“We have loved living in Orion,” said Christina Koch, mission specialist on Artemis II. “In fact, we’ve all said that sometimes you can forget where you really are, because we’re in this small space that just gives us everything we need.”

Living in microgravity makes the cramped quarters seem a little more accommodating. The astronauts can take advantage of every corner of the spacecraft.

“It is bigger in microgravity, and yes, we are bumping into each other 100 percent of the time,” Koch said. “A phrase that you often hear in the cabin is, ‘Don’t move your foot. I’m just going to reach for something right under it.’”

NASA named the crew members for the Artemis II mission three years ago. Now, the astronauts will have their names in the history books. With Artemis II, the number of people alive who have traveled to the vicinity of the Moon has nearly doubled. Just five of the 24 men who flew to the Moon are still alive. Four of them walked on its surface.

“I will miss this camaraderie. I will miss being this close with this many people and having a common purpose, a common mission,” Koch said. “This sense of teamwork is something that you don’t usually get as an adult. I mean, we are close, like brothers and sisters, and that is a privilege we will never have again.”

One of the most poignant moments of the mission was a tribute to Wiseman’s late wife, Carroll, who died of cancer in 2020. On Monday, as the crew neared the Moon, Hansen radioed down the crew’s request to name a crater for Carroll.

“When Jeremy spelled Carol’s name, C-A-R-R-O-L- L, I think, for me, that’s when I was overwhelmed with emotion,” Wiseman said. “And I looked over and Christina was crying. I put my hand down on Jeremy’s hand as he was still talking. I could just tell he was trembling, and we all pretty much broke down right there. And just for me, personally, that was kind of the pinnacle moment of the mission. For me, that was, I think, where the four of us were the most forged, the most bonded, and we came out of that really focused on the day ahead.”

https://arstechnica.com/space/2026/04/astronauts-recall-the-sci-fi-experience-of-flying-in-the-shadow-of-the-moon/

If the star is sufficiently massive, this will cause the near-instantaneous onset of oxygen fusion, releasing a massive burst of energy. That energy is thought to be enough to completely destroy the star without leaving a remnant black hole behind. Alternatively, smaller bursts of oxygen fusion may blast away the star’s outer layers, leaving a much smaller star behind that will ultimately create a far less massive black hole.

While that’s pretty well established through modeling, it’s a very difficult process to confirm. There have been a number of proposed examples of potential pair-instability events, and we don’t have a clear picture of what observations would distinguish them from more run-of-the-mill stellar explosions. And while we’ve been able to estimate the mass of the black holes we’ve observed merging, that hasn’t been as helpful as we would like.

The problem is that several of the mergers we’ve seen involve black holes that seem to have merged previously. So they’re big enough to be above the cutoff where pair-instability should have blocked the formation of a black hole, but they might have gotten that hefty by swallowing another black hole.

Numbers to the rescue

The international team behind the new work considered what kinds of collisions we might see. One is two first-generation (G1) black holes merging, in which case both should be below the mass at which pair-instability destroys everything. Then there’s a G1 colliding with a second-generation (G2) that’s the product of a previous merger, with the G2 potentially being above the mass cutoff. Finally, there’s a G2-G2 merger, where both are above the cutoff.

Any black hole mergers are likely to take place within a structure filled with lots of high-mass stars, such as a globular cluster. But the merger itself tends to impart a lot of energy to the resulting black hole, which could potentially kick it out of the cluster. As a result, G2-G2 mergers would likely be far more rare than G1-G2 mergers; the team estimates that only about 1 percent of all mergers would be G2-G2.

https://arstechnica.com/science/2026/04/black-hole-mergers-put-limits-on-star-destroying-supernovae/

Fälth noted that proponents of reform believe that “basic skills—especially reading, writing, and numeracy—must be firmly established first, and that physical textbooks are often better suited for that purpose.”

Between 2000 and 2012, Swedish students’ scores on standardized tests steadily declined in reading, math, and science. Though they recovered ground between 2012 and 2018, those scores had dropped again by 2022.

