marketrent
marketrent OP t1_iwr9vu5 wrote
Reply to Rats bop to the beat of music by Mozart, Lady Gaga, Queen; bopping was previously thought to be an ability innately unique to humans by marketrent
Excerpt:
>While animals also react to hearing noise, or might make rhythmic sounds, or be trained to respond to music, this isn’t the same as the complex neural and motor processes that work together to enable us to naturally recognize the beat in a song, respond to it or even predict it. This is referred to as beat synchronicity.
>Only relatively recently, research studies (and home videos) have shown that some animals seem to share our urge to move to the groove.
>A new paper by a team at the University of Tokyo provides evidence that rats are one of them.
>“Rats displayed innate — that is, without any training or prior exposure to music — beat synchronization most distinctly within 120-140 bpm (beats per minute), to which humans also exhibit the clearest beat synchronization,” explained Associate Professor Hirokazu Takahashi from the Graduate School of Information Science and Technology.
>“The auditory cortex, the region of our brain that processes sound, was also tuned to 120-140 bpm, which we were able to explain using our mathematical model of brain adaptation.”
>Although the main study focused on responses to K. 448 by Mozart, four other musical pieces were also played to the human and animal participants: Born This Way by Lady Gaga, Another One Bites the Dust by Queen, Beat It by Michael Jackson and Sugar by Maroon 5.
Science Advances, DOI 10.1126/sciadv.abo7019
marketrent OP t1_iwn899a wrote
Reply to comment by mechadracula in Early meteorites brought enough water to Mars to create a global ocean — Meteorites bombarding the Red Planet may have carried so much water that it could have covered the planet in a layer 300 metres deep if spread out, while also depositing molecules essential for life by marketrent
>mechadracula
>"Martin Bizzarro" is a supervillain name if I've ever heard one.
Further reading:
>Martin Bizzarro
>Professor
>Centre for Star and Planet Formation
>My research is focused on understanding the earliest evolution of our solar system through the use of high-precision isotope ratio measurements in extraterrestrial materials. I am currently director of the Center for Star and Planet Formation (www.starplan.dk), a multidisciplinary centre of excellence for research in cosmochemistry, astrophysics and astronomy located at the Natural National History Museum of Denmark.
Source: https://globe.ku.dk/staff-list/?pure=en/persons/283253
marketrent OP t1_iwmu5r5 wrote
Reply to Early meteorites brought enough water to Mars to create a global ocean — Meteorites bombarding the Red Planet may have carried so much water that it could have covered the planet in a layer 300 metres deep if spread out, while also depositing molecules essential for life by marketrent
Jacklin Kwan, 16 November 2022.
Excerpt:
>Martin Bizzarro at the University of Copenhagen in Denmark and his colleagues have analysed the concentration of a rare chromium isotope, known as chromium-54, in samples of meteorites that have come to Earth from Mars to estimate how much water was deposited on the Red Planet by asteroids.
>“It’s a bit like DNA,” says Bizzarro. “Carbonaceous-type asteroids have a very distinct chromium isotope composition relative to the inner solar system.”
>
>If the original bombarding asteroids were just 10 per cent water, the lower limit for C-type meteorites, they would have deposited enough of the molecule to create a global ocean, say the researchers. If spread out over the whole planet, the water would form a layer 300 metres deep.
>“I think this is the first time where we have a smoking gun,” says Bizzarro, and we can finally say with certainty that water-rich asteroids hit Mars’s surface.
>C-type asteroids also contain elements that are essential to life.
>This means that two of the most important ingredients necessary to life – organic molecules and water – were present on Mars during a time before Earth’s moon even formed, say the researchers.
Science Advances, DOI 10.1126/sciadv.abp8415
marketrent OP t1_iwdflb7 wrote
Reply to Known since Aristotle, no one understood the argonaut octopus—until a 19th-century seamstress turned naturalist took it upon herself to solve its mysteries by marketrent
Excerpt:
>The argonaut octopus, of the family Argonautidae, belongs to a group of pale pink-spotted octopuses. Unlike the heroes that sailed the Argo, these octopuses are known for traversing the open ocean by way of a delicate, curved, creamy white vessel—an external casing, often referred to as a “shell,” that gave them their common nickname, the “paper nautilus.”
