The asteroid that struck Earth 66 million years ago, wiping out three-quarters of the planet's plant and animal life (most famously the dinosaurs), also triggered a worldwide tsunami with mile-high waves. Space.com reports: A new study led by University of Michigan scientists reveals that this tsunami scoured the ocean floor and left geologic traces as far away as New Zealand -- thousands of miles away from the impact site off what's now Mexico's Yucatan Peninsula. The findings come from the first simulation that models the global effects of the impact of the massive asteroid -- named the Chicxulub impactor -- upon Earth to reach publication. The team took findings from previous research and modeled the asteroid as an 8.7-mile-wide (14 kilometers) body traveling at 27,000 mph (43,000 kph). The researchers supported the computer modeling by investigating the geological record at 100 sites across the globe. In particular, the scientists looked at "boundary sections," which are marine sediments laid down just before and just after the Chicxulub impact and the mass extinction that ended the era of our planet called the Cretaceous period. This investigation supported the predictions the model had made regarding the path and power of the Chicxulub-generated tsunami.

Some of the most significant geological evidence found by the team was located 7,500 miles (12,000 km) away from the Chicxulub crater on the eastern shores of islands to the north and south of New Zealand. Here the scientists found heavily disturbed sediments called olistostromal deposits that were previously believed to be the result of local tectonic activity. [The researchers] found, however, that the age and location of these deposits put them directly in the path the team modeled for the Chicxulub-triggered tsunami. The team calculated the initial energy of the impact tsunami, finding that it was as much as 30,000 times greater than the energy of the 2004 tsunami generated by an Indian Ocean earthquake. The event, one of the largest tsunamis in modern history, killed more than 230,000 people. [...]

The simulation showed that 24 hours after the Chicxulub impactor had struck Earth, waves it launched had traveled almost the full extent of the Pacific and Atlantic Oceans and had just entered the Indian Ocean from both sides. Two days after the impact, tsunami waves had hit most of the world's coastlines. The team didn't estimate how much flooding these tsunami waves would have caused, but they did calculate wave heights in the majorly impacted regions. The simulations indicated that waves in the open ocean of the Gulf of Mexico would have been over 330 feet (100 meters) high. Meanwhile, waves in North Atlantic coastal regions and parts of South America's Pacific coast would have been 10 times smaller, at around 33 feet (10 m) high. As the tsunami waves approached shorelines in these regions and hit shallow waters, however, they would have soared dramatically in height again. The findings were published in the journal AGU Advances.

Hmmmmmm shares a report from Phys.Org: Trees have long been known to buffer humans from the worst effects of climate change by pulling carbon dioxide from the atmosphere. Now new research shows just how much forests have been bulking up on that excess carbon. The study, recently published in the Journal Nature Communications, finds that elevated carbon dioxide levels in the atmosphere have increased wood volume -- or the biomass -- of forests in the United States. Although other factors like climate and pests can somewhat affect a tree's volume, the study found that elevated carbon levels consistently led to an increase of wood volume in 10 different temperate forest groups across the country. This suggests that trees are helping to shield Earth's ecosystem from the impacts of global warming through their rapid growth.

Over the last two decades, forests in the United States have sequestered about 700-800 million tons of carbon dioxide per year, which, according to the study, accounts for roughly 10% to 11% of the country's total carbon dioxide emissions. While exposure to high levels of carbon dioxide can have ill effects on natural systems and infrastructure, trees have no issue gluttoning themselves on Earth's extra supply of the greenhouse gas. To put it in perspective, if you imagine a tree as just a huge cylinder, the added volume the study finds essentially amounts to an extra tree ring. Although such growth may not be noticeable to the average person, compared to the trees of 30 years ago, modern vegetation is about 20% to 30% bigger than it used to be. If applied to the Coast Redwood forests -- home to some of the largest trees in the world -- even a modest percentage increase means a lot of additional carbon storage in forests. Researchers also found that even older large trees continue adding biomass as they age due to elevated carbon dioxide levels. "Forests are taking carbon out of the atmosphere at a rate of about 13% of our gross emissions," said Brent Sohngen, co-author of the study and professor of environmental and resource economics at The Ohio State University. "While we're putting billions of tons of carbon dioxide into the atmosphere, we're actually taking much of it out just by letting our forests grow."

techmage writes: Early this morning, Firefly Aerospace succeeded in launching their Alpha rocket to Low Earth Orbit. This marks one of a handful of companies who have reached space with that few attempts (Virgin Orbit and RocketLab are just some of the others).

Shameless plug -- I had the pleasure of building the Serenity satellite, a 3U CubeSat that flew on the mission.

Check out the video of the launch and deployment. It is quite something to watch. All three payloads were successfully deployed. Space.com reports: One of them, called Serenity, comes from the nonprofit organization Teachers in Space. Serenity was designed to collect a variety of data during today's flight, which will be shared with the educational community, according to a Firefly mission description.

