Science – Page 25

US science is being wrecked, and its leadership is fighting the last war

National Academies, research cuts, Science, science budget, Science policy / Rejus Almole / June 5, 2025

Facing an extreme budget, the National Academies hosted an event that ignored it.

WASHINGTON, DC—The general outline of the Trump administration’s proposed 2026 budget was released a few weeks back, and it included massive cuts for most agencies, including every one that funds scientific research. Late last week, those agencies began releasing details of what the cuts would mean for the actual projects and people they support. And the results are as bad as the initial budget had suggested: one-of-a-kind scientific experiment facilities and hardware retired, massive cuts in supported scientists, and entire areas of research halted.

And this comes in an environment where previously funded grants are being terminated, funding is being held up for ideological screening, and universities have been subjected to arbitrary funding freezes. Collectively, things are heading for damage to US science that will take decades to recover from. It’s a radical break from the trajectory science had been on.

That’s the environment that the US’s National Academies of Science found itself in yesterday while hosting the State of the Science event in Washington, DC. It was an obvious opportunity for the nation’s leading scientific organization to warn the nation of the consequences of the path that the current administration has been traveling. Instead, the event largely ignored the present to worry about a future that may never exist.

The proposed cuts

The top-line budget numbers proposed earlier indicated things would be bad: nearly 40 percent taken off the National Institutes of Health’s budget, the National Science Foundation down by over half. But now, many of the details of what those cuts mean are becoming apparent.

NASA’s budget includes sharp cuts for planetary science, which would be cut in half and then stay flat for the rest of the decade, with the Mars Sample Return mission canceled. All other science budgets, including Earth Science and Astrophysics, take similar hits; one astronomer posted a graphic showing how many present and future missions that would mean. Active missions that have returned unprecedented data, like Juno and New Horizons, would go, as would two Mars orbiters. As described by Science magazine’s news team, “The plans would also kill off nearly every major science mission the agency has not yet begun to build.”

A NASA graphic showing different missions focused on astrophysics. Red Xs have been superimposed on most of them. — A chart prepared by astronomer Laura Lopez showing just how many astrophysics missions will be cancelled. Credit: Laura Lopez

The National Science Foundation, which funds much of the US’s fundamental research, is also set for brutal cuts. Biology, engineering, and education will all be slashed by over 70 percent; computer science, math and physical science, and social and behavioral science will all see cuts of over 60 percent. International programs will take an 80 percent cut. The funding rate of grant proposals is expected to drop from 26 percent to just 7 percent, meaning the vast majority of grants submitted to the NSF will be a waste of time. The number of people involved in NSF-funded activities will drop from over 300,000 to just 90,000. Almost every program to broaden participation in science will be eliminated.

As for specifics, they’re equally grim. The fleet of research ships will essentially become someone else’s problem: “The FY 2026 Budget Request will enable partial support of some ships.” We’ve been able to better pin down the nature and location of gravitational wave events as detectors in Japan and Italy joined the original two LIGO detectors; the NSF will reverse that progress by shutting one of the LIGOs. The NSF’s contributions to detectors at the Large Hadron Collider will be cut by over half, and one of the two very large telescopes it was helping fund will be cancelled (say goodbye to the Thirty Meter Telescope). “Access to the telescopes at Kitt Peak and Cerro Tololo will be phased out,” and the NSF will transfer the facilities to other organizations.

The Department of Health and Human Services has been less detailed about the specific cuts its divisions will see, largely focusing on the overall numbers, which are down considerably. The NIH, which is facing a cut of over 40 percent, will be reorganized, with its 19 institutes pared down to just eight. This will result in some odd pairings, such as the dental and eye institutes ending up in the same place; genomics and biomedical imaging will likewise end up under the same roof. Other groups like the Centers for Disease Control and Prevention and the Food and Drug Administration will also face major cuts.

Issues go well beyond the core science agencies, as well. In the Department of Energy, funding for wind, solar, and renewable grid integration has been zeroed out, essentially ending all programs in this area. Hydrogen and fuel cells face a similar fate. Collectively, these had gotten over $600 billion dollars in 2024’s budget. Other areas of science at the DOE, such as high-energy physics, fusion, and biology, receive relatively minor cuts that are largely in line with the ones faced by administration priorities like fossil and nuclear energy.

Will this happen?

It goes without saying that this would amount to an abandonment of US scientific leadership at a time when most estimates of China’s research spending show it approaching US-like levels of support. Not only would it eliminate many key facilities, instruments, and institutions that have helped make the US a scientific powerhouse, but it would also block the development of newer and additional ones. The harms are so widespread that even topics that the administration claims are priorities would see severe cuts.

And the damage is likely to last for generations, as support is cut at every stage of the educational pipeline that prepares people for STEM careers. This includes careers in high-tech industries, which may require relocation overseas due to a combination of staffing concerns and heightened immigration controls.

That said, we’ve been here before in the first Trump administration, when budgets were proposed with potentially catastrophic implications for US science. But Congress limited the damage and maintained reasonably consistent budgets for most agencies.

Can we expect that to happen again? So far, the signs are not especially promising. The House has largely adopted the Trump administration’s budget priorities, despite the fact that the budget they pass turns its back on decades of supposed concerns about deficit spending. While the Senate has yet to take up the budget, it has also been very pliant during the second Trump administration, approving grossly unqualified cabinet picks such as Robert F. Kennedy Jr.

All of which would seem to call for the leadership of US science organizations to press the case for the importance of science funding to the US and highlight the damage that these cuts would cause. But, if yesterday’s National Academies event is anything to judge by, the leadership is not especially interested.

Altered states

As the nation’s premier science organization, and one that performs lots of analyses for the government, the National Academies would seem to be in a position to have its concerns taken seriously by members of Congress. And, given that the present and future of science in the US is being set by policy choices, a meeting entitled the State of the Science would seem like the obvious place to address those concerns.

If so, it was not obvious to Marcia McNutt, the president of the NAS, who gave the presentation. She made some oblique references to current problems, saying, “We are embarking on a radical new experiment in what conditions promote science leadership, with the US being the treatment group, and China as the control,” and acknowledged that “uncertainties over the science budgets for next year, coupled with cancellations of billions of dollars of already hard-won research grants, is causing an exodus of researchers.”

But her primary focus was on the trends that have been operative in science funding and policy leading up to but excluding the second Trump administration. McNutt suggested this was needed to look beyond the next four years. However, that ignores the obvious fact that US science will be fundamentally different if the Trump administration can follow through on its plans and policies; the trends that have been present for the last two decades will be irrelevant.

She was also remarkably selective about her avoidance of discussing Trump administration priorities. After noting that faculty surveys have suggested they spend roughly 40 percent of their time handling regulatory requirements, she twice mentioned that the administration’s anti-regulatory stance could be a net positive here (once calling it “an opportunity to help”). Yet she neglected to note that many of the abandoned regulations represent a retreat from science-driven policy.

McNutt also acknowledged the problem of science losing the bipartisan support it has enjoyed, as trust in scientists among US conservatives has been on a downward trend. But she suggested it was scientists’ responsibility to fix the problem, even though it’s largely the product of one party deciding it can gain partisan advantage by raising doubts about scientific findings in fields like climate change and vaccine safety.

The panel discussion that came after largely followed McNutt’s lead in avoiding any mention of the current threats to science. The lone exception was Heather Wilson, president of the University of Texas at El Paso and a former Republican member of the House of Representatives and secretary of the Air Force during the first Trump administration. Wilson took direct aim at Trump’s cuts to funding for underrepresented groups, arguing, “Talent is evenly distributed, but opportunity is not.” After arguing that “the moral authority of science depends on the pursuit of truth,” she highlighted the cancellation of grants that had been used to study diseases that are more prevalent in some ethnic groups, saying “that’s not woke science—that’s genetics.”

Wilson was clearly the exception, however, as the rest of the panel largely avoided direct mention of either the damage already done to US science funding or the impending catastrophe on the horizon. We’ve asked the National Academies’ leadership a number of questions about how it perceives its role at a time when US science is clearly under threat. As of this article’s publication, however, we have not received a response.

At yesterday’s event, however, only one person showed a clear sense of what they thought that role should be—Wilson again, whose strongest words were directed at the National Academies themselves, which she said should “do what you’ve done since Lincoln was president,” and stand up for the truth.

John is Ars Technica’s science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots.

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Science PhDs face a challenging and uncertain future

education, PhD, post-graduate education, Science, syndication / Mike M. / June 4, 2025

Smaller post-grad classes are likely due to research budget cuts.

Credit: Thomas Barwick/Stone via Getty Images

Since the National Science Foundation first started collecting postgraduation data nearly 70 years ago, the number of PhDs awarded in the United States has consistently risen. Last year, more than 45,000 students earned doctorates in science and engineering, about an eight-fold increase compared to 1958.