>These creatures baffled naturalists and philosophers for two millennia, even fooling Aristotle, who believed that they used their large pair of webbed dorsal arms as “a sail” to catch the briny breeze and floated across the ocean’s surface like paper boats.
>“It uses [the thin webs], when a breeze is blowing, for a sail, and lets down some of its feelers alongside as rudder-oars,” Aristotle wrote of the paper nautilus.
>These myths carried weight for centuries, even among naturalists in the 19th century.
>
>It wasn’t until the early 1830s when self-taught French naturalist, Jeanne Villepreux-Power began researching the Argonauta argo, or the greater argonaut, that we learned the true origins of their “shells.”
>In the 1800s, most scientists believed that the shell was made by another animal—that argonauts lived in them the same way that a hermit crab will go find a snail shell or a mollusk shell to live in, Finn says. Once the octopus grew too large for the shell, it would abandon the shelter and either search, steal, or kill the original inhabitant for a larger shell.
>But, Jeanne Villepreux-Power sided with the opposite side of the debate: The argonauts were the builders of their cases.
Lauren J. Young, June 20, 2018
marketrent OP t1_iwa77q0 wrote
Reply to New evidence establishes that footprints found at Matalascañas in southern Spain are 295,800 years old, indicating pre-Neanderthal hominin settlement in the Middle Pleistocene age by marketrent
Eduardo Mayoral, Jérémy Duveau, Ana Santos, Antonio Rodríguez Ramírez, Juan A. Morales, Ricardo Díaz-Delgado, Jorge Rivera-Silva, Asier Gómez-Olivencia & Ignacio Díaz-Martínez; 19 October 2022.
Abstract excerpt:
>In this paper, we report new Optically Stimulated Luminescence dating that places the hominin footprints surface in the range of 295.8 ± 17 ka (MIS 9-MIS 8 transition, Middle Pleistocene).
>This new age implies that the possible track-makers are individuals more likely from the Neandertal evolutionary lineage. Regardless of the taxon attributed to the Matalascañas footprints, they supplement the existing partial fossil record for the European Middle Pleistocene Hominins being notably the first palaeoanthropological evidence (hominin skeleton or footprints) from the MIS 9 and MIS 8 transition discovered in the Iberian Peninsula, a moment of climatic evolution from warm to cool.
>Thus, the Matalascañas footprints represent a crucial record for understanding human occupations in Europe in the Pleistocene.
Scientific Reports, DOI 10.1038/s41598-022-22524-2
marketrent OP t1_iw09sip wrote
Reply to ‘One of the greatest damn mysteries of physics’: we studied distant suns in the most precise astronomical test of electromagnetism yet by marketrent
Michael Murphy, 11 November 2022 06:00 GMT+11.
Excerpt:
>Our theory of electromagnetism is arguably the best physical theory humans have ever made – but it has no answer for why electromagnetism is as strong as it is.
>Only experiments can tell you electromagnetism’s strength, which is measured by a number called α (aka alpha, or the fine-structure constant).
>The American physicist Richard Feynman, who helped come up with the theory, called this “one of the greatest damn mysteries of physics” and urged physicists to “put this number up on their wall and worry about it”.
>
>In research just published in Science, we decided to test whether α is the same in different places within our galaxy by studying stars that are almost identical twins of our Sun.
>From [spectra of Sun-like stars], we have shown that α was the same in the 17 solar twins to an astonishing precision: just 50 parts per billion.
>That’s like comparing your height to the circumference of Earth. It’s the most precise astronomical test of α ever performed.
Science, DOI 10.1126/science.abi9232
marketrent OP t1_ivvn171 wrote
Reply to NASA leaders recently viewed footage of an underwater dive off the East coast of Florida, and they confirm it depicts an artifact from the space shuttle Challenger by marketrent
Excerpt:
>The artifact was discovered by a TV documentary crew seeking the wreckage of a World War II-era aircraft. Divers noticed a large humanmade object covered partially by sand on the seafloor.
