Slashdot reader sciencehabit shared this report from Science magazine: One of the classic tropes of science fiction is terraforming Mars: warming up our cold neighbor so it could support human civilization. The idea might not be so far-fetched, research published today in Science Advances suggests...

Samaneh Ansari [a Ph.D. student at Northwestern University and lead author on the new study] and her colleagues wanted to test the heat-trapping abilities of a substance Mars holds in abundance: dust. Martian dust is rich in iron and aluminum, which give it its characteristic red hue. But its microscopic size and roughly spherical shape are not conducive to absorbing radiation or reflecting it back to the surface. So the researchers brainstormed a different particle: using the iron and aluminum in the dust to manufacture 9-micrometer-long rods, about twice as big as a speck of martian dust and smaller than commercially available glitter. Ansari designed a simulation to test how these theoretical particles would interact with light. She found "unexpectedly huge effects" in how they absorbed infrared radiation from the surface and how they scattered that radiation back down to Mars — key factors that determine whether an aerosol particle creates a greenhouse effect.

Collaborators at the University of Chicago and the University of Central Florida then fed the particles into computer models of Mars's climate. They examined the effect of annually injecting 2 million tons of the rods 10 to 100 meters above the surface, where they would be lofted to higher altitudes by turbulent winds and settle out of the atmosphere 10 times more slowly than natural Mars dust. Mars could warm by about 10 degreesC within a matter of months, the team found, despite requiring 5000 times less material than other proposed greenhouse gas schemes...

Still, "Increasing the temperature of the planet is just one of the things that we would need to do in order to live on Mars without any assistance," says Juan Alday, a postdoctoral planetary science researcher at the Open University not involved with the work. For one, the amount of oxygen in Mars's atmosphere is only 0.1%, compared with 21% on Earth. The pressure on Mars is also 150 times lower than on Earth, which would cause human blood to boil. And Mars has no ozone layer, which means there is no protection from the Sun's harmful ultraviolet radiation. What's more, even once warmed, martian soils may still be too salty or toxic to grow crops. In other words, McInnes says, upping the temperature "isn't some kind of magic switch" that would make Mars habitable.

That isn't stopping Ansari and her colleagues from investigating the possibilities.

Longtime Slashdot reader schwit1 shares a report from Ars Technica: The upper stage from a Chinese rocket that launched a batch of Internet satellites Tuesday has broken apart in space, creating a debris field of at least 700 objects in one of the most heavily-trafficked zones in low-Earth orbit. US Space Command, which tracks objects in orbit with a network of radars and optical sensors, confirmed the rocket breakup Thursday. Space Command initially said the event created more than 300 pieces of trackable debris. The military's ground-based radars are capable of tracking objects larger than 10 centimeters (4 inches). Later Thursday, LeoLabs, a commercial space situational awareness company, said its radars detected at least 700 objects attributed to the Chinese rocket. The number of debris fragments could rise to more than 900, LeoLabs said. The culprit is the second stage of China's Long March 6A rocket, which lifted off Tuesday with the first batch of 18 satellites for a planned Chinese megaconstellation that could eventually number thousands of spacecraft. The Long March 6A's second stage apparently disintegrated after placing its payload of 18 satellites into a polar orbit.

Space Command said in a statement it has "observed no immediate threats" and "continues to conduct routine conjunction assessments to support the safety and sustainability of the space domain." According to LeoLabs, radar data indicated the rocket broke apart at an altitude of 503 miles (810 kilometers) at approximately 4:10 pm EDT (20:10 UTC) on Tuesday, around 13-and-a-half hours after it lifted off from northern China. At this altitude, it will take decades or centuries for the wispy effect of aerodynamic drag to pull the debris back into the atmosphere. As the objects drift lower, their orbits will cross paths with SpaceX's Starlink Internet satellites, the International Space Station and other crew spacecraft, and thousands more pieces of orbital debris, putting commercial and government satellites at risk of collision.

