NASA spacecraft will slam into asteroid in first planetary-defence test

NASA will slam a multimillion-dollar spacecraft into an asteroid to test whether it is possible to change a space rock’s trajectory. This is only a test — the asteroid, Dimorphos, is not a threat to Earth. If the mission launches successfully next week, the Double Asteroid Redirection Test (DART) spacecraft will hit Dimorphos at 6.6 kilometres per second late next year. The impact should shrink Dimorphos’s orbit so that it orbits its companion asteroid at least 73 seconds faster than before — a change that will be detectable from Earth. A tiny probe funded by the Italian Space Agency will be launched from DART and will fly past to photograph the aftermath.

Electronegativity’s role in determining bond strengths needs to be rethought

Textbook knowledge about how to determine the strengths of chemical bonds seems to be oversimplified. Chemical bonds are usually stronger between atoms that have a larger difference in their electronegativity — which is influenced by the number of protons in the nucleus and the organisation of the electrons. But in some cases, researchers have found that differences in the sizes of the atom, rather than their electronegativity, determine the bond strength. The stability and length of chemical bonds are key factors in molecules’ structure and reactivity, so understanding them is important for developing everything from pharmaceuticals to materials.

Genes Reveal How Some Rockfish Live up to 200 Years

Some Pacific Ocean rockfishes can live for more than 200 years. Their secret to longevity: slowly growing large in the frigid depths. Researchers have found that the longest-lived rockfishes, a group that includes several species that can live for more than 105 years, have genes that indirectly affect lifespan by influencing size and adaptability. They also have more copies of genes linked to DNA maintenance and resisting the inflammation that often comes with age.

Diamond delivers long-sought mineral from the deep Earth

Small black specks in a diamond mined decades ago in Botswana have turned out to be a vital ingredient of the deep Earth. This is the first time the mineral has been identified in nature, after decades of searching.

Earth’s first continents emerged from the ocean 700m years earlier than thought

Earth’s first continents emerged from the ocean between 3.3 billion and 3.2 billion years ago, before the existence of plate tectonics. An analysis of rock sediments from India places the rise of the first stable continents some 700 million years earlier than previously thought. The rocks might have been formed by lava piling up from continuous volcanic activity on Earth’s crust, and floating above the water like an iceberg.

Astrophysicists unveil glut of gravitational-wave detections

Gravitational-wave observatories have released their latest catalogue of cosmic collisions, including one featuring the lightest neutron star ever detected in this way, as well as two clashes involving surprisingly large black holes. The detections come from the LIGO and Virgo observatories in the United States and Italy, respectively, which made the landmark first detection of gravitational waves in 2015.

Sponge cells hint at origins of nervous system

Sponges are expert filter feeders, straining tens of thousands of litres of water through their bodies every day to collect their food. And they do this without a brain, or a single neuron, to their name. Now, researchers have sequenced the RNA in various individual cells from a freshwater sponge (Spongilla lacustris) and found that sponges use an intricate cell communication system to regulate their feeding and to potentially weed out invading bacteria. The findings could help to understand how animals’ nervous systems evolved.

Honeybees use social distancing when mites threaten hives

Honey bees (Apis mellifera) change the way they interact with one another when infested with the mite Varroa destructor, a pathogen that can cause colony collapse. Researchers in Italy studied video recordings of the inside of hives and found that, in mite-infested hives, older members of the colony performed dances to direct other bees to food sources at the periphery, keeping them away from the centre — where young bees, the queen and brood cells are located. The researchers also observed more grooming activity, which can help to reduce the spread of parasites, at the centre of the infested hives.

Physicists fail to find mysterious 'sterile neutrino' particles

Researchers have, once again, failed to find any signs that hypothesised particles called sterile neutrinos exist. Neutrinos are some of the most abundant elementary particles in the Universe. There are three known types, but scientists have been searching for a fourth kind of neutrino for decades. If found, it could help to solve pressing problems in particle physics. Now, an experiment called MicroBooNE at the Fermi National Accelerator Laboratory did not turn up evidence of sterile neutrinos.

DNA reveals surprise ancestry of mysterious Chinese mummies

The genomes of 13 remarkably preserved 4,000-year-old mummies from China’s Tarim Basin suggest they weren’t migrants who brought technology from the West, as was previously supposed. Instead, the remains probably belong to Indigenous people who might have adopted agricultural methods from neighbouring groups. Researchers traced the ancestry of these early Chinese farmers to Stone Age hunter-gatherers who lived in Asia some 9,000 years ago.

