Science – Page 2

Managers on alert for “launch fever” as pressure builds for NASA’s Moon mission

artemis, artemis II, human spaceflight, Kennedy Space Center, moon, NASA, orion, Science, Space, space launch system / Mike M. / January 17, 2026

“Putting crew on the rocket and taking the crew around the Moon, this is going be our first step toward a sustained lunar presence,” Honeycutt said. “It’s 10 days [and] four astronauts going farther from Earth than any other human has ever traveled. We’ll be validating the Orion spacecraft’s life support, navigation and crew systems in the really harsh environments of deep space, and that’s going to pave the way for future landings.”

NASA’s 322-foot-tall (98-meter) SLS rocket inside the Vehicle Assembly Building on the eve of rollout to Launch Complex 39B. Credit: NASA/Joel Kowsky

There is still much work ahead before NASA can clear Artemis II for launch. At the launch pad, technicians will complete final checkouts and closeouts before NASA’s launch team gathers in early February for a critical practice countdown. During this countdown, called a Wet Dress Rehearsal (WDR), Blackwell-Thompson and her team will oversee the loading of the SLS rocket’s core stage and upper stage with super-cold liquid hydrogen and liquid oxygen propellants.

The cryogenic fluids, particularly liquid hydrogen, gave fits to the Artemis launch team as NASA prepared to launch the Artemis I mission—without astronauts—on the SLS rocket’s first test flight in 2022. Engineers resolved the issues and successfully launched the Artemis I mission in November 2022, and officials will apply the lessons for the Artemis II countdown.

“Artemis I was a test flight, and we learned a lot during that campaign getting to launch,” Blackwell-Thompson said. “And the things that we’ve learned relative to how to go load this vehicle, how to load LOX (liquid oxygen), how to load hydrogen, have all been rolled in to the way in which we intend to do for the Artemis II vehicle.”

Finding the right time to fly

Assuming the countdown rehearsal goes according to plan, NASA could be in a position to launch the Artemis II mission as soon as February 6. But the schedule for February 6 is tight, with no margin for error. Officials typically have about five days per month when they can launch Artemis II, when the Moon is in the right position relative to Earth, and the Orion spacecraft can follow the proper trajectory toward reentry and splashdown to limit stress on the capsule’s heat shield.

In February, the available launch dates are February 6, 7, 8, 10, and 11, with launch windows in the overnight hours in Florida. If the mission isn’t off the ground by February 11, NASA will have to stand down until a new series of launch opportunities beginning March 6. The space agency has posted a document showing all available launch dates and times through the end of April.

John Honeycutt, chair NASA’s Mission Management Team for the Artemis II mission, speaks during a news conference at Kennedy Space Center in Florida on January 16, 2026. Credit: Jim Watson/AFP via Getty Images

NASA’s leaders are eager for Artemis II to fly. NASA is not only racing China, a reality the agency’s former administrator acknowledged during the Biden administration. Now, the Trump administration is pushing NASA to accomplish a human landing on the Moon by the end of his presidential term on January 20, 2029.

One of Honeycutt’s jobs as chair of the Mission Management Team (MMT) is ensuring all the Is are dotted and Ts are crossed amid the frenzy of final launch preparations. While the hardware for Artemis II is on the move in Florida, the astronauts and flight controllers are wrapping up their final training and simulations at Johnson Space Center in Houston.

“I think I’ve got a good eye for launch fever,” he said Friday.

“As chair of the MMT, I’ve got one job, and it’s the safe return of Reid, Victor, Christina, and Jeremy. I consider that a duty and a trust, and it’s one I intend to see through.”

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Archaeologists find a supersized medieval shipwreck in Denmark

Archaeology, maritime archaeology, medieval Europe, nautical archaeology, Science, shipwrecks / Beth Washington / January 16, 2026

the wreck and the story of the wreck

The sunken ship reveals that the medieval European economy was growing fast.

This is a replica of another cog, based on an excavated shipwreck from Bremen. Note the sterncastle. Credit: VollwertBIT

Archaeologists recently found the wreck of an enormous medieval cargo ship lying on the seafloor off the Danish coast, and it reveals new details of medieval trade and life at sea.

Archaeologists discovered the shipwreck while surveying the seabed in preparation for a construction project for the city of Copenhagen, Denmark. It lay on its side, half-buried in the sand, 12 meters below the choppy surface of the Øresund, the straight that runs between Denmark and Sweden. By comparing the tree rings in the wreck’s wooden planks and timbers with rings from other, precisely dated tree samples, the archaeologists concluded that the ship had been built around 1410 CE.

photo of a scuba diver swimming over wooden planks underwater — The Skaelget 2 shipwreck, with a diver for scale. Credit: Viking Ship Museum

A medieval megaship

Svaelget 2, as archaeologists dubbed the wreck (its original name is long since lost to history), was a type of merchant ship called a cog: a wide, flat-bottomed, high-sided ship with an open cargo hold and a square sail on a single mast. A bigger, heavier, more advanced version of the Viking knarrs of centuries past, the cog was the high-tech supertanker of its day. It was built to carry bulky commodities from ports in the Netherlands, north around the coast of Denmark, and then south through the Øresund to trading ports on the Baltic Sea—but this one didn’t quite make it.

Most cogs would have been about 15 to 25 meters long and 5 to 8 meters wide, capable of carrying about 200 tons of cargo—big, impressive ships for their time. But Svaelget 2, an absolute unit of a ship, measured about 28 meters from bow to stern, 9 meters wide, and could have carried about 300 tons. Its size alone was a surprise to the archaeologists.

“We now know, undeniably, that cogs could be this large—that the ship type could be pushed to this extreme,” said archaeologist Otto Uldum of Denmark’s Viking Ship Museum, who led the excavation, in a press release.