>The proximity to the Florida Space Coast, along with the item’s modern construction and presence of 8-inch square tiles, led the documentary team to contact NASA.
>“While it has been nearly 37 years since seven daring and brave explorers lost their lives aboard Challenger, this tragedy will forever be seared in the collective memory of our country. For millions around the globe, myself included, Jan. 28, 1986, still feels like yesterday,” said NASA Administrator Bill Nelson.
>“This discovery gives us an opportunity to pause once again, to uplift the legacies of the seven pioneers we lost, and to reflect on how this tragedy changed us. At NASA, the core value of safety is – and must forever remain – our top priority, especially as our missions explore more of the cosmos than ever before.”
>A major malfunction 73 seconds after liftoff resulted in the loss of Challenger and the seven astronauts aboard.
ETA:
NASA, November 10, 2022 ~10:00 GMT-5.
marketrent OP t1_ivsisx2 wrote
Reply to A first-of-its-kind experiment simulating the cosmos with ultracold potassium atoms suggests that in a curved, expanding universe pairs of particles pop up out of empty space by marketrent
Excerpt:
>Markus Oberthaler at Heidelberg University in Germany and his colleagues cooled more than 20,000 potassium atoms in a vacuum, using lasers to slow them down and lower their temperature to about 60 nanokelvin, or 60 billionths of a degree kelvin above absolute zero.
>At this temperature, the atoms formed a cloud about the width of a human hair and, instead of freezing, they became a quantum, fluid-like phase of matter called a Bose-Einstein condensate. Atoms in this phase can be controlled by shining light on them – using a tiny projector, the researchers precisely set the atoms’ density, arrangement in space and the forces they exert on each other.
>By changing these properties, the team made the atoms follow an equation called a space-time metric, which, in an actual, full-scale universe, determines how curved it is, how fast light travels and how much light must bend near very massive objects. This is the first experiment that has used cold atoms to simulate a curved and expanding universe, says Oberthaler.
Nature, DOI 10.1038/s41586-022-05313-9
marketrent OP t1_iv93kc9 wrote
Excerpt:
>GENEVA, Nov 5 (Reuters) - The U.N. High Commissioner for Human Rights, Volker Türk, on Saturday issued an open letter to Elon Musk, the new owner of Twitter Inc, urging him to "ensure human rights are central to the management of Twitter".
>Twitter Inc laid off half its workforce on Friday and tweets by staff of the social media company said the team responsible for human rights was among those affected, a development which Türk described as not "an encouraging start".
>"Twitter is part of a global revolution that has transformed how we communicate," Türk said in the letter. "But I write with concern and apprehension about our digital public square and Twitter's role in it."
>^Writing ^by ^Paul ^Carrel; ^editing ^by ^Jason ^Neely
Open letter from Volker Türk, United Nations High Commissioner for Human Rights, 5 November 2022, https://www.ohchr.org/sites/default/files/documents/press/2022-11-05/22-11-05_Letter_HC_to_Mr_Elon_Musk.pdf
marketrent OP t1_iv3ye7g wrote
Reply to New modelling shows how climate change may alter wave height and wave direction in New Zealand, with consequences for coastal erosion by marketrent
João Albuquerque, Jose A. A. Antolínez, Fernando J. Méndez, Giovanni Coco; published 3 November 2022.
Abstract excerpt:
>Wave climatologies from historical and projected simulations of the ACCESS1.0, MIROC5 and CNRM-CM5 Global Circulation Models (GCM) were sourced from the Coordinated Ocean Wave Climate Project (COWCLIP) and downscaled using the SWAN wave model.
>Biases between GCM's historical simulations and a regional hindcast were assessed, and the two best-performing models (ACCESS1.0, MIROC5) had their projections analysed.
>The areas of statistically significant changes are larger in the END21C than in the NEA21C period. The wave direction change is counter-clockwise along the west and clockwise along the east coasts.
>This study is a first assessment of historical and projected GCM-forced waves along New Zealand and the database we generated can be of great value for renewable energy research, risk assessment and the mitigation of future coastal hazards.