But this level of production of science and engineering PhD students is now in question. Facing significant cuts to federal science funding, some universities have reduced or paused their PhD admissions for the upcoming academic year. In response, experts are beginning to wonder about the short and long-term effects those shifts will have on the number of doctorates awarded and the consequent impact on science if PhD production does drop.

Such questions touch on longstanding debates about academic labor. PhD training is a crucial part of nurturing scientific expertise. At the same time, some analysts have worried about an oversupply of PhDs in some fields, while students have suggested that universities are exploiting them as low-cost labor.

Many budding scientists go into graduate school with the goal of staying in academia and ultimately establishing their own labs. For at least 30 years, there has been talk of a mismatch between the number of doctorates and the limited academic job openings. According to an analysis conducted in 2013, only 3,000 faculty positions in science and engineering are added each year—even though more than 35,000 PhDs are produced in these fields annually.

Decades of this asymmetrical dynamic has created a hypercompetitive and high-pressure environment in the academic world, said Siddhartha Roy, an environmental engineer at Rutgers University who co-authored a recent study on tenure-track positions in engineering. “If we look strictly at academic positions, we have a huge oversupply, and it’s not sustainable,” he said.

But while the academic job market remains challenging, experts point out that PhD training also prepares individuals for career paths in industry, government, and other science and technology fields. If fewer doctorates are awarded and funding continues to be cut, some argue, American science will weaken.

“The immediate impact is there’s going to be less science,” said Donna Ginther, a social researcher who studies scientific labor markets at the University of Kansas. In the long run, that could mean scientific innovations, such as new drugs or technological advances, will stall, she said: “We’re leaving that scientific discovery on the table.”

Historically, one of the main goals of training PhD students has been to retain those scientists as future researchers in their respective fields. “Academia has a tendency to want to produce itself, reproduce itself,” said Ginther. “Our training is geared towards creating lots of mini-mes.”

But it is no secret in the academic world that tenure-track faculty positions are scarce, and the road to obtaining tenure is difficult. Although it varies across different STEM fields, the number of doctorates granted each year consistently surpass the number of tenure-track positions available. A survey gathering data from the 2022-2023 academic year, conducted by the Computing Research Association, found that around 11 percent of PhD graduates in computational science (for which employment data was reported) moved on to tenure-track faculty positions.

Roy found a similar figure for engineering: Around one out of every eight individuals who obtain their doctorate—12.5 percent—will eventually land a tenure-track faculty position, a trend that remained stable between 2014 and 2021, the last year for which his team analyzed data. The bottleneck in faculty positions, according to one recent study, leads about 40 percent of postdoctoral researchers to leave academia.

However, in recent years, researchers who advise graduate students have begun to acknowledge careers beyond academia, including positions in industry, nonprofits, government, consulting, science communication, and policy. “We need, as academics, need to take a broader perspective on what and how we prepare our students,” said Ginther.

As opposed to faculty positions, some of these labor markets can be more robust and provide plenty of opportunities for those with a doctorate, said Daniel Larremore, a computer scientist at the University of Colorado Boulder who studies academic labor markets, among other topics. Whether there is a mismatch between the number of PhDs and employment opportunities will depend on the subject of study and which fields are growing or shrinking, he added. For example, he pointed out that there is currently a boom in machine learning and artificial intelligence, so there is a lot of demand from industry for computer science graduates. In fact, commitments to industry jobs after graduation seem to be at a 30-year high.

But not all newly minted PhDs immediately find work. According to the latest NSF data, students in biological and biomedical sciences experienced a decline in job offers in the past 20 years, with 68 percent having definite commitments after graduating in 2023, compared to 72 percent in 2003. “The dynamics in the labor market for PhDs depends very much on what subject the PhD is in,” said Larremore.

Still, employment rates reflect that postgraduates benefit from greater opportunities compared to the general population. In 2024, the unemployment rate for college graduates with a doctoral degree in the US was 1.2 percent, less than half the national average at the time, according to the Bureau of Labor Statistics. In NSF’s recent survey, 74 percent of science and engineering graduating doctorates had definite commitments for employment or postdoctoral study or training positions, three points higher than it was in 2003.

“Overproducing for the number of academic jobs available? Absolutely,” said Larremore. “But overproducing for the economy in general? I don’t think so.”

The experts who spoke with Undark described science PhDs as a benefit for society: Ultimately, scientists with PhDs contribute to the economy of a nation, be it through academia or alternative careers. Many are now concerned about the impact that cuts to scientific research may have on that contribution. Already, there are reports of universities scaling back graduate student admissions in light of funding uncertainties, worried that they might not be able to cover students’ education and training costs. Those changes could result in smaller graduating classes in future years.

Smaller classes of PhD students might not be a bad thing for academia, given the limited faculty positions, said Roy. And for most non-academic jobs, Roy said, a master’s degree is more than sufficient. However, people with doctorates do contribute to other sectors like industry, government labs, and entrepreneurship, he added.

In Ginther’s view, fewer scientists with doctoral training could deal a devastating blow for the broader scientific enterprise. “Science is a long game, and the discoveries now take a decade or two to really hit the market, so it’s going to impinge on future economic growth.”

These long-term impacts of reductions in funding might be hard to reverse and could lead to the withering of the scientific endeavor in the United States, Larremore said: “If you have a thriving ecosystem and you suddenly halve the sunlight coming into it, it simply cannot thrive in the way that it was.”

This article was originally published on Undark. Read the original article.

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Some parts of Trump’s proposed budget for NASA are literally draconian

darpa, DRACO, NASA, nasa budget, nuclear thermal propulsion, Science, Space, White House / Paul Patrick / June 4, 2025

“That’s exactly the kind of thing that NASA should be concentrating its resources on.”

Artist’s illustration of the DRACO nuclear rocket engine in space. Credit: Lockheed Martin

New details of the Trump administration’s plans for NASA, released Friday, revealed the White House’s desire to end the development of an experimental nuclear thermal rocket engine that could have shown a new way of exploring the Solar System.

Trump’s NASA budget request is rife with spending cuts. Overall, the White House proposes reducing NASA’s budget by about 24 percent, from $24.8 billion this year to $18.8 billion in fiscal year 2026. In previous stories, Ars has covered many of the programs impacted by the proposed cuts, which would cancel the Space Launch System rocket and Orion spacecraft and terminate numerous robotic science missions, including the Mars Sample Return, probes to Venus, and future space telescopes.

Instead, the leftover funding for NASA’s human exploration program would go toward supporting commercial projects to land on the Moon and Mars.

NASA’s initiatives to pioneer next-generation space technologies are also hit hard in the White House’s budget proposal. If the Trump administration gets its way, NASA’s Space Technology Mission Directorate, or STMD, will see its budget cut nearly in half, from $1.1 billion to $568 million.

Trump’s budget request isn’t final. Both Republican-controlled houses of Congress will write their own versions of the NASA budget, which must be reconciled before going to the White House for President Trump’s signature.

“The budget reduces Space Technology by approximately half, including eliminating failing space propulsion projects,” the White House wrote in an initial overview of the NASA budget request released May 2. “The reductions also scale back or eliminate technology projects that are not needed by NASA or are better suited to private sector research and development.”

Breathing fire

Last week, the White House and NASA put a finer point on these “failing space propulsion projects.”

“This budget provides no funding for Nuclear Thermal Propulsion and Nuclear Electric Propulsion projects,” officials wrote in a technical supplement released Friday detailing Trump’s NASA budget proposal. “These efforts are costly investments, would take many years to develop, and have not been identified as the propulsion mode for deep space missions. The nuclear propulsion projects are terminated to achieve cost savings and because there are other nearer-term propulsion alternatives for Mars transit.”

Foremost among these cuts, the White House proposes to end NASA’s participation in the Demonstration Rocket for Agile Cislunar Operations (DRACO) project. NASA said this proposal “reflects the decision by our partner to cancel” the DRACO mission, which would have demonstrated a nuclear thermal rocket engine in space for the first time.

NASA’s partner on the DRACO mission was the Defense Advanced Research Projects Agency, or DARPA, the Pentagon’s research and development arm. A DARPA spokesperson confirmed the agency was closing out the project.

“DARPA has completed the agency’s involvement in the Demonstration Rocket for Agile Cislunar Orbit (DRACO) program and is transitioning its knowledge to our DRACO mission partner, the National Aeronautics and Space Administration (NASA), and to other potential DOD programs,” the spokesperson said in a response to written questions.