Though it’s unclear precisely how much of the decline is due to digitization, there is some evidence that analog teaching materials for reading may be superior to screen learning. However, this applies to expository as opposed to narrative texts. Narrative texts tell a story, whether fiction or non-fiction, while expository texts are designed to inform, describe, or explain a topic in a logical, factual manner.

Swedish officials emphasize that digital technology isn’t being removed from schools altogether. Rather, digital aids “should only be introduced in teaching at an age when they encourage, rather than hinder, pupils’ learning.” Achieving digital competence remains an important objective, particularly in higher grades.

Historically, the technology industry has pushed for more use of digital learning, seeing itself as a transformer of education. In the 1980s, Apple helped bring about the use of computers in schools. Then, starting with the use of the Internet, and later integrating mobile devices, technology reshaped the educational landscape. Education experts suggest it can foster a learning experience that is more interactive, accessible, and tailored to the needs of individual students.

In the US, the trend nationally in recent years has been toward the use of increasingly sophisticated methods of digital learning, such as providing children with laptops or devices like the iPad. According to a survey conducted by the EdWeek Research Center, part of the trade publication Education Week, 90 percent of school district leaders were providing devices for every middle and high school student as of March 2021. More than 80 percent of school district leaders said the same was true for elementary school students.

https://arstechnica.com/science/2026/04/sweden-goes-back-to-basics-swapping-screens-for-books-in-the-classroom/

KENNEDY SPACE CENTER, Florida—Launching to the Moon is an all-day undertaking, something the four astronauts waiting to climb aboard NASA’s Artemis II rocket know well.

“It is actually a very long day,” said Victor Glover, the pilot on Artemis II. “We wake up about eight hours before launch, and there’s a pretty tight schedule of things to get out there.”

Glover and his three crewmates have their schedules planned to the minute throughout the nine-day Artemis II mission. If all goes according to plan, their mission will carry them more than a quarter-million miles from Earth, farther from home than anyone has ventured in human history. After looping behind the Moon, the astronauts and their Orion capsule will fall back to Earth at some 25,000 mph (40,000 km/hr), setting another record for the fastest that humans have ever traveled.

Reid Wiseman, the mission commander, will join Glover at the controls inside the Orion spacecraft’s cockpit. Mission specialist Christina Koch and Canadian astronaut Jeremy Hansen round out the crew. All four have critical roles during the mission to test the Orion spaceship, which is flying with humans for the first time after 20 years in development.

The journey could begin as soon as Wednesday at NASA’s Kennedy Space Center in Florida. The mission has a two-hour launch window opening at 6:24 pm EDT (22:24 UTC). You can watch NASA’s live coverage of the countdown and launch in the YouTube stream embedded below.

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The full Moon, Artemis II’s destination, will rise over the eastern horizon at the spaceport during the launch window.

Looking at the Moon has taken on a new meaning for the Artemis II astronauts since their selection for the mission three years ago. Artemis II is the first crew mission for NASA’s Artemis program. The long-term goal of Artemis is to build a sustained human presence at the Moon, with a lunar base at the Moon’s south pole, to set the stage for future expeditions to Mars.

https://arstechnica.com/space/2026/04/launch-day-has-arrived-for-nasas-artemis-ii-mission-heres-what-to-expect/

But observing objects in cislunar space from the Earth is not easy. First, the Moon is a quarter-million miles away, so spacecraft or debris will appear vanishingly faint to sensors near the Earth. The Moon and the Sun far outshine these objects. Second, using a satellite stationed near the Moon to obtain a fix and vector for an object requires precise navigation, a capability not readily available without reliable GPS signals.

If anyone knows exactly where a satellite is around the Moon today, it is due to the generosity of its operator. If they choose to, spacecraft owners can provide detailed ephemeris data, revealing their location and movement, but there’s no way to force any operator to publish this information. Some operators may not want to share their location for competitive or strategic advantage.

