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    NASA’s OSIRIS-Rex nabbed over 120 grams of space rocks from asteroid Bennu

    It’s official: NASA’s OSIRIS-Rex spacecraft snagged 121.6 grams of pristine space rocks when it bopped the asteroid Bennu four years ago, more than double the mission’s official science goal, the agency confirmed February 15.

    Launched in 2016, OSIRIS-Rex is NASA’s first mission to collect samples from an asteroid and return them to Earth so scientists can study our solar system’s origins. After performing its grab-and-go procedure from the diamond-shaped Bennu, the spacecraft dropped its canister into our atmosphere last year (SN: 9/22/23). Engineers swiftly shuttled it off to a specially designed sample curation center at the Johnson Space Center in Houston, where it was placed in a hermetic glove box to prevent contamination by terrestrial material.

    The diamond-shaped asteroid Bennu, seen here during OSIRIS-Rex’s approach, is a loose rubble pile held together by gravity.NASA Goddard, University of Arizona

    While researchers have been able to analyze some rocks and dust already, weighing the full sample has been delayed by a couple stuck screws that prevented anyone from accessing the entire contents of the capsule (SN: 10/11/23). Some clever workarounds finally unlocked the full sample on January 10, and it will now be distributed to scientists around the world for study.

    To learn how engineers got the canister open, as well as what kinds of science the sample will teach us, Science News spoke with Harold Connolly, a geologist at Rowan University in Glassboro, N.J., who oversees analysis of the material from Bennu. The conversation has been edited for clarity and brevity. More

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    How ‘Our Moon’ shaped life on Earth and human history

    Our MoonRebecca BoyleRandom House, $28.99

    Science journalist Rebecca Boyle has an intergenerational connection with the moon. Her grandfather Pfc. John J. Corcoran was involved in the 1943 Battle of Tarawa on the namesake atoll in the Pacific Ocean during World War II. The United States’ narrow victory against Japan came at heavy human cost. One reason: A weak high tide forced American soldiers to wade through the ocean into Japanese gunfire rather than sail their boats to meet their enemies. More

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    Saturn’s ‘Death Star’ moon might contain a hidden ocean

    An uncanny resemblance to the Death Star might not be the only intriguing thing about Saturn’s moon Mimas. It could also harbor a vast ocean of liquid water beneath its pockmarked exterior.

    A new look at data from NASA’s Cassini probe reveals that the point in Mimas’ orbit where it comes closest to Saturn changed slightly over 13 years, researchers report February 7 in Nature. Because Mimas’ internal composition affects the gravitational dance between the moon and its planet, these orbital dynamics, along with some previously seen moon wobbles, point to a liquid interior, astronomer Valéry Lainey of the Paris Observatory and colleagues say. More

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    An asteroid may have exploded over Antarctica about 2.5 million years ago

    Around 2.5 million years ago, an asteroid may have exploded over Antarctica. 

    The evidence comes from a chemical analysis of more than 100 tiny pieces of rock entrained within the White Continent’s ice, researchers report in the Feb. 1 Earth and Planetary Science Letters. The timing makes the midair detonation the oldest known airburst, the team says. Only two other ancient airburst events are known in the geologic record, dating to 480,000 and 430,000 years ago (SN: 3/31/21).   More

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    Bacteria that can make humans sick could survive on Mars

    Future interplanetary explorers beware: Hitchhiking bacteria brought to Mars on human bodies might not only survive the harsh conditions on the Red Planet’s surface but also potentially thrive.

    Recent experiments exposed four common disease-causing microbes to a simulated Mars-like environment, with its lack of water, scant atmospheric pressure, deadly ultraviolet radiation and toxic salts. The bacteria remained alive for various periods of time and, in some cases, even grew in the imitation Martian sands, researchers report in the January Astrobiology. More

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    NASA’s Ingenuity helicopter officially ends its mission on Mars

    After nearly three years, NASA’s Ingenuity helicopter, the first spacecraft to undertake a powered flight on another world, has ended its mission. Officials at the agency confirmed on January 25 that the history-making quad-copter has sustained damage to one of its rotor blades and is no longer capable of flying.

    “While we knew this day was inevitable, it doesn’t make it any easier,” said Lori Glaze, NASA’s planetary science division director, during a news conference on the status of the quad-copter. More

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    A toxic gas that could help spawn life has been found on Enceladus

    SAN FRANCISCO — For those delighted by the possibility of alien life, Enceladus, the wintry moon of Saturn, is a gift that just keeps giving.

    Key compounds that could support alien microbes or help life emerge have been detected in the enormous plume of water that erupts from vents in Enceladus’ icy shell, biophysicist Jonah Peter of Harvard University reported December 15 at the American Geophysical Union annual meeting. These include hydrogen cyanide, which can be toxic to humans, though Peter noted it’s also “a key building block for synthesizing more complex compounds including amino acids, sugars and nucleobases, which in turn are precursors for proteins, RNA and DNA.”

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    The findings are good tidings for the NASA team developing the Exobiology Extant Life Surveyor, or EELS, a snakelike robot that could one day crawl into Enceladus’ frozen crust to seek out signs of life in the ocean below.