New Zealand Journal of Marine and Freshwater Research, DOI 10.1080/00288330.2022.2135116
marketrent t1_iuzadwp wrote
Thanks. I like this:
>Lorraine Daston
>I think of history as a discipline, one that invented and is still inventing ever new rigorous methods for not only the cross-examination of the sources we have, but even more importantly, the discovery of sources we don’t yet have.
>I look upon the integration of many different strands of evidence braided together into a strong rope of argument in history as identical, philosophically to the practices of any science. This is one of the reasons why the history of science is, of use to science and scholarship.
>All of these methods, which constitute, taken in toto, rigor in any given scholarly or scientific discipline develop at different times under different circumstances.
>Without knowledge of how differently, for example, in medicine, clinical observation and randomized clinical trials developed, you have no clue, no foothold in the next task, which is: how do you weigh these two kinds of evidence? How do you integrate them?
>And that holds, I think, mutatis mutandis, for all scientific disciplines. So that’s one good reason why the history of science is of use to not only the sciences, but all branches of scholarship.
marketrent OP t1_iuk588c wrote
Reply to Number of Indigenous Australians in prisons more than doubles, despite drop in crime rates by marketrent
Excerpt:
>Australia's incarceration rate has doubled in the last three decades, and more than doubled among Indigenous Australians, with First Nations children jailed at 20 times the rate of non-First Nations children.
>The rate has risen from one per cent of Indigenous Australians in 1990 to 2.3 per cent in 2022.
>The figure is even higher in states such as WA [Western Australia], where 3.5 per cent of Indigenous adults are behind bars.
>The figures come despite the country's crime rate decreasing in the same period.
>As of this year, the national incarceration rate is 202 prisoners per 100,000 adults, compared to just 96 per 100,000 in 1985.
SBS News
marketrent OP t1_iujzzjt wrote
Excerpt:
>While about 2% of the genome of all people descended from those living outside Africa is derived from Neanderthals, there is very little evidence that this process went the other way.
>A new paper, published in the journal PaleoAnthropology, raises the prospect that interbreeding with our ancestors would have reduced the number of Neanderthals breeding with each other, leading to their eventual extinction.
>Though only 32 Neanderthal genomes have been sequenced to date, leaving it possible that the lack of Homo sapiens DNA in their genome is actually a quirk of sampling, the authors hope advances in DNA sequencing technology will be able to resolve this hypothesis by making more genomes available.
>
>Professor Chris Stringer, the Museum's Research Leader in Human Evolution, authored the new paper alongside colleague Dr Lucile Crété.
>Chris says, 'Our knowledge of the interaction between Homo sapiens and Neanderthals has got more complex in the last few years, but it's still rare to see scientific discussion of how the interbreeding between the groups actually happened.'
>'We propose that this behaviour could have led to the Neanderthals' extinction if they were regularly breeding with Homo sapiens, which could have eroded their population until they disappeared.'
>
>Neanderthals and Homo sapiens diverged from each other around 600,000 years ago and evolved in very different areas of the world.
>From genetic data, it looks like the two species first encountered each other when Homo sapiens began making occasional forays out of Africa about 250,000 years ago.
>However, the Neanderthal genes we have in us today are not the result of these early sporadic interactions Homo sapiens had when they first left Africa. Instead, they come from the much larger migrations that modern humans undertook around 60,000 years ago.
PaleoAnthropology, 27 October 2022, DOI 10.48738/2022.iss2.130
marketrent OP t1_iugu4tu wrote
Excerpt:
>Cities in central China hastily drew up plans to isolate migrant workers fleeing to their hometowns from a vast assembly facility of iPhone maker Foxconn in COVID-hit Zhengzhou, fearing they could trigger coronavirus outbreaks.
>Zhengzhou, capital of central Henan province, reported 167 locally transmitted COVID-19 cases in the seven days to Oct. 29, up from 97 infections in the prior seven-day period.
>Apple supplier Foxconn, based in Taiwan, currently has about 200,000 workers at its Zhengzhou complex and has not disclosed the number of infected workers, but said on Sunday that it would not stop workers from leaving.
