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!

'> 'We're never going to come home': Artemis II commander recalls the most terrifying moment of his 10-day trip around the moon

To understand how crows make decisions using cues in their environments, the researchers trained two carrion crows to complete a visual task on a touchscreen. The birds watched a cloud of white dots moving against a black background. Some dots moved to the left or right while others moved randomly. The crows had to determine the predominant direction of the dots' movement and peck the corresponding target on the screen to earn a mealworm reward.

By changing the proportion of dots moving together, the researchers could make the decision easier or harder for the crow. When most dots moved in the same direction, the answer was fairly obvious for the birds. But when only a small percentage moved together, the birds had weaker visual evidence to base their decisions on.

The crows reached nearly 100% accuracy when many dots were involved and the motion was clear. But even when just 3% of the dots moved in concert, both birds performed significantly better than just guessing, getting the answer right 50% of the time.

The birds maintained high accuracy in different rounds of the experiment, suggesting they were not sacrificing judgement for quickness.

The study did not directly compare crows to humans and monkeys performing the exact same task. However, previous studies suggest that humans and monkeys take roughly twice as long on comparable, self-paced visual motion tasks.

What happens inside the crow brain?

To understand how the birds reached their decisions so quickly, the researchers recorded activity from 248 neurons in the nidopallium caudolaterale (NCL) — a region of the bird brain that's considered functionally comparable to the prefrontal cortex in humans and primates. Birds lack the layered cerebral cortex found in mammalian brains, but the NCL performs similarly advanced functions.

In primates, neurons accumulate sensory information and their activity increases until it hits a critical threshold and the brain reaches a decision. The new findings suggest that crows use a comparable process, the researchers concluded.

"The bigger implication is that a brain does not need a mammalian neocortex to perform sophisticated computations," Nieder said.

The team could use neural activity to predict the crows' eventual choice "as early as 70 milliseconds after" the dots appeared, Nieder said. That was roughly 170 milliseconds before the crows' behavioral responses, meaning their pecks at the screen.

The speediness of the crows' decision-making may reflect the demands of the birds' daily lives.

"Flight places enormous demands on visual processing and sensorimotor [sensation and movement] coordination," Nieder said. "Birds must navigate three-dimensional environments, avoid obstacles, and react quickly to moving objects. Finding food and capturing prey can also require rapid, precise decisions. These pressures may have favoured fast information processing."

But for now, scientists don't know why crows seem to outpace primates in this particular type of decision-making. The study included only two birds and no direct comparisons to primates, so more work could be done to confirm the results and explore that question further.

For Nieder, observing the faster decision-making process in crows raises a broader question about how scientists define intelligence.

"Rather than assuming that the mammalian brain is the blueprint for intelligent behaviour," he said, "we can study different species to discover which computational principles are shared across animals and which reflect adaptations to their particular environments."

Are you a bird nerd? Find out with our bird quiz!

'> Crows may make lightning-fast decisions, sometimes twice as fast as humans, study hints

The brain's shared map brings different number formats into a common system based on the quantities they represent, the researchers concluded.

"For me, it is how the brain gets from a symbol to its meaning," said Abiot Derbie, a cognitive neuroscientist and founder of the company LifeByLogic, which makes psychology assessments.

The fraction "¼" contains the digit "4," but the fraction's value is much closer to zero, he noted. "The activity patterns reflected that numerical relationship, going beyond the digits themselves," Derbie, who was not involved in the research, told Live Science in an email.

The idea that the brain represents numerical magnitude in the parietal lobe is not novel. However, scientists mostly understood how the brain dealt with whole numbers, while its strategy for fractions was not well understood. The new work builds on that existing research by exploring how both numerical magnitude and number type are processed together.

"To the best of our knowledge, this is the first study to investigate the geometry of neural representations in a task involving both integers and fractions," the researchers wrote in their report. "In the future, it might be interesting to expand the present work to decimal numbers."

From previous work, "scientists already knew that fractions and whole numbers engage overlapping parts of the brain's number-processing network," Derbie said. "This study gives us a clearer picture of how their values are organized."

In the future, the team could examine how this neural representation varies across people of different ages, educational levels and mathematical backgrounds, Derbie suggested. The study also included only native French speakers, so may not reflect differences across language or culture.

"I would want to see how this organization develops as people learn," Derbie said. For instance, the team could follow children before and after they learn about fractions, to see whether changes in brain activity accompany better understanding.

In the current study, the participants found it more difficult to compare fractions than to compare whole numbers, the researchers noted; they were slower and made more errors while working with fractions, which was expected. But the study's results don't offer hints as to why.

"Our study was not designed to explain why fractions are harder to learn or understand," Valério and Dehaene told Live Science. "What is new in our study is that we show that these different types of numbers are organized within a shared map in the brain."

See how much you know about the most complex organ in the human body with our brain quiz!

'> Brain scans reveal 'number line' that's used to mentally compare values

Dwarf reed snakes are secretive, often nocturnal species that live across Southeast Asia, where they are prey for birds and other snakes. Although the snakes are extremely cryptic and usually hidden beneath leaves or other natural objects, people occasionally observe the serpents' dazzling rolls.

In a 2023 study, researchers formally documented the rolling behavior for the first time in one dwarf reed snake species (P. longiceps), which researchers observed in northwestern Malaysia in 2019. Kojima's team started independently observing the behavior around the same time in the Malaysian state of Sarawak, on Borneo.

"I had never seen anything like it before, and I immediately wanted to learn more about it," Kojima said.

For the new study, researchers filmed the rolling behavior multiple times in three dwarf reed species ‪—‬ P. saravacense, P. collaris and P. longiceps — between 2019 and 2022. The team also studied three reed snakes from another genus (Calamaria), which didn't perform the behavior.

Kojima said their study builds on the 2023 research by quantifying the rolling movements, confirming the overall movement pattern that research described, and revealing further details, including how the snakes stabilize their heads.

Snakes aren't the only tumblers in nature. For example, some desert spiders can roll away from danger, as can mother-of-pearl moth caterpillars (Pleurotya ruralis or Patania ruralis). However, the snakes are unique in that they seem to have good control over their rolls.

Rolling movements typically destabilize the head and disrupt sensory-guided adjustment, especially at high speeds, according to the authors of the new study. In other words, it's hard for animals to control their bodies when they're rolling around. The snakes' technique of keeping their heads relatively fixed and often elevated off the ground likely counters what would otherwise be destabilizing effects.

In addition to studying speed and form, the researchers found that the snakes could move in a relatively straight line, readily moving along a "racetrack" that was only 8 inches (20 centimeters) wide. The researchers noted that the snakes often ended their tumbling routine by diving underneath nearby objects, so they seem to remain aware of their surroundings.

The rolling is a behavioral innovation that allows the snakes to overcome their physical constraints and pull off an otherwise impossible movement, according to the researchers.

"Behavioral innovation can give rise to surprising new abilities that we would not expect from an animal's appearance alone," Kojima said.

Researchers have speculated that the bizarre behavior could surprise and confuse predators, in addition to being a rapid means of escape. The authors of the 2023 study also hypothesized that rolling would result in a patchy scent trail, and because king cobras (Ophiophagus) use scent cues to locate their prey, this could make it harder for the predators to hunt dwarf reed snakes.

How much do you know about snakes? Test your knowledge with our snake quiz!

'> Watch bizarre snake 'cartwheel' away from danger at more than 12 feet per second 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.

'> Japan launches world's first round-trip mission to Mars