Science – Page 10

Rocket Report: The pitfalls of rideshare; China launches next Tiangong crew

Arianespace, astra, blue origin, china, human spaceflight, launch, NASA, rocket report, Science, Space, spacex, united launch alliance / Shannon Garcia / April 25, 2025

This week, engineers ground-tested upgrades for Blue Origin’s New Glenn and Europe’s Ariane 6.

A Long March 2F carrier rocket, carrying the Shenzhou 20 spacecraft and a crew of three astronauts, lifts off from the Jiuquan Satellite Launch Center in northwest China on April 24, 2025. Credit: Photo by Pedro Pardo/AFP via Getty Images

Welcome to Edition 7.41 of the Rocket Report! NASA and its contractors at Kennedy Space Center in Florida continue building a new mobile launch tower for the Space Launch System Block 1B rocket, a taller, upgraded version of the SLS rocket being used for the agency’s initial Artemis lunar missions. Workers stacked another segment of the tower a couple of weeks ago, and the structure is inching closer to its full height of 355 feet (108 meters). But this is just the start. Once the tower is fully assembled, it must be outfitted with miles of cabling, tubing, and piping and then be tested before it can support an SLS launch campaign. Last year, NASA’s inspector general projected the tower won’t be ready for a launch until the spring of 2029, and its costs could reach $2.7 billion. The good news, if you can call it that, is that there probably won’t be an SLS Block 1B rocket that needs to use it in 2029, whether it’s due to delays or cancellation.

As always, we welcome reader submissions. If you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets, as well as a quick look ahead at the next three launches on the calendar.

Fresh details on Astra’s strategic pivot. Astra, the once high-flying rocket startup that crashed back to Earth with investors before going private last year, has unveiled new details about its $44 million contract with the Department of Defense, Space News reports. The DOD contract announced last year supports the development of Rocket 4, a two-stage, mobile launch vehicle with ambitions to deliver cargo across the globe in under an hour. While Astra’s ill-fated Rocket 3 focused on launching small satellites into low-Earth orbit, Astra wants to make Rocket 4 a military utility vehicle. Rocket 4 will still be able to loft conventional satellites, but Astra’s most lucrative contract for the new launch vehicle involves using the rocket for precise point-to-point delivery of up to 1,300 pounds (590 kilograms) of supplies from orbit via specialized reentry vehicles. The military has shown interest in developing a rocket-based rapid global cargo delivery system for several years, and it has a contract with SpaceX to study how the much larger Starship rocket could do a similar job.

Back from the brink… The Alameda, California-based company, which was delisted from Nasdaq in June 2024 after its shares collapsed, is now targeting the first test flight of Rocket 4 in 2026. Astra’s arrangement with the Defense Innovation Unit includes two milestones: one suborbital (point-to-point) and the other orbital, with the option to launch from a location outside the United States, as Astra is developing a mobile launcher. Chris Kemp, Astra’s co-founder and CEO, told Space News the orbital launch will likely originate from Australia. Astra’s first launches with the new-retired Rocket 3 vehicle were based in Alaska and Florida.

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The Army has a catchy name for its newest weapon. The Long Range Hypersonic Weapon has a new name: Dark Eagle. The US Army announced the popular name for the service’s quick strike missile this week. “Part of the name pays tribute to the eagle—a master hunter known for its speed, stealth and agility—due to the LRHW’s combination of velocity, accuracy, maneuverability, survivability and versatility,” the Army said in a press release. “In addition, the bald eagle—our national bird—represents independence, strength, and freedom.” The Dark Eagle is designed to strike targets with little or no warning via a hypersonic glide vehicle capable of maneuvering in the upper atmosphere after an initial launch with a conventional missile. The hypersonic weapon’s ability to overcome an adversary’s air and missile defenses is embodied in the word “dark” in Dark Eagle, the Army said.

Flying again soon… The Army tested the hypersonic weapon’s “all-up round” during a missile launch from Cape Canaveral, Florida, in December. The test was delayed more than a year due to unspecified issues. The Army appears to be preparing for another Dark Eagle test from Florida’s Space Coast as soon as Friday, according to airspace and maritime warning notices in the Atlantic Ocean. (submitted by EllPeaTea)

Northrop’s niche with Minotaur. Ars mentioned in last week’s Rocket Report that Northrop Grumman’s Minotaur IV rocket launched April 16 with a classified payload for the National Reconnaissance Office. This was the first Minotaur IV launch in nearly five years and the first orbital Minotaur launch from Vandenberg Space Force Base, California, in 14 years. The low-volume Minotaur IV uses solid rocket motors from the Air Force’s stockpile of retired Peacekeeper ballistic missiles, turning part of a weapon of mass destruction into, in this case, a tool to support the US government’s spy satellite agency. The Minotaur IV’s lift capability fits neatly between the capacity of smaller commercial rockets, like Firefly’s Alpha or Rocket Lab’s Electron, and larger rockets like SpaceX’s Falcon 9. The most recent Minotaur IV launch contract cost the Space Force roughly $30 million, more than a mission with Firefly but less than a dedicated ride on a Falcon 9.