>Late on Saturday, cities near Zhengzhou, including Yuzhou, Changge and Qinyang, urged Foxconn workers to report to local authorities in advance before heading home.
>Under China's ultra-strict zero-COVID policy, cities are mandated to act swiftly to quell any outbreaks, with measures that could include full-scale lockdowns.
Swiss Broadcasting Corporation/Reuters
marketrent OP t1_iudmfox wrote
Excerpt:
>Gunmen attacked a major Shiite holy site in Iran on Wednesday, killing at least 15 people and wounding dozens.
>The official website of the judiciary said two gunmen were arrested and a third is on the run after the attack on the Shah Cheragh mosque, the second holiest site in Iran.
>The state-run IRNA news agency reported the death toll and state TV said 40 people were wounded.
>The Islamic State group late Wednesday claimed responsibility for the attack on its Amaq news agency. It said an armed IS militant stormed the shrine and opened fire on its visitors. It claimed that some 20 people were killed and dozens more were wounded.
The Associated Press October 27, 2022
marketrent OP t1_iubd787 wrote
Reply to Lidar technology unearthed tropical megapolis beneath forest canopy of the Calakmul Biosphere | Ancient Maya by marketrent
Excerpt:
>Although the number of people who lived at Calakmul during the height of the Snake King’s rule was not a complete surprise because of previous mapping and archaeological investigations by the Autonomous University of Campeche and INAH [Instituto Nacional de Antropología e Historia], the team was astonished at the scale and degree of urban construction.
>Immense apartment-style residential compounds have been identified throughout the surveyed area, some with as many as 60 individual structures, the seats of large households composed of extended families and affiliated members. These large residential units were clustered around numerous temples, shrines, and possible marketplaces, making Calakmul one of the largest cities in the Americas at 700 AD.
>But that’s not all the team was able to see.
>“We were also able to see that the magnitude of landscape modification equaled the scale of the urban population,” explains [UCalgary’s] Reese-Taylor. “All available land was covered with water canals, terraces, walls, and dams, no doubt to provide maximum food and water security for the city dwellers.”
marketrent OP t1_iu5sag9 wrote
"A man's pair of trousers exploded with a loud report. Fortunately the owner was not in them at the time" the North Island’s Hutt News printed on August 12, 1931. "Although dazed by the force of the explosion, was able to seize the garment, which was hanging before the fire, and hurl it out on to the grass outside.
“There is nothing visible to warn the owner that the affected portion of the dried out clothing may catch fire (or even explode) by coming near a fire (there need not be actual contact with flame or spark), or by friction, or by the concussion of a sudden blow. Even sunheat can cause ignition.”
Farmers sprayed sodium chlorate on ragwort – an introduced species with poor effects for livestock – and trousers with the residual chemical became flammable.
• Watson, J. (2004). The Significance of Mr. Richard Buckley’s Exploding Trousers: Reflections on an Aspect of Technological Change in New Zealand Dairy Farming between the World Wars. Agricultural History, 78(3), 346–360. http://www.jstor.org/stable/3744710
marketrent t1_iu22lb0 wrote
Reply to Magma on Mars Likely - Until now, Mars has been generally considered a geologically dead planet. An international team of researchers led by ETH Zurich now reports that seismic signals indicate volcanism still plays an active role in shaping the Martian surface. by GeoGeoGeoGeo
Cerberus marsquake magma is an otherworldly discovery!
From the linked release by ETH Zurich:
>An international team of researchers, led by ETH Zurich, analysed a cluster of more than 20 recent marsquakes that originated in the Cerberus Fossae graben system.
>From the seismic data, scientists concluded that the low-frequency quakes indicate a potentially warm source that could be explained by present day molten lava, i.e., magma at that depth, and volcanic activity on Mars. Specifically, they found that the quakes are located mostly in the innermost part of Cerberus Fossae.