A nuclear rocket engine, which was to be part of NASA’s aborted NERVA program, is tested at Jackass Flats, Nevada, in 1967. Credit: Corbis via Getty Images)

Less than two years ago, NASA and DARPA announced plans to move forward with the roughly $500 million DRACO project, targeting a launch into Earth orbit aboard a traditional chemical rocket in 2027. “With the help of this new technology, astronauts could journey to and from deep space faster than ever, a major capability to prepare for crewed missions to Mars,” former NASA administrator Bill Nelson said at the time.

The DRACO mission would have consisted of several elements, including a nuclear reactor to rapidly heat up super-cold liquid hydrogen fuel stored in an insulated tank onboard the spacecraft. Temperatures inside the engine would reach nearly 5,000° Fahrenheit, boiling the hydrogen and driving the resulting gas through a nozzle, generating thrust. From the outside, the spacecraft’s design looks a lot like the upper stage of a traditional rocket. However, theoretically, a nuclear thermal rocket engine like DRACO’s would offer twice the efficiency of the highest-performing conventional rocket engines. That translates to significantly less fuel that a mission to Mars would have to carry across the Solar System.

Essentially, a nuclear thermal rocket engine combines the high-thrust capability of a chemical engine with some of the fuel efficiency benefits of low-thrust solar-electric engines. With DRACO, engineers sought hard data to verify their understanding of nuclear propulsion and wanted to make sure the nuclear engine’s challenging design actually worked. DRACO would have used high-assay low-enriched uranium to power its nuclear reactor.

Nuclear electric propulsion uses an onboard nuclear reactor to power plasma thrusters that create thrust by accelerating an ionized gas, like xenon, through a magnetic field. Nuclear electric propulsion would provide another leap in engine efficiency beyond the capabilities of a system like DRACO and may ultimately offer the most attractive option for enduring deep space transportation.

NASA led the development of DRACO’s nuclear rocket engine, while DARPA was responsible for the overall spacecraft design, operations, and the thorny problem of securing regulatory approval to launch a nuclear reactor into orbit. The reactor on DRACO would have launched in “cold” mode before activating in space, reducing the risk to people on the ground in the event of a launch accident. The Space Force agreed to pay for DRACO’s launch on a United Launch Alliance Vulcan rocket.

DARPA and NASA selected Lockheed Martin as the lead contractor for the DRACO spacecraft in 2023. BWX Technologies, a leader in the US nuclear industry, won the contract to develop the mission’s reactor.

“We received the notice from DARPA that it ended the DRACO program,” a Lockheed Martin spokesperson said. “While we’re disappointed with the decision, it doesn’t change our vision of how nuclear power influences how we will explore and operate in the vastness of space.”

Mired in the lab

More than 60 years have passed since a US-built nuclear reactor launched into orbit. Aviation Week reported in January that one problem facing DRACO engineers involved questions about how to safely test the nuclear thermal engine on the ground while adhering to nuclear safety protocols.

“We’re bringing two things together—space mission assurance and nuclear safety—and there’s a fair amount of complexity,” said Matthew Sambora, a DRACO program manager at DARPA, in an interview with Aviation Week. At the time, DARPA and NASA had already given up on a 2027 launch to concentrate on developing a prototype engine using helium as a propellant before moving on to an operational engine with more energetic liquid hydrogen fuel, Aviation Week reported.

Greg Meholic, an engineer at the Aerospace Corporation, highlighted the shortfall in ground testing capability in a presentation last year. Nuclear thermal propulsion testing “requires that engine exhaust be scrubbed of radiologics before being released,” he wrote. This requirement “could result in substantially large, prohibitively expensive facilities that take years to build and qualify.”

These safety protocols weren’t as stringent when NASA and the Air Force first pursued nuclear propulsion in the 1960s. Now, the first serious 21st-century effort to fly a nuclear rocket engine in space is grinding to a halt.

“Given that our near-term human exploration and science needs do not require nuclear propulsion, current demonstration projects will end,” wrote Janet Petro, NASA’s acting administrator, in a letter accompanying the Trump administration’s budget release last week.

This figure illustrates the major elements of a typical nuclear thermal rocket engine. Credit: NASA/Glenn Research Center

NASA’s 2024 budget allocated $117 million for nuclear propulsion work, an increase from $91 million the previous year. Congress added more funding for NASA’s nuclear propulsion programs over the Biden administration’s proposed budget in recent years, signaling support on Capitol Hill that may save at least some nuclear propulsion initiatives next year.

It’s true that nuclear propulsion isn’t required for any NASA missions currently on the books. Today’s rockets are good at hurling cargo and people off planet Earth, but once a spacecraft arrives in orbit, there are several ways to propel it toward more distant destinations.

NASA’s existing architecture for sending astronauts to the Moon uses the SLS rocket and Orion spacecraft, both of which are proposed for cancellation and look a lot like the vehicles NASA used to fly astronauts to the Moon more than 50 years ago. SpaceX’s reusable Starship, designed with an eye toward settling Mars, uses conventional chemical propulsion, with methane and liquid oxygen propellants that SpaceX one day hopes to generate on the surface of the Red Planet.

So NASA, SpaceX, and other companies don’t need nuclear propulsion to beat China back to the Moon or put the first human footprints on Mars. But there’s a broad consensus that in the long run, nuclear rockets offer a better way of moving around the Solar System.

The military’s motive for funding nuclear thermal propulsion was its potential for becoming a more efficient means of maneuvering around the Earth. Many of the military’s most important spacecraft are limited by fuel, and the Space Force is investigating orbital refueling and novel propulsion methods to extend the lifespan of satellites.

NASA’s nuclear power program is not finished. The Trump administration’s budget proposal calls for continued funding for the agency’s fission surface power program, with the goal of fielding a nuclear reactor that could power a base on the surface of the Moon or Mars. Lockheed and BWXT, the contractors involved in the DRACO mission, are part of the fission surface power program.

There is some funding in the White House’s budget request for tech demos using other methods of in-space propulsion. NASA would continue funding experiments in long-term storage and transfer of cryogenic propellants like liquid methane, liquid hydrogen, and liquid oxygen. These joint projects between NASA and industry could pave the way for orbital refueling and orbiting propellant depots, aligning with the direction of companies like SpaceX, Blue Origin, and United Launch Alliance.

But many scientists and engineers believe nuclear propulsion offers the only realistic path for a sustainable campaign ferrying people between the Earth and Mars. A report commissioned by NASA and the National Academies concluded in 2021 that an aggressive tech-development program could advance nuclear thermal propulsion enough for a human expedition to Mars in 2039. The prospects for nuclear electric propulsion were murkier.

This would have required NASA to substantially increase its budget for nuclear propulsion immediately, likely by an order of magnitude beyond the agency’s baseline funding level, or to an amount exceeding $1 billion per year, said Bobby Braun, co-chair of the National Academies report, in a 2021 interview with Ars. That didn’t happen.

Going nuclear

The interplanetary transportation architectures envisioned by NASA and SpaceX will, at least initially, primarily use chemical propulsion for the cruise between Earth and Mars.

Kurt Polzin, chief engineer of NASA’s space nuclear propulsion projects, said significant technical hurdles stand in the way of any propulsion system selected to power heavy cargo and humans to Mars.

“Anybody who says that they’ve solved the problem, you don’t know that because you don’t have enough data,” Polzin said last week at the Humans to the Moon and Mars Summit in Washington.

“We know that to do a Mars mission with a Starship, you need lots of refuelings at Earth, you need lots of refuelings at Mars, which you have to send in advance,” Polzin said. “You either need to send that propellant in advance or send a bunch of material and hardware to the surface to be set up and robotically make your propellant in situ while you’re there.”

Elon Musk’s SpaceX is betting on chemical propulsion for round-trip flights to Mars with its Starship rocket. This will require assembly of propellant-generation plants on the Martian surface. Credit: SpaceX

Last week, SpaceX founder Elon Musk outlined how the company plans to land its first Starships on Mars. His roadmap includes more than 100 cargo flights to deliver equipment to produce methane and liquid oxygen propellants on the surface of Mars. This is necessary for any Starship to launch off the Red Planet and return to Earth.

“You can start to see that this starts to become a Rube Goldberg way to do Mars,” Polzin said. “Will I say it can’t work? No, but will I say that it’s really, really difficult and challenging. Are there a lot of miracles to make it work? Absolutely. So the notion that SpaceX has solved Mars or is going to do Mars with Starship, I would challenge that on its face. I don’t think the analysis and the data bear that out.”

Engineers know how methane-fueled rocket engines perform in space. Scientists have created liquid oxygen and liquid methane since the late 1800s. Scaling up a propellant plant on Mars to produce thousands of tons of cryogenic liquids is another matter. In the long run, this might be a suitable solution for Musk’s vision of creating a city on Mars, but it comes with immense startup costs and risks. Still, nuclear propulsion is an entirely untested technology as well.