Minotaur IV will keep flying… The Space Force has at least two more missions reserved to launch on the expendable Minotaur IV rocket. One of the missions will launch multiple small satellites for the US military’s Space Test Program, and the other will place a military weather satellite into orbit. Both missions will launch from California, with planning launch dates in 2026, a Space Systems Command spokesperson told Ars. “We do have multiple launches planned using Minotaur family launch vehicles between our OSP-4 (Orbital/Suborbital Program) and SRP-4 (Sounding Rocket Program) contracts,” the spokesperson said. “We will release more information on those missions as we get closer to launch.” The Commercial Space Act of 1998 prohibits the use of surplus ICBM motors for commercial launches and limits their use to only specific kinds of military launches. The restrictions were intended to encourage NASA and commercial satellite operators to use privately developed launch vehicles.

NASA’s launch prices have somehow gone up. In an era of reusable rockets and near-daily access to space, NASA is still paying more than it did 30 years ago to launch missions into orbit, according to a study soon to be published in the scientific journal Acta Astronautica. Adjusted for inflation, the prices NASA pays for launch services rose at an annual average rate of 2.82 percent from 1996 to 2024, the report says. “Furthermore, there is no evidence of shift in the launch service costs trend after the introduction of a new launch service provider [SpaceX] in 2016.” Ars analyzed NASA’s launch prices in a story published Thursday.

Why is this? … One might think SpaceX’s reuse of Falcon 9 rocket components would drive down launch prices, but no. Rocket reuse and economies of scale have significantly reduced SpaceX’s launch costs, but the company is charging NASA roughly the same as it did before booster reuse became commonplace. There are a few reasons this is happening. One is that SpaceX hasn’t faced any meaningful competition for NASA launch contracts in the last six years. That should change soon with the recent debuts of United Launch Alliance’s Vulcan rocket and Blue Origin’s New Glenn launcher. NASA levies additional requirements on its commercial launch providers, and the agency must pay for them. These include schedule priority, engineering oversight, and sometimes special payload cleanliness requirements and the choice of a particular Falcon 9 booster from SpaceX’s inventory.

What’s holding up ULA’s next launch? After poor weather forced ULA to scrub a launch attempt on April 9, the company will have to wait nearly three weeks for another try to launch an Atlas V rocket with Amazon’s first full-up load of 27 Kuiper broadband satellites, Ars reports. The rocket and satellites are healthy, according to ULA. But the military-run Eastern Range at Cape Canaveral Space Force Station, Florida, is unable to accommodate ULA until Monday, April 28. The Space Force is being unusually cagey about the reasons for the lengthy delay, which isn’t affecting SpaceX launches to the same degree.

Finally, a theory… The publishing of airspace and maritime warning notices for an apparent test launch of the Army’s Long Range Hypersonic Weapon, or Dark Eagle, might explain the range’s unavailability. The test launch could happen as soon as Friday, and offshore keep-out zones cover wide swaths of the Atlantic Ocean. If this is the reason for the long Atlas V launch delay, we still have questions. If this launch is scheduled for Friday, why has it kept ULA from launching the last few weeks? Why was SpaceX permitted to launch multiple times in the same time period? And why didn’t the first test flight of the Dark Eagle missile in December result in similar lengthy launch delays on the Eastern Range?

Shenzhou 20 bound for Tiangong. A spaceship carrying three astronauts docked Thursday with China’s space station in the latest crew rotation, approximately six hours after their launch on a Long March 2F rocket from the Gobi Desert, the Associated Press reports. The Shenzhou 20 mission is commanded by Chen Dong, who is making his third flight. He is accompanied by fighter pilot Chen Zhongrui and engineer Wang Jie, both making their maiden voyages. They will replace three astronauts currently on the Chinese Tiangong space station. Like those before them, they will stay on board for roughly six months.

Finding a rhythm… China’s human spaceflight missions have launched like clockwork since the country’s first domestic astronaut launch in 2003. Now, with the Tiangong space station fully operational, China is launching fresh crews at six-month intervals. While in space, the astronauts will conduct experiments in medical science and new technologies and perform spacewalks to carry out maintenance and install new equipment. Their tasks will include adding space debris shielding to the exterior of the Tiangong station. (submitted by EllPeaTea)

SpaceX resupplies the ISS. SpaceX launched an uncrewed Cargo Dragon spacecraft to the International Space Station early Monday on a resupply mission with increased importance after a transportation mishap derailed a flight by another US cargo ship, Spaceflight Now reports. The Dragon cargo vessel docked at the space station early Tuesday with 4,780 pounds (2,168 kilograms) of pressurized cargo and 1,653 pounds (750 kilograms) of unpressurized payloads in the vehicle’s trunk. NASA adjusted the Dragon spacecraft’s payload because an upcoming flight by Northrop Grumman’s Cygnus supply freighter was canceled after the Cygnus cargo module was damaged during transport to the launch site.