Also reaching orbit today was TechEdSat-15 (TES-15), which is owned by NASA in coordination with San Jose State University in California. TES-15 features an "exo-brake" designed to help satellites leave their orbital perches more smoothly when their work is done. "The exo-brake will deploy after the cubesat is ejected from its dispenser to deorbit the cubesat," Firefly wrote in the mission description. TES-15 also carries an experiment designed to optimize data transfer from the little spacecraft, the company added.

The third payload -- the PicoBus deployer, from the nonprofit Libre Space -- carries five tiny payloads of its own. Those bantam "picosats" include Genesis-L & Genesis-N, from AMSAT (Radio Amateur Satellite Corporation) Spain. The pair will demonstrate a pulsed-plasma thruster system for spacecraft propulsion and "build heritage for future missions," according to Firefly. PicoBus is also carrying Libre Space's Qubik-1 and Qubik-2, which will perform communications experiments, and FossaSat-1B. This latter satellite, from the Spanish company Fossa Systems, will test communications and remote-sensing tech. It also carries a low-resolution Earth-imaging camera.

An anonymous reader quotes a report from Wired: Over the past eight years, a modified Boeing 747 jetliner has flown hundreds of flights on a unique mission: carrying a 19-ton, 2.5-meter telescope known as Sofia, or the Stratospheric Observatory for Infrared Astronomy. Flying a telescope on a jumbo jet offered a way to peer into the heavens at wavelengths that could not be glimpsed from the ground -- but the ticket was expensive. So yesterday, NASA and the German space agency grounded the mission. Its final flight landed early Thursday morning at NASA's Armstrong Flight Research Center in the desert near Los Angeles.

Sofia was an innovative way to gaze at the infrared universe. Infrared light is essentially heat radiation -- but astronomers can't probe cosmic objects like dust-enshrouded stars and galaxies without the water vapor in Earth's atmosphere absorbing that light. That confounds attempts to observe those objects with telescopes built on mountaintops, like the observatories in Hawaii and Chile. But by soaring through the stratosphere, at an elevation of 40,000 feet or higher, Sofia could fly above that water vapor and get a much better view. "Almost 50 percent of the energy of the universe comes out in the mid- to far infrared. Sofia has played an important and unique role for its lifetime, probing that entire wavelength range, and we've been able to observe all manner of phenomena that were otherwise invisible to other facilities," says Jim De Buizer, Sofia senior scientist at NASA's Ames Research Center in Mountain View, California.

De Buizer and the Sofia team have made a number of significant astronomical discoveries, including measuring cosmic magnetic fields permeating nearby galaxies, charting the growth of massive stars, observing Pluto's faint shadow as it passed in front of a distant star, and even discovering water on the sunlit surface of the moon's southern hemisphere. The data from Sofia's final flight will map stellar nebulas and help scientists study the magnetic fields of the Sculptor starburst galaxy. But while flying a telescope in a jet is much less expensive than launching one aboard a spacecraft, like NASA's Spitzer and Webb space telescopes and the European Space Agency's Herschel Space Observatory, it's still not cheap. There are costs for the pilots, staff, engineers, and mechanics -- plus a round of repairs to the aircraft that had to be made in 2018. Sofia costs NASA about $85 million per year -- a significant fraction of its astrophysics budget. And that's actually only 80 percent of the funding it needs; NASA's German counterparts provided the rest. It was ultimately the mission's high operating costs, relative to its scientific output, that took Sofia down. "At the end of the day, the project itself just wasn't productive. You're talking about almost a Hubble cost for operations, but with a fraction of the scientific productivity," says Casey Dreier, senior space policy adviser for the Planetary Society, a nonprofit research organization based in Pasadena, California.

"I feel for the scientists. They can't control the operational costs," Dreier says. "But Sofia got eight years of operations. It had a good, healthy life, for a mission."

NASA announced Thursday that it plans to study the possibility of using SpaceX's Crew Dragon vehicle to boost the aging Hubble Space Telescope into a higher orbit. Ars Technica reports: The federal agency has signed a "Space Act Agreement" with SpaceX to conduct a six-month study to determine the practicability of Dragon docking with the 32-year-old telescope and boosting it into a higher orbit. The study is not exclusive, meaning that other companies can propose similar concepts with alternative rockets and spacecraft. [...] Among the questions the new Hubble study will answer is the cost of such a mission and its technical feasibility. The principal goal is to boost Hubble's altitude from its current level of 535 km to 600 km, the same altitude it was at when first launched in 1990. Since the fifth and final servicing mission in 2009, Hubble has slowly been losing altitude, and this process is expected to accelerate as the telescope gets lower.

The telescope's project manager, Patrick Crouse, said during a teleconference with reporters that in absence of a re-boost mission, NASA might have to launch a propulsion module to the telescope by the end of the 2020s. This would ensure Hubble makes a controlled reentry into Earth's atmosphere and lands in the Pacific Ocean. A Dragon mission to boost Hubble's altitude could add 15 or even 20 years of orbital lifetime, Crouse said. The study will also look at potential servicing options, although nothing like the detailed instrument replacements and major upgrades performed during Hubble servicing missions with NASA's space shuttle. Rather, engineers from NASA and SpaceX will assess the feasibility of replacing the gyroscopes that control the pointing of the telescope. Only three of the spacecraft's six gyroscopes remain in working order.