Nearly 500 Mesoamerican monuments revealed by laser mapping — many for the first time

Scientists have uncovered nearly 500 ancient monuments in southern Mexico using an airborne laser mapping technology called lidar. Dating as far back as 3,000 years ago, the buried structures include huge artificial plateaus, built by the Olmec and Maya civilisations, that might have been used for ceremonial gatherings.

Signs of first planet found outside our galaxy

Astronomers have found hints of what could be the first planet ever discovered outside our galaxy. The possible planet, which is Saturn-sized, is in the Messier 51 galaxy, around 8 million parsecs away from the Milky Way. Nearly 5,000 planets orbiting stars beyond our Sun have been found so far, but all of these have been located within our galaxy.

Ancient DNA points to origins of modern domestic horses

Archæologists have used ancient DNA samples to identify the genetic homeland of modern horses, where the animals were first domesticated around 4,200 years ago. They found that modern domestic horses probably originated on the steppes around the Volga and Don rivers, now part of Russia, before spreading across Eurasia, ultimately replacing all pre-existing horse lineages.

Extinct Japanese wolf may hold clues to origins of dogs

The extinct Japanese wolf (Canis lupus hodophilax) might have come from a vanished population of grey wolves in east Asia that also gave rise to modern dogs. Researchers sequenced the genomes of nine specimens of the species (the last one was killed in 1905) to find where it sits on the canine evolutionary tree. The results, which have not yet been peer reviewed, show the Japanese wolf to be more closely related to the ancestor of dogs than are any other wolves found so far.

Physicists make most precise measurement ever of neutron’s lifetime

Physicists have measured the lifetime of the neutron more precisely than ever before. The average time it takes for the subatomic particle to decay is 877.75 seconds, according to an experiment that used magnetic fields to trap ultra-cold neutrons. The results have twice the precision of similar measurements, and are consistent with theoretical calculations. But they do not explain why neutrons live nearly 10 seconds longer in a different experiment that involves watching the particles decay as they move in a beam.

Blogger Comments:

The discrepancy might be explained by special relativity, according to which "clocks tick relatively more slowly" (time expands) for neutrons travelling in a beam.

First mission to the Trojan asteroids

The first spacecraft to journey to the Trojan asteroids, which share Jupiter’s orbit around the Sun, is set to lift off on 16 October. NASA’s Lucy mission — named after the iconic hominid fossil — will spend the next 12 years performing gravitational gymnastics to swoop past six of the asteroids. The Trojans probably formed when the planets were just coalescing, so exploring them can reveal more about the birth of the Solar System.

Evidence for tobacco use going back to the Pleistocene

Hunter-gatherers in North America might have been using tobacco around 12,300 years ago — 9,000 years earlier than was previously documented. Archaeologists found four burnt tobacco-plant seeds in an ancient hearth excavated in Utah. The seeds themselves were too small and fragile to be dated, but other burned woody material in the hearth is around 12,300 years old.

Jupiter’s Great Red Spot is swirling faster

The winds spinning around the outer edge of Jupiter’s striking Great Red Spot are speeding up, according to long-term observations by the Hubble telescope. Observations over the past century have already revealed that the storm is mysteriously shrinking. Hubble data collected between 2009 and 2020 add a new twist. Compared with a decade ago, when wind speeds in the Great Red Spot’s outer ring were typically just above 90 metres per second, they now exceed 100 metres per second.

First image of a solid made of electrons

If the conditions are just right, some of the electrons inside a material will arrange themselves into a tidy honeycomb pattern — like a solid within a solid. Physicists have now for the first time directly imaged these ‘Wigner crystals’, named after theorist Eugene Wigner. Researchers built a device containing atom-thin layers of two semiconductors and cooled it to just a few degrees above absolute zero. This slowed the electrons between the two layers enough so that they formed the elusive material.

Exoplanet May Be Orbiting 3 Stars at Once

A bizarre feature in a distant star system might be caused by the first known planet that orbits three stars. GW Orionis is surrounded by a spiralling disc of gas and dust — typical for a young star system. But this disc is split into rings, and the outer ring is tilted at an angle. Detailed modelling of the system suggests that the best explanation is a giant gassy planet carving out its orbits in its first million years of existence.