An anonymous reader quotes a report from Ars Technica: The past several years have been absolute scorchers, with 2023 being the warmest year ever recorded. And things did not slow down in 2024. As a result, we entered a stretch where every month set a new record as the warmest iteration of that month that we've ever recorded. Last month, that pattern stretched out for a full 12 months, as June of 2024 once again became the warmest June ever recorded. But, despite some exceptional temperatures in July, it fell just short of last July's monthly temperature record, bringing the streak to a close.

Europe's Copernicus system was first to announce that July of 2024 was ever so slightly cooler than July of 2023, missing out on setting a new record by just 0.04 degrees C. So far, none of the other major climate trackers, such as Berkeley Earth or NASA GISS, have come out with data for July. These each have slightly different approaches to tracking temperatures, and, with a margin that small, it's possible we'll see one of them register last month as warmer or statistically indistinguishable. According to the Copernicus system, July 2024 was 0.68 degrees above the average temperature for July from 1991 to 2020. It also included the warmest day ever recorded.

In terms of anomalies, July 2024 also represents the first time in a year that a month was less than 1.5 degrees C above preindustrial temperatures (defined as the average from 1850-1900).

An anonymous reader quotes a report originally published by Business Insider: A Chinese state-backed company has launched its first 18 satellites in its bid to build a vast orbital network aimed at rivaling Starlink, according to local media. The launch on Monday by Shanghai Spacecom Satellite Technology involved 18 satellites and one rocket, per The China Securities Journal, which is run by state news agency Xinhua. According to the outlet, the rocket lifted off from the Taiyuan satellite and missile launch center in Shanxi province.

These satellites mark the first step in the company's effort to create a 15,000-strong network of Low Earth Orbit satellites, which the firm has dubbed the "Thousand Sails Constellation." The company said it plans to reach that final tally by 2030, per The China Securities Journal. Domestic media has widely called the project the Chinese version of Starlink, which runs about 6,000 satellites. Elon Musk has said that he plans to eventually host a network of 42,000 satellites.

The Thousand Sails Constellation, also known as the G60 project, is one of three planned major satellite networks in the country. Each is expected to field 10,000 or more satellites. Most are anticipated to orbit between 200 and 1,200 miles above the Earth's surface, which is also where Starlink satellites are generally found. The three constellations, along with dozens of ambitious space projects from other Chinese firms, have been fueled by a recent push from the central government to loop the private sector into its science and technology goals.

An anonymous reader quotes a report from the New York Times: For weeks, NASA has downplayed problems experienced by Starliner, a Boeing spacecraft that took two astronauts to the International Space Station in June. But on Wednesday, NASA officials admitted that the problems with the spacecraft were more serious than first thought and that the astronauts may not travel home on the Boeing vehicle, after all. The agency is exploring a backup option for the astronauts, Suni Wiliams and Butch Wilmore, to hitch a ride back to Earth on a vehicle built by Boeing's competitor SpaceX instead. Their stay in orbit, which was to be as short as eight days, may extend into next year. "We could take either path," Ken Bowersox, NASA's associate administrator for the space operations mission directorate, said during a news conference on Wednesday. "And reasonable people could pick either path."

NASA and Boeing officials had maintained that the crew that launched with Starliner on its first crewed test flight was not stranded in space. Ms. Williams and Mr. Wilmore have spent two months aboard the orbital outpost while engineers continue to analyze data about the faulty performance of several of the Starliner's thrusters when it approached for docking. Under the contingency plan, a SpaceX Crew Dragon capsule would travel to the space station with two astronauts instead of its planned crew of four. Ms. Williams and Mr. Wilmore would then join as full-time members of the space station crew for a half-year stay, returning on the Crew Dragon around next February. "In the last few weeks, we have decided to make sure we have that capability there, as our community, I would say, got more and more uncomfortable," said Steve Stich, the manager of the commercial crew program at NASA. NASA officials said no decision had been made yet.

