis II mission launched from NASA's Kennedy Space Center in Florida on April 1. It was the first crewed flight of the Orion space capsule and the first crewed mission to travel to the moon since Apollo 17 in 1972, taking nearly 10 days to fly around the lunar far side and return to Earth.

Nearly every moment of the crew's activities in the Orion capsule was livestreamed to the world, garnering massive public interest in the mission. The Artemis II crewmembers were awarded the Stephen Hawking Medal for Science Communication at the Starmus VIII festival.

Are you a NASA nerd? See how well you score on our Artemis quiz to find out!

On Monday (Oct. 19), Japan's space agency launched a first-of-its-kind sample-return mission to Mars. The historic endeavor marks another major step toward humanity's shared goal of understanding — and perhaps eventually colonizing — one of our closest planetary neighbors, experts say.

The Japan Aerospace Exploration Agency's (JAXA) Martian Moons Exploration (MMX) probe is an international effort, constructed with help from NASA, the European Space Agency (ESA) and others. Over the next few years, it will closely study the Red Planet's twin moons, Phobos and Deimos. The spacecraft will snap close-up photos of the pair before attempting to land on the larger satellite, Phobos, to scoop up rocky material that will hopefully be carried back to Earth in around five years.

If the mission is successful, the returned samples will finally settle a decades-old mystery about the origins of both moons. The findings could also help paint a picture of Mars' ancient history and provide clues about what the early solar system was like.

"This mission marks a transformative leap in our capacity to investigate the Martian system," Sonia Fornasier, an astronomer at the Paris Observatory who has studied Phobos and Deimos extensively and is a project scientist for MMX's infrared spectrometer instrument (MIRS), told Live Science. It "ranks very high" among the missions we have sent to the Red Planet so far, she added.

What will MMX do?

JAXA launched the MMX probe on board an H3 rocket, which lifted off from Tanegashima Space Center in Kagoshima prefecture at 3:41 p.m. EDT Monday (4:41 a.m. Tuesday local time), Live Science's sister site Space.com reported. (The mission was initially scheduled to launch in 2024, but it was delayed due to initial concerns about the H3 rocket.)

The camper-van-sized spacecraft successfully separated from the rocket's fairing just over an hour later, and on Wednesday (Oct. 21), JAXA announced that the mission had passed the "initial critical operations phase," meaning the probe is now locked into its roughly 140 million-mile-long (225 million kilometers) journey to Mars, which will take around 10 months.

"MMX took its first step today," Naoki Murakami, general manager of Mitsubishi Electric’s space division, which led the design of the MMX probe, said in a postlaunch news conference early Tuesday morning (Oct. 20), according to The Japan Times. "This marks the beginning of a long, five-year journey."

Once the probe arrives at the Red Planet in August 2027, it will insert itself into a "quasi-satellite orbit" around Phobos. In other words, MMX will circle Mars alongside the moon but will not be gravitationally bound to it, similar to around half a dozen "quasi-moons" that currently accompany Earth around the sun.

After collecting data from a distance for a few months, MMX will swoop down and attempt to land on the surface of Phobos ‪—‬ not once, but twice.

During the first landing, MMX will hover just above the moon and deploy a mini rover, dubbed Idefix, onto the moon's surface. The wandering robot, built by the French and German space agencies, will have to contend with extremely weak gravity as it trundles across the surface of Phobos: The rover weighs around 55 pounds (25 kilograms) on Earth but will weigh only around half an ounce (15 grams) on Phobos, according to ESA.

Once Idefix has completed its initial assessment of the moon's surface, the entire MMX probe will set down on Phobos, on top of the spacecraft's four-legged lander module. Mission scientists hope this goes a lot more smoothly than the attempted landings of Japan's "Moon Sniper" and Resilience lunar landers, which crash-landed on Earth's moon in 2024 and 2025, respectively.

Two of the MMX lander's legs contain built-in sampling devices ‪—‬ one that will drill into Phobos and another that will hoover up surface material. The second device, dubbed the Pneumatic Sampler (or P-Sampler), was built by the Blue Origin-owned private company Honeybee Robotics on behalf of NASA and will collect its material in a "matter of seconds," Kris Zacny, vice president of the Exploration Technology Group at Honeybee Robotics, said at an Oct. 15 NASA news conference. "You blink, and it's all done."

In total, JAXA aims to collect around a third of an ounce (10 grams) of material from Phobos. That would be around twice as much material as the space agency managed to snag on its most recent sample-return mission, Hayabusa2, which collected samples from the "spinning-top" asteroid Ryugu in 2019, finding materials rich in surprising organic compounds.

Once the samples have been acquired, at some point between late 2028 and early 2029, the probe will conduct a series of close flybys of Mars' smaller moon, Deimos, before beginning the long trip back to Earth in late 2030 — the first return flight ever attempted by a spacecraft sent to Mars.

When the probe returns to Earth in 2031, it will release its samples in a 20-inch-wide (60 centimeters) container that will fall back to our planet's surface, most likely somewhere in Australia, according to ESA.

What could we learn about Phobos and Deimos?

Mars' twin satellites, which were first spotted by American astronomer Asaph Hall in 1877, are nothing like Earth's constant companion. For starters, they are much smaller; Phobos is around 14 miles (22 km) across, while Deimos is just 7.5 miles (12 km) wide. The duo also have lopsided shapes and are between 12 and 64 times closer to Mars than the moon is to Earth. (Phobos, meaning "fear," and Deimos, meaning "terror," are named after the sons of the Greek war god Ares, the counterpart to the Roman war god Mars.)

Phobos is dominated by the 6-mile-wide (10 km) Stickney crater, which was left by an ancient asteroid impact. The larger moon is also slowly falling toward Mars and may eventually be ripped apart before it reaches the Red Planet's surface.

Other Martian spacecraft, such as the Emirates Mars Mission orbiter, have flown close to the moons, and NASA's Mars rovers have frequently looked up to see the satellites eclipsing the sun in Mars' sky (sometimes both at the same time). Yet many mysteries remain about the pair.

"Mars is right in our cosmic backyard, and yet we haven't explored the planet's moons," Nancy Chabot, a space exploration expert at the Johns Hopkins Applied Physics Laboratory in Maryland and the deputy principal investigator of NASA's MEGANE instrument on board MMX, told Live Science in an email. "MMX will do this!"

The biggest mystery surrounding Phobos and Deimos is their origin. Some researchers suspect the satellites are asteroids, or maybe even comets, that have been captured by Mars' gravity, while others think the moons emerged from the debris of an ancient impact on the planet's surface, similar to how Earth's moon formed.

Neither theory is conclusive, meaning the moons' origins "remain enigmatic," Christopher Edwards, a planetary scientist at Northern Arizona University and one of NASA's participating scientists for MMX, told Live Science.

For example, explaining how Mars captured the moons is "quite hard from an orbital mechanics perspective," but if they did form from a debris disk from an ancient impact, they should have coalesced into better-defined spheres, Edwards said.

"MMX will solve this debate thanks to the spacecraft observations and the detailed analysis of the samples of Phobos on Earth," Fornasier said. The data the probe collects from its flybys of Deimos will also allow researchers to generate a "full characterization of this body," she added.

Fornasier is "particularly excited" by the possibility that the moons are captured asteroids because that would mean they would likely contain "organic and hydrated materials," which would have a big "astrobiological implication" and would shed light on what the early solar system was like.

What could we learn about Mars itself?

Regardless of how the twin moons formed, researchers also stand to learn a lot about Mars and how planets form and evolve.

"Phobos and Deimos are interesting, but not just in their own right," Tom Statler, an MMX program executive and scientist in NASA's Planetary Science Division, said at the Oct. 15 news conference. "Their presence is a key piece of the larger story of the Mars system. By uncovering the moons' origin, we'll gain new insights into the history of both Mars and Earth."

If the moons did form via an impact scenario, the samples MMX collects may also contain actual pieces of Mars for researchers to study.

"If these objects are in fact pieces from the Martian surface that have coalesced moons, we'll collect the best-preserved samples of the Martian surface," Edwards said. Other fragments of Mars have already reached Earth as meteorites. However, entry into Earth's atmosphere can transform them.

If Phobos is a chunk of Mars, that would be a real boon to NASA, which canceled its Mars Sample Return program — a mission that would have retrieved samples collected by the Perseverance rover — earlier this year. The agency's researchers will receive up to 15% of the MMX samples to analyze.

During its three-year stay in the Red Planet's system, the Japanese probe will also collect lots of data on Mars that could contribute to a wide range of future findings. "MMX will conduct in-depth studies of the Martian atmosphere, with a particular emphasis on dust and water transport mechanisms and the escape processes shaping Mars' atmospheric dynamics," Fornasier said.

This atmospheric data could temporarily fill a gap left by the recent death of NASA's iconic MAVEN spacecraft, which stopped sending data back to Earth late last year.

Analysis of craters on the Martian moons could also provide clues about other events in Mars' history. For example, some researchers think the Red Planet may have once had rings like Saturn or a larger moon.

Other experts are hopeful that the MMX findings could help lay the groundwork for future missions to explore ‪—‬ and perhaps colonize ‪—‬ Mars. "The samples from MMX will bring forth paradigm-shifting science on the Mars system for generations to come, especially as NASA prepares to send the first humans to Mars," Nicky Fox, associate administrator for NASA's Science Mission Directorate, said in a recent statement.

The next sample-return trip to Mars will be China's Tianwen-3 mission, which is scheduled to launch in 2028 and will aim to land on and retrieve samples directly from the Red Planet's surface, according to Space.com.

The Milky Way's supermassive black hole is surrounded by a surprising trove of heavy metals, according to new observations by the James Webb Space Telescope (JWST). The metals may offer new clues about how Earth got its share of heavy elements — but it could also make one of the greatest mysteries about our local black hole even harder to solve.

In astronomy, metals refer to any element heavier than hydrogen or helium, with common examples including oxygen, carbon, iron or gold. These elements are forged through nuclear fusion in the hearts of stars that are reaching the ends of their lives, before being sprayed into space and incorporated into new generations of stars.

Scientists say the material spotted by JWST likely came from supernovas ‪—‬ stellar explosions that blasted the metal into the region around Sagittarius A (Sgr A*), the monster black hole in the middle of our galaxy.

The metals, detected as gas, appear to have the same composition as several nearby stars, which suggests both the stars and the gas originated at the same time. Researchers shared the observations in a paper published Oct. 19 in The Astronomical Journal, following up on work published in The Astrophysical Journal in May.

"We know there's a black hole at the centre of our galaxy pulling material into itself, but we see that it's eating a lot less material than other supermassive black holes, and more slowly," Nicole Ford, first author of the new paper and a doctoral student in astrophysics at McGill University in Montreal, said in a statement. "Part of understanding why this is happening means looking at the properties of the materials available for it to consume, including gas, dust and the stars orbiting around it."

JWST orbits at Lagrange point 2, which is about 1 million miles (1.5 million kilometers) from Earth in the opposite direction of the sun. The telescope identified the heat signatures of specific gas clouds billowing near the black hole, as well as the metal content within those clouds.

"These findings could advance understanding of how metals are distributed around supermassive black holes in more distant galaxies, as well as the processes that supplied Earth with many of these elements," McGill researchers said in the statement. The metals' presence "influences how quickly gases cool, which in turn influences how readily the gas can be drawn into a black hole," they added.

The previous study in The Astrophysical Journal showed that gas emissions near the black hole have been influenced by conditions in the local clouds. Unfortunately, this means the gas alone cannot serve as a proxy for how often the black hole has been active, the researchers said.

See how much you know about black holes with our black hole quiz!

Astronomers using the James Webb Space Telescope (JWST) have found what may be one of the most distant supernovas ever observed. And in a stroke of cosmic luck, the team thinks they're seeing what the explosion looked like just days after it ignited.

The supernova, named AT 2026abck, dates to around 1.15 billion years after the Big Bang, when the universe was less than one-tenth of its current age and bursting with massive stars flickering into life. The massive exploding star violently released its light over 12.5 billion years ago, according to the researchers — so long ago that the distance between us has effectively ballooned sixfold due to the expansion of the universe.

The discovery was described in a paper that was uploaded to the preprint server arXiv Sept. 29 and has not yet been peer reviewed. According to the study authors, this ancient speck of light is stupendously bright.

"At its peak, the supernova is about 8 billion times the brightness of the sun … almost as bright as the whole Milky Way Galaxy," study co-author Xiaohui Fan, an observational cosmologist and professor of astronomy at the University of Arizona, told Live Science via email. "Over the course of the explosion, it radiates the energy that the sun will radiate over about 2 billion years."

A beacon from the beginning of space-time

The newly discovered supernova shines brilliantly at over 30,000 degrees Fahrenheit (16,000 degrees Celsius). Its incandescent shell of ejected material has billowed to a radius of approximately 46 astronomical units ‪—‬ about 46 times the distance between Earth and the sun, or about as far as Pluto swings at its farthest point from the sun.

The supernova's host galaxy, designated ID101411, holds about 6.3 billion solar masses and is "forming new stars more than ten times faster than our Milky Way," first author Mingyang Zhuang, an observational astrophysicist at the University of Illinois Urbana-Champaign, told Live Science via email.

As with other early galaxies, ID101411 is deficient in metals, meaning any elements heavier than hydrogen and helium, because not enough time had passed to create those heavier elements in the forges of massive stars and their apocalyptic explosions.

The study authors estimate that they observed the supernova as it would have looked just four to 10 days after it exploded. Although this is relatively common, spotting one at such an incredible distance "is extremely rare," Zhuang emphasized. "You have to observe the exact same tiny patch of sky repeatedly with [JWST], and the explosion has to happen at the right moment. We were lucky."

There's another layer of luck that made the discovery even more remarkable: It was observed without the aid of a cosmological quirk called gravitational lensing — a phenomenon predicted by Einstein in which the gravity of a massive object in space bends and magnifies the light emitted by objects behind it.

"Most supernovas this far away were found with help from a massive foreground galaxy cluster acting as a natural magnifying glass," Zhuang explained. "It's the most distant one we've actually seen appear."

This supernova was discovered as part of the NEXUS Treasury program, in which JWST intermittently scours patches of the sky for ancient explosions. It had previously observed the explosion's host galaxy over the past few years and finally witnessed the supernova on Aug. 7 of this year.

An explosion in slow motion

Intriguingly, the star had not yet exploded in JWST's previous viewing, on May 28, 2026, meaning that 71 days passed on our Earthly clocks, even though only about 12 days passed in the supernova's own time frame.

This highlights a mind-bending cosmological effect: The universe's expansion doesn't just stretch space; it slows down time from our perspective.

"Because the universe has expanded since this light was emitted, everything about this explosion appears to us in slow motion, about six times slower than it actually happened," Zhuang said. "Changes that took one week at the supernova take about six weeks to unfold from our point of view."

Mysteries still remain about the nature of this ancient explosion that shone so brilliantly we can observe it across nearly the entire universe.

Rather than a conventional core collapse supernova ‪—‬ in which a star between approximately eight and 50 times the mass of the sun exhaust its nuclear fuel and suffers a rapid core collapse and subsequent explosion ‪—‬ the recently discovered supernova may be one of the universe's rarest, most powerful explosions, the study authors said. Known as a superluminous supernova, this type of explosion releases tens or hundreds of times more energy than conventional supernovas. Whether the explosion continues to heat up or starts to cool could reveal exactly what is happening in its environment and what caused it, the team said.

"Our interpretation is still preliminary," Zhuang concluded. "Follow-up observations will tell us more about exactly what kind of explosion this was."

How well do you know our home galaxy? Find out with our Milky Way quiz!

One of the best fall meteor showers peaks this week, when pieces of the famous Halley's Comet streak across Earth's atmosphere as fast-moving "shooting stars."

The Orionid meteor shower will peak overnight Wednesday (Oct. 21) through Thursday (Oct. 22), potentially producing around 20 meteors per hour under a dark sky, according to Time and Date. The Orionids are caused when Earth passes through the debris left by Halley's Comet, which last passed through the inner solar system in 1986 and will return in 2061.

Halley's Comet is presently beyond the orbit of Neptune, according to The Planets Today, but it doesn't need to be close to Earth to cause "shooting stars." Every time the comet travels through the inner solar system, heat from the sun causes it to shed dust and rocky particles along its orbital path. Earth's own orbit takes the comet through streams of that ancient debris several times a year, with the particles vaporizing as they slam into our planet's atmosphere.

The Orionids are particularly fast meteors, striking Earth's atmosphere at around 41 miles per second (66 kilometers per second). They can produce bright streaks, occasional fireballs (extremely bright, sometimes colorful meteors) and "persistent trains" — glowing trails that remain visible briefly after a meteor has disappeared. The best way to view them is with the naked eye, although a nice pair of stargazing binoculars or a small backyard telescope will help you enjoy more sights during peak skywatching season this fall.

Halley's Comet produces not one but two annual meteor showers. Its orbit comes close to Earth's at two different points, so our planet encounters the comet's debris twice each year — once during the Orionids in late October, and again during the Eta Aquariid meteor shower in early May.

There's a slight complication with the Orionids this year. A 71%-illuminated waxing gibbous moon will brighten much of the night, making it harder to spot meteors. However, the moon will set early Thursday morning, creating a valuable window of darkness before dawn. That's also when the constellation Orion will be high in the sky, making the predawn hours the best time to watch.

You can trace the paths of Orionid meteors back to their radiant: the famous red supergiant star system Betelgeuse in the constellation Orion. (That's why the shower is called the Orionids.) However, there's no need to look directly at Orion. Meteors seen farther from the radiant can produce longer streaks across the sky; each one comes from a tiny piece of Halley's Comet completing a journey that began many centuries ago.

A mysterious "guest star" recorded by medieval astronomers nearly 850 years ago has revealed new secrets after scientists obtained the clearest images yet of its explosive aftermath.

New observations of Pa 30, thought to be the leftovers of a historic supernova called SN 1181, show that its spectacular firework-like filaments are not smooth streams of material. Instead, they consist of chains of tiny gas knots.

SN 1181 is so called because astronomers in China and Japan recorded its brief appearance in the year 1181, when they saw it as a naked-eye object in the constellation Cassiopeia. Eight surviving texts date its appearance to between Aug. 4 and 6 of that year. The mysterious object remained visible for 185 days.

"It's rare to get this level of detail on a supernova we can date to a specific week in history," Timothy Cunningham, an assistant professor of astronomy and astrophysics at the University of Warwick who led an international team of researchers to study the object, said in a statement.

SN 1181 is one of only five supernovas in the Milky Way galaxy known to have been witnessed from Earth before the invention of the telescope. (Those optical instruments first appeared in the Netherlands in 1608.) Now, advanced ground-based telescopes can produce wonderfully detailed images of those historic remnants. This latest image is from the Gemini North telescope on Mauna Kea in Hawaii and reveals about 10 times more filamentary structures in Pa 30 than have been seen before. This extraordinary detail gives astronomers fresh clues about the unusual explosion and the environment surrounding the star.

"These images give us the clearest picture yet of Pa 30's structure, and it's not what we expected," said Cunningham, whose team published their findings in The Astrophysical Journal. "The filaments are made of chains of tiny knots rather than smooth streaks, providing new constraints on the nature of the space around the star before it exploded and the physical processes that have shaped the expanding ejecta."

The knot-like structures may have resulted from variations in temperature or density in material surrounding the star as debris from the explosion expanded.