Something strange… The payloads aboard this Dragon cargo mission—the 32nd by SpaceX—include normal things like fresh food (exactly 1,262 tortillas), biomedical and pharmaceutical experiments, and the technical demonstration of a new atomic clock. However, there’s something onboard nobody at NASA or SpaceX wants to talk about. A payload package named STP-H10 inside Dragon’s trunk section will be installed on a mounting post outside of the space station to perform a mission for the US military’s Space Test Program. STP-H10 wasn’t mentioned in NASA’s press kit for this mission, and SpaceX didn’t show the usual views of Dragon’s trunk when the spacecraft deployed from its Falcon 9 rocket shortly after launch. These kinds of Space Test Program experiment platforms have launched to the ISS before without any secrecy. Stranger still is the fact that the STP-H10 experiments are unclassified. You can see the list here. (submitted by EllPeaTea)

There are some drawbacks to rideshare. SpaceX launched its third “Bandwagon” rideshare mission into a mid-inclination orbit Monday evening from Cape Canaveral Space Force Station, Space News reports. The payloads included a South Korean military radar spy satellite, a small commercial weather satellite, and the most interesting payload: an experimental reentry vehicle from a German startup named Atmos Space Cargo. The startup’s Phoenix vehicle, fitted with an inflatable heat shield, separated from the Falcon 9’s upper stage about 90 minutes after liftoff. Roughly a half-hour later, it began reentry for a splashdown in the South Atlantic Ocean, about 1,200 miles (2,000 kilometers) off the coast of Brazil. Until last month, the Phoenix vehicle was supposed to reenter over the Indian Ocean east of Madagascar, near the island of Réunion. The late change to the mission’s trajectory meant Atmos could not recover the spacecraft after splashdown.

Changes in longitude… Five weeks before the launch, SpaceX informed Atmos of a change in trajectory because of “operational constraints” of the primary payload, a South Korean reconnaissance satellite. Smaller payloads on rideshare launches benefit from lower launch prices, but their owners have no control over the schedule or trajectory of the launch. The change for this mission resulted in a splashdown well off the coast of Brazil, ruling out any attempt to recover Phoenix after splashdown. It also meant a steeper reentry than previously planned, creating higher loads on the spacecraft. The company lined up new ground stations in South America to communicate with the spacecraft during key phases of flight leading up to reentry. In addition, it chartered a plane to attempt to collect data during reentry, but the splashdown location was beyond the range of the aircraft. Some data suggests that the heat shield inflated as planned, but Atmos’s CEO said the company needed more time to analyze the data it had, adding that it was “very difficult” to get data from Phoenix in the final phases of its flight, given its distance from ground stations.

Ariane 6 is gonna need a bigger booster. A qualification motor for an upgraded solid rocket booster for Europe’s Ariane 6 rocket successfully fired up for the first time on a test stand Thursday in Kourou, French Guiana, according to the European Space Agency. The new P160C solid rocket motor burned for more than two minutes, and ESA declared the test-firing a success. ESA’s member states approved the development of the P160C motor in 2022. The upgraded motor is about 3 feet (1 meter) longer than the P120C motor currently flying on the Ariane 6 rocket and carries about 31,000 pounds (14 metric tons) more solid propellant. The Ariane 6 rocket can fly with two or four of these strap-on boosters. Officials plan to introduce the P160C on Ariane 6 flights next year, giving the rocket’s heaviest version the ability to haul up to 4,400 pounds (2 metric tons) of additional cargo mass to orbit.

A necessary change… The heavier P160C solid rocket motor is required for Arianespace to fulfill its multi-mission launch contract with Amazon’s Project Kuiper satellite broadband network. Alongside similar contracts with ULA and Blue Origin, Amazon reserved 18 Kuiper launches on Ariane 6 rockets, and 16 of them must use the upgraded P160C booster to deliver additional Kuiper satellites to orbit. The P160C is a joint project between ArianeGroup and Avio, which will use the same motor design on Europe’s smaller Vega C rocket to improve its performance. (submitted by EllPeaTea)

Progress toward the second flight of New Glenn. Blue Origin CEO Dave Limp said his team completed a full-duration 15-second hot-fire test Thursday of the upper stage for the company’s second New Glenn rocket. In a post on X, Limp wrote that the upper stage for the next New Glenn flight will have “enhanced performance.” The maximum power of its hydrogen-fueled BE-3U engine will increase from 173,000 pounds to 175,000 pounds of thrust. Two BE-3U engines fly on New Glenn’s second stage.

A good engine… The BE-3U engine is a derivative of the BE-3 engine flying on Blue Origin’s suborbital New Shepard rocket. Limp wrote that the upper stage on the first New Glenn launch in January “performed remarkably” and achieved an orbital injection with less than 1 percent deviation from its target. So when will New Glenn launch again? We’ve heard late spring, June, or October, depending on the source. I’ll note that Blue Origin test-fired the New Glenn upper stage for the rocket’s first flight about four months before it launched.