Ocean temperatures in the Great Barrier Reef are now the hottest in at least 400 years and are an "existential threat" to the planet's unique natural wonder , according to new scientific research. From a report: Scientists analysed long-lived corals in and around the reef that keep a record of temperature hidden in their skeleton and matched them to modern observations. The research, published in the journal Nature, used climate models to find the extreme temperatures of recent decades could not have happened without the extra greenhouse gases in the atmosphere caused mostly by burning fossil fuels.

The "existential threat" to the reef from the climate crisis was "now realised," the scientists wrote, and without ambitious and rapid cuts to greenhouse gas emissions "we will likely be witness to the demise of one of the Earth's natural wonders." The research comes two weeks after the World Heritage committee decided not to place the reef, which covers an area larger than Italy, on its list of sites "in danger," saying it would consider the question again in 2026.

According to a recent study, SpaceX's new Starlink direct-to-cell (DTC) satellites are nearly five times brighter than traditional Starlinks due to their lower orbit. While these satellites offer the promise of widespread connectivity, their increased brightness poses challenges for astronomical observations, prompting SpaceX to consider applying brightness mitigation techniques. Space.com reports: The higher luminosity of these DTCs compared to regular Starlinks is partly because they circle Earth at just 217 miles (350 kilometers) above the surface, which is lower than traditional Starlink internet satellites, whose altitude is 340 miles (550 kilometers), the study reported. [...] At the time the study was conducted, SpaceX had not yet applied its routine brightness mitigation techniques to the DTCs, such as adjusting their chassis and solar panels to reduce the portion of spacecraft illuminated by the sun, study lead author Anthony Mallama of the IAU Centre for the Protection of Dark and Quiet Skies from Satellite Constellation Interference (IAU-CPS) told Space.com.

SpaceX began applying brightness mitigation techniques to regular Starlinks in 2020, after astronomers voiced serious concerns about the satellites' trails streaking across telescope images, rendering them unusable. Prior to launch, the company now applies a mirror-like dielectric surface to the underside of each Starlink chassis, to help reflect sunlight into space rather than scattering it toward Earth. Post launch, the company adjusts spacecraft chassis and solar panels to further reduce luminosity. Together, these techniques are very effective, reducing Starlink satellites' brightness by a factor of 10, Mallama said. If SpaceX applies these brightness mitigation techniques to the DTCs, which are nearly the same size as the regular Starlinks, the DTCs would still be 2.6 times brighter than their traditional counterparts, Mallama and his colleagues reported in the recent study, which was reviewed internally by IAU-CPS and posted to the preprint server arXiv last month.

However, while DTCs are brighter objects, they move at a faster apparent rate and spend more time in Earth's shadow than regular Starlinks, which would offset some of their negative impact on astronomy observations, the study noted. "I see it as a tradeoff in parameters rather than an absolute better/worse kind of situation," John Barentine, a principal consultant at Arizona-based Dark Sky Consulting who was not involved with the new study, told Space.com.

Scientists studying lunar samples brought back by the Apollo missions have determined that the moon's thin atmosphere is produced largely by meteorite impacts. "Our findings provide a clearer picture of how the moon's surface and atmosphere interact over long timescales, [and] enhance our understanding of space weathering processes," said Dr Nicole Nie, the co-author of the new study based at MIT's department of Earth, atmospheric, and planetary sciences. The Guardian reports: Writing in the journal Science Advances, Nie and her colleagues describe how the lunar atmosphere must be constantly replenished because its atoms are continuously being lost to space, primarily because of the moon's weak gravity, or trapped on the lunar surface. Ultraviolet photons from the sun can rerelease the latter, but the researchers say replenishment of the atmosphere is thought to rely on atoms being released from within lunar minerals -- either via vaporisation by meteorite impacts, or by solar wind sputtering, a process in which charged particles from the sun hit the moon and eject atoms. But which of the two factors dominates had been unclear, with data from Nasa's lunar atmosphere and dust environment explorer, launched in 2013, suggesting both were at play.