Pa 30 contains another unusual feature: a surviving star that sits almost exactly at the center of the remnant. That's highly unusual, because a supernova explosion typically sends stars away from their original positions. It suggests that the original explosion was highly symmetrical, the researchers said.

Furthermore, Pa 30 is thought to be a Type Iax supernova. Unlike standard Type Ia supernovas, which destroy their stars, a Type Iax event is a lower-energy, incomplete explosion of a white dwarf star that can leave behind a remnant known as a "zombie star." It's the only Type Iax supernova ever found.

Stellar cores called white dwarfs come in an astonishing array of colors, including what scientists say is the first known green star and the reddest star ever found, new research reveals.

A white dwarf star is the dense, cooling core that remains after a low- to medium-mass star runs out of fuel. The new study, published Thursday (Oct. 15) in the journal RAS Techniques and Instruments, shows that white dwarfs come in far more colors than their name suggests.

White dwarf stars got their moniker because the first known examples glowed in either white or pale blue. The new study, however, suggests that "white" dwarfs also emit visible-light colors like pink, green, cyan, purple and yellow.

"Most stars, including most white dwarfs, behave like 'perfect radiators,' so their colour is set almost entirely by temperature. But nobody had really looked into what else might be possible for white dwarfs," Mark Hollands, an astronomer at the University of Warwick in the U.K. and first author of the study, said in a statement. "It turns out these incredibly dense stars can produce colours nobody expected, and some of them genuinely surprised me."

The variety of colors is possible due to white dwarfs' densities compared with main-sequence stars, the study suggests. Cooler white dwarfs have a density of about 1 gram per cubic centimeter, much like flowing water on Earth. The density of these white dwarfs is also millions of times denser than the sun's visible surface, or photosphere, leading to unusual conditions.

"Any trace elements that may be present, such as carbon, calcium and sodium, interact with the surrounding dense helium plasma and absorb light across a wider range of colours than they would at lower densities," the researchers said in a statement. "This shifts a star's colour away from the orange, white and blue [typical] of a perfect radiator."

White dwarfs are far away and small, making it difficult to verify their color. So, in the new study, astronomers inferred the colors using spectra, the distinctive chemical fingerprints produced by stars' light. The team analyzed the spectra within a model of color vision that the human eye can see, making the color pop out.

Scientists found that carbon-rich white dwarfs tend to be purple or pink, while those that contain debris from asteroids or comets are usually yellower. Cyan or pale-blue white dwarfs occur when hydrogen and helium molecules strike each other in very dense atmospheres.

The team also discovered WD J1330+6435 — a green star that contains rocky material. The green comes from the additional elements of calcium, lithium and sodium in the star's atmosphere, creating a unique "chartreuse green appearance" that would be visible to the human eye, if we could see it up close.

"The traces of sodium in the atmosphere of this white dwarf absorb the orange part of the spectrum, leaving behind a ghostly green glow," Hollands explained, adding that the one-of-a-kind green star "feels like something out of science fiction." The team also discovered what is likely the reddest star ever found. This white dwarf, called WD J1011+2845, is located roughly 48 light-years from our planet. It has carbon closer to its surface — because the element is being lifted from the interior, due to strong convection currents — that is bending the star's light. This process is making a "deep salmon-pink glow" because the carbon molecules are obstructing the star's other wavelengths.

Overall, in the sample of stars studied — 151 white dwarfs within 65 light-years of Earth — about 1 in 30 white dwarfs glowed in a color other than white. This could mean there are far more colorful stellar remnants littering the universe than anyone anticipated.

The year is 2050, and as the sun sets, the night's first constellations emerge in perfect rows. But these amber-glowing arrays aren't stars at all; they're satellite clusters, harvesting the day's last rays before beaming their power back to Earth.

If it reads like science fiction, that's because it started that way. Called space-based solar power (SBSP), the concept featured prominently in the techno-utopian imaginations of 20th-century visionaries and writers. But for decades, it was dismissed — a pie in the sky proposal.

Now, as a new space race heats up, governments and private companies in China, the U.S., the U.K. and Japan are developing several projects to reassess the idea's feasibility. These include China's ZhuRi ("Chase the Sun") program, Japan's OHISAMA project, the U.K.'s Space Solar, and power-beaming experiments by Caltech and the Air Force Research Laboratory in the U.S., all of which are targeting test launches in the next five years.

Proponents say the technology has the potential to meet Earth's energy needs many times over while causing minimal harm to the environment. But first it needs to get off the ground: In the eyes of critics, space-based solar power is exorbitantly expensive, riddled with untested assumptions, and far too complex to be deployed in time for an urgent green-energy transition.

The challenges include getting the massive solar-panel-covered satellites into space; assembling them; getting those solar panels to constantly face our star; and then finding ways to convert, concentrate and transmit their collected power back to Earth.

Despite these hurdles, researchers keep returning to the idea. Perhaps because the most crucial step — generating energy in the first place — is already being done by the sun. Every second, our star fuses hydrogen atoms to expel the same energy as nine trillion atomic bombs. All that's left to do is catch it.

"We're not a competitor to fusion. We are fusion," Peter Garretson, the U.S. Air Force's former chief of future technology and an SBSP expert, told Live Science.

From science fiction to NASA proposal

The first glimmers of SBSP as a concept came from the Russian rocket scientist and astronautics pioneer Konstantin Tsiolkovsky, who, in 1923, suggested deploying space-based mirrors that could concentrate sunlight to Earth with enough intensity to boil 10 cups of coffee.

Tsiolkovsky's fanciful proposal soon entered science fiction, appearing in the British writer Olaf Stapledon's 1937 novel "Star Maker" as a "gauze of light traps" that an advanced alien civilization used to focus "the escaping solar energy for intelligent use" — an idea later formalized by theoretical physicist Freeman Dyson as a Dyson sphere.

Then, in 1941, Isaac Asimov made the clearest, most famous early sketch of SBSP in his short story "Reason," in which a robot colony toils aboard a power station that collects solar energy and fires it back to Earth in the form of microwaves. Asimov provided few details on the fictional station's engineering, instead focusing on the robots' religious worship of the vessel.

But the transformation from science fiction to a concrete proposal didn't take long. In 1968, aerospace engineer Peter Glaser, a consultant and project manager for the Apollo 11 mission's distance-measuring laser reflectors, drew up an engineering design for a "solar power satellite" consisting of three key elements: a ray-collecting device, a converter and a transmitter.

Glaser's collector was a disk of photovoltaic panels that would be lifted some 22,400 miles (36,000 kilometers) off the ground. Locked in a geostationary orbit above Earth and bathed in near-constant sunlight, the satellite would harvest solar rays before converting them into microwaves to be beamed, largely unimpeded through the atmosphere, to receiving antennae on the ground. Once there, the microwaves would be converted into electricity and distributed across the grid.

NASA awarded Glaser a contract to study the concept further, with both domestic and international energy crises (such as the 1973 oil crisis and the 1979 Three-Mile Island nuclear accident) adding wind to his solar sails.

But Glaser's design hit technical and financial roadblocks, the most forbidding being the project's sheer size. By 1981, when the U.S. Department of Energy's four-year study of space-based solar power was released, it estimated that a "meaningful" contribution of 300 gigawatts (sufficient to power hundreds of millions of homes) would require 60 satellites, each spanning 21 square miles (55 square kilometers) and weighing 50,000 tons (45,000 metric tons). The plan was deemed unaffordable.

Later reassessments, such as a 1997 report by NASA physicist John Mankins, pointed to advances such as improved solar cells that made the concept more realistic. Yet the overall consensus remained hostile. A 2015 report released by the Strategic Studies Institute (SSI) of the U.S. Army War College stated that while SBSP systems are "technically feasible," there was "no compelling evidence that such systems will be economically competitive" with terrestrial power systems. It concluded that "the reality is that such systems always seem to be seen as just 10 years away by their advocates."

Aiming high

But a lot can change in a decade, including the cost of firing rockets. Since the SSI report, SpaceX's reusable Falcon 9 rocket has sent launch costs plummeting to around 30 times less than those of NASA's Space Shuttle, with satellites also getting cheaper due to mass production and advances to the clean rooms where they're made. And SpaceX's even bigger Starship rocket promises to more than quintuple Falcon's payload capacity, lowering prices further.

"What you have is a cadre of people in the space community that have grown up before Starlink and SpaceX," Garretson said. "They literally could not believe that, as your launch rate goes up and you amortize your costs, [the launch cost] approaches the cost of fuel." Some took notice. A 2021 assessment commissioned by the U.K. government estimated that a 2-gigawatt, mile-wide space-based solar power array would cost 17.3 billion British pounds ($23.4 billion) and generate energy at 50 British pounds ($68) per megawatt hour over its century lifetime.

That's the equivalent output of a large power station in the U.K., with the initial costs being 39% to 49% cheaper than biomass, nuclear or the most efficient gas energy sources, according to the assessment. And while it's still 14% to 52% more expensive than current terrestrial wind and solar energy, the technology could be beamed anywhere, even to remote locations.

Based on these findings, in 2023, the U.K. government awarded 4.3 million British pounds ($5.8 million) in seed funding to a handful of companies and universities to develop SBSP further.

The U.K. report chose one satellite design as its reference architecture: CASSIOPeiA. Belonging to the U.K. SBSP company Space Solar, the satellite's design is an attempt to crack a significant challenge faced by early solar satellite blueprints: how to keep solar panels constantly aligned with the sun to maximize radiation collection.

Unlike other satellite designs, such as China's Multi-Rotary Joint Solar Power Satellite or Mankins' SPS-ALPHA, which rotate the panels or use a system of mirrors to constantly redirect sunlight onto them, CASSIOPeiA is shaped like a gigantic DNA strand.

This design, alongside a sun-synchronous orbit and a slow spin, enables CASSIOPeiA to constantly receive and transmit solar energy without any heavy or failure-prone moving parts. Space Solar claims that a single CASSIOPeiA satellite, which would be about 1 mile (1.6 km) in diameter, could microwave-beam as much as 2 gigawatts of constant power to a fixed point on the ground — enough to supply a city of 2 million people.

Space Solar says that once the satellite is in space, it will be far more efficient and economical than gathering sunlight on the ground could ever be. That's because the light hitting the space-based power station isn't deflected or attenuated by the atmosphere.

"You use a lot less materials compared with terrestrial solar, and you utilize them more," Sam Adlen, co-founder and co-CEO of Space Solar, one of the funding recipients, told Live Science. "So it's 100% utilized in space rather than 10% if you're on the ground — and you've got 13 times more instant energy, so you're getting much more out of the materials."

Beaming down

However, the next step — beaming gigawatts of energy down and across tens of miles of atmosphere and through potential cloud cover — remains a major technical hurdle.

Proposed power-beaming methods are currently split between two types: lasers and microwaves. California-based startup Aetherflux, which has plans to beam power from satellites in low Earth orbit, has developed an infrared laser transmission system that it will test using a demonstration satellite launched on October 1. The microwave energy will be transmitted at around one kilowatt (enough to supply the basic electrical demands of a household).

Meanwhile, Caltech and Overview Energy, another U.S. startup, have both demonstrated respective microwave and laser-power beaming from orbit and from a plane, respectively, albeit in negligible amounts ( less than a kilowatt).

Despite their efficiency and proven ability to travel vast distances, optical beams in the infrared and near-infrared ranges are easily scattered by water droplets in the atmosphere, preventing power from being transferred on cloudy days. Persisting efficiency issues with optical power transmission also worsen at gigawatt power levels, meaning lasers are less feasible for use at the utility scale.

Microwaves, on the other hand, can be beamed at frequencies with much higher power and suffer relatively little atmospheric attenuation. That's why Space Solar, Japan's OHISAMA project and China's ZhuRi program all plan to use microwave-beaming systems. Nonetheless, microwaves have comparatively longer wavelengths, so their beams diffract more widely across longer distances. This means that even if beams are sent by transmitters hundreds of meters wide, they would need Earth-based receivers spanning dozens of square miles.

These limitations mean that "it's going to take many years" before gigawatt-scale power beaming is achieved, Remo Proietti Zaccaria, head of the DELTA Lab at the Italian Institute of Technology, told Live Science.

Improvements in power-beaming efficiency will bring their own challenges. Even battery-powered laser pointers can blind or burn, so prototypes by laser-beaming SBSP companies like Aetherflux must be designed with that possibility in mind. They promise safety mechanisms that switch off their lasers if anything flies between the transmitter and the receiver.

"Definitely for the weapon side, this technology now can be used efficiently," Proietti Zaccaria said.

If you're imagining an orbital weapon devised by a Bond villain, you may be disappointed — even fully developed power-beaming lasers and microwaves would take a while to cook an egg, or boil Tsiolkovsky's coffees. But beaming technology could still have potent military use: Scrambling communications systems on Earth to create havoc with relatively little effort.

"If you throw even that amount of intensity of power to our antennas, you're going to freeze the electronics; that's for sure," Proietti Zaccaria said. "It's not necessary to destroy them. As long as you freeze the electronics, you've done the job."

The challenges associated with power beaming have pushed some engineers to simpler concepts. One (going full circle back to Tsiolkovsky's original proposal) envisions the deployment of space-based mirrors that reflect sunlight back to Earth after sunset, with a single reflector extending the daylight delivered onto solar panels by around 20 minutes.

This may not seem like much on its own, "but then you can increase this with multiple reflectors," Onur Celik, a researcher in space technology at the University of Glasgow, told Live Science. "If you have 10 or more of them, you can arrange them in space in such a way that you can extend this to up to two hours or so at that altitude."

"The sunlight that you deliver, if it all turns into electricity, could power thousands of homes," he concluded.

The light of day

The trillion-dollar question is whether that power will be cheaper and more efficient than that generated on the ground. The median cost of the electricity generated by SBSP as estimated by the U.K. government is 50 British pounds per megawatt hour ($68), putting it roughly in line with the costs of offshore wind and terrestrial solar power.

However, this estimate is orders of magnitude too sunny for the 2024 NASA cost report, with its projections suggesting SBSP's baseline electricity costs fall between $610 and $1,590 per megawatt hour, depending on the array design. NASA concluded that the U.K.'s median estimate was achievable only after drastic future reductions in launch and manufacturing costs.

Independent studies are also divided over feasibility. One assessment suggests that SBSP could reduce Europe's need for land-based renewable energy by up to 80%, while another counters that the costs could be 12 to 80 times more expensive than those for terrestrial alternatives. This variability exists within the studies themselves, with research published in the journal Acta Astronautica estimating that SBSP could contribute to meeting anywhere from 3% to 31% of global electricity demand, depending on possible constraints in how many satellites can safely fit into an orbit, the receiver size, and where power is beamed to.

"For the numbers we found, I don't believe that this technology could actually be employed to generate energy for Earth," said Proietti Zaccaria, a co-author of the Acta Astronautica study. If humanity had used up all available space for solar panels on Earth, "then I will tell you it would make sense, because at that point, 3%, 5%, 10% could make a difference."

Proietti Zaccaria does see use cases for SBSP schemes for future moon or Mars missions, but otherwise, "the cost for building technology of this kind is really very, very high," he said. "Vice versa, the cost nowadays of buying and installing a solar panel on the roof of any building has become extremely cheap."

Among the challenges would be ferrying the raw materials for the systems into space and then assembling them. Such a feat would make the construction of the International Space Station — currently the most complex structure built in orbit — seem like child's play. Maintaining arrays and preventing them from crashing into other satellites in Earth's increasingly crowded orbits would also take significant international coordination.

Then there are the unweighed environmental costs. All modern rockets use methane, a potent greenhouse gas, to propel them into space, and they release much of it into Earth's upper atmosphere, where its effects are the strongest.

"And so clearly, there is a question there on how launching 100,000 of these superheavy vehicles into the atmosphere will actually impact the atmosphere itself, as opposed to the benefit that we get in the next 20 years or so from having solar power from space," Matteo Ceriotti, a senior lecturer in space systems engineering at the University of Glasgow, told Live Science. "It's not entirely clear."

Ceriotti said the likeliest route for overcoming all of these difficulties come from smaller companies running, and then streamlining, proof-of-concept tests in space.

"Obviously, it's not something that we have ever done," he said. "So clearly, we need to start somewhere, and we need to start small."

The hopes of SBSP proponents remain unclouded by gloomy estimates. They cite several technologies, from personal computers to reusable rockets, that were once thought to be impossibly expensive, even fictitious, that are now ubiquitous and cheap. Their eyes remain fixed on demonstration missions to be launched over the next four years by the likes of Space Solar, Reflect Orbital, Aetherflux and Virtus Solis. If these missions succeed, another once-impossible idea could appear much brighter.

"The private sector is good at this, because it has to be," Sanjay Vijendran, an SBSP consultant who led the European Space Agency's now-shuttered SOLARIS project to test the feasibility of SBSP, told Live Science. "It can break the problem down to quite a small level and start to do things with today's technology and today's way of doing things, and start to show that this can be valuable."

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What color is the moon? Ask an Earthling, and you'll get a predictably monochromatic answer: white or gray.

But ask the four crewmembers of NASA's Artemis II mission — who spent nearly seven hours circling the moon from just 4,000 miles (6,400 kilometers) from the lunar surface this April — and you'll wonder if they're talking about the same dusty satellite we can see from Earth.

Yellow, brown, green, blue and tan features fan across vast volcanic plains and lurk at the edges of ominous craters, according to the crew's in-the-moment observations, which were shared this week in NASA's Artemis II Preliminary Lunar Science Report. The 130-page document catalogs everything crewmembers Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen saw during their historic close flyby of the moon on April 6, drawing from 814 gigabytes of photo, video and audio recordings taken from the Orion crew capsule.

This rainbow of lunar color represents distinct geological features that could inform future missions on where to land and where to explore as the world's space agencies race to set up a permanent presence on the moon.

One spot that particularly enthralled the astronauts (and is featured in the image above) is the Aristarchus Plateau — a broad, elevated region on the northwestern edge of the moon's nearside. The region hosts one of the moon's densest collections of ancient volcanic features, including swaths of dark lava deposits and colorful volcanic glasses.

Koch, mission specialist for Artemis II, was shocked to see distinct yellow shades in the region; she likened the plateau to "a yellow snow-capped mountain," with sunlight-reflecting craters providing the bright "snow." She went on to call the region "a jaundiced cheek of the Moon."

"There are so many colors now," Glover, Artemis II's pilot, added while photographing the area. "There's also a green. I see brown, especially Aristarchus and north toward the north pole. … It kind of flows down from the north in brown streaks."

According to the report authors, these colorful hues "could be associated with orange (titanium-rich) and green (magnesium-rich) glass beads respectively," similar to volcanic glass beads collected by the Apollo 15 and 17 missions on separate parts of the moon.

"Chaos across the entire area"

Another colorful patch of the lunar surface that caught the crew's attention was Orientale Basin — a huge, young and multiringed impact crater that's about three times as wide as Massachusetts, according to NASA. Straddling the moon's near and far sides, this massive bull's-eye is rarely visible from Earth, but it dominated the crewmembers' field of view as they orbited around the side of the moon.

"It has just created chaos across that entire area," Wiseman, commander for the mission, said at the time.

When flying over this sprawling basin, the crew noted gray, brown, tan and green below. The largest, outermost ring in the basin contained "almost swamp-like colors," Koch reported, while Glover spotted what looked like "dusted peaks" and "white on the very edges of [the mountains], the spines, the ridgebacks." Chains of craters parading away from the impact site looked "like bubbles rising from a team of scuba divers below," Koch added.

