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    The Kuiper Belt’s dwarf planet Quaoar hosts an impossible ring

    The dwarf planet Quaoar has a ring that is too big for its metaphorical fingers. While all other rings in the solar system lie within or near a mathematically determined distance of their parent bodies, Quaoar’s ring is much farther out.

    “For Quaoar, for the ring to be outside this limit is very, very strange,” says astronomer Bruno Morgado of the Federal University of Rio de Janeiro. The finding may force a rethink of the rules governing planetary rings, Morgado and colleagues say in a study published February 8 in Nature.

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    Quaoar is an icy body about half the size of Pluto that’s located in the Kuiper Belt at the solar system’s edge (SN: 8/23/22). At such a great distance from Earth, it’s hard to get a clear picture of the world.

    So Morgado and colleagues watched Quaoar block the light from a distant star, a phenomenon called a stellar occultation. The timing of the star winking in and out of view can reveal details about Quaoar, like its size and whether it has an atmosphere.

    The researchers took data from occultations from 2018 to 2020, observed from all over the world, including Namibia, Australia and Grenada, as well as space. There was no sign that Quaoar had an atmosphere. But surprisingly, there was a ring. The finding makes Quaoar just the third dwarf planet or asteroid in the solar system known to have a ring, after the asteroid Chariklo and the dwarf planet Haumea (SN: 3/26/14; SN: 10/11/17).

    Even more surprisingly, “the ring is not where we expect,” Morgado says.

    Known rings around other objects lie within or near what’s called the Roche limit, an invisible line where the gravitational force of the main body peters out. Inside the limit, that force can rip a moon to shreds, turning it into a ring. Outside, the gravity between smaller particles is stronger than that from the main body, and rings will coalesce into one or several moons.

    “We always think of [the Roche limit] as straightforward,” Morgado says. “One side is a moon forming, the other side is a ring stable. And now this limit is not a limit.”

    For Quaoar’s far-out ring, there are a few possible explanations, Morgado says. Maybe the observers caught the ring at just the right moment, right before it turns into a moon. But that lucky timing seems unlikely, he notes.

    Maybe Quaoar’s known moon, Weywot, or some other unseen moon contributes gravity that holds the ring stable somehow. Or maybe the ring’s particles are colliding in such a way that they avoid sticking together and clumping into moons.

    The particles would have to be particularly bouncy for that to work, “like a ring of those bouncy balls from toy stores,” says planetary scientist David Jewitt of UCLA, who was not involved in the new work.

    The observation is solid, says Jewitt, who helped discover the first objects in the Kuiper Belt in the 1990s. But there’s no way to know yet which of the explanations is correct, if any, in part because there are no theoretical predictions for such far-out rings to compare with Quaoar’s situation.

    That’s par for the course when it comes to the Kuiper Belt. “Everything in the Kuiper Belt, basically, has been discovered, not predicted,” Jewitt says. “It’s the opposite of the classical model of science where people predict things and then confirm or reject them. People discover stuff by surprise, and everyone scrambles to explain it.”

    More observations of Quaoar, or more discoveries of seemingly misplaced rings elsewhere in the solar system, could help reveal what’s going on.

    “I have no doubt that in the near future a lot of people will start working with Quaoar to try to get this answer,” Morgado says. More

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    Neolithic complex dubbed ‘Stonehenge of the North’ opens to UK public

    Two sections of the Thornborough Henges near Ripon, UK, have been donated to the public body Historic England in an effort to preserve the millennia-old monuments

    Humans

    3 February 2023

    By Madeleine Cuff
    The central of the three Thornborough HengesHistoric England
    Thornborough Henges, a Neolithic complex near Ripon in North Yorkshire, UK, known as the “Stonehenge of the North”, has been donated to public ownership and is now open to visitors.  
    The site dates from 3500 to 2500 BC and features three earth circles, each 4 metres high and 200 metres across. The earthworks were probably used as ceremonial gathering places and trading centres by early Britons, archaeologists believe. 
    Two of the three henges have been donated to the public body Historic England by building firm Tarmac. They are now under the care of the charity English Heritage and are free for the public to visit. Lightwater Holdings, a local company, has also donated parts of the wider monument. Advertisement
    The henges are “a link to our ancient ancestors, through thousands of years, inspiring a sense of wonder and mystery”, Duncan Wilson at Historic England said in a statement.
    “We are thrilled to have acquired this highly significant site for the nation, ensuring that these magnificent monuments are safe and will be preserved for generations to come.” 
    The southern and central hengesHistoric England
    The transfer of ownership means the two earthworks will be removed from Historic England’s risk register. They have been on the register since 2009, over concerns the sites were being eroded by livestock and rabbits.  
    Today, all three henges are visible as large, circular banks, but thousands of years ago, they would have stood above wetlands. They may have been covered in a sulphate mineral known as gypsum, creating white landmarks visible for miles.  
    The site’s opening to the public will bring its story to new audiences, according to Kate Mavor at English Heritage. “Thornborough Henges is one of the most important ancient sites in Britain and yet almost completely unknown. We are looking forward to sharing its significance, its stories and its secrets with the public,” she said in a statement. 