NASA's Juno spacecraft has made the closest approach to Jupiter's tantalizing, icy moon Europa in more than 20 years. From a report: Juno on Thursday zipped within 222 miles (357 kilometers) of Europa, thought to have an ocean flowing beneath its thick frozen crust, raising the possibility of underwater life. Scientists hope to get lucky and observe possible water plumes shooting from the surface of Europa, close in size to Earth's moon. "We have to be at the right place at just the right time, but if we are so fortunate, it's a home run for sure," Juno's chief scientist, Scott Bolton of Southwest Research Institute in San Antonio, said in a statement. John Bordi, deputy mission manager at NASA's Jet Propulsion Laboratory, expected the spacecraft to go "screaming by pretty fast," with a relative velocity of almost 15 miles per second (23.6 kilometers per second). Pictures should be available by Friday, NASA said. The latest observations will help NASA plan for its Europa Clipper mission, due to launch in 2024. The European Space Agency also plans close encounters with its Jupiter Icy Moons Explorer, or Juice, lifting off next year.

An anonymous reader quotes a report from Science Magazine: In 2020, Ranga Dias, a physicist at the University of Rochester, and his colleagues published a sensational result in Nature, featured on its cover. They claimed to have discovered a room-temperature superconductor: a material in which electric current flows frictionlessly without any need for special cooling systems. Although it was just a speck of carbon, sulfur, and hydrogen forged under extreme pressures, the hope was that someday the material would lead to variants that would enable lossless electricity grids and inexpensive magnets for MRI machines, maglev railways, atom smashers, and fusion reactors. Faith in the result is now evaporating. On Monday Nature retracted the study, citing data issues other scientists have raised over the past 2 years that have undermined confidence in one of two key signs of superconductivity Dias's team had claimed. "There have been a lot of questions about this result for a while," says James Hamlin, an experimental condensed matter physicist at the University of Florida. But Jorge Hirsch, a theoretical physicist at the University of California, San Diego (UCSD), and longtime critic of the study, says the retraction does not go far enough. He believes it glosses over what he says is evidence of scientific misconduct. "I think this is a real problem," he says. "You cannot leave it as, 'Oh, it's a difference of opinion.'"

The retraction was unusual in that Nature editors took the step over the objection of all nine authors of the paper. "We stand by our work, and it's been verified experimentally and theoretically," Dias says. Ashkan Salamat, a physicist at the University of Nevada, Las Vegas, and another senior member of the collaboration, points out the retraction does not question the drop in electric resistance -- the most important part of any superconductivity claim. He adds, "We're confused and disappointed in the decision-making by the Nature editorial board." The retraction comes even as excitement builds for the class of superconducting materials called hydrides, which includes the carbonaceous sulfur hydride (CSH) developed by Dias's team. Under pressures greater than at the center of the Earth, hydrogen is thought to behave like a superconducting metal. Adding other elements to the hydrogen -- creating a hydride structure -- can increase the "chemical pressure," reducing the need for external pressure and making superconductivity reachable in small laboratory vises called diamond anvil cells. As Lilia Boeri, a theoretical physicist at the Sapienza University of Rome, puts it, "These hydrides are a sort of realization of metallic hydrogen at slightly lower pressure."

In 2015, Mikhail Eremets, an experimental physicist at the Max Planck Institute for Chemistry, and colleagues reported the first superconducting hydride: a mix of hydrogen and sulfur that, under enormous pressures, exhibited a sharp drop in electrical resistance at a critical temperature (Tc) of 203 K (-70C). That was nowhere near room temperature, but warmer than the Tc for most superconducting materials. Some theorists thought adding a third element to the mix would give researchers a new variable to play with, enabling them to get closer to ambient pressures -- or room temperatures. For the 2020 Nature paper, Dias and colleagues added carbon, crushed the mix in a diamond anvil cell, and heated it with a laser to create a new substance. They reported that tests showed a sharp drop in resistance at a Tc of 288 K (15C) -- roughly room temperature -- and a pressure of 267 gigapascals, about 75% of the pressure at the center of the Earth. But in a field that has seen many superconducting claims come and go, a drop in resistance alone is not considered sufficient. The gold standard is to provide evidence of another key attribute of superconductors: their ability to expel an applied magnetic field when they cross Tc and become superconducting. Measuring that effect in a diamond anvil cell is impractical, so experimentalists working with hydrides often measure a related quantity called "magnetic susceptibility." Even then they must contend with tiny wires and samples, immense pressures, and a background magnetic signal from metallic gaskets and other experimental components. "It's like you're trying to see a star when the Sun is out," Hamlin says. "The study's magnetic susceptibility data were what led to the retraction," reports Science. "The team members reported that a susceptibility signal emerged after they had subtracted a background signal, but they did not include raw data. The omission frustrated critics, who also complained that the team relied on a 'user-defined' background -- an assumed background rather than a measured one. But Salamat says relying on a user-defined background is customary in high-pressure physics because the background is so hard to measure experimentally."