Next three launches

April 27: Alpha | “Message in a Booster” | Vandenberg Space Force Base, California | 13: 37 UTC

April 27: Long March 3B/E | Unknown Payload | Xichang Satellite Launch Center, China | 15: 55 UTC

April 27: Falcon 9 | Starlink 11-9 | Vandenberg Space Force Base, California | 20: 55 UTC

Stephen Clark is a space reporter at Ars Technica, covering private space companies and the world’s space agencies. Stephen writes about the nexus of technology, science, policy, and business on and off the planet.

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A 2,000-year-old battle ended in fire, and a tree species never recovered

ancient china, ancient warfare, Archaeology, endangered species, han dynasty, save the trees, Science / 9u50fv / April 25, 2025

Then everything changed when the Fire Nation—sorry, the Han Empire—attacked.

Han rose to power in the wake of Qin’s collapse, after a short war with a rival dynasty called Chu, and spent the next century smugly referring to Nanyue as a vassal state and occasionally demanding tribute. At times, the rulers of Nanyue played along, but it all came to a head around 111 BCE, in the wake of an attempted coup and a series of assassinations. The Han Emperor sent an army of between 100,000 and 200,000 soldiers to invade Nanyue under a general named Lu Bode.

The troops marched across the countryside from five directions, converging outside Nanyue’s capital city of Panyou, which stood in the Pearl River Delta, near the modern city of Guangzhou. An enterprising company commander named Yang Pu got the bright idea to set the city on fire, and it ended badly.

“The fire not only destroyed the city but also ran out of control to the surrounding forests,” write Wang and colleagues. The cypress trees burned down to the waterline, leaving only their submerged stumps behind.

map of a coastal area showing elevation and the location of ancient forests — The brown dots mark the known sites of buried forests, and the orange diamonds mark those confirmed to be ancient. The two yellow diamonds are Wang and colleagues’ study sites. Credit: Wang et al. 2025

After war came fire and rice

At the time of the invasion, the land around Panyou was mostly swamp, forested with cypress trees. People had lived there for thousands of years, and had been growing rice for about 2,000 years. Bits of charcoal in the peat layers Wang and colleagues sampled reveal that they practiced slash-and-burn agriculture, but on a small scale, rotating their fields so the cypress forest could start to recover after a season or two.

The small burns are nothing like the forest fire Yang Pu unleashed, or the massive burning and reworking of the landscape that came after.

The stumps of the burned cypress trees slowly disappeared under several meters of peat, while above the buried ancient forest, life went on. Tigers, elephants, rhinos, and green peafowl no longer walked here. Instead, grains of pollen from the layers of clay above the peat reveal a sudden influx of plants from the grassy Poaceae family, which includes rice, wheat, and barley.

A 2,000-year-old battle ended in fire, and a tree species never recovered Read More »

Sadly for China, rare Earth elements aren’t actually all that rare

Science / Kelly Newman / April 24, 2025

relevant periodic table stuff

China has limited US access, but other sources remain.

President Trump ordered a probe on April 15, 2025, that may result in tariffs on critical minerals, rare earth metals, and associated products such as smartphones, in an escalation of his dispute with global trade partners. Credit: Patrick T. Fallon/Getty Images

As the trade war between China and the United States continues to escalate, Beijing is responding by turning to one of its favorite retaliation tactics: limiting the export of critical minerals used in many high-tech electronics, from fighter jets to wind turbines. While China’s mineral restrictions may sound scary, the reality is that they haven’t been very effective in the past and stand to become even less so if the US and other countries finally get their acts together.

It all started in July 2023, when the Chinese government announced it would restrict the export of gallium and germanium, two critical minerals that are mostly used in making solar panels and semiconductors. Over the following two years, China’s list of controlled products expanded to include antimony, graphite, and other materials. Earlier this month, the Chinese government escalated things even further, subjecting seven rare earth elements to a more comprehensive export licensing program that covers the whole world and is designed to further choke off American companies.

Rare earths are a subset of elements under the broader umbrella of critical minerals that China has long enjoyed monopoly control over. In the short term, companies that need these rare earths might be able to rely on existing stockpiles or even turn to recycled electronics to find them. But eventually, the US and other countries will be forced to either ramp up domestic mining or reduce their dependence on rare earths, both of which would make China’s policies sting less. “China has got one shot, and it knows it,” says Ian Lange, an associate professor of economics and business at the Colorado School of Mines.

Rare but not irreplaceable

The export controls China announced earlier this month cover samarium, gadolinium, terbium, dysprosium, lutetium, scandium, and yttrium—seven elements that belong to what is known as the rare earth family. They are called “rare” not because of their scarcity but because they often are mixed with other mineral resources and can be hard to separate out.

There are 17 rare earth elements in total, but the Chinese government chose these seven because they are part of a smaller subset of “heavy” rare earth minerals that the country has more control over than others, says Gracelin Baskaran, director of the Critical Minerals Security Program at the Center for Strategic and International Studies. That monopoly was built over decades as China created a robust supply chain for these minerals and the rest of the world turned away from what is a heavily polluting and niche sector. “China processes pretty much 100 percent of the world’s heavy rare earths, which means that they don’t just have a comparative advantage, they have an absolute advantage,” says Baskaran.