While these may sound like off-the-cuff observations, the Artemis II crew spent more than two years training to study and describe the moon's geology. Their regimen included visiting craters on Earth, taking lessons individually and in classrooms, conducting simulated flybys and, according to the report, bringing "self-selected reference materials" into the Orion capsule to read on the way to the moon.

Thanks to this training, the crew's observations provided a wealth of scientific information that no autonomous camera or orbiter could, the report said.

"The Artemis II mission demonstrated the exceptional value of human observation and cognition as scientific assets in planetary exploration," the report authors concluded. "Unlike cameras, which capture isolated moments and often narrow subsets of a scene, human observers continuously interpret their surroundings, integrating realtime visual perception with contextual understanding."

Or, to put that in Glover's more relatable words to mission control, "It's quite a wicked view."

How much do you know about the moon? Test your lunar smarts with our moon quiz!

Astronomers have detected the most distant burst of radio signals ever seen: an explosion that's emitting waves of energy from more than 10 billion light-years away.

The event, named FRB 20240304B, is known as a fast radio burst (FRB). Astronomers have detected thousands of FRBs before this. But because these events last only milliseconds, they are extremely difficult to study and their origin stories remain unclear.

In this case, however, astronomers managed to use a radio telescope array and the James Webb Space Telescope (JWST) to chart the event, with JWST narrowing down the precise host galaxy that FRB 20240304B came from. The study, published Thursday (Oct. 8) in the journal Science , sheds more light on a time when the universe was only about 3 billion years old, showing that FRBs arose early in our cosmos' history. The detection more than doubles the previous distance record for FRBs.

The JWST played an instrumental role in the discovery, study co-author Themiya Nanayakkara, a senior lecturer at the Sydney Institute for Astronomy, told Live Science in an email. The email was written in collaboration with study first author Manisha Caleb, a senior lecturer in astrophysics at the same university.

For example, JWST's observations showed that the host galaxy was smaller than expected, was "metal-poor" (had few elements besides hydrogen and helium), and was forming a lot of stars. These characteristics could offer new clues about the environments in which FRBs arise, giving more information about the mysterious events. Researchers suggest that this FRB may have been linked to a magnetar, a highly magnetic star core left after a supernova.

Zooming in with the James Webb telescope

The ancient FRB was initially detected with MeerKAT, an array of 64 radio telescopes in South Africa. Nanayakkara said MeerKAT revealed "both the detection of the fast radio burst and, importantly, a very precise position on the sky."

The researchers knew the FRB was far away because of the large dispersion of the radio signal, but initial searches with powerful ground-based telescopes, "saw essentially nothing; it looked like empty sky," the researchers told Live Science. "The most likely explanation was that the galaxy was simply too faint to be detected in those observations. That is where JWST became transformative."

The science team successfully got time on JWST with a program called Director’s Discretionary Time, which is aimed at time-sensitive observations. The researchers started by using JWST's Near Infrared Camera to trace the radio signal and take a very deep image of the target region.

"Suddenly, there it was: a very faint galaxy almost exactly where we expected the host of the FRB to be," Nanayakkara said. The researchers then used JWST's Near Infrared Spectrograph to obtain a spectrum (wavelengths of light broken into different chemical signatures), which showed hydrogen and oxygen.

"These spectral features act like fingerprints: because we know the wavelengths at which they are produced in the laboratory, we can measure how much they have been shifted by the expansion of the universe," Nanayakkara explained. "That gave us a very precise redshift of about 2.15. We are therefore seeing this galaxy as it was when the universe was only around three billion years old, so roughly one-fifth of its current age."

Because the host galaxy is fairly young, it supports the idea that at least some FRBs are generated by magnetars, which are more likely to appear in spry galaxies where intense star formation is occurring, the team said.

The team plans to continue hunting for FRBs with JWST.

"We do not know what the sources will be yet," Nanayakkara said, as that depends on what pops up in the sky and is spotted by ground-based radio telescopes. "Once our radio telescopes find and localize a suitable new source, we can trigger the JWST observations. So it is quite exciting, because we really have no idea what we will find when we combine the power of these two types of telescopes."

Long before it became the luminous spiral galaxy we call home, the Milky Way was a sprawling, chaotic swarm of thousands of small galaxies, new research shows.

The findings suggest that in the first 2 billion years after the Big Bang, the region of the universe that would become our galaxy was littered with thousands of smaller galaxies of many sizes and shapes. Over time, these galaxies collided and merged into the single galaxy in which we reside today.

"Looking at these results, it's very clear that the physics happening right after the Big Bang has direct impact on what we see today in the local universe," study co-author Harley Katz, an assistant professor of astronomy and astrophysics at the University of Chicago, said in a statement.

To understand more about the early universe, astronomers build sophisticated computer models that encode the laws of nature to see how the cosmos may have evolved. The new work, which is the result of three years of supercomputer simulations, is the most detailed tracing yet of how a galaxy like ours came to be. It also arrives just as astronomers need a stronger yardstick for what they're seeing in the early universe.

Megatron, the cosmic transformer

The James Webb Space Telescope (JWST) can peer farther into the early universe than any previous telescope, and its discoveries have often defied computer models. For instance, JWST found surprisingly bright early galaxies and a mysterious new class of compact galaxies dubbed "Little Red Dots." These anomalies demonstrate that current computer models need an update to handle the complex physics of the early universe, the researchers said.

To bridge that gap, the scientists built a new suite of supercomputer simulations they call Megatron. By tracing ancient gas, starlight and chemistry from 180 million years to 2 billion years after the Big Bang, Megatron predicts the distinct light signatures of its virtual galaxies, according to the statement. Because JWST collects the same type of spectral data across a similar span of cosmic time, scientists can directly cross-reference the simulation against real observations to pinpoint what the old models are missing, the team said.

The simulation also tracks how the universe's first stars formed, died and forged the essential elements that make life as we know it possible. By comparing the simulation with JWST observations of early galaxies and with the chemical traces left in ancient stars, scientists can better understand how those first stars enriched their surroundings, the researchers said.

"Together, these complementary observations allow us to test competing models of the first stars in ways that weren't previously possible," study co-author Martin Rey, a theoretical astrophysicist at the University of Bath in the U.K., said in a separate statement.

The scientists detailed their findings in one of the six papers the Megatron collaboration published Sept. 30 in The Open Journal of Astrophysics.

Assembling the Milky Way

The team's simulation begins 180 million years after the Big Bang, when the universe is devoid of stars and galaxies and holds only pristine gas. As the next 2 billion years pass,, the model captures how the very first stars light up the dark universe and kick off "cosmic dawn," eventually culminating in those stars' violent deaths. As they die, the stars spread newly forged heavy elements such as carbon, oxygen and iron into the surrounding gas, laying the building blocks for future stars and planets.

The simulation ends 2 billion years after the Big Bang, but the Milky Way's mergers continued long after this point, and scientists are still discovering traces of the small galaxies that have joined it. The most recent massive merger, with the Sagittarius dwarf galaxy, began more than 6 billion years ago and is still unfolding.

The simulation results help scientists understand how certain physics parameters impact the early universe, and better match up JWST's observations with computer models. But it also highlights areas that need further study.

"But there are also things we're not getting right, which is interesting too — what are the parts we're still missing?" Katz said in the statement. "That can lead you into new directions and new questions."

Megatron team members in the U.K. are now developing the next generation of simulations, backed by dedicated time on the country's supercomputers. Those simulations will include more complex physics, such as active black holes, which JWST has revealed to be surprisingly common in the early universe, the researchers said.

How well do you know our home galaxy? Find out with our Milky Way quiz!

A 1,000-mile-long (1,600 kilometers) Martian cloud that emerges and then quickly disappears from the Red Planet's sky nearly every day is even weirder than scientists realized. New simulations suggest that the eerie apparition can only be explained using "exotic physics" that have been theorized but never seen on Earth or anywhere else in the solar system.

The mysterious floating mass, dubbed the Arsia Mons Elongated Cloud (AMEC), frequently emerges above Arsia Mons, a 12-mile-tall (20 km) extinct volcano located in the Tharsis region, just south of the Red Planet's equator. The water vapor cloud was first spotted in 2018 by the European Space Agency's Mars Express orbiter and has since appeared nearly every morning throughout Mars' spring and summer, when increased solar radiation triggers strong surface winds. But it lasts only a few hours each day, before fully evaporating.

The AMEC can stretch up to 1,100 miles (1,800 km) long, around one-twelfth of Mars' circumference. For context, that is roughly twice the length of the U.K. or the distance between New York City and Miami.

Although the Red Planet is no stranger to giant dust clouds and occasional "iridescent streaks" of carbon dioxide, it is almost completely devoid of atmospheric water vapor. That makes it extremely rare for puffy, Earth-like clouds to form there, let alone ones so vast. As a result, scientists have struggled to explain this whacky weather.

But in a new study published Wednesday (Oct. 7) in the journal Nature Geoscience, researchers used Mars Express data to create new simulations in an effort to finally explain the AMEC. Initially, the team struggled to recreate the puzzling phenomenon. But when they abandoned traditional meteorological principles in favor of a more out-of-the-box explanation, they were eventually successful.

"To create the AMEC in our modelling, we found that we needed to include some exotic physics … physics that, while included in textbooks, is treated as theoretical and usually thought not to happen in nature," study first author Jorge Hernández-Bernal, a planetary scientist at the University of the Basque Country in Spain who was affiliated with Sorbonne University in Paris at the time of the study, said in a statement. "Once we included this physics in our simulations, the AMEC emerged just as we hoped."

"Wholly unexpected"

The AMEC is an orographic cloud, meaning it forms as strong winds push water vapor up and over a raised structure, such as a mountain. Similar clouds also exist on Earth, including the "Levanter" cloud, which occasionally forms above the Rock of Gibraltar in southern Europe. However, the Martian equivalent cannot be explained by the same processes that occur on our planet.

On Earth, clouds form via a process called heterogeneous nucleation, in which moist air cools and condenses into ice crystals that form around tiny atmospheric particles, such as dust, salt, pollen or soot. But while Mars has plenty of atmospheric dust, that's not what's happening there.

"For the AMEC, it seems that cloud formation takes place without needing any of this 'stuff' [in the air]," said Hernández-Bernal, who has been studying the AMEC for the past six years. "Water vapour turns directly into icy cloud particles without any middle step. It's akin to droplets of condensation appearing in the middle of a room, rather than on a window."

The researchers call this "homogeneous nucleation" and say it has never been seen before in a planetary atmosphere. "It's wholly unexpected," Hernández-Bernal added.

Other scientists previously predicted that homogeneous nucleation could occur in Earth's upper atmosphere or in the skies above Venus. However, this has been deemed highly unlikely because it requires humidity levels roughly 100,000 times greater than those on our planet's surface.

Given that modern-day Mars is almost completely devoid of water, it may seem unlikely that its humidity levels could reach such lofty heights. However, the Mars Express data tells a different story.

As wind rises up the slopes of Arsia Mons, which is more than twice as tall as Mount Everest, it creates a powerful wave that shoots air into the upper atmosphere at tremendous speed. The researchers calculated that the temperature of this air can drop by up to 54 degrees Fahrenheit (30 degrees Celsius) in just 10 minutes. This not only makes it easy to freeze but also greatly increases the humidity within the wave, allowing homogeneous nucleation to take place, the simulations show.

So where does all this water come from? Some of it is already in the atmosphere, but some likely originates at the summit of Arsia Mons, which is covered with a thick layer of frost, the researchers suggested.

"A big success"

The new simulations mark a big step forward in our understanding of the AMEC and wider Martian meteorology.

"We don't have nearly as much information about Mars' atmosphere as we do about Earth's, so reproducing the AMEC to this degree is a big success for the model," Hernández-Bernal said.

The findings would not have been possible without the Mars Express orbiter, which used three instruments — the Visual Monitoring Camera, the High Resolution Stereo Camera and the OMEGA instrument — to map out how the AMEC takes shape and evolves every day. It is also one of the only Mars spacecraft that can see Arsia Mons in daylight.

"Mars Express discovered the AMEC, has followed up and monitored it for years, and is now helping reveal the secrets of its formation," Colin Wilson, the project scientist for Mars Express, who was not involved in the new study, said in the statement.

The discovery is also a reminder that, despite sharing the same basic principles, weather systems do not behave the same on other worlds as they do on Earth, which could have big implications for solar system exploration and the hunt for extraterrestrial life on distant exoplanets.

"While clouds on Earth and Mars seem to be governed by the same 'rules', understanding this exotic Martian cloud required exotic physics — and this may be true elsewhere in the cosmos," Wilson said.

Astronomers have spotted a never-before-seen type of "phoenix planet" rising from the ashes of a dying alien sun. The discovery, which the scientists say was "completely unexpected," raises hopes that more of these reborn alien worlds could be lurking throughout the cosmos — and may offer a glimpse of our own solar system's fate.

The unnamed exoplanet was spotted circling the white dwarf HS 0209+0832, which is located roughly 270 light-years from Earth. White dwarfs are stellar remnants, sometimes dubbed "zombie stars," that form from the leftovers of massive red giants that run out of fuel before eventually collapsing into shriveled husks. HS 0209+0832 is a particularly young white dwarf, still burning at around 63,000 degrees Fahrenheit (35,000 degrees Celsius), which suggests it made this transition within the past few million years.

Scientists previously discovered some surprising heavy elements within the visible spectrum of HS 0209+0832, which was first captured by the Hubble Space Telescope in the late 1990s. These elements ‪—‬ which included aluminium, titanium and nickel ‪—‬ are not normally found inside white dwarfs, so their presence suggested that something unusual was going on. But until now, there was not enough data to figure out what.

In the new study, published Oct. 5 in the journal Nature Astronomy, researchers took a closer look at HS 0209+0832. Using some of Hubble's updated instruments and data from other observatories, the team captured a more detailed spectrum of the stellar zombie. This revealed a high concentration of additional heavy elements, including zinc and copper, as well as niobium, which has never been seen in a white dwarf before.

The researchers think these out-of-place elements were created during the death throes of the former red giant and later coalesced into a "second-generation" planet around the newly forged white dwarf. They suspect the atmosphere of this hypothetical planet is being stripped by the white dwarf's stellar winds, causing the rare elements to fall back onto the zombie star.

Follow-up observations then revealed a recurring dip in the brightness of HS 0209+0832, suggesting that an exoplanet was repeatedly passing in front of the undead star. Based on the alien world's orbit, which lasts approximately 4.4 Earth days, and the duration of its transits in front of the star, the team predicted that the planet is roughly the size of Jupiter. (Its close proximity to the white dwarf also supports the hypothesis that its atmosphere is being stripped away.)

"Second-generation planets are worlds that form out of the material a star casts off as it dies," study first author Jamie Williams, a doctoral candidate in astronomy and astrophysics at the University of Warwick in the U.K., said in a statement. "They're incredibly rare, and finding one around a white dwarf was completely unexpected. It's a bit like finding a planet that has risen from the ashes of the very star it once orbited."

"Completely unexpected"

This is not the first time astronomers have spotted an exoplanet around a white dwarf. For example, in 2019, some of the authors of the new study previously spotted an alien world surrounding the white dwarf WDJ0914+1914. However, in that case, they were confident that it was a first-generation world that somehow survived its star's fiery end.

But the heavy elements that seem to be falling onto HS 0209+0832 — and the relative lack of other elements common in first-generation planets, such as silicon and iron — suggest that's not what's happened for this recently detected world.

"This pattern of elements is a telltale sign of the 's-process,' a nuclear reaction that builds heavy elements inside dying stars during their bloated red giant phase," study co-author Nicholas Stone, an astronomer at the University of Wisconsin-Madison, said in the statement. "It's a chemical signature no ordinary, 'first-generation' planet should carry, which told us that this new planet was something different."

Instead, the newly detected exoplanet likely formed directly from the material that was shed by the dying red giant after it expanded and before it collapsed in on itself.

Similar phoenix planets have been spotted alongside other stellar remnants, such as pulsars, which form when stars explode as supernovas. However, until now, such worlds have never been seen around a white dwarf.

Rising from the ashes

"What's remarkable about the planet around HS 0209+0832 is that this isn't a planet from somewhere else, or a survivor from the system's birth, it looks like it was built from the very material its own star cast off as it died," study co-author Boris Gänsicke, an astrophysicist at the University of Warwick who also helped to discover the exoplanet around WDJ0914+1914 in 2019, said in the statement. "In a sense, this system has given birth to a new world using the foundations of the old one."

HS 0209+0832 may have once harbored other exoplanets when it was a red giant. But if they existed, these alien worlds likely perished in flames as the dying star ballooned — similar to what experts think will happen to Earth when the sun runs out of fuel and transitions into a red giant in around 5 billion years.

Once the sun has finished bulging, it will turn into a white dwarf too. The new discovery hints that our star could also host brand-new worlds after it has transformed, creating a sort of solar system 2.0.

"Finding this one example raises the question of how many more might be out there and might our own solar system host a second-generation planet formed from the ashes of our sun," Gänsicke said.

However, more work is required to figure out exactly how the newfound exoplanet formed and, as a result, how likely this scenario is. The researchers suspect that another object, such as a lost stellar sibling, may have been required to create the new world.

"Forming the protoplanetary disc in this situation is not easy and helps explain why these planets are so rare," Williams said. "To form a disc of material necessary to birth a planet, HS 0209+0832 likely required a companion star that pulled the ejected material back into orbit, rather than letting it escape."

The Draconids, one of the year's most unpredictable meteor showers, will peak this week. Although only a few "shooting stars" are expected, the shower has a history of producing spectacular meteor storms with little warning.

The Draconid meteor shower takes place Oct. 6-10 each year, peaking on Oct. 8-9, when around 10 "shooting stars" per hour are expected. Whereas most meteor showers are best seen after midnight or during the dark hours before dawn, the best time to view the Draconids is in the evening, according to Timeanddate.com, making it one of the more convenient meteor showers of the year. Just after dark Thursday (Oct. 8) will be the best time to look.

The Draconids are different from most other showers because their radiant — the point from which their meteors appear to originate — is in the constellation Draco, the Dragon, which is highest in the sky in the evening. It's also circumpolar in much of the Northern Hemisphere, so it never sets below the horizon. However, there's no need to stare directly at Draco, because meteors can appear anywhere in the sky.

This year, the Draconid meteor shower peaks at the perfect time of the month for dark skies. Because the new moon occurs Saturday (Oct. 10), there will be no significant moonlight when the Draconids reach maximum activity.

However, the Draconids are notoriously unpredictable; while just a handful of meteors per hour are expected, the shower can sometimes produce huge meteor storms. For example, during the Draconids' peak in 1933, Europe saw 500 meteors per minute, according to NASA, and during the 1946 peak, 50 to 100 meteors were seen per minute in the U.S.

The source of the Draconids is Comet 21P/Giacobini-Zinner, which was discovered in 1900 and orbits the sun every 6.6 years. It was last in the inner solar system in 2025 and will return in 2031.

Each October, Earth passes through streams of dust and debris left along the comet's orbit. When those tiny particles strike Earth's atmosphere, they heat up and vaporize, creating streaks of light in the night sky.

Most observers will probably see only a few Draconids this year, but with a meteor shower this unpredictable, it's always worth looking up. The best way to see the Draconids is with the naked eye, but a good pair of stargazing binoculars or a nice backyard telescope will help you enjoy the feast of fall skywatching events on the horizon. Amazon has great deals on skywatching gear this week, so it's a perfect time to get involved.