There is also the risk of a satellite breakup in lunar orbit that could create a field of space debris. There is currently no way to track such small fragments at lunar distances, raising the risk of damaging or destructive collisions. If a lunar satellite disintegrated, it could “compromise international science missions and destabilize emerging lunar economic activity,” according to a 2025 report from the Mitre Corporation, a not-for-profit organization that manages several federally funded research centers.

Some generals bring the subject of lunar military operations back to Earth. In 2024, Ars asked Space Force Maj. Gen. Anthony Mastalir, then a one-star general, about the military’s view of the Moon. He identified a potential adversary’s use of the Moon or orbits around them as a launch point for an attack directed at US assets closer to the Earth.

“We’re not fighting over mineral deposits on an asteroid somewhere. We’re not, right now, shepherding convoys to Mars,” Mastalir said. “These are terrestrial conflicts that we hope we can deter. We also don’t want them to, although it’s more and more likely that they may, extend into space or even start in space.

“Someday in the future, that may change, but for now, I’d be more concerned just about what these new orbits present, what that does for potential attack vectors to our traditional operating [areas].”

https://arstechnica.com/space/2026/03/nasa-is-leading-the-way-to-the-moon-but-the-military-wont-be-far-behind/

“While a dual-engine fire scenario is statistically rare, it falls under the broader category of dual-engine failures and critical emergencies in aviation. History has shown that dual-engine failures and emergencies, such as the famous ‘Miracle on the Hudson’ involving Captain Sullenberger, can happen and lead to severe consequences,” said co-author Chenyang (Luca) Zhang of the University of Calgary in Canada. “Our study focuses on these low-probability but high-impact events to ensure the highest safety standards.”

Zhang et al. created two passenger categories: elderly adults age 60 and older and those younger than 60 years. They modeled three different ratios of those two categories—youth-dominated, evenly balanced, and elderly dominated evacuation scenarios—to capture more realistic travel dynamics and exclude edge cases (e.g., all non-elderly or all-elderly scenarios). For each of those, the model looked at three distinct seating patterns: one where elderly passengers are evenly distributed in areas near the exits; one where the elderly were concentrated in the middle of the cabin, away from the exits; and one where elderly passengers were randomly distributed throughout the cabin.

None of the tested conditions resulted in evacuation times within the FAA-mandated 90 seconds. The shortest evacuation time—20 percent elderly passengers evenly distributed near the exits—was 141 seconds. The longest—involving 80 percent elderly passengers and the same near-exit seating distribution—was 218.5 seconds.

Zhang et al. acknowledge that their study has some limitations. For instance, not all elderly passengers are the same, and their models did not incorporate the need for crew assistance for decreased mobility or similar issues. And because they focused on just the dual-engine fire scenario, their findings might not be generalizable to other evacuation scenarios.

The authors suggest future simulations could be more accurate with the addition of empirical data from real aircraft environments under controlled conditions. Future research should also test the effectiveness of different behavioral interventions, such as providing extra safety briefings tailored to elderly passengers. Airbus and other aircraft manufacturers might also consider redesigning cabins with designated seating areas for elderly passengers, giving them easier access to exits, better visibility, wider aisles, or perhaps armrests to assist with mobility.

AIP Advances, 2026. DOI: 10.1063/5.0310405 (About DOIs).

https://arstechnica.com/science/2026/03/whats-the-best-cabin-layout-for-aircraft-evacuation/

The mission will last more than nine days from liftoff to splashdown. After separation from the SLS rocket, the Orion spacecraft will spend a little more than a day in an elliptical high-altitude orbit ranging more than 40,000 miles from Earth. The astronauts and mission controllers in Houston will spend this time activating and testing the spacecraft, with a particular focus on Orion’s environmental control and life support systems, which were not part of an unpiloted Orion test flight four years ago.