Medieval Europe’s merchant class was growing in both size and wealth in the early 1400s, and the cog was both a product of that growth and the engine driving it. The mere fact of its existence points to a society that could afford to invest in building big, expensive trading ships (and could confidently expect a return on that investment). And physically, it’s a product of the same trading networks it supplied: while the heavy timbers of its frame were cut locally in the Netherlands, the Pomeranian oak planks of Svaelget 2’s hull came from Poland.

“The cog revolutionized trade in northern Europe,” said Uldum. “It made it possible to transport goods on a scale never seen before.”

The super ship’s superb superstructure

For about 600 years, layers of sand had protected the starboard (right, for you landlubbers) side of the wreck from erosion and decay. Nautical archaeologists usually find only the very bottoms of cogs; the upper structures of the ship—rigging, decks, and castles—quickly decay in the ocean. That means that some of the most innovative parts of the ships’ construction appear only in medieval drawings and descriptions.

But Svaelget 2 offers archaeologists a hands-on look at the real deal, from rigging to the ship’s galley and the stern castle: a tall wooden structure at the back of the ship, where crew and passengers could have sought at least a little shelter from the elements. Medieval drawings and texts describe cogs having high castles at both bow and stern, but archaeologists have never gotten to examine a real one to learn how it’s put together or how it connects with the rest of the ship’s construction.

“We have plenty of drawings of castles, but they have never been found because usually only the bottom of the ship survives,” said Uldum. “[The castle] is a big step forward compared to Viking Age ships, which had only open decks in all kinds of weather.”

Lying on and around the remains of the cog’s decks, Uldum and his colleagues also found stays (ropes that would have held the mast in place) and lines for controlling the ship’s single square sail, along with ropes and chains that would once have secured the merchant vessel’s cargo in the open hold.

Life at sea in the Middle Ages

The cog would probably have sailed with between 30 and 45 crew members. No remains were found on the wreck, but the lost crew left behind small, tantalizing traces of their lives and their presence. Uldum and his colleagues found combs, shoes, and rosary beads, along with dishes and tableware.

“The sailor brought his comb to keep his hair neat and his rosary to say his prayers,” said Uldum (and one has to picture the sailor’s grandmother beaming proudly at that description). “These personal objects show us that the crew brought everyday items with them. They transferred their life on land to life at sea.”

Life at sea, for the medieval sailors aboard Svaelget 2, would have included at least occasional hot meals, cooked in bronze pots over an open fire in the ship’s galley and eaten on dishes of ceramic and painted wood. Bricks (about 200 of them) and tiles formed a sort of fireplace where the cook could safely build a fire aboard the otherwise very flammable ship.

“It speaks of remarkable comfort and organization on board,” said Uldum. “Now sailors could have hot meals similar to those on land, instead of the dried and cold food that previously dominated life at sea.” Plenty of dried meat and cold biscuits still awaited sailors for the next several centuries, of course, but when weather and time permitted, at least the crew of Svaelget 2 could gather around a hot meal. The galley would have been a relatively new part of shipboard life for sailors in the early 1400s—and it quickly became a vital one.

Cargo? Go where?

One thing usually marks the site of a shipwreck, even when everything else has disintegrated into the ocean: ballast stones. When merchant ships were empty, they carried stones in their holds to help keep the ship stable; otherwise, the empty ship would be top-heavy and prone to tipping over, which is usually not ideal. (Modern merchant vessels use water, in special tanks, for ballast.) But Uldum and his colleagues didn’t find ballast stones on Svaelget 2, which means the cog was probably fully laden with cargo when it sank.

But the cargo is also conspicuously absent. Cogs were built to carry bulk goods—things like bricks, grain and other staple foods, fabric, salt, and timber. Those goods would have been stowed in an open hold amidships, secured by ropes and chains (some of which remain on the wreck). But barrels, boards, and bolts of fabric all float. As the ship sank and water washed into the hold, it would have carried away the cargo.

Some of it may have washed up on the shores or even more distant beaches, becoming a windfall for local residents. The rest probably sank to the bottom of the sea, far from the ship and its destination.

Kiona is a freelance science journalist and resident archaeology nerd at Ars Technica.

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NASA’s first medical evacuation from space ends with on-target splashdown

commercial crew, crew dragon, crew-11, human spaceflight, international space station, NASA, Science, Space, spacex / 9u50fv / January 15, 2026

“Because the astronaut is absolutely stable, this is not an emergent evacuation,” said James “JD” Polk, NASA’s chief medical officer, in a press conference last week. “We’re not immediately disembarking and getting the astronaut down.”

Amit Kshatriya, the agency’s associate administrator, called the situation a “controlled medical evacuation” in a briefing with reporters.

But without a confirmed diagnosis of the astronaut’s medical issue, there was some “lingering risk” for the astronaut’s health if they remained in orbit, Polk said. That’s why NASA Administrator Jared Isaacman and his deputies agreed to call an early end to the Crew-11 mission.

A first for NASA

The Crew-11 mission launched on August 1 and was supposed to stay on the space station until around February 20, a few days after the scheduled arrival of SpaceX’s Crew-12 mission with a team of replacement astronauts. But the early departure means the space station will operate with a crew of three until the launch of Crew-12 next month.

NASA astronaut Chris Williams will be the sole astronaut responsible for maintaining the US segment of the station. Russian cosmonauts Sergey Kud-Sverchkov and Sergey Mikayev launched with Williams in November on a Russian Soyuz vehicle. The Crew Dragon was the lifeboat for all four Crew-11 astronauts, so standard procedure called for the entire crew to return with the astronaut suffering the undisclosed medical issue.