But the other important thing to know about rare earths is that—while they are used in a wide variety of products—those items typically only contain very small quantities, and often only in supportive roles. Last year, the United States imported about $170 million worth of rare earth elements, including some that China hasn’t restricted yet, according to the United States Geological Survey. For comparison, the US imported over $327 million worth of fresh potatoes and $300 million worth of potato chips between September 2023 and August 2024.

Perhaps the most important application for rare earth elements is creating magnets that improve the performance of products like electric motors in high temperatures. These magnets can be found in electric vehicles and consumer products like vacuum cleaners.

“The heavy rare earth elements are added as sort of a spice, a doping agent, to maintain the magnetism of the magnet at high temperatures. It also improves corrosion resistance and the longevity of the magnet,” says Seaver Wang, director of the climate and energy team at the Breakthrough Institute, an Oakland-based think tank.

Beyond magnets, these rare earth elements can also serve a range of purposes, such as making metal stronger, improving radar systems, and even treating cancer. Without them, in many cases, technological infrastructure and consumer gadgets won’t be able to perform at the same level—but they will still maintain their basic functions. “The wind turbines will just go out of service 10 years earlier; electric vehicles will not last as long,” says Wang.

Lange agrees that the impact of losing access to heavy rare earth elements would be somewhat manageable for American companies. “One place where that rare earth is in your car is in the motors that pull up and down your window,” says Lange. “There are ways to just deal with some things that are not as fun, like rolling down your windows by hand.”

Loopholes and workarounds

In the past, China’s critical mineral restrictions haven’t worked very well. One reason is that US companies that want to buy rare earth minerals can simply go through an intermediary country first. For example, Belgium has emerged as a possible re-export hub that appears to pass germanium—one of the minerals Beijing first restricted in 2023—from China to the US, according to trade data. Since the European Union has much closer ties with Washington than with Beijing, it’s difficult for the Chinese government to effectively stop this flow of trade.

Another sign that China’s export controls haven’t been very effective is that the price of critical minerals has increased only slightly since the policies were first implemented, indicating that supply levels have remained steady. “Whatever they did in 2023 hasn’t really changed the status quo” of the market, says Lange.

But China’s latest restrictions are more expansive, and there’s already some evidence that things could be different this time. Companies that need these elements have been forced to buy them from other firms with existing private stockpiles, which have become more valuable in recent weeks. “There is a very steep increase in prices to draw down on stockpiles right now,” says Baskaran, citing conversations she’s had with rare earth traders.

In the long run, however, companies may be able to find technological solutions to address a potential shortage of rare earth minerals. Tesla, for example, announced in 2023 that it had reduced the use of them in its EV motors by 25 percent, and it planned to get rid of them completely in the future. The carmaker hasn’t clarified what it would use instead, but experts speculate it could be turning to other types of magnets that don’t rely on rare earths.

Where are the American mines?

While rare earths, or critical minerals in general, are often cited along with semiconductors as industries the US wants to reshore the most, the challenges associated with bringing each of them back are very different.

Unlike making advanced semiconductors, which requires using sophisticated machinery worth hundreds of millions of dollars and building extremely complicated factories, critical minerals aren’t that hard to produce. The technologies involved to mine and refine them are mature and both the US and Canada have large natural deposits of some of them. But the mining industry was pushed out of the West because it doesn’t generate much value and is also extremely polluting.

In the past, efforts to build up the critical minerals supply chain in the US have either been slowed down or called off. That’s more due to basic economic calculations, says Lange, rather than technological difficulties. “It’s like bending down to pick up a nickel,” he says, meaning the effort isn’t worth the reward.

Because companies only need tiny quantities of these minerals, the market for them is very volatile—prices can drop when a single new factory comes online and starts mass producing and refining them. That means if a mining company were to open up shop in the US, it could inadvertently tank the price of the same mineral it’s trying to profit from, says Lange.

But if China succeeds in strictly enforcing its export control policies, it might provide just enough incentive for the US government and private companies to finally reshore the mineral refining industry. If that happens, Lange says, it could take about two years for a new critical mineral operation to open in the US.

“It’s really remarkable how China has actually maintained these monopolies in so many critical minerals for 20 years,” says Wang. “But I do think we are maybe starting to turn the corner, where China’s market share may be peaking … and you are starting to see a resurgence of interest in these industries in Northern Europe, Australia, Canada, the US, and Latin America.”

This story originally appeared on wired.com.

Wired.com is your essential daily guide to what’s next, delivering the most original and complete take you’ll find anywhere on innovation’s impact on technology, science, business and culture.

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Can the legal system catch up with climate science?

attribution, climate change, costs, liability, Science / Shannon Garcia / April 24, 2025

Similarly, it’s possible to calculate the impact of emissions within a limited number of years. For example, Callahan and Mankin note that internal oil company research suggested that climate change would be a problem back around 1980, and calculated the impact of emissions that occurred after people knew they were an issue. So, the approach is extremely flexible.