“The thing with nuclear is there are challenges to making it work, too,” Polzin said. “However, all of my challenges get solved here at Earth and in low-Earth orbit before I leave. Nuclear is nice. It has a higher specific impulse, especially when we’re talking about nuclear thermal propulsion. It has high thrust, which means it will get our astronauts there and back quickly, but I can carry all the fuel I need to get back with me, so I don’t need to do any complicated refueling at Mars. I can return without having to make propellant or send any pre-positioned propellant to get back.”

The tug of war over nuclear propulsion is nothing new. The Air Force started a program to develop reactors for nuclear thermal rockets at the height of the Cold War. NASA took over the Air Force’s role a few years later, and the project proceeded into the next phase, called the Nuclear Engine for Rocket Vehicle Application (NERVA). President Richard Nixon ultimately canceled the NERVA project in 1973 after the government had spent $1.4 billion on it, equivalent to about $10 billion in today’s dollars. Despite nearly two decades of work, NERVA never flew in space.

Doing the hard things

The Pentagon and NASA studied several more nuclear thermal and nuclear electric propulsion initiatives before DRACO. Today, there’s a nascent commercial business case for compact nuclear reactors beyond just the government. But there’s scant commercial interest in mounting a full-scale nuclear propulsion demonstration solely with private funding.

Fred Kennedy, co-founder and CEO of a space nuclear power company called Dark Fission, said most venture capital investors lack the appetite to wait for financial returns in nuclear propulsion that they may see in 15 or 20 years.

“It’s a truism: Space is hard,” said Kennedy, a former DARPA program manager. “Nuclear turns out to be hard for reasons we can all understand. So space-nuclear is hard-squared, folks. As a result, you give this to your average associate at a VC firm and they get scared quick. They see the moles all over your face, and they run away screaming.”

But commercial launch costs are coming down. With sustained government investment and streamlined regulations, “this is the best chance we’ve had in a long time” to get a nuclear propulsion system into space, Kennedy said.

Technicians prepare a nozzle for a prototype nuclear thermal rocket engine in 1964. Credit: NASA

“I think, right now, we’re in this transitional period where companies like mine are going have to rely on some government largesse, as well as hopefully both commercial partnerships and honest private investment,” Kennedy said. “Three years ago, I would have told you I thought I could have done the whole thing with private investment, but three years have turned my hair white.”

Those who share Kennedy’s view thought they were getting an ally in the Trump administration. Jared Isaacman, the billionaire commercial astronaut Trump nominated to become the next NASA administrator, promised to prioritize nuclear propulsion in his tenure as head of the nation’s space agency.

During his Senate confirmation hearing in April, Isaacman said NASA should turn over management of heavy-lift rockets, human-rated spacecraft, and other projects to commercial industry. This change, he said, would allow NASA to focus on the “near-impossible challenges that no company, organization, or agency anywhere in the world would be able to undertake.”

The example Isaacman gave in his confirmation hearing was nuclear propulsion. “That’s something that no company would ever embark upon,” he told lawmakers. “There is no obvious economic return. There are regulatory challenges. That’s exactly the kind of thing that NASA should be concentrating its resources on.”

But the White House suddenly announced on Saturday that it was withdrawing Isaacman’s nomination days before the Senate was expected to confirm him for the NASA post. While there’s no indication that Trump’s withdrawal of Isaacman had anything to do with any specific part of the White House’s funding plan, his removal leaves NASA without an advocate for nuclear propulsion and a number of other projects falling under the White House’s budget ax.

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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Milky Way galaxy might not collide with Andromeda after all

Andromeda, astronomy, astrophysics, cosmology, galactic mergers, galaxies, milky way, Science / Paul Patrick / June 3, 2025

100,000 computer simulations reveal Milky Way’s fate—and it might not be what we thought.

It’s been textbook knowledge for over a century that our Milky Way galaxy is doomed to collide with another large spiral galaxy, Andromeda, in the next 5 billion years and merge into one even bigger galaxy. But a fresh analysis published in the journal Nature Astronomy is casting that longstanding narrative in a more uncertain light. The authors conclude that the likelihood of this collision and merger is closer to the odds of a coin flip, with a roughly 50 percent probability that the two galaxies will avoid such an event during the next 10 billion years.

Both the Milky Way and the Andromeda galaxies (M31) are part of what’s known as the Local Group (LG), which also hosts other smaller galaxies (some not yet discovered) as well as dark matter (per the prevailing standard cosmological model). Both already have remnants of past mergers and interactions with other galaxies, according to the authors.

“Predicting future mergers requires knowledge about the present coordinates, velocities, and masses of the systems partaking in the interaction,” the authors wrote. That involves not just the gravitational force between them but also dynamical friction. It’s the latter that dominates when galaxies are headed toward a merger, since it causes galactic orbits to decay.

This latest analysis is the result of combining data from the Hubble Space Telescope and the European Space Agency’s (ESA) Gaia space telescope to perform 100,000 Monte Carlo computer simulations, taking into account not just the Milky Way and Andromeda but the full LG system. Those simulations yielded a very different prediction: There is approximately a 50/50 chance of the galaxies colliding within the next 10 billion years. There is still a 2 percent chance that they will collide in the next 4 to 5 billion years. “Based on the best available data, the fate of our galaxy is still completely open,” the authors concluded.

Milky Way galaxy might not collide with Andromeda after all Read More »

Research roundup: 7 stories we almost missed

acoustics, Archaeology, architecture, Biology, Physics, primates, robotics, Science / Kris Guyer / June 1, 2025

Ping-pong bots, drumming chimps, picking styles of two jazz greats, and an ancient underground city’s soundscape

Time lapse photos show a new ping-pong-playing robot performing a top spin. Credit: David Nguyen, Kendrick Cancio and Sangbae Kim

It’s a regrettable reality that there is never time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’re experimenting with a monthly collection. May’s list includes a nifty experiment to make a predicted effect of special relativity visible; a ping-pong playing robot that can return hits with 88 percent accuracy; and the discovery of the rare genetic mutation that makes orange cats orange, among other highlights.

Special relativity made visible

The Terrell-Penrose-Effect: Fast objects appear rotated — Credit: TU Wien

Perhaps the most well-known feature of Albert Einstein’s special theory of relativity is time dilation and length contraction. In 1959, two physicists predicted another feature of relativistic motion: an object moving near the speed of light should also appear to be rotated. It’s not been possible to demonstrate this experimentally, however—until now. Physicists at the Vienna University of Technology figured out how to reproduce this rotational effect in the lab using laser pulses and precision cameras, according to a paper published in the journal Communications Physics.

They found their inspiration in art, specifically an earlier collaboration with an artist named Enar de Dios Rodriguez, who collaborated with VUT and the University of Vienna on a project involving ultra-fast photography and slow light. For this latest research, they used objects shaped like a cube and a sphere and moved them around the lab while zapping them with ultrashort laser pulses, recording the flashes with a high-speed camera.

Getting the timing just right effectively yields similar results to a light speed of 2 m/s. After photographing the objects many times using this method, the team then combined the still images into a single image. The results: the cube looked twisted and the sphere’s North Pole was in a different location—a demonstration of the rotational effect predicted back in 1959.

DOI: Communications Physics, 2025. 10.1038/s42005-025-02003-6 (About DOIs).

Drumming chimpanzees

A chimpanzee feeling the rhythm. Credit: Current Biology/Eleuteri et al., 2025.

Chimpanzees are known to “drum” on the roots of trees as a means of communication, often combining that action with what are known as “pant-hoot” vocalizations (see above video). Scientists have found that the chimps’ drumming exhibits key elements of musical rhythm much like humans, according to a paper published in the journal Current Biology—specifically non-random timing and isochrony. And chimps from different geographical regions have different drumming rhythms.

Back in 2022, the same team observed that individual chimps had unique styles of “buttress drumming,” which served as a kind of communication, letting others in the same group know their identity, location, and activity. This time around they wanted to know if this was also true of chimps living in different groups and whether their drumming was rhythmic in nature. So they collected video footage of the drumming behavior among 11 chimpanzee communities across six populations in East Africa (Uganda) and West Africa (Ivory Coast), amounting to 371 drumming bouts.

Their analysis of the drum patterns confirmed their hypothesis. The western chimps drummed in regularly spaced hits, used faster tempos, and started drumming earlier during their pant-hoot vocalizations. Eastern chimps would alternate between shorter and longer spaced hits. Since this kind of rhythmic percussion is one of the earliest evolved forms of human musical expression and is ubiquitous across cultures, findings such as this could shed light on how our love of rhythm evolved.

DOI: Current Biology, 2025. 10.1016/j.cub.2025.04.019 (About DOIs).