The space station regularly operated with just three crew members for the first decade of its existence. The complex has been permanently staffed since 2000, sometimes with as few as two astronauts or cosmonauts. The standard crew size was raised to six in 2009, then to seven in 2020.

SpaceX’s Crew Dragon *Endeavour* spacecraft descends toward the Pacific Ocean under four main parachutes. Credit: NASA

Williams will have his hands full until reinforcements arrive. The scaled-down crew will not be able to undertake any spacewalks, and some of the lab’s science programs may have to be deferred to ensure the crew can keep up with maintenance tasks.

This is the first time NASA has called an early end to a space mission for medical reasons, but the Soviet Union faced similar circumstances several times during the Cold War. Russian officials cut short an expedition to the Salyut 7 space station in 1985 after the mission’s commander fell ill in orbit. A similar situation occurred in 1976 with the Soyuz 21 mission to the Salyut 5 space station.

NASA’s first medical evacuation from space ends with on-target splashdown Read More »

Scientists sequence a woolly rhino genome from a 14,400-year-old wolf’s stomach

Megafauna, megafaunal extinction, paleoecology, paleogenomics, Science, siberia, woolly rhino / Mike M. / January 14, 2026

That came as a surprise, since woolly rhinos disappear from the fossil record about 400 years later. Already, the species was making its last stand in northeastern Siberia; its range had been shrinking eastward since around 35,000 years ago. But apparently, on the cusp of extinction, the species was still doing pretty well in northeastern Siberia (except for this particular rhino, who got eaten by a wolf after what one can only assume was a bad day).

This is the piece of woolly rhino meat in question, extracted from the stomach of a wolf puppy who lived near the end of the last Ice Age. Guðjónsdóttir et al. 2026

Woolly rhino population was small but healthy

So what counts as a stable population?

In the genome of a 49,000-year-old woolly rhino from a few hundred miles east in Rakvachan, Siberia, Guðjónsdóttir and her colleagues found clues about the species’ even more ancient history. Big changes in population size, among other events, can leave traces in the genome, and the researchers used those to estimate that between 114,000 and 63,000 years ago, the woolly rhino population dropped sharply, from about 15,600 to about 1,600.

Those numbers refer to what ecologists call the “effective population,” which means the number of rhinos breeding and contributing to the group’s gene pool (so there would have been more than 1,600 running around, but not all of them were reproducing). After 63,000 years ago, the woolly rhino population seems to have leveled out.

According to ecologists, an effective population of 1,600 rhinos would have been more than enough to keep the species thriving. Smaller populations, especially with shrinking ranges, are more vulnerable to being wiped out by events like environmental change, natural disasters, or disease outbreaks. And small populations are also more likely to face the genetic consequences of inbreeding, a loss of genetic diversity, and genetic drift (in which potentially harmful mutations can pile up), leaving the species even more vulnerable. The whole thing can turn into a vicious cycle.

For most species, the threshold for avoiding those genetic pitfalls is an effective population of around 1,000.

The end came suddenly for woolly rhinos

Researchers had expected to find woolly rhinos in dire straits by 14,400 years ago. Prior to discovering the Tumat genome inside a wolf’s stomach, the most recently sequenced woolly rhino genome dated to 18,400 years ago (and it was found just a few miles from the Rakvachan rhino). That genome showed all the signs of a healthy, stable population. But by 14,000 years ago, woolly rhinos disappeared from the fossil record—so it looked like their population must have started its death spiral shortly after 18,400 years ago.

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EPA moves to stop considering economic benefits of cleaner air

air pollution, Environmental Protection Agency, Science / Kelly Newman / January 13, 2026

The move to exclude the estimated benefits relates specifically to fine particulate matter smaller than 2.5 micrometers (known as PM_2.5) and ozone. This particulate matter, commonly produced by combustion, is small enough to make it through your respiratory system and into your bloodstream. For this reason, it is associated with a host of health impacts even beyond respiratory conditions. That has made research on those impacts the target of anti-regulation advocates who claim scientists exaggerate the harm.

Ozone is also a familiar enough pollutant in smoggy areas to be mentioned in weather forecasts as a warning for people with conditions like asthma. Ozone pollution in the lower atmosphere results from reactions between nitrogen oxides and volatile organic compounds emitted by various anthropogenic sources.

The new EPA language claims that past analyses have failed to adequately represent the scientific uncertainty of the economic value of reducing these pollutants. The new economic impact analysis for stationary combustion turbines, for example, says this “leads the public to believe the Agency has a better understanding of the monetized impacts of exposure to PM2.5 and ozone than in reality.” It continues, “Therefore, to rectify this error, the EPA is no longer monetizing benefits from PM2.5 and ozone but will continue to quantify the emissions until the Agency is confident enough in the modeling to properly monetize those impacts.”

A 2024 regulatory impact analysis for stationary combustion turbines had estimated those benefits at $27–$92 million per year for a tightening of emissions limits.

This is not the first time that these numbers have become political targets. Between 2004 and 2008, the Bush administration reduced the EPA’s value of a statistical life by around 11 percent. But instead of moving numbers to the lower end of scientific estimates, the Trump administration is more aggressively weaponizing scientific uncertainty. Functionally, the logic is that since estimates of benefits vary from large to extremely large, the EPA will default to a value of zero. Only the costs will be calculated, and those numbers are sure to be highlighted as justification for loosening pollution limits.

Currently, documentation for how the EPA previously calculated pollution regulation benefits based on research—including transparent assessments of scientific uncertainties—is still available on the EPA website.

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Switching water sources improved hygiene of Pompeii’s public baths

Archaeology, hydraulics, Pompeii, Science / Mike M. / January 12, 2026

From well to aqueduct

The specific sites studied included the Stabian baths and related structures, which were built after 130 BCE and remained active until the aforementioned eruption; the Republican baths, built around the same period but abandoned around 30 BCE; the Forum baths, built after 80 BCE; and the aqueduct and its 14 water towers, constructed during the Augustan period.