    Though that ocean has never been directly observed, it is thought to be the source of the huge water plume spouting from Enceladus’ south pole (SN: 6/9/23). Researchers had previously reported that the plume contains phosphorous in the form of phosphate, establishing Enceladus as the first alien ocean world known to possess all the elements essential for life (SN: 12/16/23). The detection of phosphorus bolstered the moon as a prime candidate for hosting extraterrestrial life, and the new findings from Peter’s team offer even more support.

    With hydrogen cyanide and phosphate, “Enceladus might be seen as a favorable prebiotic system,” or a chemical setting capable of giving rise to life, said Christopher Glein, a geochemist at the Southwest Research Institute in San Antonio who was not involved in the study.

    Peter and colleagues conducted a detailed analysis of data collected by NASA’s Cassini probe as it flew through Enceladus’ plume in 2011 and 2012. In addition to hydrogen cyanide, the spray contains acetylene, ethane and various alcohols, the team also reported December 14 in Nature Astronomy. These compounds fuel some microbes on Earth, Peter said, “and could supply large amounts of metabolic energy for any potential life” on Enceladus.

    Though NASA has no missions scheduled for Enceladus, its habitability has already spurred the development of EELS. The 100-kilogram, 4-meter-long robot consists of ringed, cylindrical segments. These pieces can be angled and rotated in different ways to make EELS slither, sidewind or move vertically inside crevasses.

    The EELS robot (seen here) operates on the snow at the Big Bear Mountain Resort in Southern California, during a field test in February 2023.JPL-Caltech/NASA

    The robot’s most recent field test occurred in September, on the Athabasca Glacier in Alberta, Canada, reported technologist Masahiro Ono on December 13 at the meeting. On the glacier, Ono, of the Jet Propulsion Laboratory in Pasadena, Calif., and his colleagues tested the vertical mobility of EELS inside three ice shafts, or moulins. The robot first succeeded at holding itself steady in the moulins, unfurling its body to lodge itself between the frozen walls. Then, by carefully rotating treaded rings on its body, EELS safely completed multiple 1.5-meter descents.

    Following further tests on the glacier, the next step for EELS might be Earth’s moon. For instance, a small version of the space snake could be deployed to assist stationary lunar landers, Ono said. This robot “is a game changer,” he said, “and not just for Enceladus.” More

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    Giant polygon rock patterns may be buried deep below Mars’ surface

    Enormous polygon patterns in rock lie dozens of meters below Mars’ surface, ground-penetrating radar data suggest.

    Similar patterns develop on the surface in Earth’s polar regions when icy sediments cool and contract. A comparable process long ago may have created the shapes on Mars, found near the planet’s dry equator, researchers report November 23 in Nature Astronomy.

    If so, the finding hints that the Red Planet’s equator was much wetter and icier, more like a polar region, when the polygons formed 2 billion to 3 billion years ago.

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    “Buried possible polygons at that depth have yet to be reported” on Mars, says planetary scientist Richard Soare of Dawson College in Montreal, who was not involved in the study. Searching for ancient polygonal terrain on Mars using ground-penetrating radar is a new idea that “could be powerful,” he adds, and could help scientists understand how Mars’ climate has changed in the past.

    On Earth, polygonal terrain forms in chilly climes when sharp temperature drops cause icy ground to contract and crack open. These thermal fractures are small at first. But the little cracks can fill with ice, sand, or a bit of both, forming “wedges” that prevent the cracks from healing and gradually pry open the earth as they grow. Because this wedging process requires multiple cycles of freezing and thawing, polygonal ground is a good hint that the terrain was icy when the patterns formed.

    Polygonal surface patterns on Mars — like these in western Utopia Planitia, glimpsed from orbit by the Mars Global Surveyor satellite —might have been carved by “ice wedges” that form over many cycles of freezing and thawing.JPL/NASA, Malin Space Science Systems

    But the Chinese Zhurong rover’s landing site, on a part of Mars called Utopia Planitia, is not the kind of place one would expect to find the terrain on Earth — at least not today (SN: 5/19/21). Polygons have been spotted at higher latitudes on the Martian surface from orbit, but the landing site sits near the Martian equator in a dry, sandy dune field (SN: 8/24/04).

    The polygons appear to be roughly 70 meters across and are bordered by wedges nearly 30 meters wide and tens of meters deep — about 10 times as large as typical polygons and wedges on Earth. So it’s possible, Soare says, the structures here formed a bit differently than ice-wedge polygons on Earth.Forming polygons near the Martian equator wouldn’t be possible today, says study coauthor Ross Mitchell, a geoscientist also at the Institute of Geology and Geophysics. To form polygons, the region must have been colder and wetter in the past, he says — much like a polar region.

    Changes in the tilt of Mars’ axis could explain such a shift in climate. Simulations of Mars’ orbit have suggested that the planet’s spin axis has at times been so extremely tilted that the planet essentially lay halfway on its side. This would cause the poles to receive more direct sunlight while equatorial regions froze. Finding potential polygons buried near the Martian equator, Mitchell says, is “smoking gun evidence” supporting the idea that the tilt of Mars’ axis has varied so substantially in the past.

    “We think of every planet other than Earth as dead,” Mitchell says. But if Mars’s axis does swing around often, he says, our neighboring planet’s climate would be far more dynamic than currently believed. More