Glover and Wiseman will take manual control of the spacecraft to assess Orion’s handling characteristics, commanding thrusters to guide the capsule back toward the SLS rocket’s upper stage to practice for docking maneuvers on future Artemis missions. Assuming everything checks out, Orion will fire its main engine for a translunar injection, or TLI, burn about 25 hours into the mission. This is the event that will send the astronauts toward the Moon.

This mission will not land. That will come on a future Artemis mission—currently slated for Artemis IV—no earlier than 2028. NASA is working with SpaceX and Blue Origin to develop commercial human-rated landers to ferry astronauts from the Orion spacecraft in lunar orbit down to the Moon’s surface and back. Those landers, along with new lunar spacesuits, won’t be ready for a landing mission next year, as NASA officials hoped.

NASA Administrator Jared Isaacman announced a shakeup of the Artemis program last week, shifting focus from building a space station in orbit around the Moon to constructing a base on the lunar surface. The program changes also included replanning the next Artemis mission—Artemis III—from a landing mission to a flight to dock an Orion crew capsule with one or both commercial landers closer to Earth.

The change will increase the chances of launching Artemis III next year. Sending SpaceX or Blue Origin’s landers to the Moon will require a mastery of in-orbit refueling, and neither company has demonstrated the capability yet. Refueling is not required for a test mission in low-Earth orbit on Artemis III.

“Over the last 10 weeks, the agency has prepared a crewed lunar test vehicle and also restructured the program that it belongs to,” said Amit Kshatriya, NASA’s associate administrator. “This was done deliberately. A crew that understands that campaign flies with greater purpose, a workforce that sees the road ahead holds a higher standard. This flight and the future reinforce each other. This is how Apollo worked, and this is how we will work.

“Behind this flight stands a campaign, landings, a lunar base, nuclear propulsion into deep space. That begins, not ends, with what happens on Wednesday evening,” Kshatriya said.

https://arstechnica.com/space/2026/03/after-more-than-53-years-humans-may-finally-return-to-the-moon-this-week/

Three main theories

There are many theories about what happened to Earhart, including a 1970 book claiming that Earhart had not only survived the flight but also changed her name and remarried, becoming Irene Craigmile Bolam. Bolam vehemently denied this and sued the publisher, which pulled the book off the market and eventually reached a settlement. But three theories in particular have come to dominate among Earhart enthusiasts. First, she and Noonan lost their bearings, ran out of gas, and crashed in the ocean. Second, one or both of them ended up as castaways on Nikumaroro Island (formerly Gardner Island), eventually dying there of starvation or injury. Third, Japanese forces captured Earhart and Noonan and (most likely) executed them.

Disney Publishing

Disney Publishing

Disney Publishing

Disney Publishing

Disney Publishing

Disney Publishing

Hartigan takes on these three theories in turn in Lost, interweaving efforts to find evidence for each with an account of Earhart’s life. She admits that originally, she had been quite impressed with the case for the island castaway hypothesis, given that the 2017 expedition had found such telltale 1930s objects as a zipper pull and pocket knife, as well as a fire feature and water bottles. And trained cadaver dogs had identified the campsite as a place where there might be human remains.

“But none of that is actually tied specifically to Amelia Earhart or Fred Noonan,” said Hartigan. “It’s just confirmation that somebody died there, and we don’t know who it was. No bones have been found. So by the second trip, I was a little more skeptical. There’s so many things I like about the castaway theory. But if I’m thinking about the most likely thing to have happened, the simplest explanation that matches with most of what we know, it’s that she got lost, ran out of gas, and crashed.”

In some sense, there has never been a better time to hunt for Earhart, given all the new science and technology at our disposal, particularly for deep-sea exploration. In 2003 and 2006, for example, David Jourdan used deep-sea sonar devices to search a 1,200-square-mile area north and west of Howland Island. His company, Nauticos, even conducted an elaborate experiment using 1930s equipment to determine how far off course Earhart and Noonan might have been when she sent her various radio messages. Most recently, a 2024 expedition searched for Earhart’s plane around Howland Island, the original planned landing site, but found no evidence of it.

https://arstechnica.com/science/2026/03/what-happened-to-amelia-earhart-new-book-takes-on-the-case/

To start, he built a neural predictor to tell whether someone was lying. It seemed to work. But in a second experiment, he and his research team used that neural lie detector to look at people who were telling the truth, but truths that were selfish. It threw a wrench in: “And then we show that brain decoder, that lie detector that we thought we had, can also predict when somebody’s just being selfish,” he said.