Dias and Salamat posted a paper to arXiv in 2021 containing the raw susceptibility data and purported to explain how the background was subtracted, but it "raised more questions than it answered," says Brad Ramshaw, a quantum materials physicist at Cornell University. "The process of going from the raw data to the published data was incredibly opaque."

Hirsch accused the data of being "fabricated," noting suspicious similarities to data in a 2009 paper on superconductivity in europium under high pressures. It too was later retracted.

NASA's DART spacecraft successfully slammed into a distant asteroid at hypersonic speed on Monday in the world's first test of a planetary defense system, designed to prevent a potential doomsday meteorite collision with Earth. From a report: Humanity's first attempt to alter the motion of an asteroid or any celestial body played out in a NASA webcast from the mission operations center outside Washington, D.C., 10 months after DART was launched. The livestream showed images taken by DART's camera as the cube-shaped "impactor" vehicle, no bigger than a vending machine with two rectangular solar arrays, streaked into the asteroid Dimorphos, about the size of a football stadium, at 7:14 p.m. EDT (2314 GMT) some 6.8 million miles (11 million km) from Earth. The $330 million mission, some seven years in development, was devised to determine if a spacecraft is capable of changing the trajectory of an asteroid through sheer kinetic force, nudging it off course just enough to keep Earth out of harm's way. Whether the experiment succeeded beyond accomplishing its intended impact will not be known until further ground-based telescope observations of the asteroid next month. But NASA officials hailed the immediate outcome of Monday's test, saying the spacecraft achieved its purpose.

A beautiful blue flaw in a gem-quality diamond from Botswana is actually a tiny fragment of Earth's deep interior -- and it suggests our planet's mantle contains oceans' worth of water. Scientific American: The flaw, technically called an inclusion, looks like a fish eye: a deep blue center surrounded by a white haze. But it's really a pocket of the mineral ringwoodite from 660 kilometers down, at the boundary between the upper and lower mantle. This is just the second time scientists have found this mineral in a chunk of crystal from this zone, and the sample is the only one of its kind currently known to science. The last example was destroyed during an attempt to analyze its chemistry.

[...] The discovery indicates that this very deep zone of Earth is soggy, with vast amounts of water locked up tight within the minerals there. Though this water is chemically bound to the minerals' structure and doesn't flow around like an actual ocean, it does likely play an important role in how the mantle melts. This in turn affects big-picture geology, such as plate tectonics and volcanic activity. For example, water could contribute to the development of areas of mantle upwelling known as plumes, which are hotspots for volcanoes.

The stunning bit of diamond-encased mantle was discovered by Tingting Gu, a mineral physicist now at Purdue University, who was at the time doing research at the Gemological Institute of America. Her job was to study rare inclusions found in diamonds. Inclusions are undesirable for jewelry because they cloud a diamond's sparkle. But they're often interesting to scientists because they trap bits of the environment where the diamond formed millennia earlier. The vast majority of diamonds form between about 150 to 200 km below Earth's surface. But a handful come from much deeper. It is often difficult to pinpoint exactly how deep, but the new sample was remarkably accommodating on that front, Gu and her colleagues reported on Monday in a study published in Nature Geoscience. Ringwoodite can only form at incredibly high pressures. It is not found in Earth's crust, but it is sometimes seen trapped in meteorites that underwent major cosmic trauma. In Earth's mantle, ringwoodite exists at the pressures present down to 660 km.

Most mission scientists would wince at the thought of their spacecraft being smashed to smithereens. But for those behind Nasa's Dart probe, anything short of total destruction will be chalked up as a failure. From a report: The $330m spacecraft is due to slam head-on into an asteroid about 11m kilometres above the Indian Ocean soon after midnight on Monday. The impact, at nearly seven kilometres a second, will obliterate the half-tonne probe, all in the name of planetary defence. Not that Dimorphos, the asteroid in question, poses any threat to humanity. The Dart, or double asteroid redirection test, is an experiment, the first mission ever to assess whether asteroids can be deflected should one ever be found on a collision course with Earth. A well-placed nudge could avert Armageddon, or so the thinking goes, and spare humans the same fate as the dinosaurs.

"It's a very complicated game of cosmic billiards," said Prof Alan Fitzsimmons, an astronomer and member of the Nasa Dart investigation team at Queen's University Belfast. "What we want to do is use as much energy [as we can] from Dart to move the asteroid." With telescopes constantly scanning the skies, scientists hope to have some notice if an asteroid were ever to present a major threat. "If we are able to see far enough in advance and know that an asteroid might be a problem, pushing it out of the way will be much safer than the big Hollywood idea of blowing it up," said Catriona McDonald, a PhD student at Warwick University. The Dart mission launched from Vandenberg space force base in November last year. On Monday night, mission controllers will hand control to Dart's software and let the probe steer itself into oblivion.