Nie and colleagues unpicked the conundrum by studying the different forms, or isotopes, of potassium and rubidium in 10 samples of lunar soil from the Apollo missions. The team say meteorite impacts and solar wind sputtering both favor the release of lighter forms of the elements, but that the actual proportion of heavy to light isotopes that end up in the lunar atmosphere and soil would differ depending on the process. "After measuring the isotopic compositions of lunar soils, we built a mathematical model taking into account various space weathering processes, and solve for the contribution of each of them by matching the measured isotopic compositions," said Nie. The results suggest about 70% of the moon's atmosphere is down to impact vaporization and 30% to solar wind sputtering.

A professor in the University of Chicago's department of geophysical sciences "believes that by intentionally releasing sulfur dioxide into the stratosphere, it would be possible to lower temperatures worldwide," reports the New York Times.

He's not the only one promoting the idea. "Harvard University has a solar geoengineering program that has received grants from Microsoft co-founder Bill Gates, the Alfred P. Sloan Foundation and the William and Flora Hewlett Foundation. It's being studied by the Environmental Defense Fund along with the World Climate Research Program.... But many scientists and environmentalists fear that it could result in unpredictable calamities." Because it would be used in the stratosphere and not limited to a particular area, solar geoengineering could affect the whole world, possibly scrambling natural systems, like creating rain in one arid region while drying out the monsoon season elsewhere. Opponents worry it would distract from the urgent work of transitioning away from fossil fuels. They object to intentionally releasing sulfur dioxide, a pollutant that would eventually move from the stratosphere to ground level, where it can irritate the skin, eyes, nose and throat and can cause respiratory problems. And they fear that once begun, a solar geoengineering program would be difficult to stop...

Keith, a professor in the University of Chicago's department of geophysical sciences, countered that the risks posed by solar geoengineering are well understood, not as severe as portrayed by critics and dwarfed by the potential benefits. If the technique slowed the warming of the planet by even just 1 degree Celsius, or 1.8 degrees Fahrenheit, over the next century, Keith said, it could help prevent millions of heat-related deaths each decade...

Opponents of solar geoengineering cite several main risks. They say it could create a "moral hazard," mistakenly giving people the impression that it is not necessary to rapidly reduce fossil fuel emissions. The second main concern has to do with unintended consequences. "This is a really dangerous path to go down," said Beatrice Rindevall, the chair of the Swedish Society for Nature Conservation, which opposed the experiment. "It could shock the climate system, could alter hydrological cycles and could exacerbate extreme weather and climate instability." And once solar geoengineering began to cool the planet, stopping the effort abruptly could result in a sudden rise in temperatures, a phenomenon known as "termination shock." The planet could experience "potentially massive temperature rise in an unprepared world over a matter of five to 10 years, hitting the Earth's climate with something that it probably hasn't seen since the dinosaur-killing impactor," Pierrehumbert said. On top of all this, there are fears about rogue actors using solar geoengineering and concerns that the technology could be weaponized. Not to mention the fact that sulfur dioxide can harm human health.

Keith is adamant that those fears are overblown. And while there would be some additional air pollution, he claims the risk is negligible compared to the benefits.
The opposition is making it hard to even conduct tests, according to the article — like when Keith "wanted to release a few pounds of mineral dust at an altitude of roughly 20 kilometers and track how the dust behaved as it floated across the sky."

The experiment was called off after opposition from numerous groups — including Greta Thunberg and an organization representing Indigenous people who felt the experiment was disrespecting nature.

The planet Mercury could have "a layer of diamonds," reports CNN, citing new research suggesting that about 310 miles (500 kilometers) below the surface...could be a layer of diamonds 11 miles (18 kilometers) thick.

And the study's co-author believes lava might carry some of those diamonds up to the surface: The diamonds might have formed soon after Mercury itself coalesced into a planet about 4.5 billion years ago from a swirling cloud of dust and gas, in the crucible of a high-pressure, high-temperature environment. At this time, the fledgling planet is believed to have had a crust of graphite, floating over a deep magma ocean.