From there, the researchers could use empirical information that links elevated temperatures to economic damage. “Recent peer-reviewed work has used econometrics to infer causal relationships between climate hazards and outcomes such as income loss, reduced agricultural yields, increased human mortality, and depressed economic growth,” Callahan and Mankin write. These metrics can be used to estimate the cost of things like flooding, crop losses, and other economic damages. Alternately, the researchers could analyze the impact on individual climate events where the financial costs have been calculated separately.

Massive damages

To implement their method, the researchers perform lots of individual models, collectively providing the most probable costs and the likely range around them. First, they translate each company’s emissions into the impact on the global mean surface temperature. That gets translated to an impact on extreme temperatures, producing an estimate of what the days with the five most extreme temperatures would look like. That, in turn, is translated to economic damages associated with extreme heat.

Callahan and Mankin use Chevron as an example. By 2020, Chevron’s emissions were responsible for 0.025° C of the warming that year. If you perform a similar analysis for the ears between 1991 and 2020, the researchers come up with a range of damages that runs from a low of about $800 billion all the way up to $3.6 trillion. Most of the damage affected nations in the tropics.

Carrying on through the five companies that have led to the most carbon emissions, they calculate that Saudi Aramco, Gazprom, Chevron, and Exxon Mobile have all produced damages of about $2 trillion. BP brings up the rear, with “just” $1.45 trillion in damage. For the full list of 111 carbon majors, Callahan and Mankin place the total damages at roughly $28 trillion.

Can the legal system catch up with climate science? Read More »

Republican space officials criticize “mindless” NASA science cuts

NASA, Science, Space / Shannon Garcia / April 23, 2025

In the nearly two weeks since Ars reported on the Trump administration’s proposed budget cuts for NASA’s science programs, scientists and Democratic lawmakers have both expressed deep concerns about the future of the space agency.

However, in a pattern consistent across a host of issues in which GOP lawmakers do not want to be seen to be publicly criticizing the Trump administration, the response to these sweeping cuts from Republican officials has been much more muted.

But this week, three prominent Republican space policy officials broke their silence. In an op-ed published Tuesday on Real Clear Science, former speaker of the House Newt Gingrich, former House Chair Robert Walker, and the head of the landing team for NASA for the Trump-Vance transition team, Charles Miller, said they were “deeply disturbed” by the proposed cuts. All three men have played an important role in setting Republican space policy over the last decade.

Slashing the Sun

The cuts were part of a “passback” proposal sent to NASA leadership by the White House Office of Management and Budget two weeks ago. Overall, the White House sought a 20 percent cut for NASA, but by far the deepest cuts were earmarked for the agency’s science division: a two-thirds cut to astrophysics, down to $487 million; a nearly 50 percent cut to heliophysics, down to $455 million; a greater than 50 percent cut to Earth science, down to $1.033 billion; and a 30 percent cut to planetary science, down to $1.929 billion.

“Certainly, the space agency needs to modernize and reform practices and personnel management—but not at the expense of world-class science programs,” the Republican officials wrote this week. “Deep cuts to NASA’s science programs would be the end of America’s leadership in space science. It would clearly signal to the world (and to America’s children) that America is a declining power.”

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Universities (finally) band together, fight “unprecedented government overreach”

culture, funding, Science, Trump, universities / Shannon Garcia / April 23, 2025

We speak with one voice against the unprecedented government overreach and political interference now endangering American higher education… We must reject the coercive use of public research funding…

American institutions of higher learning have in common the essential freedom to determine, on academic grounds, whom to admit and what is taught, how, and by whom… In their pursuit of truth, faculty, students, and staff are free to exchange ideas and opinions across a full range of viewpoints without fear of retribution, censorship, or deportation.

This is fine, as far as it goes. But what are all these institutions going to do about the funding cuts, attempts to revoke their nonprofit status, threats not to hire their graduates, and student speech-based deportations? They are going to ask the Trump administration for “constructive engagement that improves our institutions and serves our republic.”

This sounds lovely, if naive, and I hope it works out well for every one of them as they seek good-faith dialogue with a vice president who has called universities the “enemy” and an administration that demanded Harvard submit to the vetting of every department for unspecified “viewpoint diversity.”

As a first step to finding common ground and speaking with a common voice, the statement is a start. But statements, like all words, can be cheap. We’ll see what steps schools actually take—and how much they can speak and act in concert—as Trump’s pressure campaign continues to ratchet.

Universities (finally) band together, fight “unprecedented government overreach” Read More »

Drunk man walks into climate change, burns the bottoms of his feet off

asphalt, burns, climate change, health, Science / Mike M. / April 23, 2025

In the burn unit, doctors gave the man a pain reliever, cleaned the burns, treated them with a topical antibiotic, and gave them an antimicrobial foam dressing. At a follow-up appointment, the wounds appeared to be healing without complications.

While the man recovered from the injury, the author of the case study—Jeremy Hess, an expert in emergency medicine and global environmental health at the University of Washington—warned that the risk of such injuries will only grow as climate change continues.

“Extreme heat events increase the risk of contact burns from hot surfaces in the environment,” he wrote. “Young children, older adults, unhoused persons, and persons with substance use disorder are at elevated risk for these types of burns.”