There were variations in the chemical composition of the deposits, indicating the replacement of boilers for heating water and a renewal of water pipes in the infrastructure of Pompeii, particularly during the time period when modifications were being made to the Republican baths. The results for the Republican baths’ heated pools, for instance, showed clear contamination from human activity, specifically human waste (sweat, sebum, urine, or bathing oil), which suggests the water wasn’t changed regularly.

That is consistent with the limitations of supplying water at the time; the water-lifting machines could really only refresh the water about once a day. After the well shaft was enlarged, the carbonate deposits were much thinner, evidence of technological improvements that reduced sloshing as the water was raised. Once the aqueduct had been built, the bathing facilities were expanded with a likely corresponding improvement in hygiene.

On the whole, the aqueduct was a net good for Pompeii. “The changes in the water supply system of Pompeii revealed by carbonate deposits show an evolution from well-based to aqueduct-based supply with an increase in available water volume and in the scale of the bathing facilities, and likely an increase in hygiene,” the authors concluded. Granted, there was evidence of lead contamination in the water, particularly that supplied by the aqueduct, but carbonate deposits in the lead pipes seem to have reduced those levels over time.

The results may also help resolve a scientific debate about the origins of the aqueduct water: Was it water from the town of Avella that connected to the Aqua Augusta aqueduct or from the wells of Pompeii/springs of Vesuvius? Per the authors, the stable isotope composition of carbonate in the aqueduct is inconsistent with carbonate from volcanic rock sources, thus supporting the Avella source hypothesis.

PNAS, 2025. DOI: 10.1073/pnas.2517276122 (About DOIs).

Switching water sources improved hygiene of Pompeii’s public baths Read More »

NASA launches new mission to get the most out of the James Webb Space Telescope

astrophysics, exoplanets, goddard space flight center, launch, NASA, pandora, Science, Space, spacex / Mike M. / January 12, 2026

“It was not recognized how serious a problem that is until… about 2017 or 2018.”

The Pandora observatory, seen here inside a clean room, is about the size of a refrigerator. Credit: Blue Canyon Technologies

Among other things, the James Webb Space Telescope is designed to get us closer to finding habitable worlds around faraway stars. From its perch a million miles from Earth, Webb’s huge gold-coated mirror collects more light than any other telescope put into space.

The Webb telescope, launched in 2021 at a cost of more than $10 billion, has the sensitivity to peer into distant planetary systems and detect the telltale chemical fingerprints of molecules critical to or indicative of potential life, like water vapor, carbon dioxide, and methane. Webb can do this while also observing the oldest observable galaxies in the Universe and studying planets, moons, and smaller objects within our own Solar System.

Naturally, astronomers want to get the most out of their big-budget observatory. That’s where NASA’s Pandora mission comes in.

The Pandora satellite rocketed into orbit early Sunday from Vandenberg Space Force Base, California. It hitched a ride with around 40 other small payloads aboard a SpaceX Falcon 9 rocket, launching into a polar Sun-synchronous orbit before deploying at an altitude of roughly 380 miles (613 kilometers).

Over the next few weeks, ground controllers will put Pandora through a series of commissioning and calibration steps before turning its eyes toward deep space. Pandora is a fraction of the size of Webb. Its primary mirror is about the size of the largest consumer-grade amateur telescopes, less than one-tenth the dimension of Webb’s. NASA capped Pandora’s budget at $20 million. The budget to develop Webb was more than 500 times higher.

Double-checking Webb

So what can little Pandora add to Webb’s bleeding-edge science? First, it helps to understand how scientists use Webb to study exoplanets. When a planet passes in front of its parent star, some of the starlight shines through its atmosphere. Webb has the sensitivity to detect the filtered starlight and break it apart into its spectral components, telling astronomers about the composition of clouds and hazes in the planet’s atmosphere. Ultimately, the data is useful in determining whether an exoplanet might be like Earth.

“I liken it often to holding a glass of wine in front of a candle, so that we can see really what’s inside,” said Daniel Apai, a member of Pandora’s science team from the University of Arizona. “We can assess, basically, the quality of the wine. In this case, we use the light that filters through the star’s [atmosphere] through the planetary atmosphere to judge what chemicals, gases in particular, may be present. Water vapor is one that we are the most sensitive to.”

But there’s a catch. Stars shine millions to billions of times brighter than their planetary companions, and starlight isn’t constant. Like the Sun, other stars have spots, flares, and variability over hours, days, or years. Hot spots and cool spots rotate in and out of view. And the star’s own atmospheres can contain some of the same molecules scientists are seeking to find on exoplanets, including water vapor.

Therefore, a star’s spectral signature easily outshines the signal coming from a nearby planet. Astronomers discovered this signal “contamination” when they started looking for potentially habitable worlds, injecting confounding uncertainties into their findings. Were the promising spectra they were seeing coming from the planet or the star?

Artist’s concept of the Pandora telescope with an exoplanet and two stars in the background. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab

“One of the ways that this manifests is by making you think that you’re seeing absorption features like water and potentially methane when there may not be any, or, conversely, you’re not seeing the signatures that are there because they’re masked by the stellar signal,” said Tom Barclay, deputy project scientist and technical lead on the Pandora mission at NASA’s Goddard Space Flight Center.

The problem became apparent in the 2010s as astronomers used more powerful telescopes to see the finer details of exoplanets.

“This is something that we always suspected as a community,” Apai told Ars. “We always suspected that stars are not perfect. At some point, it becomes a problem. But it was not recognized how serious a problem that is until, I would say, about 2017 or 2018.”