Researchers have observed the strongest candidate yet for a "microblazar" — a dazzling object that has long been predicted to exist but never spotted.

Observations of microblazars would give astronomers closer views of black holes emitting powerful jets of energy and help them understand how these extreme objects behave.

Blazars are some of the most energetic objects in the universe. They are a type of quasar — a brightly glowing object fueled by a supermassive black hole stripping material from its host galaxy and then ejecting some of it in powerful, opposing jets of particles and radiation. To qualify as a blazar, one of those near-light-speed jets needs to point directly at Earth. Astronomers have previously discovered smaller versions of quasars, dubbed microquasars, and long theorized that there must be smaller versions of blazars as well.

Now, an international team led by astronomers in Spain, the Netherlands and Argentina has described a microblazar in a study accepted for publication in the journal Astronomy and Astrophysics.

"It is the first time that we have a serious candidate," Josep Martí, an astronomer at the University of Jaén in Spain and first author of the study, told Live Science.

The object, called IRAS 18293-0941, is located in our galaxy, about 12,000 light-years from Earth, and it's hidden behind a veil of dust. It is a binary system that includes a black hole that orbits a hot, gigantic star every 11 days. Matter from the star falls into the black hole, and some of this material is jettisoned into the surrounding environment in two opposing jets. One of those jets flares toward Earth.

These objects, as well as microquasars in general, are tricky to observe, Martí said. "Because of stellar evolution, you need to catch the system at the right time," he added. "The microquasar phase of evolution is very short, and so it is difficult to find one in that phase."

Theorists predicted that microblazars would have special characteristics that should help define them. These features include powerful emissions across the electromagnetic spectrum, rapid changes in brightness (variability), and a hotspot behind them where its opposing jet heats up the interstellar medium in the opposite direction of Earth.

To observe IRAS 18293-0941, the study authors used a variety of instruments ‪—‬ including the Calar Alto Astronomical Observatory in Spain, a network of radio astronomy telescopes called the European VLBI Network, and the MeerKAT radio telescope array in South Africa ‪—‬ as well as archival data from the Very Large Array in New Mexico.

They found that IRAS 18293-0941 has all of the expected microblazar characteristics, except one ‪—‬ variability. Microblazars have rapid variability, which means their brightness changes a lot in a short period, because one of the jets is facing Earth and small changes in brightness are amplified by an effect called Doppler boosting.

Martí said IRAS 18293−0941's lack of rapid variability could be explained by the dense cloud of gas surrounding it, which could smooth out quick fluctuations in brightness.

The researchers are currently investigating whether the observed area behind the microblazar is in fact a hotspot, study co-author Pedro Luque-Escamilla, an astronomer at the University of Jaén, told Live Science.

Even with one of the expected features missing, this object is a promising candidate for the first known microblazar. "The claims and the results of the paper are sensible and there are no questionable hidden assumptions," Kinwah Wu, a theoretical astrophysicist at University College London who was not involved in the research, told Live Science in an email. "The source in this paper had shown signatures of interactions between the jets and the ambient material, which naturally leads to [particle] interaction."

Svetlana Jorstad, a senior research scientist at the Institute for Astrophysical Research at Boston University who was not involved in the research, told Live Science in an email that the new study was "very interesting, important and comprehensive."

Itumeleng Monageng, an astronomer at the University of Cape Town who was also not involved in the research, added that the team's observations "presents a previously overlooked mechanism for generating some of the highest energy emissions observed."

Microblazars "may power some of the universe's most energetic processes," Monageng told Live Science in an email.

Martí, J., Luque-Escamilla, P. L., Marcote, B., Abaroa, L., Aguasca-Cabot, A., Combi, J. A., Romero, G. E., Paredes, J. M., García, F., Fogantini, F., Saavedra, E. A., Del Ser, D., & Van Den Eijnden, J. (2026). A Galactic microblazar as a potential accelerator of ultra-high-energy particles. Astronomy and Astrophysics. https://doi.org/10.1051/0004-6361/202661105

See how much you know about black holes with our black hole quiz!

You may have watched the moon block out the sun during a solar eclipse, but have you ever seen it do that to a planet? Early Tuesday (Oct. 6) morning, skywatchers across much of eastern North America will have an opportunity to watch a crescent moon pass directly in front of Jupiter. The rare alignment won't happen again for 11 years.

During the event, known as a lunar occultation, Jupiter will disappear behind the moon for up to about an hour before suddenly reappearing. The occultation will be visible before dawn from much of the eastern and central U.S., Canada and the Caribbean, while parts of Africa will experience the event during daylight, according to In-The-Sky.org.

The moon will be a beautiful waning crescent, just 20% illuminated, and Jupiter will shine brightly alongside it. The pair will rise together in the east early Tuesday morning and gradually appear to move closer as the moon travels eastward against the background stars.

When the occultation begins, Jupiter will remain hidden behind the moon for roughly an hour. No telescope will be needed to watch Jupiter disappear and reappear. However, a pair of binoculars or a small telescope will make the event much more dramatic.

Through a telescope, Jupiter will look like a tiny disc rather than a point of light and will take about a minute to disappear completely behind the moon. An easy way to photograph the event is to use a smart telescope to image the moon. (Here's everything you need to know about lunar photography).

Below are the times when Jupiter will disappear and reappear in 10 major cities Tuesday morning, according to the International Occultation Timing Association.

• Chicago: 3:22-4:17 a.m. CDT
• Atlanta: 4:15-5:17 a.m. EDT
• Detroit: 4:16-5:20 a.m. EDT
• Miami: 4:20-5:09 a.m. EDT
• Washington, D.C.: 4:20-5:24 a.m. EDT
• Philadelphia: 4:22-5:26 a.m. EDT
• New York: 4:23-5:27 a.m. EDT
• Toronto: 4:25-5:22 a.m. EDT
• Boston: 4:26-5:30 a.m. EDT
• Montreal: 4:30-5:26 a.m. EDT

Outside the occultation path, Jupiter won't disappear at all. Instead, it will appear to be skimmed by the crescent moon — still a potentially spectacular sight that could produce some amazing photos. From across much of the world, the crescent moon and Jupiter will appear exceptionally close together.

The next lunar occultation of Jupiter visible from North America will occur on Nov. 27, 2037, according to When The Curves Line Up.

The debut images from a new Earth-observing satellite have just given us a view of the impossible: giant auroras rippling over the North Pole in broad daylight.

Earth's auroras are one of our planet's signature wonders — a sight worth advertising in interstellar travel guides, alongside our perfect total solar eclipses, bright shooting stars and majestic blobfish. They are the beautiful result of electrical storms in the atmosphere, appearing when charged solar particles skate along Earth's magnetic-field lines and collide with light-emitting molecules near the poles. (Auroras do exist on other planets, but they are usually not in bright visible colors like ours.)

To human eyes, auroras come out only at night and rarely stray from the poles. That's what makes these first observations from the joint European-Chinese Smile mission, which officially began science operations this week, so special.

Captured in ultraviolet light, the stunning images show a huge, serpent-like ring of charged particles coiling around the North Pole in July 2026. In the foreground, Earth appears ghostly and featureless, glowing like a half moon. The aurora writhes around our planet's sunlit side, covering about a third of it, while Earth's dark nightside bleeds into the background sky. Far behind, bright stars fall like raindrops as Smile shifts subtly in its orbit.

The view alone is worth smiling about, but the new images also promise exciting science to come. Taken just two weeks after scientists first turned Smile's Ultraviolet Aurora Imager on, the observations show that the satellite's instruments are working as they should and that the joint European Space Agency (ESA) and Chinese Academy of Sciences mission can officially begin.

Launched on May 19, Smile will spend the next three years watching Earth from a highly elliptical orbit that takes it about 75,000 miles (121,000 kilometers) over the North Pole — about a third of the way to the moon. From there, Smile can observe the North Pole for a record-breaking 45 hours at a time, offering an unprecedented view of solar activity there.

In addition to the Ultraviolet Aurora Imager, Smile carries three more science instruments to detect X-rays, magnetic fields and light ions over Earth.

This week, scientists also tested the spacecraft's soft X-ray imager by pointing it at the distant supernova remnant Cassiopeia A, located about 11,000 light-years from Earth (image above). Although the camera is working fine, the detector is still picking up a bit too much light when aimed at Earth, so it will require a bit more calibration from scientists on the ground.

Among the many risks astronauts face during long-haul spaceflight, an extended stay in microgravity is one of the most consequential for long-term health, with effects on vision, bones, muscles and many other aspects of the body.

One solution might be artificial gravity —‬ some way to create forces similar to Earth's gravity on a spaceship, akin to the giant rotating ring from Stanley Kubrick's 1968 film "2001: A Space Odyssey."

But is that technology ever coming, or will it remain science fiction?

"There's really no reason it couldn't happen," Torin Clark, an associate professor of aerospace engineering at the University of Colorado Boulder, told Live Science. "From a technical perspective, this is something that could happen in the very near future."

In fact, artificial gravity has almost made its way to space before. The Centrifuge Accommodation Module was a planned 8.2-foot-wide (2.5 meters) centrifuge for the International Space Station (ISS), but the project was canceled in 2005 for budgetary reasons.

"[Artificial gravity] is one of those things ‪—‬ like all of a sudden, it's super popular, and then all of the scientists at NASA and everybody … have a lot of funding to understand how to actually implement this, and then it just dies," Ana Diaz Artiles, an associate professor of aerospace engineering at Texas A&M University, told Live Science. "And then it comes back, and dies, and comes back. I've been going through a couple of these cycles in the time that I've been doing this."

Besides budgetary concerns, there are questions about how such a solution would be implemented.

"Everybody agrees it's a good thing to do. The problem is that we don't know how to implement it," Diaz Artiles said. "How much gravity do you need? How big does [the device] have to be? How long do you need it to be? And how long do you have to use this? Should we use continuous gravity or a short-radius centrifuge, something where you go in and out?"

Researchers have three main approaches for creating artificial gravity. One is the classic sci-fi idea: a giant ring that rotates passengers' entire living quarters so they live and work under forces similar to Earth's gravity.

"You have a relatively long radius, which means you don't have to spin very fast to create gravity," Diaz Artiles said. "But this is massive. You can't get all the parts up there in the same spacecraft — you need multiple spacecraft and to assemble everything. So, of course, you can see what a big endeavor this is."

A short-radius centrifuge is a more feasible option. It's essentially a tube with a radius of 6 to 10 feet (1.8 to 3 m) that spins to simulate gravity. A passenger sits or stands inside, with their head closest to the center of rotation, so the spin generates the strongest pull down toward their feet.

Instead of allowing passengers to live in artificial gravity, this smaller device would be used in short daily sessions. "It's kind of like an exercise device," Diaz Artiles said. "In the ISS, you have a treadmill, you have this resistive exercise machine, so you go there for 30 minutes to do your exercise, and then you get out."

The final option is for spacecraft to create gravity via linear acceleration. This works in the same way that an accelerating car pushes passengers back into their seats, except the spacecraft would be oriented to push an astronaut's feet into the floor. To slow down, the spacecraft would turn around, firing its thrusters in the opposite direction to decelerate smoothly while maintaining a roughly similar gravity for its occupants.

"But then you need something like an engine that is able to accelerate all the time," Diaz Artiles said. "And propulsion-wise, I think we're not there yet."

Although a short-radius centrifuge is the most feasible approach in terms of both cost and engineering, it does have some drawbacks. For one, its fast spin can induce the Coriolis cross-coupled illusion ‪—‬ a sensation of tilting or tumbling that happens when you tilt your head off-axis while rotating.

This is the effect that causes motion sickness, Clark said.

However, Clark and his team have found that people can build a tolerance to the sensation with training, simply by being in a slowly spinning centrifuge and gradually increasing the speed when they no longer feel the sensation.

"If you very slowly, incrementally increase the spin rate … and do that not just over one session but over multiple sessions across multiple days, as far as we could tell, anyone can be made to incrementally acclimate to the rotating environment [of] up to 20 to 30 rotations per minute," Clark said.

Would artificial gravity prevent harmful effects on the body?

But researchers still don't know how fast the centrifuge would need to rotate, or how long someone needs to spend inside it, to benefit. Long periods in microgravity can lead to bone and muscle loss, loss of aerobic fitness, blood clots, and visual issues from fluid shifts in the eyes. The hope is that artificial gravity could prevent those effects, but exactly how much gravity is necessary remains an open question.

Studies of people on head-down tilt bed rest ‪—‬ the standard research method for simulating spaceflight deconditioning ‪—‬ have found that 30 minutes a day in a centrifuge did prevent some loss of muscle function.

"Thirty minutes a day … maybe is not enough," Clark said. "Maybe an hour or even two hours a day, and maybe at higher G levels, would be beneficial."

But these studies are expensive and time-consuming. "It's very difficult," Diaz Artiles said. "I think people are interested in this concept, but we just don't have a good answer."

In the end, it's not a technological challenge that's keeping artificial gravity from being used in space; it's knowing the best way to employ it and securing the budget for it.

"We know how to do this. As humans, we have done more difficult things," Diaz Artiles said. "We need the money, but we also need to better understand the need."

See how much you know about human exploration into space with our spaceflight quiz!

Scientists have a new tool for mapping the universe's perplexing acceleration.

A Canadian telescope designed to chart the distribution of hydrogen gas across the ancient universe has proved it can do so using only its own data for the first time, without the help of other telescopes. The results took seven years to prove, but the payoff could be huge.

According to the authors of a new study published Monday (Sept. 28) in The Astrophysical Journal, the telescope could give scientists a new, cost-effective way to study dark energy, the poorly understood force that is causing the universe to expand at an accelerating rate over time.

"Hydrogen is the most common element in the universe and the raw material from which stars form," study co-author Arnab Chakraborty, a postdoctoral fellow at the University of Toronto, said in a statement. "Its faint radio emission acts like a cosmic tracer, revealing how matter is distributed across space."

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a set of radio telescopes, principally located near Penticton, British Columbia, that map the entire northern sky every day. Before the results from the new study, CHIME had to confirm its own observations with other telescopes — an expensive and time-consuming process.

It was important for CHIME to look at the universe's ancient hydrogen gas with its own data, to serve as an independent point of measurement that did not rely on other telescopes, the team explained. The new paper, which was nearly a decade in the making, is based on 94 nights of observations in 2019 that were carefully double-checked before publication. The telescope can detect radio signals as far back as 3 billion years after the Big Bang, when the universe was a fraction of its current age.

"We worked very hard to convince ourselves that this wasn't a false alarm," Chakraborty said. "After all the tests, the signal remained. That gave us confidence we were seeing real hydrogen from the distant universe."

An accompanying paper published in The Astrophysical Journal includes more information about where hydrogen is found in the cosmos. This study suggests that about 2% of hydrogen is "neutrally atomic" — meaning the atoms contain a balance of just one proton and one electron, resulting in no overall electric charge — which is "broadly consistent" with measurements by other telescopes, Shabbir Shaikh, a postdoctoral fellow in the School of Earth and Space Exploration at Arizona State University and a co-author of both papers, said in the statement.

Mapping the distribution of this common gas could reveal new clues about the expansion of the universe at different times in cosmic history. In future research, the team plans to go through CHIME's other seven years of observations to gather more information about its hydrogen gas studies.

Researchers have discovered an exoplanet that travels around its small, red star backward, much like a rubber duck spinning against the current in a whirlpool. The discovery could give insight about how exoplanets form around the most common types of stars in our galaxy.

It's a mystery why the alien world, called GJ 3090 b, orbits its star backward (also called a retrograde orbit). Stars and planets usually form from the same rotating disk of gas and dust, called a protoplanetary disk. Newly formed celestial objects normally rotate in the same direction as the protoplanetary disk, because changing the rotational direction requires a lot of energy applied in the right way.

Astronomers have discovered a few exoplanets with retrograde orbits before; these orbits often happen when the gravitational attraction of other massive objects in their star systems scrambles the planets' orbits. However, this newly discovered planetary system doesn't seem to have any massive objects that could have changed the retrograde planet's orbit, researchers reported in a study published Sept. 21 in the journal Astronomy and Astrophysics.

"We looked for the kind of massive companion that could have forced the planet into such an extreme orbit," study co-author Yann Carteret, an astronomer at the University of Geneva, said in a statement. "We may need to think differently about how this system acquired its unusual architecture."

A planetary mystery

For their new study, the researchers analyzed 23 hours of observations from two exoplanet-hunting instruments installed on a 12-foot-wide (3.6 meters) telescope at La Silla Observatory in Chile. They saw the retrograde planet cross in front of its star 10 times. Each time it passed in front of the star, the starlight reaching Earth dimmed a little. Measuring the extent and duration of that dimming revealed the planet's size and information about its orbit.

What made this detection particularly difficult was the type of star: an M dwarf. These stars are small, relatively cool and so dim that even the closest M dwarf stars to Earth can't be seen with the naked eye. About three-quarters of the stars in the Milky Way are M dwarfs, so studying them is particularly important for understanding our galaxy's exoplanets.

The star system in question is made of two, or possibly three, planets smaller than Neptune, each of which takes less than 16 days to orbit the star. GJ 3090 b is the innermost planet, completing an orbit about once every 2.9 days. Its orbit is one of the most misaligned ones scientists have detected so far, at a whopping 136 degrees out of alignment with the star's spin, making the planet nearly upside down ‪—‬ similar to Venus in our solar system.

Because GJ 3090 b is the planet closest to the star, it's unlikely that its orbit was disturbed by a massive planet or a hidden binary star; the other planets in the system are not upside down. And because they're farther from the star, a large gravitational disruption would probably affect them more, not less.

Instead, the researchers suggested that the unusual planet may have simply been born upside down. If a lot of gas and dust from outside the star system got sucked into the system, it might have replaced the protoplanetary disk with a second, newer disk at a different angle to the original, which could have formed the retrograde planet. The amount of material making up the inner planets (formed from the dusty, gaseous disk) is less than the amount that would pull on the star's spin enough to make the star change its rotational direction, keeping the system in a balanced misalignment, the researchers explained.

"The idea that a planetary system could be rebuilt from a second, differently oriented disk is particularly exciting," Vincent Bourrier, an astronomer at the University of Geneva and co-author of the study, said in the statement. "It suggests that the environment around a young star can play a much bigger role in determining the architecture of its planets than we might have expected."

Saturn is about to reach its annual opposition this week, when it appears at its brightest and biggest all year and becomes the only planet visible all night.

The short, exciting period for skywatchers has more to do with where Earth is in its orbit than with Saturn's journey around the sun. Opposition occurs when Earth moves directly between a planet and the sun, placing the two planets on the same side of the solar system. For observers on Earth, that means Saturn appears opposite the sun in the sky, just like a full moon (hence the name "opposition"). Saturn therefore rises in the east around sunset, 100% illuminated, before reaching its highest point around midnight and finally sinking toward the western horizon around sunrise.

This year's opposition occurs Sunday (Oct. 4), making the few weeks on each side an excellent time to start looking. At 784 million miles (1.26 billion kilometers) away, Saturn will be relatively close to Earth, causing its disk to appear about as large as it gets through a telescope and making its pale-yellow light shine more brightly than at other times of the year. You won't need any equipment to find it; under a clear sky, Saturn will be easily visible to the naked eye as a bright, steady point of light, between the constellations Pisces and Cetus.