Fossil of large penguin provides a new window into New Zealand’s long-lost past

In 2006, children from a junior naturalists’ club in New Zealand discovered the fossilised remains of a penguin the size of a ten-year-old child. Standing about 1.38 metres tall, the giant bird turns out to be a new species that was taller than other ancient giant penguins, as well as the tallest modern penguin, the 1.2-metre-tall emperor (Aptenodytes forsteri). Researchers named the species Kairuku waewaeroa; the second part of the name is Māori for ‘long legs’.

Ancient footprints could be oldest traces of humans in the Americas

Human footprints from an ancient lakeshore in what is now New Mexico seem to be between 21,000 and 23,000 years old. If the dating is accurate, the prints represent the earliest unequivocal evidence of human occupation anywhere in the Americas. The footprints contribute to ongoing debate about whether human settlers from Siberia skirted down the Pacific coast of the Americas or waited until ice-age glaciers retreated from inland routes.

Saudi Arabia camel carvings dated to neolithic period

Stunning reliefs of camels in a rock formation in Saudi Arabia are far older than was first thought: they were carved more than 7,000 years ago, when the climate of Arabian Peninsula was markedly cooler and wetter than it is today. The revised estimate means that the camels are probably the world’s oldest surviving large-scale animal reliefs. Ancient builders seem to have restored the reliefs time and again as the animal features eroded, and the monuments might have retained their form and function for millennia.

Extinction of Indigenous languages leads to loss of exclusive knowledge about medicinal plants

Threatened Indigenous languages convey unique knowledge of medicinal plants. Researchers analysed ethnobotanical datasets for North America, northwest Amazonia and New Guinea, which link more than 3,500 medicinal-plant species with 236 Indigenous languages. They found that 75% of the medicinal uses for these species are known in only one language. And those languages are the ones at greatest risk of being lost forever.

Single-cell proteomics takes centre stage

Most single-cell studies focus on nucleic acids, especially the transcriptome, which represents all the expressed genes in a cell. That’s about to change. Advances in instrumentation, analytical tools and sample preparation are allowing a closer look at the cell’s ‘worker bees’: the proteins.

New type of dark energy could solve Universe expansion mystery

A previously unknown, primordial form of dark energy could explain why the cosmos now seems to be expanding faster than theory predicts. This second type of dark energy — the ubiquitous but enigmatic substance that is pushing the current expansion of the Universe to accelerate — might have existed in the first 300,000 years after the Big Bang. If the findings are confirmed, they could help to solve a long-standing conundrum surrounding data about the early Universe, which seem to be incompatible with today’s measured rate of cosmic expansion.

Made-Up Sounds Convey Meaning across Cultures

Nonsense words can be recognisable to people around the world — and not just when they’re onomatopoeic. Researchers asked English-speaking people, mostly from the United States, to make up sounds to represent a wide range of concepts, including ‘sleep’, ‘tiger’, ‘many’ and ‘good’. These vocalisations were played for volunteers in 7 countries, who spoke a total of 28 languages, and had to guess the sounds’ meanings from a list of options. Across the board, people guessed the intended meanings at rates better than chance. The findings might hint at ‘iconic’ sounds that serve as the foundations for language.

Wave-particle duality quantified for the first time

One of quantum physics’s most bizarre and fundamental concepts — that quantum objects behave both as particles and as waves — has a new and more quantitative foundation. Researchers have reimagined the archetypal double-slit experiment, using lasers and lithium niobate crystals to create two photons with a single quantum state. One photon’s wave-like nature was quantified using the interference pattern it created in an interferometer. The other photon’s particle-like qualities were measured by observing its trajectory. What’s more, scientists were able to tweak the lasers to test how the source influenced a single quantum particle’s wave–particle duality. This revealed how the whole system — photons, sources and detectors — is linked by quantum entanglement.

Fossil DNA hints at mysterious Toalean Culture

The 7,000-year-old skeleton of a teenage hunter-gatherer from Sulawesi in Indonesia might be the first remains found from a mysterious, ancient culture known as the Toaleans. Sulawesi has some of the world’s oldest cave art, but ancient human remains have been scarce on the island. The largely complete fossil of a roughly 18-year-old Stone Age woman was found in 2015, buried in the fœtal position in a limestone cave. DNA extracted from the skull suggests that she shared ancestry with New Guineans and Aboriginal Australians, as well with the extinct Denisovan subspecies of ancient human. The Toalean people, known only from scant archæological evidence, such as distinctively notched stone tools, were thought to have lived in Sulawesi at around the same time.