Scientists quickly got to work looking for a solution, and NASA selected the Pandora mission for development in 2021, just months before the launch of Webb.

“When we’re trying to find water in the atmospheres of these small Earth-like planets, we want to be really sure it’s not coming from the star before we go tell the press and make a big stink about it,” said Elisa Quintana, Pandora’s lead scientist at NASA’s Goddard Space Flight Center. “So we designed the Pandora mission specifically to solve this problem.”

From low-Earth orbit, Pandora will observe exoplanets and their stars simultaneously, allowing astronomers to correct their measurements of the planet’s atmospheric composition and structure based on the ever-changing conditions of the host star itself. Webb could theoretically do this work, but scientists already fill every hour of Webb’s schedule. Pandora will point and stare at 20 preselected exoplanets 10 times during its one-year prime mission, collecting 24 hours of visible and infrared observations with each visit. This will capture short-term and longer-term changes in each star’s behavior.

SpaceX launched Pandora into a so-called “twilight orbit” that follows the boundary between day and night on Earth, allowing the satellite to keep its solar panels illuminated by the Sun while performing its observations.

“We can send this small telescope out, sit on a star for a really long time, and sort of map all the star spots, and really disentangle the star and planet signals,” Quintana said in a recent panel discussion at NASA Goddard. “It’s filling a really nice gap in helping us to sort of calibrate all these stars that James Webb is going to look at, so we can be really confident that all of these molecules that we’re detecting in planets are real.”

“I think this is really the most important scientific barrier that we have to break down to fully unlock the potential of Webb and future missions,” Apai said.

Looking down the barrel of Pandora’s 17-inch-wide (45-centimeter) telescope. Credit: NASA/Jordan Karburn, LLNL

Ben Hord, a member of Pandora’s science team at Goddard, singled out one example in a presentation at an American Astronomical Society meeting last year. This planet, named GJ 486 b, is a “super-Earth” discovered in 2021 circling a relatively cool red dwarf star. Hord said astronomers had trouble determining if the planet has a water-rich atmosphere based on Webb’s observations alone.

“We want to know if water is in the atmospheres of these exoplanets, and this stellar contamination from the spots on the star can mask or mimic features like water,” Hord said. “Our hope is that Pandora will help James Webb data be even more precise by providing context and understanding for these host stars and these planetary systems.”

Planets around small dwarf stars are some of the best candidates for finding a true Earth analog. Because these stars put out a fraction of the heat of the Sun, a potentially habitable planet could lurk very close to its host, completing a year in a handful of days. This allows astronomers to see the planet repeatedly as it passes in front of its star, rapidly building a dataset on its size, structure, and environment.

Scientists hope they can extend the lessons learned from Pandora’s observations of a sample of 20 exoplanets to other worlds in our galactic neighborhood. As of late last year, astronomers have confirmed detections of more than 6,000 exoplanets.

“With a well-corrected spectrum, we can say there’s water, there’s nitrogen,” Quintana said. “So with every mission, as we evolve, we’re chipping away and taking bigger and bigger steps toward that question of, ‘OK, we know Earths are out there. We know they’re abundant. We know they have atmospheres. How do we know if they have life on them?’”

Building on a budget

A mission like Pandora was not possible until recently, certainly not on the $20 million budget NASA devoted to the project. With Pandora, the agency took advantage of a fast-growing small satellite industry churning out spacecraft at a fraction of what it cost 10 or 15 years ago.

The Pandora spacecraft weighed approximately 716 pounds (325 kilograms) at launch and likely would have required a dedicated rocket to travel to space before SpaceX started offering shared rides on its workhorse Falcon 9 rocket. NASA did not disclose what it paid SpaceX to launch Pandora, but publicly available pricing suggests SpaceX charges a few million dollars to launch a satellite of the same size. Before the rideshare option became available, NASA would have paid tens of millions of dollars for the launch alone.

The Pandora mission is part of NASA’s Astrophysics Pioneers program, an initiative set up to solicit ideas for lower-cost astronomy missions.

“It’s been very, very challenging to try and squeeze this big amount of science into this small cost box, but that’s kind of what makes it fun, right?” Barclay told Ars. “We have to be pretty ruthless in making sure that we only fund the things we need to fund. We accept risk where we need to accept the risk, and at times we need to accept that we may need to give up performance in order to make sure that we hit the schedule and we hit the launch [schedule].”

It helps that Pandora’s 17-inch (45-centimeter) telescope comes from Lawrence Livermore National Laboratory in California, which had the technology on the shelf from a national security program. Pandora uses a small satellite platform from Blue Canyon Technologies, a Colorado company.

“There is no way we could have done Pandora 10 years ago,” Barclay said. “The small launch capabilities that come from companies like Rocket Lab and SpaceX and others meant that now the vendors of spacecraft buses and spacecraft instruments are able to push their costs down because they know that there’s a market for small missions out there. Other parts of the government are investing heavily in small spacecraft, and so that allows us on the science side to make use of that economies of scale.”

For comparison, the European Space Agency launched an exoplanet observatory about the same size as Pandora in 2019 at a cost of more than $100 million.

There are companies now looking at how to scale up production of larger satellites, too. Cheaper, heavy satellites could launch on new heavy- and super-heavy rockets like SpaceX’s Starship or Blue Origin’s New Glenn.

“I think it is an amazing capability to have for astrophysicists because science is moving fast,” Apai said. “Exoplanet science is changing. I would say every three or four years, we have breakthroughs. And the product keeps changing. We push the boundaries, and if you ever have to work with 20- or 25-year-long mission lifetimes, that really just limits progress.”

Stephen Clark is a space reporter at Ars Technica, covering private space companies and the world’s space agencies. Stephen writes about the nexus of technology, science, policy, and business on and off the planet.