Last year, The New York Times reported that burn centers in the southwest have already begun seeing larger numbers of burns from contact with sidewalks and asphalt during heat waves. In some cases, the burns can turn fatal if people lose consciousness on hot surfaces—for instance, from overdoses, heat stroke, intoxication, or other health conditions. “Your body just literally sits there and cooks,” Clifford Sheckter, surgeon and a burn prevention researcher at Stanford University, told the Times last year. “When somebody finally finds you, you’re already in multisystem organ failure.”

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Are these chimps having a fruity booze-up in the wild?

animal behavior, Biology, chimpanzees, primates, Science / DJ Henderson / April 22, 2025

Is there anything more human than gathering in groups to share food and partake in a fermented beverage or two (or three, or….)? Researchers have caught wild chimpanzees on camera engaging in what appears to be similar activity: sharing fermented African breadfruit with measurable alcoholic content. According to a new paper published in the journal Current Biology, the observational data is the first evidence of the sharing of alcoholic foods among nonhuman great apes in the wild.

The fruit in question is seasonal and comes from Treculia africana trees common across the home environment of the wild chimps in Cantanhez National Park in Guinea-Bissau. Once mature, the fruits drop from the tree to the ground and slowly ripen from a hard, deep green exterior to a yellow, spongier texture. Because the chimps are unhabituated, the authors deployed camera traps at three separate locations to record their feeding and sharing behavior.

They recorded 10 instances of selective fruit sharing among 17 chimps, with the animals exhibiting a marked preference for riper fruit. Between April and July 2022, the authors measured the alcohol content of the fruit with a handy portable breathalyzer and found almost all of the fallen fruit (90 percent) contained some ethanol, with the ripest containing the highest levels—the equivalent of 0.61 percent ABV (alcohol by volume).

That’s comparatively low to alcoholic drinks typically consumed by humans, but then again, fruit accounts for as much as 60 to 80 percent of the chimps’ diet, so the amount of ethanol consumed could add up quickly. It’s highly unlikely the chimps would get drunk, however. It wouldn’t confer any evolutionary advantage, and per the authors, there is evidence in the common ancestor of African apes of a molecular mechanism that increases the ability to metabolize alcohol.

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Ghost forests are growing as sea levels rise

ghost forest, rising sea, Science, sea level rise, syndication / Shannon Garcia / April 20, 2025

Like giant bones planted in the earth, clusters of tree trunks, stripped clean of bark, are appearing along the Chesapeake Bay on the United States’ mid-Atlantic coast. They are ghost forests: the haunting remains of what were once stands of cedar and pine. Since the late 19th century, an ever-widening swath of these trees have died along the shore. And they won’t be growing back.

These arboreal graveyards are showing up in places where the land slopes gently into the ocean and where salty water increasingly encroaches. Along the United States’ East Coast, in pockets of the West Coast, and elsewhere, saltier soils have killed hundreds of thousands of acres of trees, leaving behind woody skeletons typically surrounded by marsh.

What happens next? That depends. As these dead forests transition, some will become marshes that maintain vital ecosystem services, such as buffering against storms and storing carbon. Others may become home to invasive plants or support no plant life at all—and the ecosystem services will be lost. Researchers are working to understand how this growing shift toward marshes and ghost forests will, on balance, affect coastal ecosystems.

Many of the ghost forests are a consequence of sea level rise, says coastal ecologist Keryn Gedan of George Washington University in Washington, DC, coauthor of an article on the salinization of coastal ecosystems in the 2025 Annual Review of Marine Science. Rising sea levels can bring more intense storm surges that flood saltwater over the top of soil. Drought and sea level rise can shift the groundwater table along the coast, allowing saltwater to journey farther inland, beneath the forest floor. Trees, deprived of fresh water, are stressed as salt accumulates.

Yet the transition from living forest to marsh isn’t necessarily a tragedy, Gedan says. Marshes are important features of coastal ecosystems, too. And the shift from forest to marsh has happened throughout periods of sea level rise in the past, says Marcelo Ardón, an ecosystem ecologist and biogeochemist at North Carolina State University in Raleigh.

“You would think of these forests and marshes kind of dancing together up and down the coast,” he says.

Marshes provide many ecosystem benefits. They are habitats for birds and crustaceans, such as salt marsh sparrows, marsh wrens, crabs, and mussels. They are also a niche for native salt-tolerant plants, like rushes and certain grasses, which provide food and shelter for animals.

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Lichens can survive almost anything, and some might survive Mars

Biology, lichens, Mars, radiation resistance, Science / Kelly Newman / April 19, 2025

Whether anything ever lived on Mars is unknown. And the present environment, with harsh temperatures, intense radiation, and a sparse atmosphere, isn’t exactly propitious for life. Despite the red planet’s brutality, lichens that inhabit some of the harshest environments on Earth could possibly survive there.