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    Vikings brought horses and dogs to England, cremated bones confirm

    The first physical proof that Vikings brought horses and dogs to England has been unearthed

    Humans

    1 February 2023

    By Jeremy Hsu
    Excavations at Heath Wood in EnglandJulian Richards, University of York
    Archaeologists have uncovered the first physical evidence that confirms some Vikings shipped their own horses and dogs from Scandinavia to England.
    The animal bone evidence comes from a burial mound at the only known Viking cremation cemetery in the British Isles. The Heath Wood cemetery – located in what is now Derbyshire in central England – is believed to be a burial ground for the first large Viking army to travel to the country. The soldiers arrived in AD 873 on a campaign of … More

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    Neanderthals hunted enormous elephants that fed 100 people for a month

    The extinct straight-tusked elephant was even larger than modern African elephants, making it unclear if Neanderthal hunters could take one down, but a newly analysed trove of bones suggests it was possible

    Humans

    1 February 2023

    By Clare Wilson
    A reconstruction of the straight-tusked elephantLUTZ KINDLER, MONREPOS
    Neanderthals regularly hunted and butchered elephants in Europe thousands of years ago, according to an analysis of marks made by stone tools on a trove of bones.
    The find suggests the ancient humans either lived in larger groups than previously suspected or that they had ways of processing the flesh so it didn’t spoil, says Wil Roebroeks at Leiden University in the Netherlands, given the amount of meat involved. “These elephants are really big calorie bombs.”
    There has long been debate over whether Neanderthals, distant cousins of modern humans, could have hunted the straight-tusked elephants (Palaeoloxodon antiquus). These extinct giants stood 4 metres tall, making them larger than modern African elephants and woolly mammoths.Advertisement
    To find out more, Roebroeks’s team took a closer look at elephant bones found alongside other animal remains and stone tools in a quarry near Halle, Germany, which was dug out from the 1980s. The bones have been dated to about 125,000 years ago, when Neanderthals were the only humans known to be in the area.
    The remains were from more than 70 elephants, with a few found as nearly complete skeletons. The marks left on the bones suggest the animals were thoroughly butchered to obtain every last scrap of meat and fat – including, for instance their brains and all of the bulky fat pads in their feet.
    There were also few gnaw marks left by scavenging carnivores, suggesting little food was left on the carcass. “There’s maybe a bit of nibbling on isolated vertebra, but most of these remains were so clean they weren’t attractive for carnivores,” says team member Lutz Kindler at the Museum for Human Behavioural Evolution in Neuwied, Germany.
    The team has calculated that all the flesh from one of the elephants would have fed about 100 adults for a month. Some researchers have previously suggested that Neanderthals lived in fairly small groups of up to about 25 people, based on factors such as the size of their caves or analysis of their footprints. “There’s a perception they lived in small groups, but when you look for the evidence, there’s nothing,” says Clive Finlayson at the Gibraltar National Museum, who wasn’t involved in the new study.
    If a smaller group of, say, 25 people had killed an elephant, they would have had to spend about three to five days working to strip the carcass of flesh and processing it so that it wouldn’t spoil, for instance by drying or smoking it, says Roebroeks. The marks on the bones mean the meat wasn’t simply left to rot once the Neanderthals had eaten their fill.

    The team found a higher proportion of male and older elephants among the remains, suggesting that the Neanderthals were specifically targeting these animals, rather than scavenging from ones that had died of natural causes.
    This makes some sense, as in modern elephants older males tend to live alone. Targeting loners would making hunting easier, says Roebroeks, as they could be driven into traps or muddy shores. “Large mammals are [easier] to kill as long as you are able to limit their mobility, and then they are finished off with spears,” he says.
    Previous work has shown that Neanderthals may have cleared forests in the region where the bones were found, which also supports the idea they lived in larger groups.