A team of researchers recreated that searing environment in an experiment, with a machine called an anvil press that's normally used to study how materials behave under extreme pressure but also for the production of synthetic diamonds. "It's a huge press, which enables us to subject tiny samples at the same high pressure and high temperature that we would expect deep inside the mantle of Mercury, at the boundary between the mantle and the core," said Bernard Charlier, head of the department of geology at the University of Liège in Belgium and a coauthor of a study reporting the findings.

The team inserted a synthetic mixture of elements — including silicon, titanium, magnesium and aluminum — inside a graphite capsule, mimicking the theorized composition of Mercury's interior in its early days. The researchers then subjected the capsule to pressures almost 70,000 times greater than those found on Earth's surface and temperatures up to 2,000 degrees Celsius (3,630 degrees Fahrenheit), replicating the conditions likely found near Mercury's core billions of years ago.

After the sample melted, the scientists looked at changes in the chemistry and minerals under an electron microscope and noted that the graphite had turned into diamond crystals.
The researchers believe this mechanism "can not only give us more insight into the secrets hidden below Mercury's surface, but on planetary evolution and the internal structure of exoplanets with similar characteristics."

New preliminary evidence for phosphine and ammonia in Venus's atmosphere deepens the mystery of their origins, suggesting the possibility of a biological source. The detections, made using the James Clerk Maxwell Telescope and the Green Bank Telescope, point to potential microbial life in Venus's clouds despite the planet's extreme surface conditions. Space.com reports: The new detections of phosphine and ammonia were obtained by a team led by Jane Greaves of the University of Cardiff using submillimeter radio wavelength data collected by the James Clerk Maxwell Telescope (JCMT) in Hawaii and the Green Bank Telescope in West Virginia. "We don't know how you make phosphine or ammonia in an oxygenating atmosphere like that of Venus," said team member and astrophysicist Dave Clements of Imperial College, London, in an interview with Space.com. Then again, it's not clear why biology on Earth produces phosphine, either." Whether it's in penguin poop or badger guts, we don't know why bacteria make phosphine, but they do."

The JCMT's initial detection of phosphine on Venus in 2020 by Greaves and her team was met by fierce disagreement from some quarters. This disagreement focused on how the data was processed and whether that was creating spurious signals since observations by other telescopes struggled to detect the phosphine. Clements said those technical disagreements have now been resolved and that the latest measurements, using a new detector on the JCMT called Namakanui (meaning 'Big Eyes' in Hawaiian), have come from three observing campaigns, each providing 140 times as much data as the initial detection. [...]

Clements is open to the possibility that both phosphine and ammonia are being produced by some rare photochemistry in Venus' upper atmosphere involving solar ultraviolet breaking up molecules and allowing phosphine and ammonia to form from the molecular debris. If that is the case, nobody has observed this process yet, not even in the laboratory. Another possibility that has been mooted is that the phosphine could be produced by Venusian volcanoes. Clements also pointed out that the European Space Agency's Jupiter Icy Moons Explorer (JUICE) is making a fly-by of Venus in August 2025 to help slingshot it towards the Jovian system. JUICE carries instruments capable of detecting phosphine and ammonia, but there's no guarantee that its instruments will be switched on and deployed at Venus.

An anonymous reader quotes a report from The Guardian: With thousands of species at risk of extinction, scientists have devised a radical plan: a vault filled with preserved samples of our planet's most important and at-risk creatures located on the moon. An international team of experts says threats from climate change and habitat loss have outpaced our ability to protect species in their natural habitats, necessitating urgent action. A biorepository of preserved cells, and the crucial DNA within them, could be used to enhance genetic diversity in small populations of critically endangered species, or to clone and create new individuals in the worst-case scenario of extinction.