Once you've located Saturn, the best way to view it is in a backyard telescope so you can see the planet's rings in sharp relief. Try it yourself — observing Saturn's rings for the first time is one of the most memorable sights available to amateur astronomers. Larger apertures and higher magnifications may also reveal some of Saturn's moons, including Titan, the planet's largest satellite, but even a relatively modest backyard telescope can reveal Saturn's rings.

The rings themselves are particularly interesting this year. Saturn's axial tilt means our viewing angle of the planet's rings changes throughout its roughly 29-year journey around the sun. After the rings appeared almost edge-on from Earth in 2025, they're gradually opening up again, giving observers an increasingly clear view.

You don't need to restrict your observing to the night of opposition; Saturn will remain a prominent evening target throughout October. However, the nights of Sept. 30 to Oct. 4 offer an ideal combination of brightness, visibility and all-night observing. There are also plenty of other great stargazing sights to look for this fall.

If you've been waiting for an excuse to point a telescope at Saturn, this is your moment. The next time Saturn will be at opposition will be Oct. 18, 2027.

Starship has made it to orbit for the first time ever. But the loss of an engine during its nail-biting ascent meant SpaceX's mission ended earlier than planned — with an explosion to boot.

The tallest and most powerful rocket ever built blasted off from SpaceX's Starbase in Boca Chica, Texas on Monday (Sept. 28) at 8.49 a.m. ET (7.49 a.m. local time).

Soon after launch, one of Starship's six main upper-stage Raptor engines failed after separating from the lower-stage booster rocket. A tense few minutes followed while the mission team deliberated over whether the mission should continue to orbit. Eventually, the call came through: "Go for orbit."

A short fire of Starship's boosters nudged the rocket into orbit, where it zoomed around Earth at a highest point of 170 miles (275 kilometers) above the planet's surface.

However, after successfully deploying 26 Starlink V3 satellites, SpaceX decided not to leave Starship up in space for the remainder of the mission, which was originally expected to last 10 hours.

The rocket splashed down in the Pacific Ocean after 3 hours and 8 minutes, and then promptly exploded with a fiery bang. An explosive landing was always expected for Starship, and there were audible cheers during that part of the SpaceX livestream of the mission, but SpaceX would have probably preferred to have kept its rocket intact — like it did on Flight 13.

SpaceX called this mission, Starship's Flight 14, the company's "most ambitious launch to date" during its livestream. Prior to this launch, Starship had only flown suborbitally, and this was SpaceX's first attempt to send its flagship rocket into orbit. The company said reaching orbit represents the "next phase" for Starship toward becoming a fully reusable rocket.

Starship flight 14

The day started with promise for SpaceX: Engineers weren't tracking any holds in the lead-up to launch; tanking and launch progressed smoothly; and Starship served up some spectacular images of Earth as it raced into space.

Shortly after launch, Starship's booster separated and safely splashed down in the Gulf of Mexico. Then the problems started. Starship had lost one of the 6 main engines on its upper-stage. Initially, commentary on SpaceX's livestream suggested that officials planned to abandon the push for orbit, but after several tense minutes, they confirmed the attempt was a go.

The latest mission had a few objectives. In addition to making it to orbit, SpaceX deployed Starlink V3 satellites, designed to boost the speeds and reliability of the internet services provided by its satellite megaconstellation.

The mission also tested the Starship's booster, which had experienced some hardware and software modifications after Flight 13.

SpaceX has experienced multiple setbacks with Starship. The seventh and eighth Starship test flights exploded and rained fiery debris from the sky. The ninth flight fell short of its target, and a Starship exploded on the launchpad during a routine test leading up to the 10th mission. However, Starship did end up having a successful 10th flight in August 2025, despite taking some damage, and its 11th run, in October, was clean.

The last two flights, in March and July 2026, saw successful launches and controlled landings but experienced booster problems.

To the moon?

The stakes are high for the rocket: Starship's success could be essential for NASA's plans to return humans to the moon in early 2028. The U.S. space agency needs a commercial lunar lander to ferry astronauts to the lunar surface during the upcoming Artemis IV mission. (Artemis III, a practice attempt above Earth, is slated for 2027.)

NASA wants to take astronauts to the moon in its Orion spacecraft, as tested in the Artemis II mission. Once in lunar orbit, the crew is then supposed to rendezvous with a commercial lander, which will take the astronauts to the surface and launch them back up to Orion for the trip home.

SpaceX has been developing a moon-landing variant of its Starship for that job. With rival Blue Origin (whose New Glenn rocket dramatically exploded in May) lagging behind, the Artemis program's success could be tied to Starship's.

During Artemis III next summer, NASA will test docking Orion with one or both of its commercial lander options in low Earth orbit. The space agency has made clear that lander readiness will determine which commercial provider gets to take astronauts to the lunar surface as soon as 2028.

There are some doubts about whether NASA will be ready by then. But today's Starship issues also leave key questions about whether SpaceX can meet the tight deadline.

Editor's note: This article was corrected on Sept. 30 at 1:15 p.m. ET. The article initially stated that one of Starship's 33 lower-stage booster engines had failed. In fact, it was one of the spacecraft's six main upper-stage engines that failed to fire. We apologize for this error.

An American spy satellite deployed during the Cold War has exploded above our planet without warning — and, so far, scientists can't explain why. The debris cloud from this sudden fragmentation, which experts are still trying to measure, could pose a very "real threat" to other spacecraft in a highly crowded region of low Earth orbit (LEO), experts warn.

The spacecraft, known as USA 32 or Farrah III, was launched by the National Reconnaissance Office (NRO) in 1988. Its mission, which was only fully declassified earlier this year, was to intercept Soviet radar and radio signals from space, according to Futura. The cylindrical spacecraft, whose shape has been described as a giant "tuna can," likely stopped functioning decades ago and has been silently circling Earth ever since. (It was nicknamed after actor Farrah Fawcett, in line with the NRO's former custom of naming its satellites after famous figures from the 1970s and '80s.)

On Sept. 17, Space-Track — the satellite observation arm of the U.S. Space Force — announced that USA 32 suffered a sudden "fragmentation" event four days earlier, on Sept. 13. This essentially means the spacecraft exploded, potentially breaking apart into dozens, hundreds or even thousands of pieces. However, the agency did not specify what had caused this explosion or how many pieces of debris were created. And, as of Sept. 28, no one else has been able to answer either question.

Other organizations have since confirmed the fragmentation event, including the private satellite-tracking company s2a systems, which photographed the largest remaining piece of USA 32 in orbit.

The explosion occurred 480 miles (775 kilometers) above Earth's surface, according to Spaceweather.com. Considering the satellite's speed, the resulting debris likely spread into a giant ring around Earth within 24 hours after the spacecraft's sudden breakup, a simulation from the website suggests.

What happened to USA 32?

It is still unclear what happened to the Cold War-era spacecraft, but there are several potential explanations.

Collisions with other satellites or smaller pieces of space junk are one of the most common causes of satellite breakups. But no one has reported any other spacecraft being impacted, and researchers can often predict potential space junk collisions days or weeks in advance, making these scenarios unlikely. However, it is possible that an undetected space rock struck the satellite at high speeds instead.

Another leading theory is that the satellite died of old age. It was likely not designed for long-term spaceflight, and after nearly four decades of being exposed to the harsh conditions of LEO, the spy craft may have simply broken down, similar to the demise of the NOAA-17 satellite in 2021.

"Old spacecraft carry batteries and leftover propellant," Spaceweather.com representatives wrote. "After 38 years of heating and cooling, a pressurized tank or a battery cell on USA 32 may have simply ruptured."

But it is also too soon to rule out that the satellite was hit by some form of anti-satellite weaponry, according to Spaceweather.com. Earlier this month, U.S. Air Force Secretary Troy E. Meink revealed, for the first time, that the U.S. had launched unspecified weapons into orbit, and experts have long suspected that other countries, including China and Russia, possess similar technologies. (The latter country has already destroyed one satellite using Earth-based weaponry.)

However, there is currently no evidence that anti-satellite weapons were used in this instance, so "there may be nothing sinister about this event," Spaceweather.com representatives wrote.

Researchers will likely be able to establish the cause of the satellite's breakup by reverse-engineering the incident ‪—‬ first by identifying the resulting fragments, and then by retracing those pieces' trajectories back to the original explosion. However, this could take months, if not years. (For example, scientists are still trying to piece together what happened to the Boeing-made Intelsat 33e satellite, which similarly shattered out of nowhere in 2024.)

"The collision threat is real"

Regardless of the recent explosion's cause, experts are now concerned about the potential knock-on effects of its fallout.

The region of LEO where USA 32 exploded is thought to be home to at least 200 other satellites, and it is already littered with debris from a 2009 collision between American and Russian satellites. As a result, "the collision threat is real" for spacecraft in this area, Spaceweather.com representatives wrote, especially as the newly created fragments remain unquantified.

So far, the incident has not caused any issues or affected the launch of new spacecraft. For example, Russia went ahead with the Sept. 16 launch of a resupply mission to the International Space Station (ISS), which orbits about 250 miles (400 km) above our planet, or roughly half the exploded satellite's altitude. (SpaceX also launched classified missions for the U.S. Space Force on Sept. 16 and Sept. 26, and it launched the first orbital test flight of its supersize Starship rocket on Sept. 28.)

Although the ISS and China's Tiangong space station are currently out of reach of the debris field, the fragments may shift over time as Earth's gravity and atmospheric drag pull them closer to our planet. In that case, the stations may have to carry out maneuvers to dodge the debris, as they have done dozens of times before.

Could it happen again?

As LEO becomes increasingly crowded with newly launched spacecraft, the risk that they will smash into one another or get struck by space junk has also shot up, which strongly suggests that this will not be the last fragmentation event.

Additionally, the longer these new spacecraft remain in orbit, the higher the chances they'll break apart suddenly due to accumulated wear and tear, as USA 32 may have. Previous research has also shown that if satellites were knocked offline, either due to a software malfunction or a powerful solar storm, they could start crashing into one another within days. And there's also the threat that they could be destroyed by anti-satellite weaponry —‬ a scenario that "worries" Live Science readers.

Some experts warn that, if we continue on our current path, we may be doomed to reach an irreversible tipping point, known as the Kessler syndrome, where the accumulation of space junk means we can no longer launch anything into space.

Moving toward Lagrange point L2 around a million miles (1.6 million kilometers) from Earth, NASA's Nancy Grace Roman Space Telescope is about to begin its study of our universe.

Launched on Aug. 30, the space telescope has already released its first images before its 300-megapixel camera is fully calibrated, capturing clusters of stars as blurry green rings. Once Roman's Wide Field Instrument is fully functional, the telescope should produce images as crisp as those from the Hubble Space Telescope but encompassing an area 100 times larger in each snap, NASA has stated. Experts hope to use these images to uncover more information about dark energy and possible habitable exoplanets.

With Roman's first test images now published, we asked our readers what they're most excited about with this new space telescope.

Over 270 readers responded, with the largest voting group, 57%, picking "Habitable exoplanets" as their response.

When talking about the possibility of life on other planets, one reader commented, "I'm sure the telescope will find plenty of new worlds outside our solar system, and a fair amount in habitable zones as well, but on if these planets have life of any sort I can't imagine any space telescope will [be] able to detect any signs."

Following behind this majority, 27% of readers chose "The possible source of dark energy." One reader reflected their interest in dark energy by writing, "Since dark matter and dark energy seem to make up most of our Universe, it seems imperative that we at least know SOMETHING about them. Except that they exist."

Another commenter echoed this statement, writing, "Dark energy and dark matter, according to our current knowledge, composes the majority of the mass of the Universe yet we are not really sure what they are and exactly what their influence is on our Universe. That is a huge gap in our knowledge base. It is not something that would be good to know, it is something we must know before we go where no man has gone before."

The smallest voting group, representing 9% of respondents, admitted, "I don't know, but I will use its pictures for my desktop wallpaper." If you fall into that group, we recommend checking out our Space Photo of the Week and Earth from Space series to get more image options for all your devices.

An enormous, ongoing cosmic "fart" is causing a mysterious zombie star to flare up repeatedly, shining bright pulses of X-rays toward Earth, a new study reveals. The unprecedented observations shed light on how some of the universe's most extreme objects interact with one another.

Around 13,000 light-years from Earth lies an unusual binary star system, known as BP Crucis. It contains a blue hypergiant star roughly 60 times larger than the sun, dubbed Wray 977, alongside a neutron star — the undead and ultradense remains of a star that exploded via a supernova — that astronomers have labeled GX 301-2.

This stellar "zombie," which contains the same mass as our home star packed into an object roughly 12 miles (20 kilometers) across, is a type of neutron star called a pulsar, which has an extremely powerful magnetic field and spins rapidly. This means it constantly shoots out a wobbling beam of powerful electromagnetic radiation, including X-rays, into the cosmos at regular intervals. When this beam aligns with Earth — approximately every 11 minutes, in the case of GX 301-2 — our planet's telescopes detect a flash.

However, unlike most other known pulsars, GX 301-2 also emits frequent X-ray flares (separate from the regular beams), which cause it to shine much brighter at repeated intervals. And, until now, researchers were unsure why.

In the new study, published Sept. 18 in the journal Science Advances, researchers used the X-ray Imaging and Spectroscopy Mission (XRISM) — a space telescope jointly operated by NASA and the Japan Aerospace Exploration Agency — to take a closer look at BP Crucis. In doing so, they discovered that the neutron star flared up every time it passed through a giant plume of "stellar wind plasma" shooting out of its hypergiant partner.

This is the first time that researchers have ever detected this type of stellar material interacting with a neutron star, or with any other similar stellar remnant, opening the door to studying similar systems in the future.

"We've never before seen clear indications of wind plasma falling onto a compact object," study first author Roi Rahin, a researcher at the University of Maryland, Baltimore County (UMBC) and NASA's Goddard Space Flight Center, said in a statement. "We can now test our understanding of these processes in much greater detail."

Whoever smelt it … explodes?

All stars that actively burn via nuclear fusion release streams of radiation and charged particles known as stellar wind. The sun emits such a stream, known as the solar wind, which can trigger vibrant aurora displays near Earth's poles.

However, massive stars like Wray 977 blow stellar winds that are much more extreme. The blue hypergiant emits a single giant plume of concentrated ionized gas, or plasma, that spills out at around 335,000 mph (540,000 km/h). (Scientists think the stellar wind is likely sculpted into a single, concentrated plume due to the gravitational effects of the star's ultradense neighbor.)

GX 301-2 circles Wray 977 every 41.5 days and experiences its X-ray flares when it reaches its closest and farthest points from its partner, with the strongest flares occurring at its closest point. As a result, researchers had long suspected that the flares occurred when the neutron star passed through the stellar wind plume. However, they had no way of proving this without more evidence.

During a 16-hour observation period coinciding with one of the neutron star's flares, researchers used XRISM to capture highly detailed X-ray spectra, revealing "rapidly changing emission and absorption lines" that showed how the plume ebbed and flowed around GX 301-2, NASA representatives wrote.

"We could see how the dense stream of plasma acts very close to the neutron star," study co-author Nazma Islam, an astronomer at the Manipal Centre for Natural Sciences in India and formerly a researcher at UMBC and NASA Goddard, said in the statement. "It was clear that these observations were groundbreaking, but at the same time this meant the analysis had to be especially detailed."

Using this data, the researchers could simulate exactly how the plasma fell onto and swirled around the passing neutron star. When enough stellar material has accumulated on its surface, the stellar zombie explodes, unleashing the bright flashes we can detect on Earth.

The team now hopes to use XRISM to study future flaring events to better understand the relationship between GX 301-2 and Wray 977's windy plume.

"The BP Crucis system is an ideal laboratory for studying wind-fed pulsar accretion," Brian Williams, XRISM project scientist at NASA Goddard, said in the statement, and XRISM is "an ideal instrument for advancing our understanding of the processes involved."

Behold: one of the largest panoramas from the James Webb Space Telescope (JWST) released to date. This busy and breathtaking image offers a remarkably detailed view of IC 348, a nearby stellar nursery where astronomers are investigating some of the smallest objects produced by star formation.

IC 348 is one of the closest stellar nurseries to Earth and appears in this near-infrared image as an intricate landscape of stars, glowing material and sweeping clouds of gas and dust.

Across the scene, young stars punctuate the dark and luminous clouds. The concentration is greatest around the center, where bright stars show JWST's distinctive diffraction spikes — a result of the telescope's optical structure. In the upper-right of the image, still-forming protostars launch streams of material.

And lurking all around this colorful nursery are strange objects that challenge the very definition of a star.

Stars come in all shapes and sizes, from massive stars that explode as supernovas after only a few million years to the smallest and most common stars, red dwarfs, which last for many billions of years. However, there is also a class of substellar objects called brown dwarfs — objects halfway between giant gas planets, like Jupiter, and stars.

In the hunt for tiny brown dwarfs in IC 348, researchers used Webb’s NIRCam instrument in 2024 to survey part of IC 348 and found 39 brown dwarf candidates. The following year, Webb’s NIRSpec instrument studied the light of 15 of them. Nine were identified as new substellar members of the cluster, with the faintest estimated to have masses of around two Jupiters — the least massive brown dwarfs ever found.

How small the smallest brown dwarf can be is an open question in astrophysics. They form as molecular clouds of dust and gas collapse under their own gravity, much like regular stars do. However, unlike stars, brown dwarf cores never become hot enough to fuse hydrogen into helium. The brown dwarfs — or "failed stars," as they're sometimes called — in this JWST image will help researchers constrain the limits of how tiny these strange objects can get.

The upper-right portion of the panorama provides a dramatic look at another stage of star formation. Protostars hidden within the dusty environment fire jets into nearby gas and dust, producing luminous, eye-catching jets and streams known as Herbig-Haro objects. These gargantuan jets can stretch trillions of miles into space; just one tiny detail in one of JWST's biggest images yet.

But if that tremendous view still isn't enough for you, IC 348 was also recently snapped by NASA's Chandra Observatory, which captured the stellar nursery and other cosmic objects shining purple in brilliant X-ray light.

When you think of objects close to the sun, Mercury, the solar system's innermost planet, probably comes to mind. But has any other object — natural or artificial — gotten closer to our star? And what's the closest an object has gotten to the sun while still escaping?

Many objects have reached much closer than Mercury, including asteroids, comets and spacecraft, experts told Live Science.

At its closest point to the sun, called perihelion, Mercury comes within 29 million miles (47 million kilometers) of our star, according to NASA.

But several known asteroids come even closer. Scott Sheppard, an astronomer at Carnegie Science, an independent research institute in Washington, D.C., said such asteroids, with orbits that cross Mercury's, are called Mercury-crossers. They have highly eccentric orbits, meaning "they did not form in this location but were likely scattered from the main asteroid belt towards the Sun," he told Live Science in an email. A search through NASA's Small-Body Database for such asteroids shows 2024 YL3 is the current record holder. This 463-foot-long (141 meters), skyscraper-size rock has a perihelion of 6.4 million miles (10.3 million km).

Another group of celestial objects, though, may beat 2024 YL3. These are proposed asteroids that are thought to have circular orbits within Mercury's path. Dubbed Vulcanoids, their name comes from Vulcan, a theoretical planet once hypothesized to exist in this region.