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    Stunning photos show nomadic life of Mongolian goat herders

    Mongolia produces 40 per cent of the world’s cashmere supply from its goats, but climate change and overproduction are threatening this unique way of life

    Humans

    1 February 2023

    By Matteo Fagotto
    Ganbaatar Davaasuren (known as “Bukhuu”) in Uvurkhangai province, MongoliaMatilde Gattoni
    FORTY per cent of the world’s cashmere is sourced from the windswept plateau of Mongolia.
    Bukhuu’s 14-year-old son Mungun Huleg gathers the goats before selecting those that need to be combed that dayMatilde Gattoni
    The fabric is made from the undercoats of the local goats, which develop a particularly tight fur to survive the harsh winters, where temperatures can drop as low as -40°C. In past decades, cashmere has made a fortune for local herders, becoming the main source of income for a third of the Mongolian population.Advertisement
    Tserennadmid Khaltarkhuu cuts a baby goat’s ears to mark them with the help of his childrenMatilde Gattoni
    But lately climate change and overproduction have threatened the cashmere supply, and a unique way of life with it. In Mongolia, temperatures have warmed by more than 2°C in the past 80 years, above the world average, and could rise by up to 5°C by the end of the century. Milder winters – which can negatively affect the quality of cashmere – are now followed by long, dry springs and short summers, when not enough rain falls to sustain the pastures.
    Bukhuu’s father Davaasuren Tsogt sits outside his ger (a traditional Mongolian dwelling)Matilde Gattoni
    The global cashmere boom saw the number of goats skyrocket from 10.2 million to 26.5 million, causing overgrazing and desertification. Seventy per cent of Mongolia’s pastures are already considered degraded.
    A herd of goats on a wall built from stones from the Gobi desertMatilde Gattoni
    To address the problem, local herders are reviving traditional pastureland management practices. Cooperatives have also been set up to coordinate grazing and rotation between pastures, to give nature the chance to replenish itself, and the national government has imposed a tax on livestock to curb numbers.
    Orkhontuya Oidovdagva answers the family mobile phone from the centre of a ger, where the phone is left to hang all dayMatilde Gattoni
    But so far, no alternative source of income seems a ready substitute to a fabric that has provided an economic lifeline for a nomadic way of life that would otherwise have been lost.
    A goat being combedMatilde Gattoni

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    Don’t Miss: Innervate, an EP reflecting on epilepsy by Liza Bec

    New Scientist’s weekly round-up of the best books, films, TV series, games and more that you shouldn’t miss

    Humans

    1 February 2023

    BEN HUGHES
    Listen
    Innervate is an EP by composer Liza Bec (pictured above), who almost lost their performance career to a rare epilepsy triggered by playing music. The EP spotlights the roborecorder, an instrument they built. On release 10 February.

    Read
    The Meaning of Geese is teased out by Nick Acheson, whose epic bicycle adventures trace the incoming paths of pink-footed and brent geese as they arrive from Iceland and Siberia to fill the skies of his native Norfolk, UK. On sale from 9 February.
    Dan Weill
    Visit
    Drug experiments and forays into medicines, narcotics and everyday … More

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    Arch-Conspirator review: Ancient Greek tragedy spun into sci-fi gold

    Veronica Roth’s dystopian take on Sophocles’s 2500-year-old tragedy reminds us that human nature is timeless, finds Sally Adee

    Humans

    1 February 2023

    By Sally Adee
    In an unnamed dystopia, citizens face dangerous reproductive rulesGremlin/getty images
    Arch-Conspirator
    Veronica Roth (Tor)
    THERE isn’t much world-building in Veronica Roth’s sci-fi retelling of Sophocles’s classic Greek tragedy Antigone. Then again, in Arch-Conspirator, there isn’t much world. A dusty dystopian city (Thebes in the original, but it isn’t clear where we are in the reboot) is all that remains after a thinly sketched environmental polycrisis has turned humanity into an endangered species.
    Or, at least, that is what a reader surmises. The citizens don’t seem to know much about the arid … More

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    Impulse review: An authoritative, if dry, sexual behaviours manual

    Impulse: The science of sex and desire by psychiatrists Jon Grant and Samuel Chamberlain delivers on its bid to answer our hidden questions about sex, but it can be a little perfunctory

    Humans

    1 February 2023

    By Elle Hunt
    Everyone has a question about sex they would like answered – even if it is just “am I normal?”Beatriz Vera/shutterstock
    Impulse: The science of sex and desire
    Jon Grant and Samuel Chamberlain (Cambridge University Press)
    LET’S talk about sex – or not. Many of us have trouble striking the right tone or even finding the right words, caught between obfuscating with the birds and the bees or titillating with undue detail. For the topics too awkward to raise in person, there is always the internet, but its answers are many and highly variable.
    Factor … More