Lichens are symbionts, or two organisms that are in a cooperative relationship. There is a fungal component (most are about 90 percent fungus) and a photosynthetic component (algae or cyanobacteria). To see if some species of lichen had what it takes to survive on Mars, a team of researchers led by botanist Kaja Skubała used the Space Research Center of the Polish Academy of Sciences to expose the lichen species Diploschistes muscorum and Cetrarea aculeata to simulate Mars conditions.

“Our study is the first to demonstrate that the metabolism of the fungal partner in lichen symbiosis was active while being in a Mars-like environment,” the researchers said in a study recently published in IMA Fungus. “X-rays associated with solar flares and SEPs reaching Mars should not affect the potential habitability of lichens on this planet.”

Martian ionizing radiation is threatening to most forms of life because it can cause damage at the cellular level. It can also get in the way of physical, genetic, morphological, and biochemical processes, depending on the organism and radiation level.

Going to extremes

Lichens have an edge when it comes to survival. They share characteristics with other organisms that can handle high levels of stress, including a low metabolism, not needing much in the way of nutrition, and longevity. Much like tardigrades, lichens can stay in a desiccated state for extended periods until they are rehydrated. Other lichen adaptations to extreme conditions include metabolites that screen out UV rays and melanin pigments that also defend against radiation.

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To regenerate a head, you first have to know where your tail is

Biology, planaria, regeneration, Science / Shannon Garcia / April 19, 2025

Before a critical point in development, the animals failed to close the wound made by the cut, causing the two embryo halves to simply spew cells out into the environment. Somewhat later, however, there was excellent survival, and the head portion of the embryo could regenerate a tail segment. This tells us that the normal signaling pathways present in the embryo are sufficient to drive the process forward.

But the tail of the embryo at this stage doesn’t appear to be capable of rebuilding its head. But the researchers found that they could inhibit wnt signaling in these posterior fragments, and that was enough to allow the head to develop.

Lacking muscle

One possibility here is that wnt signaling is widely active in the posterior of the embryo at this point, blocking formation of anterior structures. Alternatively, the researchers hypothesize that the problem is with the muscle cells that normally help organize the formation of a stem-cell-filled blastema, which is needed to kick off the regeneration process. Since the anterior end of the embryo develops earlier, they suggest there may simply not be enough muscle cells in the tail to kick off this process at early stages of development.

To test their hypothesis, they performed a somewhat unusual experiment. They started by cutting off the tails of embryos and saving them for 24 hours. At that point, they cut the front end off tails, creating a new wound to heal. At this point, regeneration proceeded as normal, and the tails grew a new head. This isn’t definitive evidence that muscle cells are what’s missing at early stages, but it does indicate that some key developmental step happens in the tail within the 24-hour window after the first cut.

The results reinforce the idea that regeneration of major body parts requires the re-establishment of the signals that lay out organization of the embryo in development—something that gets complicated if those signals are currently acting to organize the embryo. And it clearly shows that the cells needed to do this reorganization aren’t simply set aside early on in development but instead take some time to appear. All of that information will help clarify the bigger-picture question of how these animals manage such a complex regeneration process.

Current Biology, 2025. DOI: 10.1016/j.cub.2025.03.065 (About DOIs).

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Rover finds hints of an ancient Martian carbon cycle

carbon cycle, Climate science, Curiosity rover, greenhouse gasses, Mars, minerals, Science / Mike M. / April 19, 2025

The Curiosity mission started near the bottom of the crater, at the base of a formation called Aeolis Mons, or Mount Sharp, where NASA expected to find the earliest geological samples. The idea then was to climb up Mount Sharp and collect samples from later and later geological periods at increasing elevations, tracing the history of habitability and the great drying up of Mars. On the way, the carbon missed by the satellites was finally found.

An imperfect cycle

Tutolo’s team focused their attention on four sediment samples Curiosity drilled after climbing over a kilometer up Mount Sharp. The samples were examined with the rover’s Chemistry and Mineralogy instrument, which uses X-ray diffraction to determine their composition. It turned out the samples contained roughly between 5 and 10 percent of siderite. “It was an iron carbonate, directly analogous to a mineral called calcite found in sedimentary rocks like limestone. The difference is it has iron in its cation site rather than calcium,” Tutolo explained. “We expected that because Mars is much richer in iron—that’s why it is the red planet.”

The siderite found in the samples was also pure, which Tutolo thinks indicates it has formed through an evaporation process akin to what we see in evaporated lakes on Earth. This, in turn, was the first evidence we’ve found of the ancient Martian carbon cycle. “Now we have evidence that confirms the models,” Tutolo claims. The carbon from the atmosphere was being sequestered in the rocks on Mars just as it is on Earth. The problem was, unlike on Earth, it couldn’t get out of these rocks.

“On Earth, whenever oceanic plates get subducted into the mantle, all of the limestone that was formed before gets cooked off, and the carbon dioxide gets back to the atmosphere through volcanoes,” Tutolo explains. Mars, on the other hand, has never had efficient plate tectonics. A large portion of carbon that got trapped in Martian rocks stayed in those rocks forever, thinning out the atmosphere. While it’s likely the red planet had its own carbon cycle, it was an imperfect one that eventually turned it into the lifeless desert it is today.

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