An anonymous reader quotes a report from Interesting Engineering: Florida-based tech startup Undefined Technologies announced its unique ionic propulsion drone has passed an outdoor flight test, meaning it's on track for commercial release in 2024, according to a report from New Atlas. The drone, called Silent Ventus, uses proprietary technology to ionize the oxygen and nitrogen molecules in the surrounding air to create an "ionic wind" that propels the machine in the direction it wants to go. According to Undefined, the drone could be used for cargo. Though it's not been used for large-scale drone projects on Earth before, ionic propulsion isn't a new technology. In fact, it's currently one of the best technologies humans currently possess for deep space exploration propulsion and other space applications. According to Undefined, its "Air Tantrum" ionic propulsion technology produces up to 150 percent more thrust than current ion thruster technologies.

Earlier this year, the company released footage of a two-and-a-half-minute indoor flight test, saying the drone emitted 85 decibels of noise. Now, it claims it's flown a prototype for four and a half minutes, though it's only released one minute, 17 seconds of footage. The drone firm also says it achieved a noise level below 75 dB. It's now aiming to secure further investment to build a zero-emissions cargo delivery drone by 2023 that could fly for 15 minutes and make less than 70 dB. Undefined claims its "silent" 70-dB drones will lead to far fewer noise complaints in areas that will be served by urban cargo delivery drones in the future. However, it's worth pointing out that Undefined had yet to test its drone with large payloads, which will require extra thrust and will likely make more noise.

An anonymous reader quotes a report from Ars Technica: In January this year, an undersea volcano in Tonga produced a massive eruption, the largest so far this century. The mixing of hot volcanic material and cool ocean water created an explosion that sent an atmospheric shockwave across the planet and triggered a tsunami that devastated local communities and reached as far as Japan. The only part of the crater's rim that extended above water was reduced in size and separated into two islands. A plume of material was blasted straight through the stratosphere and into the mesosphere, over 50 km above the Earth's surface. We've taken a good look at a number of past volcanic eruptions and studied how they influence the climate. But those eruptions (most notably that of Mount Pinatubo) all came from volcanoes on land. Hunga Tonga may be the largest eruption we've ever documented that took place under water, and the eruption plume contained unusual amounts of water vapor -- so much of it that it actually got in the way of satellite observations at some wavelengths. Now, researchers have used weather balloon data to reconstruct the plume and follow its progress during two circuits around the globe.

Your vocabulary word of the day is radiosonde, which is a small instrument package and transmitter that can be carried into the atmosphere by a weather balloon. There are networks of sites where radiosondes are launched as part of weather forecasting services; the most relevant ones for Hunga Tonga are in Fiji and Eastern Australia. A balloon from Fiji was the first to take instruments into the eruption plume, doing so less than 24 hours after Hunga Tonga exploded. That radiosonde saw increasing levels of water as it climbed through the stratosphere from 19 to 28 kilometers of altitude. The water levels had reached the highest yet measured at the top of that range when the balloon burst, bringing an end to the measurements. But shortly after, the plume started showing up along the east coast of Australia, which again registered very high levels of water vapor. Again, water reached to 28 km in altitude but gradually settled to lower heights over the next 24 hours.

The striking thing was how much of it there was. Compared to normal background levels of stratospheric water vapor, these radiosondes were registering 580 times as much water even two days after the eruption, after the plume had some time to spread out. There was so much there that it still stood out as the plume drifted over South America. The researchers were able to track it for a total of six weeks, following it as it spread out while circling the Earth twice. Using some of these readings, the researchers estimated the total volume of the water vapor plume and then used the levels of water present to come up with a total amount of water put into the stratosphere by the eruption. They came up with 50 billion kilograms. And that's a low estimate, because, as mentioned above, there was still water above the altitudes where some of the measurements stopped. The recent findings appear in a new study published in the journal Science.

A pair of researchers who previously identified what may be the first known interstellar meteor to impact Earth have now presented evidence of a second object that could have originated beyond the solar system, before it burned up in our planet's skies and potentially fell to the surface, according to a new study. Motherboard reports: Amir Siraj, a student in astrophysics at Harvard University, and astronomer Avi Loeb, who serves as Harvard's Frank B. Baird Jr. Professor of Science, suggest that a fast-moving meteor that burst into a fireball hundreds of miles off the coast of Portugal on March 9, 2017, is an "additional interstellar object candidate" that they call interstellar meteor 2 (IM2) in a study posted to the preprint server arXiv this week. The paper has not been peer-reviewed. In addition to their potential origin beyond the solar system, these objects appear to be extraordinarily robust, as they rank as the first- and third-highest meteors in material strength in a NASA catalog that has collected data about hundreds of fireballs.

"We don't have a large enough sample to say how much stronger interstellar objects are than solar system objects, but we can say that they are stronger," Siraj said in an email. "The odds of randomly drawing two objects in the top 3 out of 273 is 1 in 10 thousand. And when we look at the specific numbers relative to the distribution of objects, we find that the Gaussian odds are more like 1 in a million." This makes IM2 "an outlier in material strength," Loeb added in a follow-up call with Siraj. "To us, it means that the source is different from planetary systems like the solar system."