The proposed lunar biorepository, as described in the journal BioScience, would be beyond the reach of climate breakdown, geopolitical events or other Earth-based disasters. The moon's naturally frigid environment means samples would remain frozen year-round without the need for human involvement or an energy source. By taking advantage of deep craters near the polar regions that are never exposed to sunlight, the moon is one of few places that can provide the ultra-low temperature of -196C necessary to preserve the samples in a way suitable for future cloning. [...] Besides those facing the imminent risk of extinction, the proposed repository would prioritize species with important functions in their environment and food webs. Through careful selection, those housed could be used to re-establish an extinct population on Earth or even to terraform another planet. Dr Mary Hagedorn of the Smithsonian's national zoo and conservation biology institute and the proposal's lead author believes the biorepository proposal will come to fruition, although perhaps not in our lifetime: "We know how to do this and can do this and will do this, but it may take decades to finally achieve," she said.

The report says the next steps "will be to develop packaging for the cryopreserved samples that can withstand the conditions of space, and to work out the logistics of transporting samples to the moon."

Scientists say the drying Great Salt Lake in Utah is now becoming a significant contributor to global greenhouse gas emissions that are causing the climate to warm, according to a new study. From a report: Due largely to water diversions by farmers and Utah's booming population growth, the Great Salt Lake has shrunk by almost half in recent years. Scientists spent seven months in 2020 sampling emissions coming off the dried saline lake bed. Canada's Royal Ontario Museum published the study on Thursday in the journal One Earth. [...]

The researchers found that the drying lake bed emitted 4.1 million tons of carbon dioxide and other greenhouse gases into the atmosphere, which would translate to a 7% increase in Utah's human-caused emissions. According to scientists, 4 million tons of CO2 is roughly equivalent to the total annual emissions of 140 commercial planes. The Great Salt Lake is the largest saline lake left in the Western Hemisphere. The study occurred during one of the most notorious dry stretches of the West's mega drought, which had lasted two decades at the time of the study.

An anonymous reader shared this report from the Washington Post: Earth's land lost much of their ability to absorb the carbon dioxide humans pumped into the air last year, according to a new study that is causing concern among climate scientists that a crucial damper on climate change underwent an unprecedented deterioration. Temperatures in 2023 were so high — and the droughts and wildfires that came with them were so severe — that forests in various parts of the world wilted and burned enough to have degraded the ability of the land to lock away carbon dioxide and act as a check on global warming, the study said.

The scientists behind the research, which focuses on 2023, caution that their findings are preliminary. But the work represents a disturbing data point — one that, if it turns into a trend, spells trouble for the planet and the people on it...

Philippe Ciais [a scientist at France's Laboratory of Climate and Environmental Sciences who co-authored the new research] and his colleagues saw that the concentration of CO2 measured at an observatory on Mauna Loa in Hawaii and elsewhere spiked in 2023, even though global fossil fuel emissions increased only modestly last year in comparison. That mismatch suggests that there was an "unprecedented weakening" in the Earth's ability to absorb carbon, the researchers wrote. The scientists then used satellite data and models for vegetative growth to try to pinpoint where the carbon sink was weakening. The team spotted abnormal losses of carbon in the drought-stricken Amazon and Southeast Asia as well as in the boreal forests of Canada, where record-breaking wildfires burned through tens of millions of acres.

Speaking at the Bitcoin Conference in Nashville, Republican presidential nominee Donald Trump made a number of cryptocurrency-related pledges:

• Trump promised that if elected, he'd commute the sentence of Silk Road creator Ross Ulbricht to a sentence of time served. "It's enough."

• Trump promised to change the top personnel at America's Securities and Exchange Commission. "On Day One, I will fire Gary Gensler and appoint a new SEC chairman," Trump told the crowd, drawing a long round of applause. ("I didn't know he was that unpopular," Trump joked — then repeated his promise to appoint "a new SEC chairman who believes America should build the future, not block the future, which is what they're doing.")

• Trump also promised that "As president, I will immediately shut down Operation Chokepoint 2.0." (For context, Operation Chokepoint was an Obama-era program — ended during Trump's presidency — to scrutinize bank lending to "high-risk" merchants, mostly predatory "payday" lenders. Concerns were raised that bank regulators were pressuring banks to cut off certain businesses, and while there is no official "Choke Point 2.0," the phrase has been used colloquially to describe the possibility of bank regulators pressuring specific industries like cryptocurrency.)