Martin Beech, a professor emeritus of physics at the University of Regina in Canada, told Live Science in an email that numerical models show such asteroids would have stable orbits between 5.58 million and 23.23 million miles (8.98 million to 37.39 million km) from the sun's center. This means some Vulcanoids may whiz even nearer the sun than Mercury-crossers do. There's just one glitch: Like their namesake planet, Vulcanoids haven't been shown to exist, and a 2013 study found no trace of them.

But some spacecraft have come much, much closer. For instance, NASA's Parker Solar Probe, which launched in 2018, studied the sun's outer atmosphere, or corona. For the primary mission's final three orbits, the probe took an eccentric path with a perihelion of merely 4.5 million miles (7.3 million km) from the sun's center. At this distance, illustrated graphically on the mission's official webpage, the spacecraft flew through the corona, where a carbon foam shield protected the probe from the extreme heat.

"Sungrazers" and "sun-diving" comets

Another class of natural objects — dubbed sungrazing comets — reach closer still. A 2018 study described such comets as coming closer than 1.49 million miles (2.39 million km) of the sun's center, although any of these comets' precise solar proximity would depend on their orbital parameters.

Man-To Hui, a researcher at the Shanghai Astronomical Observatory, told Live Science that small sungrazers — some of which are just 30 feet (10 m) wide —break up as they rotate because they get nonuniformly heated, while the sun's powerful gravity pulls apart larger ones. Nonetheless, several escape unscathed; one of the closest observed so far was the Great Southern Comet of 1887, which came within an incredible 446,187 miles (718,070 km) from the sun.

But the real "winners" are "sundiving," or "sunstriking," comets. Such comets likely abounded in the early solar system, although they're thought to be rare nowadays. These comets would cross the sun's visible surface, or photosphere, plunging into the sun. Although no one has detected such a sundiver yet, the 2018 study noted that a comet would need a perihelion less than the sun's radius, or 432,244 miles (695,630 km) from the sun's center. There are no second passes, though ‪—‬ all sundiving comets are destroyed within the sun.

So, the detected object that got closest to the sun was the Great Southern Comet of 1887. If a sundiver is ever spotted, however, it would become the new record-holder, edging out the Great Southern Comet by 13,943 miles (22,439 km).

See how much you know about the sun with our sun quiz!

One of the most famous full moons of the year will climb into the eastern sky on Saturday, Sept. 26. This year, the Harvest Moon will make its appearance with Saturn shining nearby — and you'll have another chance to see it rise on Sunday, Sept. 27, too.

Officially full at 12:49 p.m. EDT on Saturday, the full moon will be best seen rising in the eastern sky later that day, at the time of moonrise where you are. It will appear in the constellation Pisces.

This month's full moon earns the Harvest Moon nickname because it's the full moon closest to the September equinox, which fell on Tuesday (Sept. 22). This year, it coincides with the Mid-Autumn Festival — also called the Moon Festival — which is held in Chinese and Vietnamese communities on the day of the Harvest Moon, according to Timeanddate.com. However, the Harvest Moon's significance goes beyond traditional nicknames, because the moon behaves a bit differently around this point in the calendar.

Typically, moonrise occurs roughly 50 minutes later from one day to the next. Around the Northern Hemisphere's autumnal equinox, however, the moon's path meets the eastern horizon at a relatively shallow angle. That geometry reduces the day-to-day shift in moonrise times, resulting in a string of evenings with bright moonlight arriving soon after the sun goes down. Before electric lighting and modern farm machinery, those brighter early evenings provided useful extra illumination during the autumn harvest.

That's not the case anymore, but skywatchers nevertheless have more than one night when the full lunar disk emerges above the eastern horizon into a sky still filled with twilight. Across North America, the moon will rise only about 25 minutes later on Sunday, Sept. 27 than on the previous evening.

Saturn will add another reason to watch. The ringed planet will appear close to the Harvest Moon, rising just beneath it as seen from North America and is easily bright enough to see without a telescope. However, a backyard telescope or stargazing binoculars can give you an even crisper view of both Saturn and the moon. To get the best chance of catching the moon as it appears, find an observing spot with an unobstructed view to the eastern horizon.

The next full moon, known as the Hunter's Moon, will occur on Friday, Oct. 25 or Saturday, Oct. 26, depending on your time zone. It will also be a supermoon, making it appear larger and brighter than average.

How much do you know about the moon? Test your lunar smarts with our moon quiz!

NASA is moving forward with designing a new space telescope that can see even deeper into the infrared universe than the James Webb Space Telescope (JWST) can.

The new mission, called PRIMA (Probe far-Infrared Mission for Astrophysics), is continuing its development to Phase B — the preliminary design and tech phase — according to a NASA statement. Managers will review the mission's progress before officially beginning the telescope's journey to launch; if all goes to plan, PRIMA will embark on a five-year mission no earlier than 2033.

PRIMA's objective is to use a 5.9-foot [1.8 meters] telescope to examine the cosmos in the far-infrared, in a different set of wavelengths than the more famous JWST, which launched in 2021. (Other telescopes, such as Hubble and the newly launched Nancy Grace Roman Space Telescope, can also see some infrared wavelengths, but JWST was specifically designed to detect near- and mid-infrared light.) PRIMA's mission focus will be to uncover more information about exoplanet origins, galaxy growth and black hole evolution.

"The key science questions that PRIMA aims to address in relation to planet formation are to quantify the role of water in driving planet formation, [and to] determine the total gas masses and carbon and oxygen abundances in disks to reveal where exoplanets form," Meredith MacGregor, an associate professor of physics and astronomy at Johns Hopkins University who studies how planetary systems form, told Live Science in an email.

"We can't actually address these science questions with JWST," MacGregor added, "because the spectral lines that are required are only in the far-infrared — longer wavelengths than JWST is sensitive to."

The University of Maryland (UMD) and Caltech, which helped develop the mission, each issued statements about the upcoming work.

"I'm most excited about the things I don't yet know," Alberto Bolatto, an observational astronomer at UMD and a co-investigator who leads galaxy evolution research for PRIMA, said in a statement. "I am elated to be part of the future of astronomy — to produce an instrument that is going to be an enormous tool for the astronomy community to move humanity's knowledge forward."

"I am particularly excited about how PRIMA will help us discover and understand the role of powerful molecular outflows in galaxies over cosmic time, and how they shape star formation and the growth of supermassive black holes in the centers of galaxies," Lee Armus, a staff scientist at Caltech and the PRIMA co-investigator and science operations lead, said in a separate statement.

Dawn of the Probe Explorers

PRIMA has a project cost cap of $1.2 billion, excluding launch and other nonproject expenses; for comparison, JWST cost $10 billion at launch in 2021, not accounting for inflation or launch expenses.

PRIMA is also the first in a new class of spacecraft that NASA is calling Probe Explorers, which are meant to sit somewhere in between flagship, JWST-style missions and smaller agency efforts. Probe Explorers are a part of the decades-old Explorers Program that began with the Explorer 1 launch in 1958 and followed with more than 100 missions. Explorers perform "a wide variety of research and scientific exploration programs for Earth studies, space weather, the solar system, and the universe," according to the agency.

The Probe Explorers were implemented after a recommendation from astrophysicists through the 2020 Decadal Survey, which is a consensus report issued by the National Academies of Sciences, Engineering, and Medicine on behalf of the community. NASA funded two concepts at $5 million apiece in 2024 and considered both PRIMA and the Advanced X-ray Imaging Satellite before announcing the decision to proceed with PRIMA this week.

"NASA selected PRIMA for development after detailed evaluation of concept studies for Probe Explorer missions, based on their scientific merit in alignment with the Decadal Survey's recommendations, feasibility of their development plans on cost and schedule, and use of technologies that could support the development of future large missions," the agency stated Wednesday (Sept. 23).

Should the mission fly as hoped, NASA's Jet Propulsion Laboratory will manage PRIMA, with contributions from numerous other NASA centers and international agencies.

Fusion-powered space travel has long held the promise of rapid trips across the solar system: Mars in weeks, Saturn in months, Pluto in years.

For decades, such possibilities have remained theoretical, like something plucked out of a science fiction novel. But several companies are now working to build practical nuclear fusion propulsion engines, with significant milestones being hit.

Pulsar Fusion, a U.K.-based startup, hopes to launch a demonstration mission to space in 2027, while Princeton University and Helicity Space in the U.S. are continuing their own work on fusion drives.

If any of these efforts prove successful, missions across the solar system for robots and humans could be unlocked like never before, turning us into a true spacefaring species.

"If we continue on the current trajectory, everything we know about space travel is going to change within a decade," Stephane Lintner, CEO and co-founder of Helicity Space, told Live Science.

But is it too good to be true? Can the dream of nuclear fusion propulsion ever be fully realized, or will it remain a sketchbook fantasy? After decades of dreaming, we might be on the cusp of finding out.

Fusion power

Nuclear fusion is a process whereby two atoms combine, or fuse, to form a heavier one, releasing excess energy in the form of light and heat. The best-known type of fusion is the process that occurs inside the sun at up to 27 million degrees Fahrenheit (15 million degrees Celsius), where atoms of hydrogen fuse to form helium.

If this process could be replicated on Earth, it would provide us with huge amounts of energy. "The holy grail is free energy for everyone," Lintner said. Entire cities and countries would be transformed, bringing about a new age of clean and abundant power.

Many experiments and tests have been performed, and large fusion experiments, like the International Thermonuclear Experimental Reactor (ITER) in France, are under construction. However, commercially viable fusion reactors have yet to be built. One of the main problems is keeping the turbulent, superhot plasma required for fusion confined and at the right temperature. The record is currently 22 minutes.

If you take the same concept and put it in space, you suddenly have a means to power a spacecraft. What's more, the same problems with sustaining the plasma don't arise. Instead, the plasma can be fired out of the spacecraft, providing a steady thrust that can be used to accelerate a spacecraft to enormous speeds in the frictionless vacuum of space.

"Fusion propulsion in some ways is harder, and in some ways is easier, than terrestrial energy production," Bhuvana Srinivasan, a professor of aeronautics and astronautics at the University of Washington, told Live Science.

A fusion-powered spacecraft could be accelerated to hundreds ‪—‬ or even thousands ‪—‬ of miles per second through this method, multiple times faster than any spacecraft in history. In the most optimistic scenario, such a spacecraft could reach significant fractions of light speed, making interstellar travel a possibility.

There are tremendous challenges, of course. A space-based fusion reactor must be small enough to fit inside a spacecraft on a rocket. That's no easy feat, considering fusion reactors like ITER are the size of houses. You also need a way to create the immense heat required for fusion to occur, a source of fuel and propellant, and powerful magnets to keep the plasma from burning through the engine's walls.

Producing meaningful thrust requires staggering numbers of fusion reactions every second. A quintillion reactions would provide about 10 newtons of thrust ‪—‬ equivalent to the weight of a 1-liter bottle of water in your hand. But a fusion-powered engine would provide this thrust for months, rather than minutes for typical chemical propulsion, allowing large speeds to be reached eventually.

At first glance, this might sound nearly impossible, but some recent tests have shown it could be plausible

First plasma

In March, Pulsar Fusion demonstrated "first plasma" inside a nuclear fusion engine for the first time. In the test, which took place at the company's facility in Bletchley, one of Pulsar's Sunbird engines briefly transformed krypton gas into a plasma, demonstrating how the company might confine plasma within its exhaust system.

The demonstration showed "the plasma will sit in the system where you want it to sit," confined by an electromagnetic field, Richard Dinan, the company's CEO and founder, told Live Science. "The difficult work now is to be able to heat the plasma to temperatures nearer to fusion."

Dinan founded Pulsar Fusion in 2011 with the goal of building a fusion-powered propulsion system. The company's plan is to fuse helium-3 and deuterium, a lighter form of helium and a heavier form of hydrogen, and use the energy produced to heat helium-4 and expel it as propellant to produce thrust. The amount of thrust that can be produced depends on "how good you are at diverting those particles out the back of the spacecraft," Dinan said. "And right now, nobody knows how efficient we can be."

Just a few hundred grams of deuterium and helium-3 fuel would be needed to sustain the fusion process on a trip to Mars, Dinan said, but he claims their rocket would need 10 to 20 metric tons (11 to 22 U.S. tons) of deuterium propellant to provide the thrust to reach the speeds they're hoping for.

If they can make it work, their plans are ambitious. The company imagines fleets of its Sunbird vehicles traversing the solar system, taking people and cargo to and from destinations at speeds of up to 329,000 mph (529,000 km/h) ‪—‬ about 10 times faster than the Voyager 1 spacecraft currently traveling outside the solar system.

At those speeds ‪—‬ which aren't reached instantly, as the spacecraft need months to accelerate and decelerate ‪—‬ travel time to Mars could be halved from the nine months it takes with conventional chemical propulsion. Weight could be freed up for equipment because fusion is more efficient and needs less fuel. Quicker missions to farther destinations, such as to Saturn's moon Titan or the metal-rich asteroid Psyche, would also be in reach.

"I think we will see fusion as a propulsion system pretty soon," Dinan said. "The demand is certainly there."

A billion degrees

Pulsar Fusion's method of propulsion is known as dual direct fusion, where the plasma from the process is directly used to provide thrust. Samuel Cohen, a physics professor at Princeton University, is working on a similar concept, the Direct Fusion Drive, as part of a project called Starfire.

Cohen and his team have been investigating this concept for more than 20 years. Their idea is to fuse deuterium and helium-3, which is rare on Earth but abundant on the moon. His team has built a prototype fusion thruster at Princeton with plasma that reaches 18 million F (10 million C).

"It's a start, but you've got to get to a billion degrees" Celsius for deuterium and helium-3 fusion to occur, Cohen told Live Science. There are a few promising approaches to reaching those temperatures, including squishing the plasma or heating it up with radio or neutron beams.

Using their current plasma, Cohen claims the team has demonstrated a small amount of thrust ‪—‬ a few milligrams, or a few hundred-thousandths of a newton. Now, they hope to get more funding to take their concept further. "We need a few million dollars to start things off," Cohen said.

With enough support, Cohen said, they could have a working fusion propulsion system in 10 to 20 years. Meanwhile, Pulsar Fusion, which has received support from the European Space Agency and the U.K. Atomic Energy Authority, hopes to perform a demonstration of its thrusters in orbit by 2027.

Helicity Space is targeting a launch of its fusion propulsion system in the 2030s. The company, which raised $5 million in 2023, is developing the Helicity Drive, which relies on pulses of plasma, rather than continuous fusion, to provide thrust.

"If you get a reaction every few seconds, that's an amazing science experiment on Earth, but you can't do anything with it," Lintner said. "In space, you have the most advanced electric propulsion drive ever built. You change the game for propulsion."

Lintner said the company is aiming "for fusion temperatures very, very soon," and is then "planning on flying a first prototype within three years." By the 2030s, Lintner hopes to reach net gain in its fusion engines ‪—‬ producing more energy than is put in ‪—‬ to have a true fusion drive ready for use in space.

Going interstellar

But not everyone is convinced that fusion drives will propel us through the solar system. John Slough, who is working on his own fusion rocket design called the Fusion Driven Rocket (FDR), said he is wary of "false promises" in the field. He noted that much of the underlying physics around fusion propulsion remains extremely difficult.

"It still relies on scientific discovery for us to push it," Srinivasan said. "We need to figure out, how do we keep this fuel stable? Have we sorted a lot of the engineering and scientific challenges? It's not going to happen next year."

Remaining challenges include not only keeping the plasma stable, but also developing walls that can sufficiently contain the plasma, and shrinking the fusion system to fit inside a spacecraft, she added.

Other forms of nuclear propulsion might be more promising. NASA is developing SR-1 Freedom, a spacecraft powered by nuclear fission, not fusion. The goal for the spacecraft, announced in March, is to launch to Mars by December 2028, where three small robotic helicopters would be sent to explore the surface. The fission reactor would split uranium-235 to generate thrust.

"SR-1 Freedom will pave the way for space nuclear hardware," Steven Sinacore, the Space Reactor-1 Freedom Program Director at NASA, told Live Science in response to questions via email. "To sustain a presence on the Moon, send crews to Mars, and explore the outer solar system, the nation needs power that works everywhere, independent of the sun, and fission is that power."

However, fission-based propulsion, while extremely useful, cannot match the speeds promised by fusion propulsion. That's because fusion systems magnetically confine the plasma, meaning much higher temperatures can be reached. Fission temperatures, by contrast, are limited by the materials of the reactor where the fission reactions take place.

If any of the proposed fusion concepts were to become a reality, however, the possibilities would be enormous. Last year, Elena Ancona, a flight dynamics engineer at the Polytechnic University of Bari in Italy, and her colleagues described how a direct fusion drive could enable a mission to Sedna, a remote icy dwarf planet far beyond Neptune. For that mission, time is of the essence.

The dwarf planet will reach its closest point to the sun in 2075, and it will not be that close again for another 11,000 years. "If we want to make this mission, it's either now or in 11,000 years," Ancona said. With a traditional chemical spacecraft, a mission would need to be launched 30 years in advance. But with fusion propulsion, it could get to Sedna in just 10 years.

Many more destinations would be within reach if fusion propulsion were to become a reality. Perhaps even interstellar travel would be possible much further down the line. "People have known that fusion is the answer to deep-space travel since the 1960s," Lintner said. "It's only in the last decade that, commercially, people started to spend a lot of time on cracking the fusion code."

But there's a long way to go. "It's not for the faint of heart," Lintner said. But if fusion propulsion is ever going to happen, the next few years look as good a bet as any.

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In July 2025, a large, bright cosmic object visited from beyond our solar system. Only the third interstellar object ever discovered, the comet — named 3I/ATLAS — swooped through the inner solar system for about four months, briefly making it one of the biggest science celebrities in the world.

The interstellar object's fame stemmed in large part from controversial (and unsubstantiated) claims that it could be a source of intelligent alien technology, even though 3I/ATLAS behaved like a natural comet. However, according to the astronomers who are studying its mysteries in the data collected by dozens of telescopes and spacecraft, the ancient object may still have lessons to teach us about life in the cosmos.

3I/ATLAS is likely a preserved fragment of a planetesimal — a building block of a planet — from a distant system, Martin Cordiner, a researcher in astrochemistry and planetary science at NASA's Goddard Space Flight Center, told Live Science. Therefore, the comet's composition could offer clues to the prevalence of life's building blocks around distant stars. Some astronomers even hope this cosmic interloper will help constrain how likely life is elsewhere in our galaxy.

Blast from the past

Comets like 3I/ATLAS are important because scientists think they help "seed" planets with carbon-containing chemicals, Darryl Seligman, an assistant professor of astronomy at Michigan State University, told Live Science in an email. Some of these chemicals, like methanol, have simple structures. Others, like amino acids, are more complex. Together, these carbon-containing, or organic, compounds form the basis for biomolecules, like proteins and nucleic acids, that interact to produce life.

Samples returned from space rocks in our neighborhood strongly support the idea that they transported such molecules within the solar system. For instance, fragments from the solar system asteroid Bennu obtained during NASA's OSIRIS-REx mission contain all five nucleotide bases, the building blocks of nucleic acids. Matthew Belyakov, a postdoctoral researcher in planetary science at Caltech, noted that the Bennu samples also contained 14 of the 20 amino acids that form naturally on Earth.

Inferences about such deliveries are possible only because the rocks are like time capsules: They emerge from the same swirling disk of gas and dust from which planets are born, and the chemical compositions of asteroids and comets don't change much after that. So, by studying space rocks that originate in other exoplanetary systems, "we can learn if they also contain the building blocks of life and could have helped to start life in exoplanetary systems," Seligman said.