Loeb has attracted widespread attention in recent years over his speculation that the first interstellar object ever identified, known as 'Oumuamua, was an artifact of alien technology. Spotted in 2017, 'Oumuamua sped through the solar system and was up to a quarter-mile in scale, making it much larger than the interstellar meteor candidates identified by Siraj and Loeb, which are a few feet across. Loeb's claims of an artificial origin for 'Oumuamua have provoked substantial pushback from many scientists who do not consider a technological explanation to be likely. Loeb also thinks these interstellar meteor candidates could be alien artifacts, though he and Siraj present a mind-boggling natural explanation for the strangely robust objects in the study: The meteors may be a kind of interstellar shrapnel produced by the explosions of large stars, called supernovae. [...] Loeb, of course, is keeping his mind open. "We don't say, necessarily, that it is artificial," Loeb said in the call, referring to the supernovae explanation. But, he added, "obviously, there is a possibility that a spacecraft was designed to sustain such harsh conditions as passing through the Earth's atmosphere, so we should allow for that."

An anonymous reader quotes a report from Scientific American: Vultures are hard birds for humans to love. They are an obligate scavenger, meaning they get all their food from already dead prey -- and that association has cast them as a harbinger of death since ancient times. But in reality, vultures are nature's flying sanitation crew. And new research adds to that positive picture by detailing these birds' role in a surprising process: mitigating greenhouse gas emissions. With their impressive vision and the range they can cover in their long, soaring flights, the 22 species of vultures found around the world are often the first scavengers to discover and feed on a carcass. This cleanup provides a vital service to both ecosystems and humans: it keeps nutrients cycling and controls pathogens that could otherwise spread from dead animals to living ones.

Decaying animal bodies release greenhouse gases, including carbon dioxide and methane. But most of these emissions can be prevented if vultures get to the remains first, a new study in Ecosystem Services shows. It calculates that an individual vulture eats between 0.2 and one kilogram (kg) of carcass per day, depending on the vulture species. Left uneaten, each kg of naturally decomposing carcass emits about 0.86 kg of CO2 equivalent. This estimate assumes that carcasses not eaten by vultures are left to decay. But many carcasses are composted or buried by humans, which result in more emissions than natural decay, so vulture consumption can avert even more emissions when replacing those methods. The avoided emissions may not sound like much, but multiply those estimates by the estimated 134 million to 140 million vultures around the world, and the number becomes more impressive: tens of millions of metric tons of emissions avoided per year.

But this ecosystem service is not evenly distributed around the world. It occurs mostly in the Americas, says the study's lead author Pablo Plaza, a biologist at the National University of Comahue in Argentina. Three species found only in the Americas -- the Black, Turkey and Yellow-headed vultures -- are responsible for 96 percent of all vulture-related emissions mitigation worldwide, Plaza and his colleagues found. Collectively, vultures in the Americas keep about 12 million metric tons of CO2 equivalent out of the atmosphere annually. Using estimates from the U.S. Environmental Protection Agency, that is akin to taking 2.6 million cars off the road each year. The situation outside of the Americas stands in stark contrast. "The decline in vulture populations in many regions of the world, such as Africa and Asia, has produced a concomitant loss of the ecosystem services vultures produce," Plaza says.

A couple of climate tech startups plan to suck a hell of a lot of carbon dioxide out of the air and trap it underground in Wyoming. The Verge reports: The goal of the new endeavor, called Project Bison, is to build a new facility capable of drawing down 5 million metric tons of carbon dioxide annually by 2030. The CO2 can then be stored deep within the Earth, keeping it out of the atmosphere, where it would have continued to heat up the planet. A Los Angeles-based company called CarbonCapture is building the facility, called a direct air capture (DAC) plant, that is expected to start operations as early as next year. It'll start small and work up to 5 million metric tons a year. If all goes smoothly by 2030, the operation will be orders of magnitude larger than existing direct air capture projects.

CarbonCapture's equipment is modular, which is what the company says makes the technology easy to scale up. The plant itself will be made of modules that look like stacks of shipping containers with vents that air passes through. At first, the modules used for Project Bison will be made at CarbonCapture's headquarters in Los Angeles. In the first phase of the project, expected to be completed next year, around 25 modules will be deployed in Wyoming. Those modules will collectively have the capacity to remove about 12,000 tons of CO2 a year from the air. The plan is to deploy more modules in Wyoming over time and potentially manufacture the modules there one day, too.