Saturn might have a fluid, sloshy core

Saturn’s core might be a slushy mixture of ice and rock, rather than a compact solid made of mostly one or the other material, as is generally thought. The diffuse core extends to approximately 60% of the planet’s radius — much bigger than the 10–20% of a planet’s radius that would be occupied by the expected core. Researchers gleaned the surprising discovery by analysing gravitational perturbations in the planet’s rings caused by the oscillating core.

Pi calculated to the 62.8 trillionth digit

Researchers have broken a world record by calculating the mathematical constant pi to 62.8 trillion digits, beating the previous record of 50 trillion digits. The calculation took a supercomputer 108 days to complete. Researchers say the effort was an important benchmarking exercise for computational hardware and software.

Baby bats babble like human infants

Pups of the greater sac-winged bat develop their vocal skills by babbling in a similar way to human babies — a discovery that could help researchers to explore the underlying neuroscience of how mammals learn to communicate. Human infants babble to practise speech sounds, which require precise motor control over their voice boxes, research suggests. Young songbirds also babble, but there are very few other recorded examples of babbling behaviour among animals — the bat research is the first to identify baby babble produced by a mammal that isn’t a primate.

Cuttlefish Memory Abilities

Cuttlefish can remember what, when and where information about specific things that happened — right up to their final days. Researchers taught six older common cuttlefish (Sepia officinalis) that a seafood snack in their tanks changed location depending on the time of day. The old cuttlefish learnt to associate the time and location just as well as six young cuttlefish did.

Mammoth’s epic travels preserved in tusk

Researchers have reconstructed the detailed movements of a single woolly mammoth (Mammuthus primigenius) from one of its tusks. Every place on Earth has a distinct chemical signature based on geological differences. The ratios of various isotopes of elements, such as strontium and oxygen in the bedrock and water, create a unique profile specific to that location that remains consistent over millennia, and is incorporated into soil and plants. As mammoths grazed on the Arctic plains, these isotopic signatures were integrated into their ever-growing tusks, creating a permanent record of the animals’ whereabouts from birth to death, with almost daily resolution.

Exotic four-quark particle spotted at Large Hadron Collider

Scientists using the Large Hadron Collider (LHC) — which memorably revealed the Higgs boson in 2012 — have discovered a previously unknown exotic particle made of four quarks. The new ‘tetraquark’, Tcc+, is extremely unusual: most known hadrons, including protons and neutrons, are made of two or three quarks. This brings the LHC’s bounty of new hadrons — non-elementary particles that are made of quarks — up to 62.

Astronomers detect light behind black hole for first time

Astronomers have detected light behind a supermassive black hole at the centre of a galaxy 245 million parsecs away. As well as spotting bright flares of X-rays bursting from the black hole, telescopes picked up unexpected ‘luminous echoes’, smaller and later X-ray flashes.

Sponge-like fossil could be Earth’s earliest known animal

Most major groups of animals first appear in the fossil record during the Cambrian explosion, 541 million years ago. But fossils resembling sponges found in northwestern Canada could be 350 million years older, significantly pushing back the date of Earth’s earliest-known animals.

Massive DNA structures perplex scientists

Scientists analysed samples from muddy sites in the western United States and found DNA structures that seem to scavenge and ‘assimilate’ genes from microorganisms in their environment. These extra-long DNA strands join a diverse collection of genetic structures — circular plasmids, for example — known as extrachromosomal elements.

Dolphins learn their teammates’ names

Male dolphins learn the signature whistles — unique ‘names’ given to dolphins by their mothers — of each member of their extensive, lifelong network of allies. The finding suggests that the cetaceans have a concept of team membership — a first in the animal kingdom. Scientists used underwater sound systems and drones to observe how dolphins responded to each other’s hails. The animals were quickest to heed the call of pals who had helped them in the past.

Extinct beetle species found in coprolite

The only known members of an extinct family of beetles have been found in the fossilised fæces of a Triassic reptile. Several Triamyxa coprolithica were spotted in the coprolite, some still sporting their delicate legs and antennae. Researchers used synchrotron microtomography to construct a 3D image of the interior of dung presumed to have been excreted by Silesaurus opolensis, an ancestor of the dinosaurs.

Mysterious skull fossils expand human family tree

Fossils found in Israel hint that a previously unknown group of hominins — the Nesher Ramla people — were the direct ancestors of Neanderthals. And researchers have suggested that an ancient human skull found in China in the 1930s could belong to a new species, Homo longi (Dragon Man), which might be an even closer relative of modern humans than are Neanderthals. But both findings have sparked debate among scientists. The studies are based on analyses of the size, shape and structure of fossilised bones — methods that are subject to individual judgement and interpretation. As is often the case for fossil finds, there is no DNA evidence.