Distinctive styles of two jazz greats

Wes Montgomery (left)) and Joe Pass (right) playing guitars

Jazz lovers likely need no introduction to Joe Pass and Wes Montgomery, 20th century guitarists who influenced generations of jazz musicians with their innovative techniques. Montgomery, for instance, didn’t use a pick, preferring to pluck the strings with his thumb—a method he developed because he practiced at night after working all day as a machinist and didn’t want to wake his children or neighbors. Pass developed his own range of picking techniques, including fingerpicking, hybrid picking, and “flat picking.”

Chirag Gokani and Preston Wilson, both with Applied Research Laboratories and the University of Texas, Austin, greatly admired both Pass and Montgomery and decided to explore the underlying the acoustics of their distinctive playing, modeling the interactions of the thumb, fingers, and pick with a guitar string. They described their research during a meeting of the Acoustical Society of America in New Orleans, LA.

Among their findings: Montgomery achieved his warm tone by playing closer to the bridge and mostly plucking at the string. Pass’s rich tone arose from a combination of using a pick and playing closer to the guitar neck. There were also differences in how much a thumb, finger, and pick slip off the string: use of the thumb (Montgomery) produced more of a “pluck” compared to the pick (Pass), which produced more of a “strike.” Gokani and Wilson think their model could be used to synthesize digital guitars with a more realistic sound, as well as helping guitarists better emulate Pass and Montgomery.

Sounds of an ancient underground city

A collection of images from the underground tunnels of Derinkuyu. — Credit: Sezin Nas

Turkey is home to the underground city Derinkuyu, originally carved out inside soft volcanic rock around the 8th century BCE. It was later expanded to include four main ventilation channels (and some 50,000 smaller shafts) serving seven levels, which could be closed off from the inside with a large rolling stone. The city could hold up to 20,000 people and it was connected to another underground city, Kaymakli, via tunnels. Derinkuyu helped protect Arab Muslims during the Arab-Byzantine wars, served as a refuge from the Ottomans in the 14th century, and as a haven for Armenians escaping persecution in the early 20th century, among other functions.

The tunnels were rediscovered in the 1960s and about half of the city has been open to visitors since 2016. The site is naturally of great archaeological interest, but there has been little to no research on the acoustics of the site, particularly the ventilation channels—one of Derinkuyu’s most unique features, according to Sezin Nas, an architectural acoustician at Istanbul Galata University in Turkey. She gave a talk at a meeting of the Acoustical Society of America in New Orleans, LA, about her work on the site’s acoustic environment.

Nas analyzed a church, a living area, and a kitchen, measuring sound sources and reverberation patterns, among other factors, to create a 3D virtual soundscape. The hope is that a better understanding of this aspect of Derinkuyu could improve the design of future underground urban spaces—as well as one day using her virtual soundscape to enable visitors to experience the sounds of the city themselves.

MIT’s latest ping-pong robot

Robots playing ping-pong have been a thing since the 1980s, of particular interest to scientists because it requires the robot to combine the slow, precise ability to grasp and pick up objects with dynamic, adaptable locomotion. Such robots need high-speed machine vision, fast motors and actuators, precise control, and the ability to make accurate predictions in real time, not to mention being able to develop a game strategy. More recent designs use AI techniques to allow the robots to “learn” from prior data to improve their performance.

MIT researchers have built their own version of a ping-pong playing robot, incorporating a lightweight design and the ability to precisely return shots. They built on prior work developing the Humanoid, a small bipedal two-armed robot—specifically, modifying the Humanoid’s arm by adding an extra degree of freedom to the wrist so the robot could control a ping-pong paddle. They tested their robot by mounting it on a ping-pong table and lobbing 150 balls at it from the other side of the table, capturing the action with high-speed cameras.

The new bot can execute three different swing types (loop, drive, and chip) and during the trial runs it returned the ball with impressive accuracy across all three types: 88.4 percent, 89.2 percent, and 87.5 percent, respectively. Subsequent tweaks to theirrystem brought the robot’s strike speed up to 19 meters per second (about 42 MPH), close to the 12 to 25 meters per second of advanced human players. The addition of control algorithms gave the robot the ability to aim. The robot still has limited mobility and reach because it has to be fixed to the ping-pong table but the MIT researchers plan to rig it to a gantry or wheeled platform in the future to address that shortcoming.

Why orange cats are orange

Cat lovers know orange cats are special for more than their unique coloring, but that’s the quality that has intrigued scientists for almost a century. Sure, lots of animals have orange, ginger, or yellow hues, like tigers, orangutans, and golden retrievers. But in domestic cats that color is specifically linked to sex. Almost all orange cats are male. Scientists have now identified the genetic mutation responsible and it appears to be unique to cats, according to a paper published in the journal Current Biology.

Prior work had narrowed down the region on the X chromosome most likely to contain the relevant mutation. The scientists knew that females usually have just one copy of the mutation and in that case have tortoiseshell (partially orange) coloring, although in rare cases, a female cat will be orange if both X chromosomes have the mutation. Over the last five to ten years, there has been an explosion in genome resources (including complete sequenced genomes) for cats which greatly aided the team’s research, along with taking additional DNA samples from cats at spay and neuter clinics.

From an initial pool of 51 candidate variants, the scientists narrowed it down to three genes, only one of which was likely to play any role in gene regulation: Arhgap36. It wasn’t known to play any role in pigment cells in humans, mice, or non-orange cats. But orange cats are special; their mutation (sex-linked orange) turns on Arhgap36 expression in pigment cells (and only pigment cells), thereby interfering with the molecular pathway that controls coat color in other orange-shaded mammals. The scientists suggest that this is an example of how genes can acquire new functions, thereby enabling species to better adapt and evolve.

DOI: Current Biology, 2025. 10.1016/j.cub.2025.03.075 (About DOIs).

Not a Roman “massacre” after all

Two of the skeletons excavated by Mortimer Wheeler in the 1930s, dating from the 1st century AD. — Credit: Martin Smith

In 1936, archaeologists excavating the Iron Age hill fort Maiden Castle in the UK unearthed dozens of human skeletons, all showing signs of lethal injuries to the head and upper body—likely inflicted with weaponry. At the time, this was interpreted as evidence of a pitched battle between the Britons of the local Durotriges tribe and invading Romans. The Romans slaughtered the native inhabitants, thereby bringing a sudden violent end to the Iron Age. At least that’s the popular narrative that has prevailed ever since in countless popular articles, books, and documentaries.

But a paper published in the Oxford Journal of Archaeology calls that narrative into question. Archaeologists at Bournemouth University have re-analyzed those burials, incorporating radiocarbon dating into their efforts. They concluded that those individuals didn’t die in a single brutal battle. Rather, it was Britons killing other Britons over multiple generations between the first century BCE and the first century CE—most likely in periodic localized outbursts of violence in the lead-up to the Roman conquest of Britain. It’s possible there are still many human remains waiting to be discovered at the site, which could shed further light on what happened at Maiden Castle.

DOI: Oxford Journal of Archaeology, 2025. 10.1111/ojoa.12324 (About DOIs).

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

Research roundup: 7 stories we almost missed Read More »

Why incels take the “Blackpill”—and why we should care

incel culture, incels, manosphere, psychology, Science, sociology / Kris Guyer / May 31, 2025

“Don’t work for Soyciety”

A growing number of incels are NEET (Not in Education, Employment, or Training). That should concern us all.

The Netlix series Adolescence explores the roots of misogynistic subcultures. Credit: Netflix

The online incel (“involuntary celibate”) subculture is mostly known for its extreme rhetoric, primarily against women, sometimes erupting into violence. But a growing number of self-identified incels are using their ideology as an excuse for not working or studying. This could constitute a kind of coping mechanism to make sense of their failures—not just in romantic relationships but also in education and employment, according to a paper published in the journal Gender, Work, & Organization.

Contrary to how it’s often portrayed, the “manosphere,” as it is often called, is not a monolith. Those who embrace the “Redpill” ideology, for example, might insist that women control the “sexual marketplace” and are only interested in ultramasculine “Chads.” They champion self-improvement as a means to make themselves more masculine and successful, and hence (they believe) more attractive to women—or at least better able to manipulate women.

By contrast, the “Blackpilled” incel contingent is generally more nihilistic. These individuals reject the Redpill notion of alpha-male masculinity and the accompanying focus on self-improvement. They believe that dating and social success are entirely determined by one’s looks and/or genetics. Since there is nothing they can do to improve their chances with women or their lot in life, why even bother?