Inside each of the 40-foot modules are about 16 "reactors" with "sorbent cartridges" that essentially act as filters that attract CO2. The filters capture about 75 percent of the CO2 from the air that passes over them. Within about 30 to 40 minutes, the filters have absorbed all the CO2 they can. Once the filters are fully saturated, the reactor goes offline so that the filters can be heated up to separate out the CO2. There are many reactors within one module, each running at its own pace so that they're constantly collecting CO2. Together, they generate concentrated streams of CO2 that can then be compressed and sent straight to underground wells for storage. DAC is still very expensive -- it can cost upwards of $600 to capture a ton of carbon dioxide. That figure is expected to come down with time as the technology advances. But for now, it takes a lot of energy to run DAC plants, which contributes to the big price tag. The filters need to reach around 85 degrees Celsius (185 degrees Fahrenheit) for a few minutes, and getting to those kinds of high temperature for DAC plants can get pretty energy-intensive. Eventually, [...] Bison plans to get enough power from new wind and solar installations. When the project is running at its full capacity in 2030, it's expected to use the equivalent of about 2GW of solar energy per year. For comparison, about 3 million photovoltaic panels together generate a gigawatt of solar energy, according to the Department of Energy. But initially, the energy used by Project Bison might have to come from natural gas, according to Corless. So Bison would first need to capture enough CO2 to cancel out the amount of emissions it generates by burning through that gas before it can go on to reduce the amount of CO2 in the atmosphere. "The geology in Wyoming allows Project Bison to store the captured CO2 on-site near the modules," adds The Verge. "Project Bison plans to permanently store the CO2 it captures underground. Specifically, project leaders are looking at stowing it 12,000 feet underground in 'saline aquifers' -- areas of rock that are saturated with salt water."

Specks of dust that a Japanese space probe retrieved from an asteroid about 186 million miles (300m kilometers) from Earth have revealed a surprising component: a drop of water. The discovery offers new support for the theory that life on Earth may have been seeded from outer space. The Guardian reports: The findings are in the latest research to be published from analysis of 5.4 grammes of stones and dust that the Hayabusa-2 probe gathered from the asteroid Ryugu. "This drop of water has great meaning," the lead scientist, Tomoki Nakamura of Tohoku University, told reporters before publication of the research in the journal Science on Friday. "Many researchers believe that water was brought [from outer space], but we actually discovered water in Ryugu, an asteroid near Earth, for the first time."

Hayabusa-2 was launched in 2014 on its mission to Ryugu, and returned to Earth's orbit two years ago to drop off a capsule containing the sample. The precious cargo has already yielded several insights, including organic material that showed some of the building blocks of life on Earth, amino acids, may have been formed in space. The team's latest discovery was a drop of fluid in the Ryugu sample "which was carbonated water containing salt and organic matter," Nakamura said. That bolsters the theory that asteroids such as Ryugu, or its larger parent asteroid, could have "provided water, which contains salt and organic matter" in collisions with Earth, he said. "We have discovered evidence that this may have been directly linked to, for example, the origin of the oceans or organic matter on Earth." "The fact that water was discovered in the sample itself is surprising," given its fragility and the chances of it being destroyed in outer space, said Kensei Kobayashi, an astrobiology expert and professor emeritus at Yokohama National University. "It does suggest that the asteroid contained water, in the form of fluid and not just ice, and organic matter may have been generated in that water."

Maarten Schmidt, who in 1963 became the first astronomer to identify a quasar, a small, intensely bright object several billion light years away, and in the process upended standard descriptions of the universe and revolutionized ideas about its evolution, died on Sept. 17 at his home in Fresno, Calif. He was 92. The New York Times reports: Dr. Schmidt's discovery of what was then among the farthest known objects in the universe answered one of the great conundrums of postwar astronomy, and like all great breakthroughs it opened the door to a whole host of new questions. Advances in radio technology during World War II allowed scientists in the 1950s to probe deeper into the universe than they could with traditional optical telescopes. But in doing so they picked up radio signals from a plethora of faint or even invisible, but intensely energetic, objects that did not fit with any conventional category of celestial body. Researchers called them "quasi-stellar radio sources," or quasars, for short -- even though no one could figure out what a quasar was. Many thought they were small, dense stars nearby, within the Milky Way.

In 1962, two scientists in Australia, Cyril Hazard and John Bolton, finally managed to pinpoint the precise position of one of these, called 3C 273. They shared the data with several researchers, including Dr. Schmidt, an astronomer at the California Institute of Technology. Using the enormous 200-inch telescope at the Palomar Observatory, in rural San Diego County, Dr. Schmidt was able to hone in on what appeared to be a faint blue star. He then plotted its light signature on a graph, showing where its constituent elements appeared in the spectrum from ultraviolet to infrared. What he found was, at first, puzzling. The signatures, or spectral lines, did not resemble those of any known elements. He stared at the graphs for weeks, pacing his living room floor, until he realized: The expected elements were all there, but they had shifted toward the red end of the spectrum -- an indication that the object was moving away from Earth, and fast.

And once he knew the speed -- 30,000 miles a second -- Dr. Schmidt could calculate the object's distance. His jaw dropped. At about 2.4 billion light years away, 3C 273 was one of the most distant objects in the universe from Earth. That distance meant that it was also unbelievably luminous: If it were placed at the position of Proxima Centauri, the closest star to Earth, it would outshine the sun. Dr. Schmidt shared his results with his colleagues, and then in a paper in the journal Nature -- and not without trepidation, knowing how disruptive his findings would be. [...] The revelation shocked the astronomy world, and for a time made Dr. Schmidt something of a celebrity. Time magazine put him on its cover in 1966, with a fawning profile that compared him to Galileo. "The 17th century Italian startled scientists and theologians alike; the 20th century Dutchman has had an equally jarring effect on his own contemporaries," Time wrote, a bit breathlessly but not inaccurately. [...] For their work on quasars, in 2008 Dr. Schmidt and Dr. Lynden-Bell shared the prestigious Kavli Prize in Astrophysics.