Simulations suggest that comets that circle one planet before moving to another could similarly deliver such prebiotic molecules to baby exoplanets. However, there was no supporting observational data to back up this claim.

A chemical potpourri

To figure out which chemicals 3I/ATLAS contains, astronomers have been recording the comet's light intensity across a range of frequencies, using more than a dozen instruments on Earth and around the solar system. This was possible because the comet spewed tons of gas and dust to create a fuzzy bright halo, or coma, after the sun warmed it. Observations of this coma have turned up an eclectic group of chemicals essential for life as we know it.

One is hydrogen cyanide (HCN), which was detected by the Atacama Large Millimeter/submillimeter Array (ALMA). Despite its notorious reputation as a poisonous gas, HCN is important for creating life. A commentary noted that laboratory experiments dating back to the 1950s ‪—‬ including the famous Miller-Urey experiment, which attempted to recreate the conditions of primordial Earth ‪—‬ have found that HCN is involved in building molecules like amino acids.

The list of ingredients goes on. ALMA data also revealed that 3I/ATLAS released gigantic amounts of formaldehyde and methanol. Additionally, observations from the James Webb Space Telescope showed 3I/ATLAS spewing the greenhouse gas methane. This is important because, assuming the methane formed on planets in the comet's home system, it could have trapped heat on those planets, thus warming them and making them more hospitable to life.

The presence of all these molecules is significant, Cordiner said, because they are "heavily implicated in terrestrial prebiotic chemistry studies as key carbon and nitrogen feedstocks [raw materials] for helping build life's molecular precursors," he said. 3I/ATLAS is proof that these "feedstocks" also exist in pastures far beyond our solar system's fences.

These findings are especially important because astronomers couldn't study the previous two interstellar objects to the same extent, Seligman said. He noted that 1I/'Oumuamua, the first interstellar object ever detected in the solar system, was observable for only a few weeks.

"The second interstellar comet 2I/Borisov was discovered right before COVID, so a lot of observations were canceled because of that," Seligman added. (Cordiner noted that the few observations conducted on 2I/Borisov showed that it, too, appears to contain HCN.) In comparison, researchers had almost a year to study 3I/ATLAS with telescopes. These observations have shown that "3I/ATLAS is unique in terms of the *measured* chemical inventory," Cordiner said.

Not indicative of life

All of the chemicals that 3I/ATLAS appears to possess give us data about just one planetary system. But when combined with observations of other astronomical phenomena, 3I/ATLAS shows that the chemical building blocks of life are abundant across our galaxy. For instance, giant molecular clouds — dense regions of gas and dust that give rise to stars — contain nitriles and sugar acids that can form amino acids. The stuff of life, it seems, is plentiful in space.

Ingredients aside, these findings don't prove that life itself has developed in 3I/ATLAS' home system (or anywhere else). All of the organic molecules that 3I/ATLAS appears to contain have simple chemical structures. Cordiner said mixtures of such molecules in the lab have transformed into more complex ones via processes like ice irradiation. However, such compounds have not been found on 3I/ATLAS, despite the billions of years the comet likely spent exposed to the unabated radiation of interstellar space.

Most of the chemicals 3I/ATLAS released while zipping past the sun come from the comet's radiation-exposed upper layers and not from its pristine interior, a January study found. This would mean that what astronomers have measured may not be present in the comet's home system.

Nonetheless, many astronomers, including Seligman's group, are continuing to study 3I/ATLAS' composition. There is also the exciting possibility of future interstellar visitors, which are all but guaranteed to make an appearance, thanks to the Vera C. Rubin Observatory in Chile, which is expected to spot dozens more. The elements and isotopes found in these objects will help in "building a map of where bio-precursors reside, across the history of the Galaxy," Cordiner said.

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For the first time, astronomers have detected radio signals coming directly from a planet outside our solar system, according to a new preprint study. Spoiler alert: It's not aliens. But astrophysicists are still very excited about this discovery.

"Astronomers have been looking for radio signals from exoplanets for some time," Suzanne Aigrain, a professor of astrophysics at the University of Oxford who was not involved in the study, told Live Science in an email. "There have been tentative, indirect detections before, but this is the first truly convincing direct detection, and it hopefully paves the way for many more."

Artificial radio signals are a key focus in the search for extraterrestrial intelligence (SETI), which involves scanning the cosmos for signs of alien life. Such "technosignatures" could suggest advanced technologies built by intelligent extraterrestrial civilizations. However, radio signals can be emitted by natural sources, too.

"There are two natural processes that can produce radio emission in exoplanets," Aigrain said. "One is magnetic reconnection, when the planet orbits really close to the star and its magnetic field interacts directly with that of the star. The other is aurorae (like those we have on Earth and on other solar system planets like Saturn, but much stronger), when energetic charged particles streaming from the star interact with the upper atmosphere of the planet."

"This second effect is what the authors of the paper believe they have detected," Aigrain added.

In the study, a research group led by Kevin Ortiz Ceballos, a graduate student at the Harvard and Smithsonian Center for Astrophysics, turned MeerKAT, a radio telescope array in South Africa, toward a massive gas giant called Beta Pictoris b, an exoplanet that's 64 light-years from Earth and has a mass roughly 10 times that of Jupiter, according to NASA. They picked up rapid, repeating bursts of radio signals coming from the planet.

At first, it wasn't clear whether the signal was coming from the planet or the star it orbits (named simply Beta Pictoris). However, after comparing the radio images of both the planet and the star with the positions of distant background quasars (bright, active galaxies that act as fixed reference points), the team confirmed that the radio bursts were indeed emanating from the gas giant.

"No radio detection has previously been unambiguously localized to an extrasolar planet rather than its host star," they wrote in the study, which has not been peer-reviewed yet.

Aigrain emphasized that "this is definitely not aliens!" The signals are consistent with what would be expected from auroras, and this finding offers insight into the planet itself. From these measurements, the team calculated the planet's magnetic-field strength, which they estimated to be roughly 1,250 gauss. For comparison, Jupiter's magnetic-field strength is only about 4.3 gauss and Earth's is a measly 0.5 gauss, according to Live Science's sister site Space.com.

Magnetic-field measurements like these are important because we don't fully understand how planets' magnetospheres are generated and what controls how strong they are, Aigrain said. The ability to measure a planet's magnetic field could also help in our search for potentially habitable exoplanets.

"[A] planet's magnetic field shields its atmosphere from the 'wind' of charged particles from [its] star, which might otherwise carry material away from the atmosphere," Aigrain said. "On Earth, for example, the magnetic field has played a key role in retaining the atmosphere and shielding life on the planet from harmful high-energy radiation.

"The planet in this paper is quite massive and has a thick atmosphere, so even without a strong magnetic field it could probably hold on to its atmosphere, and it is not expected to host life," Aigrain added. "But in the future we might be able to make similar measurements for smaller planets, for which this shielding effect would be more important."

MeerKAT is a pathfinder instrument for a new large telescope called the Square Kilometre Array, which is expected to come online in the next few years. This observatory "will be significantly more powerful," Aigrain said, "so there will be many more systems where we can look for this type of signal."

As of Aug. 30, 2026, NASA's Curiosity rover has officially seen the sun rise and set over Mars' reddish horizon more than 5,000 times in its quest to discover if life ever existed there. The rover was originally planned to operate for only two years, but the mission is still going strong more than 14 years after landing on Mars in August 2012.

During that time, the rover has weathered global dust storms and climbed more than 3,200 feet (1,000 meters) up a mountain — although its tires have gotten some rather large holes in them in the process. The rover still uses its 17 cameras to take hundreds of photos every single sol (Martian day), beaming a total of more than 780,000 photos back to Earth for scientists to analyze while mission controllers decide where the rover should roam next.

In honor of the intrepid rover's 5,000th day on the Red Planet, here are 10 of the most iconic photos Curiosity has snapped for Earthlings to admire.

Sol 548: Mount Sharp on the horizon

Curiosity snapped this photo of Mount Sharp on Feb. 19, 2014, about a year and a half after it landed on Mars. At the time, scientists were hopeful the rover could make it to the base of the 3.4-mile-high (5.5 kilometers high) mountain to explore interesting terrain previously seen from space. As the years passed, Curiosity more than surpassed that goal; the rover has climbed more than half a mile up into the mountain's foothills, traveling a total of more than 23.6 miles (38 km) from its landing spot, all while conducting important science along the way.

Sol 956: Blue skies on Mars

Curiosity took a photo of the Martian sunset in color for the first time on April 15, 2015, revealing a brilliant blue sky just before the sun dipped behind the shrouded mountains in the distance. The Martian sky is usually yellow to orange, according to NASA. Fine dust particles in the atmosphere scatter red and yellow light across the entire sky. However, the dust is just the right size for some blue light to slip past, so most of the light in the sky near the sun is blue. The effect is much more pronounced when the sun is low in the horizon.

Sol 1128: Curiosity Selfie at Namib Dune

Curiosity has taken numerous selfies over the course of its mission, although the process is a bit more involved than holding up a camera and smiling. This selfie was made from 57 separate images taken on Jan. 19, 2016 using a camera attached to its robotic arm. Here, Curiosity is standing next to Namib Dune, one of the many dark sand dunes that make up the Bagnold Dune Field near Mount Sharp. Curiosity sampled the sand for analysis and scuffed the dune with its wheels so scientists could see how the sand moved.

Sol 1819: Curiosity leaves a thumbprint in the dust

Mars is extremely dusty. The reddish dust gets swept into the atmosphere and cast across most of the planet's surface, making it difficult for scientists to figure out what materials are on the surface just by looking at them. On Sept. 17, 2017, Curiosity dusted off the surface of a rock at Vera Rubin Ridge and took a picture for geologists to compare to rocks on Earth. Based on the reddish purple color, geologists think this rock is fine-grained hematite split by fractures filled with calcium sulfate minerals. It hints that Mars might be a lot more colorful underneath its dusty blanket. Scientists have since discovered ruby-like materials embedded in Martian rocks.

Sol 3466: Totally not a door for aliens

On May 7, 2022, Curiosity sent a curious photo back to Earth that appears to show a small door carved into the face of a cliff. It's hard not to imagine little green people entering it after taking their little green dogs for a stroll across the dusty landscape, but it's not actually a doorway for Martians. The 3-foot-tall opening's boxy shape is caused by vertical fractures intersecting with horizontal layers in the rock, according to NASA. The cliff is highly fractured, and a large chunk of rock that likely fell from the "doorway" is clearly visible nearby.

Sol 3724: Iridescent feather in the sky

Just after the sun went down on Jan. 27, 2023, Curiosity took this photo of a noctilucent (night-shining) cloud that formed much higher in the Martian atmosphere than most other clouds do. Any clouds on Mars are rare, but this one is extra special. Since this cloud is so high up, it's much colder — making scientists think it's made of carbon dioxide (dry ice) instead of water ice. The iridescent colors in the cloud indicate the ice particles making up the cloud are all around the same size, which means the cloud likely just formed at the time of the photo.

Sol 3725: Curiosity finds "Cacao"

The very next day after cloud-gazing, on Jan. 28, 2023, Curiosity found an iron-nickel meteorite measuring about a foot across. The meteorite, nicknamed "Cacao," is one of a handful of meteorites Curiosity has photographed. The rover zapped part of the meteorite with a laser and measured the vapor released to identify what materials the rock was made of. Since Mars is cold and dry compared to Earth, meteorites last much longer on its surface than they do here, and they give clues about how the Martian atmosphere has changed over time. Large iron meteorites discovered on Mars indicate the planet once had a denser atmosphere than it does today.

Sol 4208: Elemental sulfur crystal surprise

In June 2024, Curiosity unintentionally ran over a rock and crushed it, revealing a yellow, odorless surprise: rare crystals of elemental sulfur. While Mars has plenty of minerals that contain sulfur, like sulfate, this was the first time pure sulfur was found. The crystal fragments are about 5 inches (12.7 centimeters) across. On Earth, pure sulfur is formed from volcanic and hydrothermal activity, along with other geologic processes. It's not clear yet how these crystals formed on Mars.

Sol 182 - 4263: All 42 drill samples

Curiosity has collected and analyzed 42 rock samples so far using a small drill attached to a robotic arm. The drill powders the rock so that the samples can be transported to Curiosity's science instruments, which measure their chemical composition. Each sample site is carefully chosen because the rover can only do a limited number of samples before it runs out of special sample cups. This mosaic image shows the impressive variety of materials that Curiosity has sunk its drill into.

Sol 4671: Exploring Martian spiderwebs

Researchers have been intrigued by large geologic structures like stone "spiderwebs" on the Martian surface, previously seen by spacecraft orbiting the planet. Curiosity visited them on the ground, taking this picture of the low ridges and hollows, called boxwork, on Sept. 26, 2025. The ridges, made from hardened minerals deposited by water seeping into cracked rock, are what's left after billions of years of erosion wore away the softer rock around them.

Curiosity's journey continues today. After leaving the boxwork structures last March, the rover set off to explore more of the Martian landscape with its cameras as busy as ever, looking for more evidence that Mars once had the water and chemistry to possibly support ancient microbial life.

What do you know about the Red Planet? Test your knowledge with our Mars quiz!

The hunt for extraterrestrial life on distant planets may be operating with a big blind spot.

That's because we aren't accounting for the nature of the light coming from the host star itself when we interpret the chemical signatures of life, or biosignatures, on some of the most promising candidate planets beyond the solar system. If we don't consider that crucial factor, we could be led on a wild-goose chase across the cosmos.

Despite having discovered thousands of exoplanets, we have not detected convincing evidence of alien life on any of them. But astronomy is reaching a point where powerful telescopes can zoom in on many more potentially habitable worlds. Planets that orbit M dwarfs, which are small stars cooler than the sun, are particularly promising targets because they have a unique observation window. When a planet passes in front of one of these stars, it blocks a relatively large fraction of the star's light, making the planet and its atmosphere easier to detect.

There are also a lot of them. M dwarfs are the most common type of star in the Milky Way. However, if we misunderstand how these stars interact with planetary atmospheres, we may misinterpret the significance of observations from some of the most promising planets.

The most-studied biosignatures are methane, oxygen and ozone. On Earth, these are often produced by biological processes, with ozone acting as an indirect indicator of oxygen. But even on our home planet, molecules typically associated with life are not unambiguous biological fingerprints. These molecules can be produced by geological and chemical processes, as well as via atmospheric reactions with light from the sun.

A potential biosignature detection found elsewhere in the cosmos is therefore a clue, not proof of life. We can't interpret the chemical signals coming from a potentially habitable planet without understanding the star that illuminates it. M dwarfs produce ultraviolet radiation that can break apart molecules and trigger chemical reactions in the atmosphere of an orbiting planet. The intensity and wavelength of the radiation influence which molecules form and survive, as well as how abundant they become. Two planets with otherwise identical properties could develop very different atmospheres simply because they orbit stars with different ultraviolet emissions. Radiation from a star could therefore make the same level of biological activity appear stronger on one planet than on another, or make nonbiological chemistry look like life. A recent study submitted to the preprint server arXiv Aug. 19 demonstrated this using entirely simulated planets. The researchers, led by University of California, Santa Cruz astronomy graduate student C. Evan Davis, simulated Earth-like planets orbiting two different types of M dwarf with ages ranging from 650 million to 5 billion years.

The team considered atmospheres resembling that of Earth during the oxygen-rich preindustrial era and the Archean eon (about 4 billion to 2.5 billion years ago), during which the first life-forms emerged but atmospheric oxygen was scarce. The models considered the stars' usual, or "quiescent," ultraviolet emission rather than short-lived flares. By changing the modeled stars' ages and ultraviolet radiation while keeping the planets comparable, they investigated how a star's evolution changed an atmosphere and the signals astronomers might observe.

One of the clearest differences the team found appeared in methane. Simulated planets with preindustrial atmospheres orbiting 5 billion-year-old M dwarfs accumulated up to 10 times more methane than equivalent planets simulated to orbit the younger 650 million-year-old stars. The methane signals produced in the simulated data were up to 68% stronger for the older systems. The weaker UV emission from the older M dwarf allowed methane to survive longer and accumulate in the simulated planetary atmospheres. The stronger methane signal could make a planet orbiting an older star appear to support more biological activity, when this difference was actually caused by the UV emission of the host star.

An even more striking result came from ozone. For the simulated Archean Earth-like planets, which were low in oxygen and rich in carbon dioxide (CO₂), the stronger UV radiation from younger M dwarfs broke apart more CO₂. This kick-started reactions that created oxygen and ozone without any life involved. Some model planetary atmospheres contained more than 100,000 times as much ozone as equivalent models around older stars. A hypothetical observer could misinterpret the resulting ozone signal as indirect evidence of biologically produced oxygen. Ozone is not useless as a biosignature, but these simulations show that it cannot be interpreted confidently without knowing the UV environment that shaped the atmosphere.

Of course, astronomers are already aware that a single molecule would not prove the existence of life on an exoplanet. Researchers use atmospheric models, look for combinations of gases, and consider nonbiological explanations before describing a signal as a potential biosignature. These methods remain valuable for identifying the most promising planets for further investigation, even when our knowledge of their stars is incomplete. Some might argue that these methods provide a sufficiently reliable first assessment and we should reserve more detailed stellar observations for the strongest candidates.

But even the best atmospheric model can mislead us if the stellar radiation isn't accounted for correctly. Ultraviolet observations of M dwarfs remain limited, so researchers often rely on estimates from similar stars. However, two M dwarfs that might appear similar can produce very different levels of UV radiation. Atmospheric models based on currently available stellar measurements may be sufficient for selecting promising targets but not for deciding whether the origin of a signal is biological. Simply acknowledging that the star matters isn't enough; we need accurate information about the specific star hosting the planet.

So before we train our telescopes on promising exoplanets, we need to study their host stars. This requires repeated UV observations, typically with different telescopes or instruments or at different time periods than you'd use to study the exoplanet. These observations can characterize how the host star's emission varies over time, while better stellar-age estimates — which can be calculated from properties such as rotation and magnetic activity— will reveal how that radiation has evolved.

Then, once we do start studying an exoplanet, potential biosignatures must be analyzed and interpreted using models informed by accurate measurements of the host star. As recommended in the preprint study, astronomers should also search for accompanying molecules, such as carbon monoxide, that could reveal whether ozone arose through reactions between light and carbon dioxide rather than from biology. The first convincing discovery of life on another planet will depend on an understanding of not only that planet but also the star that shaped the atmosphere we observe.

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In one of the first major discoveries from the Vera C. Rubin Observatory in Chile, scientists have revealed a previously unknown galaxy orbiting the Milky Way. Described in a study that hasn’t been peer-reviewed, the galaxy, named Aquarius IV, is one of the lightest, faintest and farthest satellite galaxies ever seen.

This dim cluster of ancient stars was discovered on the extreme periphery of the Milky Way in early test data from the Rubin Observatory, offering a glimpse of the telescope's impressive abilities and shedding new light on our cosmic neighborhood.

Ultrafaint dwarf galaxies (UFDGs) are among the tiniest and faintest galaxies in the universe. These dim little clusters contain at most a few hundred thousand stars, compared with the Milky Way's approximately 100 billion, said Joshua Simon, an astronomer at the Observatories of the Carnegie Institution for Science who was not involved in the new research. Instead, "these galaxies are composed almost entirely of dark matter: 99 to 99.9% of their mass is dark, and only 0.1 to 1% is made up of stars," Simon told Live Science in an email.