“People have a tendency to lump all these different groups together as the manosphere,” co-author AnnaRose Beckett-Herbert of McGill University told Ars. “One critique I have of the recent Netflix show Adolescence—which was well done overall—is they lump incels in with figures like Andrew Tate, as though it’s all interchangeable. There’s areas of overlap, like extreme misogyny, but there are really important distinctions. We have to be careful to make those distinctions because the kind of intervention or prevention efforts that we might direct towards the Redpill community versus the Blackpill community might be very different.”

Incels constitute a fairly small fraction of the manosphere, but the vast majority of incels appear to embrace the Blackpill ideology, per Beckett-Herbert. That nihilistic attitude can extend to any kind of participation in what incels term “Soyciety”—including educational attainment and employment. When that happens, such individuals are best described by the acronym NEET (Not in Education, Employment, or Training).

“It’s not that we have large swaths of young men that are falling into this rabbit hole,” said Beckett-Herbert. “Their ideology is pretty fringe, but we’re seeing the community grow, and we’re seeing the ideology spread. It used to be contained to romantic relationships and sex. Now we’re seeing this broader disengagement from society as a whole. We should all be concerned about that trend.”

The NEET trend is also tied to the broader cultural discourse on how boys and young men are struggling in contemporary society. While prior studies tended to focus on the misogynistic rhetoric and propensity for violence among incels, “I thought that the unemployment lens was interesting because it’s indicative of larger problems,” said Beckett-Herbert. “It’s important to remember that it’s not zero-sum. We can care about the well-being of women and girls and also acknowledge that young men are struggling, too. Those don’t have to be at odds.”

“Lie down and rot”

Beckett-Herbert and her advisor/co-author, McGill University sociologist Eran Shor, chose the incels.is platform as a data source for their study due to its ease of public access and relatively high traffic, with nearly 20,000 members. The pair used Python code to scrape 100 pages, amounting to around 10,000 discussion threads between October and December 2022. A pilot study revealed 10 keywords that appeared most frequently in those threads: “study,” “school,” “NEET,” “job,” “work,” “money,” “career,” “wage,” “employ,” and “rot.” (“They use the phrase ‘lie down and rot’ a lot,” said Beckett-Herbert.)

This allowed Beckett-Herbert and Shor to narrow their sample down to 516 threads with titles containing those keywords. They randomly selected a subset of 171 discussion threads for further study. That analysis yielded four main themes that dominated the discussion threads: political/ideological arguments about being NEET; boundary policing; perceived discrimination; and bullying and marginalization.

Roughly one-quarter of the total comments consisted of political or ideological arguments promoting being NEET, with most commenters advocating minimizing one’s contributions to society as much as possible. They suggested going on welfare, for instance, to “take back” from society, or declared they should be exempt from paying any taxes, as “compensation for our suffering.” About 25 percent—a vocal minority—pushed back on glorifying the NEET lifestyle and offered concrete suggestions for self-improvement. (“Go outside and try at least,” one user commented.)

Such pushback often led to boundary policing. Those who do pursue jobs or education run the risk of being dubbed “fakecels” and becoming alienated from the rest of the incel community. (“Don’t work for a society that hates you,” one user commented.) “There’s a lot of social psychological research on groupthink and group polarization that is relevant here,” said Beckett-Herbert. “A lot of these young men may not have friends in their real life. This community is often their one source of social connection. So the incel ideology becomes core to their identity: ‘I’m part of this community, and we don’t work. We are subhumans.'”

There were also frequent laments about being discriminated against for not being attractive (“lookism”), both romantically and professionally, as well as deep resentment of women’s increased presence in the workplace, deemed a threat to men’s own success. “They love to cherry-pick all these findings from psychology research [to support their position],” said Beckett-Herbert. For instance, “There is evidence that men who are short or not conventionally attractive are discriminated against in hiring. But there’s also a lot of evidence suggesting that this actually affects women more. Women who are overweight face a greater bias against them in hiring than men do, for example.”

Beckett-Herbert and Shor also found that about 15 percent of the comments in their sample concerned users’ experiences being harassed or bullied (usually by other men), their mental health challenges (anxiety, depression), and feeling estranged or ostracized at school or work—experiences that cemented their reluctance to work or engage in education or vocational training.

Many of these users also mentioned being autistic, in keeping with prior research showing a relatively high share of people with autism in incel communities. The authors were careful to clarify, however, that most people with autism “are not violent or hateful, nor do they identify as incels or hold explicitly misogynistic views,” they wrote. “Rather, autism, when combined with other mental health issues such as depression, anxiety, and hopelessness, may make young men more vulnerable to incel ideologies.”

There are always caveats. In this case, the study was limited to a single incel forum, which might not be broadly representative of similar discussions on other platforms. And there could be a bit of selection bias at play. Not every incel member may actively participate in discussion threads (lurkers) and non-NEET incels might be less likely to do so either because they have less free time or don’t wish to be dismissed as “fakecels.”However, Beckett-Herbert and Shor note that their findings are consistent with previous studies that suggest there are a disproportionately large number of NEETs within the incel community.

A pound of prevention

Is effective intervention even possible for members of the incel community, given their online echo chamber? Beckett-Herbert acknowledges that it is very difficult to break through to such people. “De-radicalization is a noble, worthy line of research,” she said. “But the existing evidence from that field of study suggests that prevention is easier and more effective than trying to pull these people out once they’re already in.” Potential strategies might include fostering better digital and media literacy, i.e., teaching kids to be cognizant of the content they’re consuming online. Exposure time is another key issue.

“A lot of these young people don’t have healthy outlets that are not in the digital world,” said Beckett-Herbert “They come home from school and spend hours and hours online. They’re lonely and isolated from real-world communities and structures. Some of these harmful ideologies might be downstream of these larger root causes. How can we help boys do better in school, feel better prepared for the labor market? How can we help them make more friends? How can we get them involved in real-world activities that will diminish their time spent online? I think that that can go a long way. Just condemning them or banning their spaces—that’s not a good long-term solution.”

While there are multiple well-publicized instances of self-identified incels committing violent acts—most notably Elliot Rodger, who killed six people in 2014—Beckett-Herbert emphasizes not losing sight of incels’ fundamental humanity. “We focus a lot on the misogyny, the potential for violence against women, and that is so important,” she said. “You will not hear me saying we should not focus on that. But we also should note that statistically, an incel is much more likely to commit suicide or be violent towards themselves than they are toward someone else. You can both condemn their ideology and find it abhorrent and also remember that we need to have empathy for these people.”

Many people—women especially—might find that a tall order, and Beckett-Herbert understands that reluctance. “I do understand people’s hesitancy to empathize with them, because it feels like you’re giving credence to their rhetoric,” she said. “But at the end of the day, they are human, and a lot of them are really struggling, marginalized people coming from pretty sad backgrounds. When you peruse their online world, it’s the most horrifying, angering misogyny right next to some of the saddest mental health, suicidal, low self-esteem stuff you’ve ever seen. I think humanizing them and having empathy is going to be foundational to any intervention efforts to reintegrate them. But it’s something I wrestle with a lot.”

Why incels take the “Blackpill”—and why we should care Read More »

Testing a robot that could drill into Europa and Enceladus

astronomy, Enceladus, Europa, exobiology, icy moon, planetary science, Science, Space / Mike M. / May 31, 2025

We don’t currently have a mission to put it on, but NASA is making sure it’s ready.

Geysers on Saturn’s moon Enceladus Credit: NASA

Europa and Enceladus are two ocean moons that scientists have concluded have liquid water oceans underneath their outer icy shells. The Europa Clipper mission should reach Europa around April of 2030. If it collects data hinting at the moon’s potential habitability, robotic lander missions could be the only way to confirm if there’s really life in there or not.

To make these lander missions happen, NASA’s Jet Propulsion Laboratory team has been working on a robot that could handle the search for life and already tested it on the Matanuska Glacier in Alaska. “At this point this is a pretty mature concept,” says Kevin Hand, a planetary scientist at JPL who led this effort.

Into the unknown

There are only a few things we know for sure about conditions on the surface of Europa, and nearly all of them don’t bode well for lander missions. First, Europa is exposed to very harsh radiation, which is a problem for electronics. The window of visibility—when a potential robotic lander could contact Earth—lasts less than half of the 85 hours it takes for the moon to complete its day-night cycle due to the Europa-Jupiter orbit. So, for more than half the mission, the robot would need to fend for itself, with no human ground teams to get it out of trouble. The lander would also need to run on non-rechargeable batteries, because the vast distance to the Sun would make solar panels prohibitively massive.

And that’s just the beginning. Unlike on Mars, we don’t have any permanent orbiters around Europa that could provide a communication infrastructure, and we don’t have high-resolution imagery of the surface, which would make the landing particularly tricky. “We don’t know what Europa’s surface looks like at the centimeter to meter scale. Even with the Europa Clipper imagery, the highest resolution will be about half a meter per pixel across a few select regions,” Hand explains.