In the final stage of the experiment, though, the researchers wanted to see if they could subtract out the brain activity that represented selfishness and separate it from the lying part. They could. In the future, Lee said, they might find out that the remaining signal they thought was simply “lying” is still entangled with another mental state, like arousal. After finding and excising all entanglements, he said, what’s left must be straight lying. Theoretically, at least. “It could also be an empirical result that if we take enough of these compounded processes away, deception disintegrates,” he said. There might not be a straight-lying state, in other words; maybe lying is just the sum of many parts.

Scientists like Lee may be getting closer to an accurate lie detector, and improving on the traditional polygraph. But there’s currently no superhero solution. And the problem, as Lee’s research hints, may be ontological, not technological.

That’s definitely Maschke’s view. “It’s all pseudoscience,” he said. “There is no lie detector. So my thinking is that it’s better not to pretend that you can detect lies, because it’s a way of deceiving yourself.”

Maybe it’s true no one can know, for sure, if another person is lying. After all, humans are, famously, individuals. “Everybody’s so different in how they tell their lie,” said Denkinger. And, apparently, in how they tell their truths.

This article was originally published on Undark. Read the original article.

https://arstechnica.com/science/2026/03/polygraphs-have-major-flaws-are-there-better-options/

Three-hundred million years ago, the skies of the late Palaeozoic era were buzzing with giant insects. Meganeuropsis permiana, a predatory insect resembling a modern-day dragonfly, had a wingspan of over 70 centimeters and weighed 100 grams. Biologists looked at these ancient behemoths and asked why bugs aren’t this big anymore. Thirty years ago, they came up with an answer known as the “oxygen constrain hypothesis.”

For decades, we thought that any dragonflies the size of hawks needed highly oxygenated air to survive because insect breathing systems are less efficient than those of mammals, birds, or reptiles. As atmospheric oxygen levels dropped, there wasn’t enough to support giant bugs anymore. “It’s a simple, elegant explanation,” said Edward Snelling, a professor of veterinary science at the University of Pretoria. “But it’s wrong.”

Insect breathing

Unlike mammals, insects don’t have a centralized pair of lungs and a closed circulatory system that delivers oxygen-rich blood to their tissues. “They breathe through internalized tubing called the tracheal system,” Snelling explained.

Air enters the insect’s body through specialized portholes on their exoskeleton called spiracles. From there, it travels down larger tubes, the tracheae, which gradually branch into microscopically thin, blind-ending tubes known as tracheoles. These tracheoles are embedded deep within the insect’s tissues, and mitochondria in neighboring cells cluster next to them.

Insects can actively pump air in and out of the larger tracheae by flexing their bodies, but this active pumping stops at the very end of the line, in the tiny tracheoles. Here, oxygen delivery relies on passive diffusion to cross the final barrier into the tissue.

The problem with diffusion is that it’s notoriously slow. The oxygen constraint hypothesis argued that the larger the insect grows, the further the oxygen must travel to reach the deepest tissues.

“As the insects get bigger and bigger, the challenge of diffusion becomes greater,” Snelling said.

To prevent the muscles from suffocating, a bigger insect would need significantly wider or far more numerous tracheoles to maintain the supply of oxygen, which implied there had to be a structural tipping point. If an insect gets too big, the volume of breathing tubes required to supply its muscles with oxygen would take up too much physical space. The tracheoles would crowd the very muscle fibers they were trying to fuel, leaving the insect with severely impaired flight performance.

https://arstechnica.com/science/2026/03/leading-explanation-for-ancient-giant-flying-insects-gets-squashed/