Ancient Siberian cave hosted Neanderthals, Denisovans, and modern humans—possibly at the same time

In the past decade, a mere eight human fossils unearthed in the Denisova Cave in southern Siberia have rewritten the human story, from the tiny finger bone that revealed the extinct human Denisovans, to the discovery of a first-generation Neanderthal–Denisovan hybrid. Now a study of DNA in the cave’s soil reveals the complex history of human and animal habitation there. Hundreds of soil samples show a cycle of inhabitants, starting with Denisovans about 300,000 years ago. Different groups of Denisovans and Neanderthals left their marks on the cave, and modern humans appeared about 45,000 years ago.

Neolithic Diets Before The Domestication Of Crops

The people who built the ancient monumental structures at Turkey’s Göbekli Tepe were fuelled by vat-fulls of starchy porridge and stew, not just meaty feasts. Archæologists are uncovering evidence that ancient people were grinding grains for hearty, starchy dishes long before we domesticated crops. These discoveries shred the long-standing idea that early people subsisted mainly on meat.

Giant rhino unearthed in China

A new species of ancient giant rhino, Paraceratherium linxiaense, weighed about 21 tonnes and could reach up to 7 metres high. But they wouldn't have had the rhino’s namesake horn — which evolved later — and would have looked more like a really, really big horse.

Quantum microscope can examine cells in unprecedented detail

A microscope that harnesses quantum entanglement can image biological structures with unprecedented sharpness. The technique ‘squeezes’ light to produce correlations between photons in one of the lasers used by an optical imaging method called stimulated Raman scattering gain microscopy. The squeezed light suppresses noise in the microscope’s signal, improving the sensitivity.

Mysterious fast radio bursts come in two distinct flavours

A bumper crop of fast radio bursts (FRBs) shows that the mysterious signals come in two distinct types. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope has detected 535 FRBs — quadrupling the known tally of these powerful cosmic flashes, which flare for just milliseconds. Most of them are one-offs, but a minority repeat periodically and last at least ten times longer than average. The findings suggest that FRBs might originate from at least two astrophysical phenomena — bringing us a step closer to solving one of astronomy’s biggest puzzles.

Microfossils reveal mysterious shark die-off

Up to 90% of the global shark population was wiped out in a mass extinction around 19 million years ago. Researchers identified the disappearance by studying microfossils in deep-sea sediment cores collected in the North and South Pacific oceans. After thriving for some 40 million years, shark numbers and diversity suddenly dropped and have not recovered since.

Radioactivity May Fuel Life Deep Underground and Inside Other Worlds

Scientists have long puzzled over how microbes living deep underground feed themselves without sunlight or heat. Now, two studies suggest that these organisms could feed off the radioactive decay of hydrogen and other elements. The findings open up new possibilities for life on other worlds — and could shed some light on our planet’s own history.

How Slime Moulds Remember Where They Ate

The slime mould Physarum polycephalum has no brain or nervous system — yet it somehow ‘remembers’ the location of food that it ate. Slime moulds are simple organisms made up of interlacing tubes — but previous research has shown they can solve complex problems, such as finding the shortest path through a maze. Scientists found that when parts of P. polycephalum come into contact with a food source, they release a substance that softens the gel-like walls of its tubes, making them widen. The slime mould moves by expanding along wider tubes and pruning narrower ones, so the enlarged tubes effectively record past food sites.

Prehistoric carvings of red deer found in Scottish neolithic tomb

Rock carvings depicting red deer have been found in a Bronze Age burial mound in Scotland. Archaeology graduate Hamish Fenton discovered the carvings by chance while visiting Kilmartin Glen in Argyll, an area known for Neolithic and Bronze Age sites. They are between 4,000 and 5,000 years old, the oldest known carvings of this type in the United Kingdom.

The most detailed 3D map of the Universe ever made

A survey of the southern sky has reconstructed how mass is spread across space and time in the biggest study of its kind. Cosmologists observed the sky between 2013 and 2019 using a 570-megapixel camera at the Víctor M. Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. The resulting 3D cosmic map provides a record of the Universe’s history. By tracking how galaxies spread out over time, researchers can measure the forces at play. These include the gravitational pull of dark matter — the invisible stuff that constitutes some 80% of the Universe’s mass — and dark energy, the mysterious force that appears to be pushing the Universe to accelerate its expansion.