>When they scanned observational orbital images of the same area, they noticed that the epicentres were located very close to a structure that has previously been described as a “young volcanic fissure.” Darker deposits of dust around this fissure are present not only in the dominant direction of the wind, but in all directions surrounding the Cerberus Fossae Mantling Unit.
>“The darker shade of the dust signifies geological evidence of more recent volcanic activity – perhaps within the past 50,000 years - relatively young, in geological terms,” explains Simon Stähler, the lead author of the paper, which has now been published in the journal Nature.
>Stähler is a Senior Scientist working in the Seismology and Geodynamics group led by Professor Domenico Giardini at the Institute of Geophysics, ETH Zurich.
ETA spacing.
marketrent OP t1_itt8qas wrote
Reply to Fossil bird’s skull reconstruction reveals a brain made for sense of smell more than birds today, and eyes made for seeing in daytime more than in nighttime. by marketrent
Hu H, Wang Y, Fabbri M, et al. Cranial osteology and palaeobiology of the Early Cretaceous bird Jeholornis prima (Aves: Jeholornithiformes). Zoological Journal of the Linnean Society.
>Abstract
>Jeholornis is a representative of the earliest-diverging bird lineages, providing important evidence of anatomical transitions involved in bird origins. Although ~100 specimens have been reported, its cranial morphology remains poorly documented owing to poor two-dimensional preservation, limiting our understanding of the morphology and ecology of the key avian lineage Jeholornithiformes, in addition to cranial evolution during the origin and early evolution of birds.
>Here, we provide a detailed description of the cranial osteology of Jeholornis prima, based primarily on high-quality, three-dimensional data of a recently reported specimen. New anatomical information confirms the overall plesiomorphic morphology of the skull, with the exception of the more specialized rostrum.
>Data from a large sample size of specimens reveal the dental formula of J. prima to be 0–2–3 (premaxillary–maxillary–dentary tooth counts), contrary to previous suggestions that the presence of maxillary teeth is diagnostic of a separate species, Jeholornis palmapenis.
>We also present evidence of sensory adaptation, including relatively large olfactory bulbs in comparison to other known stem birds, suggesting that olfaction was an important aspect of Jeholornis ecology. The digitally reconstructed scleral ring suggests a strongly diurnal habit, supporting the hypothesis that early-diverging birds were predominantly active during the day.
marketrent OP t1_itszsow wrote
Progress 82 freighter will arrive at the orbiting lab on Thursday, October 27.
Coverage of the unpiloted mission, carrying food, fuel, and supplies for the multi-national Expedition 68 crew aboard the ISS, began at 8 p.m. EDT (5:20 a.m. Baikonur time) Tuesday, October 25 on NASA Television, the NASA app, and the agency’s website.
marketrent OP t1_itoonk9 wrote
Texas-based RealPage Inc. provides software and services to the real estate industry.
The complaint, filed in the Southern District of California against RealPage Inc. and nine landlords, claims they violated Section 1 of the Sherman Antitrust Act by eliminating natural imbalances and competitive pricing for multifamily residential real estate leases.
The complaint also quotes from a marketing video used to attract additional real estate clients, in which a RealPage Vice President discusses the recent and never-before seen price increases for residential real estate leases, as high as 14.5% in some markets. When another RealPage executive asks: “What role has the [RealPage] software played” in those increases, the RealPage Vice President responded: “I think it’s driving it, quite honestly.”
(Link submitted 25 October 2022 04:10 UTC.)
marketrent OP t1_itfwh47 wrote
Reply to Formation of Namibia’s fairy circles isn’t due to termites. Plants are "ecosystem engineers" that survive by forming optimal geometric patterns. by marketrent
Filed by Jennifer Ouellette, 22 October 2022 07:23 GMT+11.
Excerpt:
>"For the first time, we went right after rainfall to the fairy circles and checked the new grasses for termite herbivory," Getzin told Ars. "Our excavations demonstrate that termites did certainly not cause the death of the grasses. If you come too late to the fairy circles, the grasses are long dead and detritivores like termites may have already fed on the lignified grass. But they did not kill the grass. We are showing unambiguously that the grasses die before and completely independent of any termite action."