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That time Will Smith helped discover new species of anaconda

anacondas, Biology, culture, Disney Plus, National Geographic, Science, Taxonomy, zoology / Kelly Newman / January 11, 2026

In 2024, scientists announced the discovery of a new species of giant anaconda in South America. A National Geographic camera crew was on hand for the 2022 expedition that documented the new species—and so was actor Will Smith, since they were filming for NatGeo’s new documentary series, Pole to Pole with Will Smith. Now we can all share in Smith’s Amazon experience, courtesy of the three-minute clip above.

Along with venom expert Bryan Fry, we follow Smith’s journey by boat with a team of indigenous Waorani guides, scouring the river banks for anacondas. And they find one: a female green anaconda about 16 to 17 feet long, “pure muscle.” The Waorani secure the giant snake—anacondas aren’t venomous but they do bite—so that Fry (with Smith’s understandably reluctant help) can collect a scale sample for further analysis. Fry says that this will enable him to determine the accumulation of pollutants in the water.

That and other collected samples also enabled scientists to conduct the genetic analysis that resulted in the declaration of a new species: the northern green anaconda (Eunectes akayama, which roughly translates to “the great snake”). It is genetically distinct from the southern green anaconda (Eunectes murinus); the two species likely diverged some 10 million years ago. The northern green anaconda’s turf includes Venezuela, Colombia, Suriname, French Guyana, and the northern part of Brazil.

Local Waorani guides subdue a giant green anaconda YouTube/National Geographic

Smith’s time in the Amazon also brought the arachnophobic actor face to face with a giant tarantula while scientists extracted the venom. His further adventures brought him to the South Pole, where he trekked across frigid ice fields; to the Himalayas, where he trekked to a small village in Bhutan; to the Pacific Islands to record a lost native language; to the Kalahari desert, where he joined the hunter-gatherer San people on a hunt; and to the North Pole, where he joined an expedition to dive under the ice to collect scientific samples.

Pole to Pole with Will Smith premieres on January 13, 2026, and will stream on Disney+ the following day.

poster art showing bearded will smith in a parka with snow crystallizing on his beard — Credit: National Geographic

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The oceans just keep getting hotter

global warming, ocean ecology, Science, syndication / DJ Henderson / January 11, 2026

Since 2018, a group of researchers from around the world has crunched the numbers on how much heat the world’s oceans are absorbing each year. In 2025, their measurements broke records once again, making this the eighth year in a row that the world’s oceans have absorbed more heat than in the years before.

The study, which was published Friday in the journal Advances in Atmospheric Science, found that the world’s oceans absorbed an additional 23 zettajoules’ worth of heat in 2025, the most in any year since modern measurements began in the 1960s. That’s significantly higher than the 16 additional zettajoules they absorbed in 2024. The research comes from a team of more than 50 scientists across the United States, Europe, and China.

A joule is a common way to measure energy. A single joule is a relatively small unit of measurement—it’s about enough to power a tiny lightbulb for a second, or slightly heat a gram of water. But a zettajoule is one sextillion joules; numerically, the 23 zettajoules the oceans absorbed this year can be written out as 23,000,000,000,000,000,000,000.

John Abraham, a professor of thermal science at the University of St. Thomas and one of the authors on the paper, says that he sometimes has trouble putting this number into contexts that laypeople understand. Abraham offers up a couple options. His favorite is comparing the energy stored in the ocean to the energy of atomic bombs: The 2025 warming, he says, is the energetic equivalent to 12 Hiroshima bombs exploding in the ocean. (Some other calculations he’s done include equating this number to the energy it would take to boil 2 billion Olympic swimming pools, or more than 200 times the electrical use of everyone on the planet.)

“Last year was a bonkers, crazy warming year—that’s the technical term,” Abraham joked to me. “The peer-reviewed scientific term is ‘bonkers’.”

The world’s oceans are its largest heat sink, absorbing more than 90 percent of the excess warming that is trapped in the atmosphere. While some of the excess heat warms the ocean’s surface, it also slowly travels further down into deeper parts of the ocean, aided by circulation and currents.

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NASA orders “controlled medical evacuation” from the International Space Station

commercial crew, crew dragon, crew-11, dragon, human spaceflight, international space station, jared isaacman, NASA, Science, Space, spacex / Kelly Newman / January 10, 2026

“The crew is highly trained, and they came to the aid of their colleague right away.”

The International Space Station orbits 260 miles (420 kilometers) above the Earth. Credit: NASA

NASA officials said Thursday they have decided to bring home four of the seven crew members on the International Space Station after one of them experienced a “medical situation” earlier this week.

The space agency has said little about the incident, and officials have not identified which crew member suffered the medical issue. James “JD” Polk, NASA’s chief health and medical officer, told reporters Thursday the crew member is “absolutely stable” but that the agency is “erring on the side of caution” with the decision to return the astronaut to Earth.

The ailing astronaut is part of the Crew-11 mission, which launched to the station August 1 and was slated to come back to Earth around February 20. Instead, the Crew-11 astronauts will depart the International Space Station (ISS) in the coming days and head for reentry and a parachute-assisted splashdown in the Pacific Ocean off the coast of California.

“After discussions with our chief health and medical officer, Dr. JD Polk, and leadership across the agency, I’ve come to the decision that it’s in the best interests of our astronauts to return Crew-11 ahead of their planned departure,” NASA Administrator Jared Isaacman said Thursday.

The Crew-11 mission is led by commander Zena Cardman, 38, who is wrapping up her first mission to space. Second in command is pilot Mike Fincke, a 58-year-old astronaut on his fourth spaceflight. Japanese astronaut Kimiya Yui, 55, and Russian cosmonaut Oleg Platonov, 39, round out the crew.