Because Europa has an extremely thin atmosphere that doesn’t provide any insulation, the temperatures on top of its ice shell are estimated to vary between minus-160° Celsius during the daytime maximum and minus-220° C during the night, which means the ice the lander would be there to sample is most likely hard as concrete. Hand’s team, building their robot, had to figure out a design that could deal with all these issues.

The work on the robotic system for the Europa lander mission began more than 10 years ago. Back then, the 2013–2022 decadal strategy for planetary science cited the Europa Clipper as the second-highest priority large-scale planetary mission, so a lander seemed like a natural follow-up.

Autonomy and ice drilling

The robot developed by Hand’s team has legs that enable it to stabilize itself on various types of surfaces, from rock-hard ice to loose, soft snow. To orient itself in the environment, it uses a stereoscopic camera with an LED light source for illumination hooked to computer-vision algorithms—a system similar to the one currently used by the Perseverance rover on Mars. “Stereoscopic cameras can triangulate points in an image and build a digital surface topography model,” explains Joseph Bowkett, a JPL researcher and engineer who worked on the robot’s design.

The team built an entirely new robotic arm with seven degrees of freedom. Force torque sensors installed in most of its joints act a bit like a nervous system, informing the robot when key components sustain excessive loads to prevent it from damaging the arm or the drill. “As we press down on the surface [and] conduct drilling and sampling, we can measure the forces and react accordingly,” Bowkett says. The finishing touch was the ICEPICK, a drilling and sampling tool the robot uses to excavate samples from the ice up to 20 centimeters deep.

Because of long periods the lander would need operate without any human supervision, the team also gave it a wide range of autonomous systems, which operate at two different levels. High-level autonomy is responsible for scheduling and prioritizing tasks within a limited energy budget. The robot can drill into a sampling site, analyze samples with onboard instruments, and decide whether it makes sense to keep drilling at the same spot or choose a different sampling site. The high-level system is also tasked with choosing the most important results for downlink back to Earth.

Low-level autonomy breaks all these high-level tasks down into step-by-step decisions on how to operate the drill and how to move the arm in the safest and most energy-efficient way.

The robot was tested in simulation software first, then indoors at JPL’s facilities, and finally at the Matanuska Glacier in Alaska, where it was lowered from a helicopter that acted as a proxy for a landing vehicle. It was tested at three different sites, ranked from the easiest to the most challenging. It completed all the baseline activities as well as all of the extras. The latter included a task like drilling 27 centimeters deep into ice at the most difficult site, where it was awkwardly positioned on an eight-to-12-degree slope. The robot passed all the tests with flying colors.

And then it got shelved.

Switching the ocean worlds

Hand’s team put their Europa landing robot through the Alaskan field test campaign between July and August 2022. But when the new decadal strategy for planetary science came out in 2023, it turned out that the Europa lander was not among the missions selected. The National Academies committee responsible for formulating these decadal strategies did not recommend giving it a go, mainly because they believed harsh radiation in the Jovian system would make detecting biosignatures “challenging” for a lander.

An Enceladus lander, on the other hand, remained firmly on the table. “I was also on the team developing EELS, a robot intended for a potential Enceladus mission, so thankfully I can speak about both. The radiation challenges are indeed far greater for Europa,” Bowkett says.

Another argument for changing our go-to ocean world is that water plumes containing salts along with carbon- and nitrogen-bearing molecules have already been observed on Enceladus, which means there is a slight chance biosignatures could be detected by a flyby mission. The surface of Enceladus, according to the decadal strategy document, should be capable of preserving biogenic evidence for a long time and seems more conducive to a lander mission. “Luckily, many of the lessons on how to conduct autonomous sampling on Europa, we believe, will transfer to Enceladus, with the benefit of a less damaging radiation environment,” Bowkett told Ars.

The dream of a Europa landing is not completely dead, though. “I would love to get into the Europa’s ocean with a submersible and further down to the seafloor. I would love for that to happen,” Hand says. “But technologically it’s quite a big leap, and you always have to balance your dream missions with the number of technological miracles that need to be solved to make these missions possible.”

Science Robotics, 2025. DOI: 10.1126/scirobotics.adi5582

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.

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Blue Origin boss: Government should forget launch and focus on “exotic” missions

artemis, blue origin, Commercial space, dave limp, Jeff Bezos, launch, Mars, moon, Science, Space / Rejus Almole / May 30, 2025

“There’s not yet a commercial reason only to go to the Moon with humans.”

In this long exposure photograph, Blue Origin’s New Glenn rocket pierces a cloud deck over Florida’s Space Coast on its inaugural flight January 16. Credit: Blue Origin

Eighteen months after leaving his job as a vice president at Amazon to take over as Blue Origin’s chief executive, Dave Limp has some thoughts on how commercial companies and government agencies like NASA should explore the Solar System together.

Limp had no background in the space industry before taking the helm of Jeff Bezos’ space company in December 2023. He started his career as a computer scientist at Apple, took a stint at a venture capital firm, and joined Amazon in 2010, where he managed development of consumer devices like Alexa, Kindle, and the Fire TV.

“I had no thoughts of ever running a space company,” Limp said Thursday at a space conference in Washington, DC. “I’ve done consumer electronics my whole life. Started at Apple and did a bunch of other things, and so when I decided to retire from Amazon, I was looking for something that I could give back a little bit, be a little bit more philanthropic in the sort of second half of my career. I didn’t want to stop working, just wanted to do something different. And about that same time, Jeff was looking for a CEO.”

While he’s still a relative newcomer to the space business, Limp’s views align with those of many policy wonks and industry leaders who have the ears of senior officials in the Trump administration, including Jared Isaacman, President Trump’s nominee to become the next NASA administrator. Limp’s long tenure at Amazon and his selection as Blue Origin’s new CEO demonstrate that he also has the trust of Bezos, who was dissatisfied with his company’s slow progress in spaceflight.

“I think Jeff convinced me, and he’s very persuasive, that Blue didn’t need another rocket scientist,” Limp said. “We have thousands of the world’s best rocket scientists. What we needed was a little bit more decisiveness, a little bit more ability to think about: How do we manufacture at scale? And those are things I’ve done in the past, and so I’ve never looked back.”

David Limp, CEO of Blue Origin, speaks during the 2025 Humans to the Moon and Mars Summit at George Washington University in Washington, DC, on May 29, 2025. Credit: Alex Wroblewski / AFP via Getty Images

Leave it to us

In remarks Thursday at the Humans to the Moon & Mars Summit, Limp advocated for commercial companies, like his own, taking a larger role in developing the transportation and infrastructure to meet lofty national objectives established by government leaders.

In some ways, NASA has long been moving in this direction, beginning with initiatives ceding most launch services to private industry in the 1990s. More recently, NASA has turned to commercial companies for crew and cargo deliveries to the International Space Station and cargo and human-rated Moon landers.

However, NASA, with the backing of key congressional leaders, has held an iron grip on having its own heavy-lift launcher and crew capsule to ferry astronauts between Earth and destinations beyond low-Earth orbit. Now, these vehicles—the Space Launch System and Orion spacecraft—may be canceled if Congress agrees with Trump’s proposed NASA budget.

Commercial rockets close to matching or exceeding the Space Launch System’s lift capability are available for purchase or likely will be soon. These include SpaceX’s Starship mega-rocket and Blue Origin’s New Glenn launcher. Both are already key elements of NASA’s Artemis program, which aims to land US astronauts on the Moon as a stepping stone toward human expeditions to Mars.

But NASA still plans to use its government-owned Space Launch System rocket and Orion spacecraft to transport astronauts out to the Moon, where they will rendezvous with a Starship or Blue Origin’s Blue Moon lander to fly to and from the lunar surface.

SLS and Orion are expensive vehicles, costing more than $4 billion per launch for the initial set of four Artemis missions, according to a report by NASA’s inspector general. While commercial companies like Boeing, Lockheed Martin, and Northrop Grumman build elements of SLS and Orion, NASA acts as the prime integrator. The agency signed cost-plus contracts with the companies building SLS and Orion, meaning the government is on the hook for cost overruns. And there have been many.

Artist’s concept of Blue Ring, a propulsive spacecraft platform Blue Origin says it is developing to carry payloads to different orbits, and possibly all the way to Mars, at lower costs than feasible today. Credit: Blue Origin

NASA’s robotic science probes are also getting more expensive, even when accounting for inflation. Given the way NASA procures science probes, it would cost NASA more today to send an orbiter to Mars than it did for a similarly sized spacecraft a quarter-century ago.

This has to change in order for NASA and private companies like Blue Origin and SpaceX to make their ambitions a reality, Limp said Thursday.