• Trump also announced he'd oppose a central bank digital currency — although his wording was a little idiosyncratic. "Next I will immediately order the Treasury Department and other federal agencies to cease and desist all steps necessary — because, you know, there's a thing going on in your industry. They want to move the creation of a central bank digital currency. It's over, forget it." [Audience boos CBDC's ] "CBDC — there will never be a CBDC while I'm president of the United States." (In fact a 2023 statement from America's Federal Reserve about CBDC's stresses that "no decisions have been made at this time" and that the Federal Reserve would only proceed with a CBDC after passage of an authorizing law.)

• Trump also told the audience that "We will create a framework to enable the safe and responsible expansion of staple — stablecoins," then teased the crypto-friendly audience by asking playfully "Do you know what a stablecoin is? Does anybody know — please raise your hand." Trump promised the move would "allow us to extend the dominance of the U.S. dollar to new frontiers all around the world," and that "there will be billions and billions of people brought into the crypto economy and storing their savings in bitcoin."

• Toward the end Trump said that if elected, he would direct the government not to sell any of its currently-held bitcoin, keeping it instead as the core of a "strategic national bitcoin stockpile."
  
  "As you know, most of the bitcoin currently held by the U.S. government was obtained through law enforcement action — you know that, they took it from you. 'Let's take that guy's life, let's take his family, his house, his bitcoin — we'll turn it into bitcoin.' It's been taken away from you because that's where we're going now. That's where this country is going. It's a facist regime."

In a speech which lasted for over an hour, the 78-year-old former president also criticized his political opponents, touching on topics like inflation, immigration, and his promise to "drill, baby, drill."

But Trump closed by thanking the 3,000 attendees, telling them to "have a good time with your bitcoin, and your crypto and everything else that you're playing with. And we're going to make that one of the greatest industries on earth."

"Scientists working with NASA's Perseverance rover state emphatically that they are not claiming to have discovered life on Mars," writes the New York Times.

"But many would regard a rock that the rover just finished studying as 'Most Likely to Contain Fossilized Microbial Martians'..." The rover has drilled and stashed a piece of the rock, which scientists hope can be brought back to Earth in the coming years for closer analysis and more definitive answers. "What we are saying is that we have a potential biosignature on Mars," said Kathryn Stack Morgan, the mission's deputy project scientist. She describes a biosignature as a structure, composition or texture in a rock that could have a biological origin.

The rock, which scientists named Cheyava Falls, possesses features that are reminiscent of what microbes might have left behind when this area was warm and wet several billion years ago, part of an ancient river delta. The scientists clarified that they did not spot anything that they thought might be actual fossilized organisms... Within the rock, Perseverance's instruments detected organic compounds, which would provide the building blocks for life as we know it. The rover also found veins of calcium sulfate — mineral deposits that appear to have been deposited by flowing water. Liquid water is another key ingredient for life. Perseverance also spotted small off-white splotches, about 1 millimeter in size, that have black rings around them, like miniature leopard spots. The black rings contain iron phosphate.

The chemical reactions that created the leopard spots could also have provided energy for microbes to live on.
"One of the key parts of Perseverance's mission is to drill samples of interesting rocks for a future mission to bring samples back to Earth for scientists to study with state-of-the-art instruments in their laboratories," the article points out. And while exactly how those rocks would be return has yet to be determined, deputy project scientist Morgan tells the Times, "I think this sample comes to the top of the list."

As part of a team exploring Utah's Great Salt Lake, climate researcher Melissa Cobo "discovered more disturbing evidence that dried-out lakes are a significant source of carbon dioxide emissions," reports the Washington Post.

But more disturbingly, they write that this source of emissions "has not been included in the official accounting of how much carbon the world is releasing into the warming atmosphere." In a new study in the journal One Earth, the researchers calculated that 4.1 million tons of carbon dioxide and other greenhouse gases were released from the drying bed of the Great Salt Lake in 2020, the year Cobo and others collected the samples. This would amount to about a 7 percent increase in Utah's human-caused emissions, the authors found.