Isaacman said NASA will release more information about the schedule for Crew-11’s undocking and reentry within the next 48 hours. The crew will come home aboard the same SpaceX Crew Dragon spacecraft they launched in more than five months ago. The entire crew must return to Earth together because they rely on the same Dragon spacecraft as a lifeboat.

“For over 60 years, NASA has set the standard for safety and security in crewed spaceflight,” Isaacman said. “In these endeavors, including the 25 years of continuous human presence onboard the International Space Station, the health and well-being of our astronauts is always and will be our highest priority.”

From left to right: Crew-11 mission specialist Oleg Platonov, pilot Mike Fincke, commander Zena Cardman, and mission specialist Kimiya Yui. This photo was taken during training at SpaceX’s facility in Hawthorne, California. Credit: SpaceX

Lingering risk

Polk, a physician who has served as NASA’s chief medical officer since 2016, said the agency is not ready to release details about the medical issue, citing privacy concerns. “I’m not going to speak about any particular astronaut or any particular specific diagnosis,” Polk said. “I’d ask that we still respect the privacy of the astronaut.”

Two of the Crew-11 astronauts, Cardman and Fincke, were preparing to head outside the space station on a spacewalk early Thursday. Spacewalk preps at the space station include a period of time breathing high concentrations of oxygen to purge nitrogen from the astronauts’ bloodstreams, a mitigation to avoid decompression sickness when crew members are sealed inside their spacesuits’ pure oxygen atmosphere.

Polk said whatever happened Wednesday “had nothing to do” with preparing for the spacewalk. “This was totally unrelated to any operations onboard,” he said. “It’s mostly having a medical issue in the difficult areas of microgravity with the suite of hardware that we have at our avail to complete a diagnosis.”

Yui radioed mission controllers in Houston on Wednesday afternoon requesting a private medical conference with a flight surgeon, then asked ground teams to turn on camera views inside the station ahead of the session. Medical sessions are carried out on private radio channels and are not heard on the regular communication loops between the space station and mission control. Those open loops are streamed around the clock online, but NASA removed the audio feed from YouTube soon after the crew asked for the medical conference.

NASA publicly revealed a medical concern with one of the astronauts later Wednesday afternoon, then announced late Wednesday night that officials were considering bringing the crew home early.

“I won’t go into specific details about the medical incident itself,” Polk said. “But the crew is highly trained, and they came to the aid of their colleague right away, and that’s part of why we do that training.”

The space station is stocked with medical gear and medications to help astronauts respond to emergencies. Crew members are trained to perform ultrasounds, defibrillate patients, and start IVs, among other things. The medical treatment available on the ISS is akin to what an EMT might provide in transit to a hospital, former astronaut Tom Marshburn, himself a medical doctor, said in 2021.

“We have a very robust suite of medical hardware onboard the International Space Station, but we don’t have the complete amount of hardware that I would have in the emergency department, for example, to complete the workup of a patient,” Polk said.

NASA Administrator Jared Isaacman, associate administrator Amit Kshatriya, and chief medical officer James “JD” Polk brief reporters on the status of the Crew-11 mission Thursday. Credit: NASA/Joel Kowsky

Space station managers will take a few days to determine when the Dragon spacecraft will leave the station. SpaceX will dispatch a recovery ship from Southern California to sail for the splashdown zone in the Pacific, and officials will assess weather and sea conditions before selecting the best opportunity to depart the station. Like every crew return, the vessel will be staffed with medical personnel to examine the astronauts after exiting from the Dragon capsule.

“Because the astronaut is absolutely stable, this is not an emergent evacuation,” Polk said. “We’re not immediately disembarking and getting the astronaut down.”

But without a confirmed diagnosis of the astronaut’s medical issue, there’s some “lingering risk” for the astronaut’s health if they remained in orbit, Polk said. That’s why Isaacman and his deputies agreed to call an early end to the Crew-11 mission.

This was the most significant decision of Isaacman’s young tenure as NASA administrator. He was sworn in as NASA chief last month after clearing a confirmation vote in the Senate. Before taking the helm at NASA, Isaacman charted a career as an entrepreneur and private astronaut, flying to space twice on commercial missions with SpaceX.

An inevitability

After Crew-11’s departure, the space station will operate with a smaller crew of three until the arrival of SpaceX’s Crew-12 mission with a fresh team of astronauts next month. Isaacman said NASA and SpaceX are looking at options to move up the launch of Crew-12 from its current target date of February 15.

Until then, the station’s crew will consist of NASA astronaut Chris Williams and two Russian cosmonauts, who launched to the space station in November on a Russian Soyuz vehicle. Williams and his crewmates—Sergey Kud-Sverchkov and Sergey Mikayev—have their own lifeboat in the Soyuz spacecraft, so they will still have a ride home in the event of a future emergency.

NASA astronaut Zena Cardman works with a spacesuit helmet inside the International Space Station’s airlock. Credit: NASA

Williams will be solely responsible for overseeing the lab’s US segment until Crew-12 arrives. He will be busy keeping up with maintenance tasks, so managers will likely defer some of the station’s scientific investigations until the complex is back to a full crew.

The early departure of Crew-11, leaving Williams as the only US astronaut aboard, also means NASA will be unable to perform spacewalks. This will mean a “slightly elevated risk” in NASA’s ability to respond to a major hardware failure that might require a spacewalk to fix, said Amit Kshatriya, the agency’s associate administrator.

NASA and the Russian space agency, Roscosmos, inked an agreement in 2022 to fly multinational crews on Dragon and Soyuz missions to ensure an American and a Russian are always at the space station. The so-called “seat swap” deal is proving worthwhile with this week’s events.

NASA has never before cut short a human spaceflight mission for medical reasons. “It’s the first time we’ve done a controlled medical evacuation from the vehicle, so that is unusual,” Kshatriya said.