Saturn has quite the collection of moons, more than any other planet in the solar system. There's Enceladus, blanketed in ice, with a briny ocean beneath its surface. There's Iapetus, half of which is dusty and dark, and the other shiny and bright. There are Hyperion, a rocky oval that bears a striking resemblance to a sea sponge, and Pan, tiny and shaped just like a cheese ravioli. But one moon might be missing. From a report: According to a new study, Saturn once had yet another moon, about the same size as Iapetus, which is the third-largest satellite in Saturn's collection. The moon orbited the ringed planet for several billion years, minding its own business, doing moon things, until about 100 million to 200 million years ago, when other Saturnian moons started messing with it. The interactions between them pushed the unlucky moon closer to Saturn -- too close to remain intact. Gravity shredded it to bits.

Something remarkable might have come out of all this. While most of the moon debris fell into Saturn's atmosphere, some of the pieces hung back, whirling around the planet until they splintered further and flattened into a thin, delicate disk. This lost moon, the authors of the study say, is responsible for Saturn's trademark feature: the rings. These astronomers didn't set out to find a missing moon. They were trying to better understand why Saturn is the way it is now -- specifically, why the planet is tilted just so. "Planetary tilts are an interesting indicator of a planet's history," Zeeve Rogoszinski, an astronomer at the University of Maryland who was not involved in this recent work but who studies orbital dynamics, told me. Most of the planets in our solar system spin at an angle relative to the plane in which they orbit the sun. Earth's tilt, for example, is a result of the collision that scientists believe might have created our moon. Mars's tilt is chaotic, thanks to the influence of next-door neighbor Jupiter. Uranus likely got its dramatic lean after the planet was whacked with a massive rocky object a few billion years ago.

An anonymous reader quotes a report from the Washington Post: A new estimate for the total number of ants burrowing and buzzing on Earth comes to a whopping total of nearly 20 quadrillion individuals. That staggering sum -- 20,000,000,000,000,000, or 20,000 trillion -- reveals ants' astonishing ubiquity even as scientists grow concerned a possible mass die off of insects could upend ecosystems. In a paper released Monday by the Proceedings of the National Academy of Sciences, a group of scientists from the University of Hong Kong analyzed 489 studies and concluded that the total mass of ants on Earth weighs in at about 12 megatons of dry carbon. Put another way: If all the ants were plucked from the ground and put on a scale, they would outweigh all the wild birds and mammals put together.

"It's unimaginable," said Patrick Schultheiss, a lead author on the study who is now a researcher at the University of Wurzburg in Germany, in a Zoom interview. "We simply cannot imagine 20 quadrillion ants in one pile, for example. It just doesn't work." Counting all those insects -- or at least enough of them to come up with a sound estimate -- involved combining data from "thousands of authors in many different countries" over the span of a century, Schultheiss added. To tally insects as abundant as ants, there are two ways to do it: Get down on the ground to sample leaf litter -- or set tiny pitfall traps (often just a plastic cup) and wait for the ants to slip in. Researchers have gotten their boots dirty with surveys in nearly every corner of the world, though some spots in Africa and Asia lack data. "It's a truly global effort that goes into these numbers," Schultheiss said.

"The poles are warming several times faster than the global average," Phys.org reminds us, "causing record smashing heatwaves that were reported earlier this year in both the Arctic and Antarctic. Melting ice and collapsing glaciers at high latitudes would accelerate sea level rise around the planet.

"Fortunately, refreezing the poles by reducing incoming sunlight would be both feasible and remarkably cheap, according to new research published Friday in Environmental Research Communications." Scientists laid out a possible future program whereby high-flying jets would spray microscopic aerosol particles into the atmosphere at latitudes of 60 degrees north and south — roughly Anchorage and the southern tip of Patagonia. If injected at a height of 43,000 feet (above airliner cruising altitudes), these aerosols would slowly drift poleward, slightly shading the surface beneath. "There is widespread and sensible trepidation about deploying aerosols to cool the planet," notes lead author Wake Smith, "but if the risk/benefit equation were to pay off anywhere, it would be at the poles."

Particle injections would be performed seasonally in the long days of the local spring and early summer. The same fleet of jets could service both hemispheres, ferrying to the opposite pole with the change of seasons.

newly designed high-altitude tankers would prove much more efficient. A fleet of roughly 125 such tankers could loft a payload sufficient to cool the regions poleward of 60 degreesN/S by 2 degreesC per year, which would return them close to their pre-industrial average temperatures. Costs are estimated at $11 billion annually — less than one-third the cost of cooling the entire planet by the same 2 degreesC magnitude and a tiny fraction of the cost of reaching net zero emissions.
Smith calls the idea "game-changing" (while also warning it's "not a substitute for decarbonization").