>So what's next for Getzin? He believes more research is needed on the swarm intelligence of plants, likening plants to beavers in the sense that they can act as "ecosystem engineers" that modify their environment. "Most people cannot believe this or are unwilling to believe that, because plants have no brains," said Getzin. "But plants act similarly like the beaver as ecosystem engineers because their only way to survive is forming optimal, strictly geometric patterns"—in other words, Turing patterns.
>DOI: Perspectives in Plant Ecology, Evolution and Systematics, 2022. 10.1016/j.ppees.2022.125698
marketrent OP t1_it82c9m wrote
Reply to comment by shiruken in As many as a fifth of all asteroids in the asteroid belt may have been formed out on the fringes of the solar system. Findings suggest that both Ryugu and the CI chondrites originate from the same region of space, and could even have shared the same parent body. by marketrent
Thanks! (The press release didn’t include hyperlinks.)
>Abstract
>Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inwards to be implanted into the Main Belt.
>In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.
marketrent OP t1_it7k5t8 wrote
Reply to As many as a fifth of all asteroids in the asteroid belt may have been formed out on the fringes of the solar system. Findings suggest that both Ryugu and the CI chondrites originate from the same region of space, and could even have shared the same parent body. by marketrent
Papers published 20 October 2022:
>First asteroid gas sample delivered by the Hayabusa2 mission: A treasure box from Ryugu
>https://www.science.org/doi/10.1126/sciadv.abo7239
>Abstract
>The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on December 6, 2020. One day after the recovery, the gas species retained in the sample container were extracted and measured on-site, and stored in gas collection bottles. The container gas consists of helium and neon with an extraterrestrial 3He/4He and 20Ne/22Ne ratios, along with some contaminant terrestrial atmospheric gases. A mixture of solar and Earth’s atmospheric gas is the best explanation of the container gas composition. Fragmentation of Ryugu grains within the sample container is discussed based on the estimated amount of indigenous He and the size distribution of the recovered Ryugu grains. This is the first successful return of gas species from a near-Earth asteroid.
and
>Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution
>https://www.science.org/doi/10.1126/science.abo0431
>Abstract
>The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth’s volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measure noble gas and nitrogen isotopes in Ryugu samples, finding they are dominated by pre-solar and primordial components, incorporated during Solar System formation. Noble gas concentrations are higher than those in Ivuna-type carbonaceous (CI) chondrite meteorites. Several host phases of isotopically distinct nitrogen have heterogeneous abundances between the samples. Our measurements support a close relationship between Ryugu and CI chondrites. Noble gases produced by galactic cosmic rays, indicating ~5 Myr exposure, and from implanted solar wind, record the recent irradiation history of Ryugu after it migrated to its current orbit.
marketrent OP t1_iws2g29 wrote
Reply to Earth’s oldest evidence of life – Australian fossils dating to about 3.48 billion years ago – could provide hints of what scientists should look for on Mars by marketrent
James Ashworth, 11 November 2022.
Excerpt:
>Structures found in 3.48-billion-year-old Australian rocks are the oldest evidence of life on Earth.
>Detailed analyses of geological samples from the Dresser Formation conclude that, despite previous scientific controversy, they represent fossils formed by early life and could provide hints of what scientists should look for on Mars.
>
>Around 3.5 billion years ago, the area where Western Australia's Dresser Formation is now found would have featured shallow lagoons fed by water enriched in nutrients due to volcanism and hydrothermal activity.
>These lagoons are believed to have been inhabited by photosynthetic organisms, with the fossilised remains of the structures they formed preserved within the sedimentary rocks of the Dresser Formation.
>
>On Mars, very similar habitats could have existed more than three billion years ago when the planet is considered to have been habitable.
>If life ever existed on Mars, it is possible that similar fossilised remains could be found.
>In a new study, published in the journal Geology, researchers examined samples from the Dresser Formation in greater detail than ever before.
>Not only do they add weight to arguments that these structures represent some of the earliest traces of life on this planet, but also provide a dry run of the process that will be performed on Martian rocks when they are returned to Earth.
Geology, DOI 10.1130/G50390.1