The Soviet Union called an early end for an expedition to the Salyut 7 space station in 1985 after the mission’s commander fell ill in orbit.

In a sense, it is surprising that it took this long. Polk said predictive models suggested the ISS would have a medical evacuation about once every three years. It ended up taking 25 years. In that time, NASA has improved astronauts’ abilities to treat aches and pains, minor injuries, and routine illnesses.

Crews in orbit can now self-treat ailments that might have prompted a crew to return to Earth in the past. One astronaut was diagnosed with deep vein thrombosis, or a blood clot, in 2018 without requiring an early departure from the space station. Another astronaut suffered a pinched nerve in 2021 and remained in orbit for another seven months.

One of the more compelling reasons for the space station’s existence is its ability to act as a testbed for learning how to live and work off the planet. The station has served as a laboratory for studying how spaceflight affects the human body, and as a platform to test life support systems necessary for long-duration voyages to deep space.

“We are doing all this to continue to learn,” Isaacman said. “We will absolutely learn from this situation as well, to see if that informs our future on-orbit operations, whether that be on the space station or our future lunar base that we’re pursuing right now, and eventually for deep space missions to Mars.”

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These 60,000-year-old poison arrows are oldest yet found

anthropology, Archeology, poison arrows, Science / Mike M. / January 9, 2026

Poisoned arrows or darts have long been used by cultures all over the world for hunting or warfare. For example, there are recipes for poisoning projective weapons, and deploying them in battle, in Greek and Roman historical documents, as well as references in Greek mythology and Homer’s Iliad and Odyssey. Chinese warriors over the ages did the same, as did the Gauls and Scythians, and some Native American populations.

Archaeologists have now found traces of a plant-based poison on several 60,000-year-old quartz Stone Age arrowheads found in South Africa, according to a new paper published in the journal Science Advances. That would make this the oldest direct evidence of using poisons on projectiles—a cognitively complex hunting strategy—and pushes the timeline for using poison arrows back into the Pleistocene.

The poisons commonly used could be derived from plants or animals (frogs, beetles, venomous lizards). Plant-based examples include curare, a muscle relaxant that paralyzes the victim’s respiratory system, causing death by asphyxiation. Oleander, milkweeds, or inee (onaye) contain cardiac glucosides. In Southeast Asia, the sap or juice of seeds from the ancar tree is smeared on arrowheads, which causes paralysis, convulsions, and cardiac arrest due to the presence of toxins like strychnine. Several species of aconite are known for their use as arrow poisons in Siberia and northern Japan.

According to the authors, up until now, the earliest direct evidence of poisoned arrows dates back to the mid-Holocene. For instance, scientists found traces of toxic glycoside residues on 4,000-year-old bone-tipped arrows recovered from an Egyptian tomb, as well as on bone arrow points from 6,700 years ago excavated from South Africa’s Kruger Cave. The only prior evidence of using poisons for hunting during the Pleistocene is a “poison applicator” found at Border Cave in South Africa, along with a lump of beeswax.

Milk of the poisonous onion

The authors sampled 10 quartz-backed arrowheads recovered from the Umhlatuzana Rock Shelter site in KwaZulu-Natal, South Africa. The results revealed that five of the 10 tested tips had traces of compounds found in Boophone disticha, aka gifbol (poisonous onion), sometimes called the century plant, which is common throughout South Africa. Various parts of the plant have been used as an analgesic (specifically a volatile oil called eugenol) as well as for poisonous hunting purposes. Its more toxic compounds include buphandrine, crinamidine, and buphanine; the latter is similar in effect to scopolamine and can cause hallucinations, coma, or death.

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These dogs eavesdrop on their owners to learn new words

animal behavior, animal cognition, animals, dog language, Dogs, Science / Mike M. / January 8, 2026

Next, the entire experiment was repeated with one key variation: This time, during the training protocol, rather than addressing the dogs directly when naming new toys, the dogs merely watched while their owners talked to another person while naming the toys, never directly addressing the dogs at all.

The result: 80 percent of the dogs correctly chose the toys in the direct address condition, and 100 percent did so in the overhearing condition. Taken together, the results demonstrate that GWL dogs can learn new object labels just by overhearing interactions, regardless of whether the dogs are active participants in the interactions or passive listeners—much like what has been observed in young children around a year-and-a-half old.

To learn whether temporal continuity (a nonsocial factor) or the lack thereof affects label learning in GWL dogs, the authors also devised a third experimental variation. The owner would show the dog a new toy, place it in a bucket, let the dog take the toy out of the bucket, and then place the toy back in. Then the owner would lift the bucket to prevent the dog from seeing what was inside and repeatedly use the toy name in a sentence while looking back and forth from the dog to the bucket. This was followed by the usual testing phase. The authors concluded that the dogs didn’t need temporal continuity to form object-label mappings. And when the same dogs were re-tested two weeks later, those mappings had not decayed; the dogs remembered.

But GWL dogs are extremely rare, and the findings don’t extend to typical dogs, as the group discovered when they ran both versions of the experiment using 10 non-GWL border collies. There was no evidence of actual learning in these typical dogs; the authors suggest their behavior reflects a doggy preference for novelty when it comes to toy selection, not the ability to learn object-label mappings.

“Our findings show that the socio-cognitive processes enabling word learning from overheard speech are not uniquely human,” said co-author Shany Dror of ELTE and VetMedUni universities. “Under the right conditions, some dogs present behaviors strikingly similar to those of young children. These dogs provide an exceptional model for exploring some of the cognitive abilities that enabled humans to develop language. But we do not suggest that all dogs learn in this way—far from it.”

Science, 2025. DOI: 10.1126/science.adq5474 (About DOIs).

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