Because UFDGs are so small and faint, even ones in the Milky Way's vicinity are difficult to detect. Such dwarf galaxies orbit ours, similar to how Earth orbits the sun. In a 2020 study, scientists estimated that hundreds of these satellite UFDGs may exist. However, only around 60 have been found so far, Aashay Pai, a graduate student in physics at the University of Chicago and a co-author of the new study, told Live Science in an email.

But the Rubin Observatory's supersharp vision is poised to increase that total. The telescope's 3,200-pixel, car-sized camera can detect objects up to 100 million times dimmer than those visible to the naked eye as it takes repeat observations of the night sky every few nights. This makes the observatory well equipped to find UFDGs.

However, the data analyzed in the new study wasn't from the LSST; it came from an earlier test run. This test data, collected between April 2025 and January 2026, was called Early Data Preview 2 (EDP2) and covered roughly 7% of the night sky.

The researchers used computer models on the EDP2 data to identify UFDGs as groups of stars whose brightness and colors suggested they had evolved together. The researchers assumed that these stars were around 13 billion years old, Pai said — nearly as old as the universe itself. This framework allowed them to distinguish UFDGs from stars and other galaxies in front of or behind the observed areas.

With this approach, the researchers detected the previously unseen UFDG. Their findings were published in August in the journal Research Notes of the AAS, which presents non-peer-reviewed work in progress. In the research article, the team states that the newfound UFDG was detected at the eight-sigma significance limit, meaning the chance that this group of stars is a random collection is about 1 in 1.6 quadrillion.

The researchers also verified the galaxy's discovery using older images snapped by the 570-megapixel Dark Energy Camera on the NSF Victor M. Blanco Telescope in Chile; the photos showed faint stars that had been overlooked. Although this analysis had a lower significance limit of six sigma — giving it about a 1-in-100-billion chance of being a random fluke — it still supported the tiny galaxy's existence.

The newly discovered satellite galaxy, which the researchers named Aquarius IV, lies in the direction of the constellation Aquarius. Pai described it as "one of the faintest and most compact UFDGs at a large distance." The analyses suggest that the galaxy lies approximately 359,000 light-years from the Milky Way's center. (For comparison, the Milky Way itself is roughly 100,000 light-years long.)

Pai estimated Aquarius IV's mass at about 1,500 times that of the sun. That makes it lightweight relative to the Milky Way, whose mass equals that of 1.5 trillion suns, according to NASA. Furthermore, the absolute magnitude — or intrinsic brightness — of Aquarius IV is -1.9, making it 14 million times dimmer than the Milky Way.

Simon described the discovery of Aquarius IV as robust. However, Pai cautioned that follow-up observations will be required to confirm the object's identity.

Besides fleshing out our map of the nearby universe, studying UFDGs can reveal more clues about the mysterious nature of dark matter, which makes up about 85% of all matter in the universe but doesn't interact with light. Additionally, "the stars in ultra-faint dwarfs are also extremely old, dating back to just after the Big Bang, so they give us a unique window to the properties of the first galaxies that formed," Simon explained.

Pai noted that the Rubin Observatory is expected to find up to 100 such UFDGs during the LSST survey, which officially began in June. The survey will create the most detailed time-lapse video of the universe ever recorded and is expected to reveal millions of changes in the night sky every night, leading to an untold number of discoveries.

How well do you know our home galaxy? Find out with our Milky Way quiz!

Since launching in 2009, NASA's Lunar Reconnaissance Orbiter (LRO) — a robotic satellite about the size of a minivan — has taken more than 3 million photos of the lunar surface. This week, scientists studying a few hundred of those photos announced what they're calling a "once-in-a-century" discovery: the biggest, freshest impact crater ever seen in the solar system. ‪It's the result of a building-size meteorite that slammed into the moon just two years ago.

The new lunar pockmark, named McGetchin crater after the late geologist and lunar scientist Tom McGetchin, is about 728 feet (222 meters) wide, on average, and 141 feet (43 m) deep ‪—‬ imagine a hole as long as two American football fields and deep enough to fit a 14-story building inside.

"We know generally that there's more small things in space than there are large things, so that means we tend to get a lot of small craters on the moon and very few large craters," Julie Stopar, a senior scientist at the Lunar and Planetary Institute and deputy principal investigator on the LRO's camera team, told Live Science. "So something the size of this crater, we only expect to encounter that once every 130 years, approximately."

McGetchin is nowhere near the moon's largest crater; that honor goes to the South Pole-Aitken basin, a gargantuan gouge about 10,000 times wider than the newly discovered crater. But McGetchin is the largest new crater. Appearing seemingly out of nowhere in images from spring 2024, it's the biggest one scientists have seen in the 17 years that LRO has been active. And now that it's known to the world, some intrepid skywatchers think they've spotted the crater's bright, white debris ring from Earth.

The team described their findings in two papers published Sept. 16 in the journal Science Advances. Live Science spoke with Stopar to find out what this fresh crater can teach us about lunar geology, impact rates and potential risks to the future human visitors to the moon.

Brandon Specktor: The moon is riddled with craters. What's so interesting about this new one?

Julie Stopar: On one hand, it's a nice crater because it's so fresh and new. It hasn't been weathered. On Earth, we see the remnants of impact craters, but a lot of the original details are lost through weathering and degradation and time. But the moon preserves all of that much better.

This crater, in particular, is so fresh and young — it's only about 2.5 years old. It's in really, really good condition. We can study it to understand how impact cratering occurs and all the processes that go along with it.

The other cool thing is that it impacted on the boundary between two different types of deposits on the moon. There's the volcanic mare deposits [dark patches visible from Earth] and there's the highlands, which are ancient crustal material. The highlands are brighter and tend to be hillier, more mountainous, whereas the mare are flat plains, and they're very dark. This impact seems to have occurred right on the boundary between those two areas, so that's reflected in the materials that are excavated by that crater.

BS: The meteorite that made this crater was the size of a three-to-six-story building, according to your team's estimates. Could we have seen this impact from Earth?

JS: Yes. This is a relatively large impact, and from Earth, we have observed flashes associated with smaller impacts. So I think it's possible, under good conditions, that this may have made a flash. We don't know if anyone was watching, though — so if somebody out there has videos that they can dig through, they could go back and look for it.

BS: This impact happened in April or May 2024. One of your colleagues discovered the crater in LRO data in October 2025. Why did it take so long?

JS: LRO orbits the moon about 12 times each day. While we're going around, we can only image a really small portion of the moon on each pass. So you can imagine it takes many, many orbits to go around the moon and to reimage each part of the surface. When we don't have an impact flash to help us decide where to look for these craters, it's basically a random search.

Over time, we eventually will get repeat imaging [of the same area], but it takes years to get that. On top of that, the processing that it takes to make the before and after images

takes a lot of work; basically, you're looking through all the images that have been taken of the moon under the right conditions, and it just takes a lot of time and effort to process that.

BS: Your colleague, Robert Wagner, says he "stopped and dropped everything" when he discovered the crater in LRO's data. What was your reaction when he first showed it to you?

JS: I was surprised that it was so large! But I've seen a lot of similar craters on the moon, so my actual first thought was, "Oh my gosh; this crater might actually help me constrain how old all of these other craters are!"

BS: So because you know this crater is so fresh, it's helping you date other craters you've seen too?

JS: Yes, I've been looking at a bunch of craters, which I think look morphologically [their shape] and albedo-wise [how much light they reflect into space] very fresh. They have the bright ejecta [the material that gets blasted out from the meteor impact]; they have crisp rims. But I don't know how old they are, because they were there before the LRO. I think they're young, but I don't have any proof of age. So that was my first thought: "Oh my gosh; this makes me feel so much better if all these other craters I'm studying are still in really good condition like this one is."

BS: What, specifically, do you hope to learn about the moon from this crater?

JS: There's hope that we can use this to help understand the current impact cratering rate. How much and how often do different sizes of debris in the solar system impact the moon?

And that's important, because people want to go to the surface for exploration, send landers, start building moon bases and so forth, and there's some concern that impactors will be a hazard. So it would be helpful to have a better idea of whether that's a really frequent concern or only a once-in-a-while concern. We can also study things like how the impact angle, the target materials, and the velocity and type of impactor play a role in forming craters.

This crater will help us better interpret all of the others as well. I think this would be a really good crater to go get samples from, because we know when it formed and we have a lot of questions we can answer with that.

BS: How do you see human-made impacts fitting into this? In recent years, several spacecraft have crashed into the moon. Do you see any risks there or more opportunities to study craters?

JS: At this point, it's not too much of a concern to myself about human-made objects destroying natural habitats on the moon. Other spacecraft impacts, like the boosters from the Apollo program, made craters a long time ago. But I think, as there are more people and countries and even companies going to the moon, they'll have to get coordinated so as to not interfere with each other's activities — because that would be a problem. It's just a reminder like, "Hey, guys; you need to talk to each other and get coordinated and make sure you're keeping track of these impacts and your debris, and you're working together."

Otherwise, those craters are interesting because we know the impactor's mass and shape beforehand. It gives us a new insight into how craters form when you have irregularly shaped masses, like hollow cylinders and things like that. They'll also tell us about the moon's surface as well, because it's a different type of impact and it's got a different kind of energy to it and a different shape. So we do learn a lot about the cratering process in general from those.

This interview has been condensed and edited lightly for clarity.

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NASA's latest space telescope has officially taken its first photos of our universe. Launched on Aug. 30, the Nancy Grace Roman Telescope is on its way to Lagrange point L2, a "parking spot" in space about a million miles (1.6 million kilometers) from Earth where it will begin scanning deep space.

Using its 300-megapixel camera, Roman captured hundreds of stars as green rings of light. The telescope's Wide Field Instrument hasn't been fully focused yet, which is why these balls of gas appear blurry in the debut test image. But once the instrument is calibrated over the next few months, it should produce images as clear as those taken by the Hubble Space Telescope — but which cover an area 100 times larger. Astronomers hope to use these images to help solve some of the biggest mysteries in our universe, including the possible source of dark energy and the search for alien life.

With Roman's first test images now available, what are you most excited about for the future of this space telescope? Answer in the poll below, and let us know your thoughts in the comments!

Lab mice who spend time in space seem to bear offspring with reduced reproductive capacity, a new study suggests. But what that might mean for human astronauts and their families is still unclear.

The research, published June 30 in the journal PNAS, looked at female mice that had spent extended periods on the International Space Station (ISS). These mice had similar levels of fertility as Earth-bound mice. However, their children and grandchildren produced smaller-than-average litters, had fewer litters overall and had lower levels of key reproductive hormones, among other measurable differences.

"The offspring of those that came back from space were altered in their behavior, their muscle, their ability to reproduce further," study co-author Lane Christenson, a professor of cell biology and physiology at the University of Kansas Medical Center, told Live Science. And "just about every marker we looked at had some differences."

As the study was conducted in mice, it’s difficult to determine whether the effects might carry over to human astronauts. However, mice are good biological models for understanding the health impacts of space travel, given that they are mammals with a similar reproductive system to humans, experts told Live Science.

As scientists explore the feasibility of long-term space travel, this study highlights the need for further research on the impact of long-term spaceflight on the reproductive system, the study authors argue.

A "void" in research

Past research, such as the NASA Twins Study, has suggested that short-term spaceflight has modest effects on human health. That study compared astronaut Scott Kelly, who completed a year-long mission on the ISS, to his identical twin brother, Mark Kelly, who remained on Earth.

However, few studies have explored the long-term health impacts of spaceflight, including those that might affect reproduction.

A 2019 study looked at male mice that spent time aboard the ISS and found they could father healthy offspring. The new study, by contrast, was conducted to "fill a void" in research investigating how space travel might impact the female reproductive system, Christenson said.

Such investigations are especially important because hormones like estrogen affect more than just reproduction; they "influence almost all organ systems in the female body," he added. For example, estrogen supports processes like bone maintenance, too.

For the new study, 20 female mice lived on the ISS for 42 days. The female mouse reproductive cycle is very short, only about four to five days long, while the human menstrual cycle is 28 days on average, Christenson noted. "But a lot of the molecular background is very similar" in terms of how hormones fluctuate each cycle, he explained.

Upon their return to Earth, the mice could still get pregnant and give birth to live offspring. Their litters were slightly smaller than those of comparison groups of mice that did not spend time in space. But that difference was not statistically significant, meaning it could be coincidence.

Researchers saw clearer differences in the next generation of mice. The offspring of the spacefaring mice had about 15% less muscle strength than the control groups' offspring. Additionally, the female mice in that second generation were more prone to stress than the female offspring in the control groups, based on a behavioral experiment.

"We were pretty surprised that a relatively short period of time, 42 days, was able to induce these striking changes," Christenson said.

The second generation of mice could also get pregnant, but these mice had fewer litters and much smaller litters than the control mice did. Further testing also showed that the offspring of spacefaring mouse mothers had lower levels of anti-müllerian hormone (AMH), a hormone whose levels correlate to overall egg count. Higher AMH means higher egg reserves and vice versa. The subsequent third generation also had lower levels of AMH compared with mice in the control groups.

Christenson theorizes that this pattern may be the result of an "acceleration of aging" caused by the mice's predecessors being exposed to microgravity. Previous mouse and human-tissue studies have suggested that a lack of gravitational force may leave cells more vulnerable to stress. This has been tied to dysfunction in mitochondria, the powerhouses of cells that contain special DNA that's exclusively passed from mother to child.

This theoretical mechanism and its relationship to mice's reproductive capacity still needs to be confirmed, though.

For now, "this study adds to the growing body of literature on the effects of space travel in general on the reproductive system," said Dr. Ulrike Luderer, director of the Center for Occupational and Environmental Health at the University of California, Irvine, who was not involved in the research.

Luderer noted that, given that the research was conducted on the ISS, which has less exposure to cosmic radiation than deeper regions of space do, the impacts of traveling in deep space — say, on a journey to Mars — may be even more consequential. Earlier this year, Luderer published research that found that exposing mice to radiation levels similar to the ones an astronaut might experience on a trip to Mars lead to a "very significant decrease in the number of eggs and follicles in the ovaries."

She hopes that further research can focus on additional reproductive markers, such as hormonal levels, to pinpoint the long-term consequences of deep-space travel. Those will be especially relevant if "humans spend long periods of time in [space] or colonize some other planet."

This article is for informational purposes only and is not meant to offer medical advice.

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One of the longest-running meteor showers of the year began on Sunday (Sept. 20), as the Southern Taurids start sending occasional "shooting stars" — and, potentially, spectacular fireballs — across the night sky.

The Southern Taurid meteor shower runs from Sept. 20 through Nov. 20, peaking overnight on both Oct. 13-14 and Nov. 4-5, according to the American Meteor Society. Although only about five to 10 meteors per hour can be expected during the shower's peak, the Taurids have a reputation for producing fireballs — very bright meteors that appear as flashes while falling through the atmosphere.

Patience is often rewarded with some of the most impressive meteors of the year, partly because the Southern Taurid meteors strike Earth's atmosphere at the relatively leisurely pace of around 17 miles per second (27 kilometers per second), meaning they can be visible longer than most meteors and leave glowing trails.

The Southern Taurids are associated with a trail of rocky debris left in the inner solar system by Comet 2P/Encke, according to NASA, and they form half of the broader Taurid meteor complex. Their companion shower, the Northern Taurids, becomes active later in the fall, creating an extended period when Earth encounters debris associated with the same complex.

Although meteor activity begins this month, you'll have to wait a little longer to see the Southern Taurids at their best. An early increase in activity is expected around Oct. 13-14, with rates of regular shooting stars potentially slightly stronger than usual this year, while the principal peak for fireballs will arrive around the night of Nov. 4-5.

The sky conditions will be ideal for the Southern Taurids, with a moonless night sky on Oct. 13-14 and an 18%-lit waning crescent moon rising in the early morning on Nov. 5, though you will also need a clear night to see any shooting stars or fireballs. However, the rates will be too low for most urbanites to justify a trip to a dark location.

Southern Taurid meteors appear to radiate from the constellation Taurus, which climbs higher as the night progresses, but there's no need to stare directly at it. Meteors can appear anywhere overhead, so a wide, unobstructed view of the sky is more useful. Stargazing binoculars and telescopes will not help you spot meteors — however, they may come in handy for some of fall's other skywatching treats, including some rare planetary appearances.

Because the shower's radiant lies close to the ecliptic (the apparent path of the sun as seen from Earth), the Southern Taurids are observable from both hemispheres. However, Northern Hemisphere observers generally enjoy more favorable viewing conditions.

Don't expect celestial fireworks; the Southern Taurids are a slow burn. But with brilliant fireballs possible, they're worth keeping an eye on whenever you're outside after dark this fall.

Imagine opening your eyes for the first time and seeing that the sky is full of green doughnuts.

This was the view that greeted NASA's Nancy Grace Roman Space Telescope, which just activated its powerful, 300-megapixel infrared camera for the first time.

The telescope, which launched to space on Aug. 30, is partway through a months-long commissioning process, with NASA scientists testing and tuning each of the spacecraft's instruments as it undertakes a million-mile (1.6 million kilometers) journey to Lagrange point L2 — an orbital "parking spot" where the competing gravity of Earth and the sun will hold Roman in place, alongside the James Webb Space Telescope (JWST) and other scientific spacecraft.

Roman's camera system, known as the Wide Field Instrument (WFI), hasn't been fully focused yet, so the stars look like lime-colored loops in this debut test image. But so far, all systems are working as they should, according to a NASA statement.

By the time Roman is ready to beam home its first full science images in early 2027, it will be capturing cosmic snapshots as crisp and detailed as those from the Hubble Space Telescope ‪—‬ but each of Roman's images will cover an area 100 times larger than Hubble's.

"After years of effort to build and test the instrument on the ground, we now have confirmation that it is operational in space. This is a huge milestone," Josh Schlieder, chief WFI scientist at NASA's Goddard Space Flight Center in Maryland, said in the statement. "There is much to do, but we are on our way to groundbreaking science."

The wavy rows of squares in the new image are key to Roman's photo-taking power. Each square represents one of Roman's 18 detectors, which translate photons from distant light sources into electrical signals that encode enormous images of the universe. Scientists are preparing for the telescope to beam roughly 1.4 terabytes of data — about five to 10 times the storage capacity of an average smartphone — back to Earth every day.

With all that data, NASA scientists expect Roman to push the frontiers of some of the biggest mysteries in astronomy. Planned long-term surveys of distant galaxies will help scientists discover new objects and calculate the expansion of the universe, potentially shedding new light on the phenomenon of dark energy.

The telescope will also contribute to the search for alien life. By selectively blocking out starlight with Roman's built-in coronagraph — another instrument that NASA successfully tested this week — the telescope will be able to zoom in on exoplanets with unprecedented precision, free from stellar glare. These observations could increase the number of known alien worlds from the current count of over 6,000 to more than 100,000 by the end of Roman's planned 10-year mission.

But in a final piece of good news, that 10-year mission now looks likely to double. According to NASA, a successful thruster burn (combined with bonus fuel loaded onto the spacecraft at launch) means that Roman may be looking at 22 years worth of power rather than 10. Like Hubble, which has continued operating far beyond its initial mission parameters, Roman may be an orbital gift that keeps giving for decades.

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