While other researchers have documented carbon emissions from dried-out lakes — including the Aral Sea in Central Asia — [climate change museum curator Soren] Brothers said that his study tried to calculate what part of the emissions from this major saline lake could be attributed to humans, as the Great Salt Lake has been drawn down for human use, a decline worsened by climate change and the West's megadrought of the past two decades.

"This is the first time we're saying, 'This is something that's on us,'" said Brothers, now a climate change curator with the Royal Ontario Museum. Lakes around the world normally store carbon. Plant and animal remains settle on the bottom over thousands of years as sediment, much of it in low-oxygen layers that degrade slowly. "When lakes are inundated with water, let's say their useful state, they are kind of allies in our struggle for removing CO2 from the atmosphere," said Rafael Marcé, a research scientist at the Centre for Advanced Studies in Blanes, Spain, who has collaborated with Brothers on prior work but wasn't involved in this study. When lakes dry out, oxygen can penetrate deep into the sediment, waking up microorganisms that start to feast on the organic matter, releasing carbon dioxide, Marcé said.

UN: The UN Secretary-General's Call to Action on Extreme Heat brings together the diverse expertise and perspectives of ten specialized UN entities (FAO, ILO, OCHA, UNDRR, UNEP, UNESCO, UN-Habitat, UNICEF, WHO, WMO) in a first-of-its-kind joint product, underscoring the multi-sectoral impacts of extreme heat.

Earth is becoming hotter and more dangerous for everyone, everywhere. Billions of people around the world are wilting under increasingly severe heatwaves driven largely by a fossil-fuel charged, human-induced climate crisis. Extreme heat is tearing through economies, widening inequalities, undermining the Sustainable Development Goals, and killing people.

The Call for Action calls for an urgent and concerted effort to enhance international cooperation to address extreme heat in four critical areas: Caring for the vulnerable - Protecting workers - Boosting resilience of economies and societies using data and science - Limiting temperature rise to 1.5C by phasing out fossil fuels and scaling up investment in renewable energy. From earlier today: Monday Was Hottest Recorded Day on Earth: 'Uncharted Territory'.

World temperature reached the hottest levels ever measured on Monday, beating the record that was set just one day before, data suggests. From a report: Provisional data published on Wednesday by the Copernicus Climate Change Service, which holds data that stretches back to 1940, shows that the global surface air temperature reached 62.87F (17.15C), compared with 62.76F (17.09C) on Sunday.

Earlier this month, Copernicus found that global temperatures between July 2023 and July 2024 were the highest on record. The previous record before this week was set a year ago on 6 July. Before that, the previous recorded hottest day was in 2016, according to the Associated Press.

On Sunday, global temperatures reached their highest levels in recorded history (source may be paywalled; alternative source), with a daily average of 17.09 degrees Celsius (62.76 degrees Fahrenheit). "The historic day comes on the heels of 13 straight months of unprecedented temperatures and the hottest year scientists have ever seen," adds the Washington Post, citing preliminary data from the Copernicus Climate Change Service. From the report: Though Sunday was only slightly warmer than the world's previous hottest day, Copernicus researchers noted, it was extraordinarily hotter than anything that came before. Before July 2023, Earth's daily average temperature record -- set in August 2016 -- was 16.8 degrees Celsius (62.24 degrees Fahrenheit). But in the past year, the global has exceeded that old record on 57 days.

Scientists have been tracking global temperatures only for the past few centuries. Yet there is good reason to believe that Sunday was the hottest day on Earth since the start of the last Ice Age more than 100,000 years ago. Research from paleoclimate scientists -- who use tree rings, ice cores, lake sediments and other ancient material to understand past environments -- suggests that recent heat would have been all but impossible over the last stretch of geologic time. "We are in truly uncharted territory," Copernicus director Carlo Buontempo said in a statement. "And as the climate keeps warming, we are bound to see records being broken in future months and years. What is truly staggering is how large the difference is between the temperature of the last 13 months and the previous temperature records."