“I think commercial folks can worry about the infrastructure,” he said. “We can do the launch. We can build the satellite buses that can get you to Mars much more frequently, that don’t cost billions of dollars. We can take a zero, and over time, maybe two zeros off of that. And if the governments around the world leave that to the commercial side, then there are a lot more resources that are freed up for the science side, for the national prestige side, and those types of things.”

The bottom line

Limp followed these comments with a dose of realism you don’t often hear from space industry executives. While there’s a growing list of commercially viable markets in space (things like Starlink and satellite servicing wouldn’t have been money-makers 20 years ago), the market for human spaceflight still requires some level of government commitment.

“I think the thing about bringing commercial aspects to exploration, to science, to the Moon, to Mars, is that we have to see a business prospect for it,” Limp said. “We have to turn it into a business, and that benefits American taxpayers because we will use that capital as efficiently as we can to get to the Moon, to get to Mars in a safe way, but in a way that’s the most efficient.

“We’re committed to that, no matter what the architecture looks like, but it does take the US government and international governments to have the motivation to do it,” he continued. “There’s not yet a commercial reason only to go to the Moon with humans. There are lots of commercial reasons to put robotics on the Moon and other types of things. So, we do need to have conviction that the Moon is important and Mars is important as well.”

Trump and Musk, an ally and advisor to the president, rekindled the question of Moon or Mars in a series of remarks during the early weeks of the new Trump administration. The Artemis Moon program began during the first Trump administration, with the goal of returning astronauts to the Moon for the first time since 1972. NASA would establish a sustained presence at the Moon, using our nearest planetary body as a proving ground for the next destination for humans in Solar System exploration: Mars.

Space industry rivals Jeff Bezos, second from left, and Elon Musk, second from right, inside the US Capitol for President Donald Trump’s inauguration on January 20, 2025. Credit: Chip Somodevilla/Getty Images

SpaceX’s Starship, while capable of one day landing on the Moon, was designed for long-duration cruises to Mars. Blue Origin’s Blue Moon is tailored for lunar landings.

“As an American, I don’t want another Sputnik moment,” Limp said. “From my standpoint, getting boots on the Moon and setting the groundwork for permanence on the Moon is of national importance and urgency. Rest assured, Blue will do everything in its power to try to make that happen, but in a cost-effective way.”

NASA, please don’t leave us

Since retaking office in January, Trump has mentioned human missions to Mars multiple times, but not the Moon. Isaacman, who may be confirmed as NASA administrator by the Senate as soon as next week, told lawmakers in April that the agency should pursue human missions to the Moon and Mars simultaneously. The details of how that might work haven’t been released but could come out in the White House’s detailed budget proposal for fiscal-year 2026.

A blueprint of Trump’s spending proposal released May 2 includes a 25 percent cut to NASA’s overall budget, but the plan would provide additional money for human space exploration at the Moon and Mars. “The budget funds a program to replace SLS and Orion flights to the Moon with more cost-effective commercial systems that would support more ambitious subsequent lunar missions,” the White House budget office wrote.

This part of the budget request is not controversial for industry leaders like Limp. On the other hand, the budget blueprint proposes slashing NASA’s space science budget by nearly $2.3 billion, Earth science by almost $1.2 billion, and space technology by $531 million.

While Limp didn’t directly address these budget proposals, these parts of NASA are largely focused on research projects that lack a commercial business case. Who else but a government space agency, or perhaps an especially generous type of philanthropic multi-billionaire, would pay to send a probe to study Jupiter’s icy moon Europa? Or a robot to zip by Pluto? Or how about a mission like Landsat, which documents everything from water resources to farms and urban sprawl and makes its data freely available to anyone with an Internet connection?

Most experts agree there are better ways to do these things. Reusable rockets, mass-produced satellite platforms, and improved contracting practices can bring down the costs of these missions. Bezos’ long-term goal for Blue Origin, which is to move all polluting factories off the Earth and into space, will be easier to achieve with government support, not just funding, Limp said.

“Getting up there, building factories on the Moon is a great step, and the government can really help with research dollars around that,” he said. “But it still does need the labs. The science missions need the JPLs [Jet Propulsion Laboratory] of the world. To make the human experience right, we need the Johnson Space Centers of the world to be able to kind of use that gold mine of institutional knowledge.

“I would say, and it might be a little provocative, let’s have those smart brains look on the forward-thinking types of things, the really edge of science, planning the really exotic missions, figuring out how to get to planetary bodies we haven’t gotten to before, and staying there,” Limp said.

Mark it down

For the first decade after Bezos founded Blue Origin in 2000, the company operated under the radar and seemed to move at a glacial pace. It launched its first small rocket in 2006 to an altitude of less than 300 feet and reached space with the suborbital New Shepard booster in 2015. Blue Origin finally reached orbit in January of this year on the debut test flight of its heavy-lift New Glenn rocket. Meanwhile, Blue Origin inked a deal with United Launch Alliance to supply a version of its New Glenn main engine to power that company’s Vulcan rocket.

Blue Origin’s Blue Moon MK1 lander, seen in the center, is taller than NASA’s Apollo lunar lander, currently the largest spacecraft to have landed on the Moon. Blue Moon MK2 is even larger, but all three landers are dwarfed in size by SpaceX’s Starship, NASA’s other Artemis lunar lander. Credit: Blue Origin

The next big mission for Blue Origin will be the first flight of its Blue Moon lander. The first version of Blue Moon, called MK1, will launch on a New Glenn rocket later this year and attempt to become the largest spacecraft to ever land on the Moon. This demonstration, without anyone onboard, is fully funded by Blue Origin, Limp said.

A future human-rated version, called MK2, is under development with the assistance of NASA. It will be larger and will require refueling to reach the lunar surface. Blue Moon MK1 can make a landing on one tank.

These are tangible achievements that would be the envy of any space industry startup not named SpaceX. But Musk’s rocket company left Blue Origin in the dust as it broke launch industry records repeatedly and began delivering NASA astronauts to the International Space Station in 2020. My colleague, Eric Berger, wrote a story in January describing Blue Origin’s culture. For much of its existence, one former employee said, Blue Origin had “zero incentive” to operate like SpaceX.

To ensure he would be in lock-step with his boss, Limp felt he had to ask a question that was on the minds of many industry insiders. He got the answer he wanted.

“The only question I really asked Jeff when I was talking about taking this job was, ‘What do you want Blue to be? Is it a hobby, or is it a business?'” Limp said. “And he had the right answer, which is, it’s a business, because I don’t know how to run a hobby, and I don’t think it’s sustainable.”

Blue Origin boss: Government should forget launch and focus on “exotic” missions Read More »

Your next gaming dice could be shaped like a dragon or armadillo

3D printing, computational science, Computer simulations, geometry, probability, Science, shape analysis / Paul Patrick / May 30, 2025

“Let it roll, baby, roll”

Statistically, “the real behavior of a rolling object is largely a function of its geometry.”

What if you could make your dice any shape at all—not just boxes and polyhedra, but dragons or other game-relevant shapes?

Most people are familiar with conventional cubical six-sided dice, but there are also polyhedral versions like the 20-sided dice used in ancient Rome and to play Dungeons and Dragons. Researchers have figured out how to design dice with even more exotic shapes, like a kitten, a dragon, or an armadillo. And they are “fair” dice: Experiments with 3D-printed versions produced results that closely matched predicted random outcomes, according to a forthcoming paper currently in press at the journal ACM Transactions on Graphics.

Dice are examples of so-called “rigid bodies,” broadly defined as shapes that move as one solid piece, with no need for bending or twisting. Such shapes “are of scientific interest because they model so many of the phenomena we encounter in our daily lives: anything from the way your dishes roll around on the floor when you drop them, to how the gears in your watch push on each other, to how a satellite tumbles around under the pull of gravity,” co-author Keenan Crane of Carnegie-Mellon University told Ars. “So there’s an intense focus on developing computational methods for understanding and predicting how rigid bodies are going to behave.”

Crane and his co-authors—including lead author and CMU graduate student Hossein Baktash, as well as co-authors from Nvidia Research and Adobe Research—wanted to explore where and how a rigid body will land when tossed. They chose dice as the best (and most fun) context in which to explore that question.

“But it’s also helpful to understand, for instance, if you load up a 3D model on your computer, how should it be displayed on screen—which direction is ‘up’?” said Crane. “Or if you drop a rigid object in the ocean, can you design it so that it lands with the proper orientation, with high probability?”

Conducting trial throws of each of seven unusually shaped dice. Credit: Keenan Crane

The group began with the assumption that when it comes to the rest behavior of a rolling irregularly shaped rigid body—such as the pig-shaped “dice” from the commercial game Pass the Pigs—the effects of momentum would be negligible. They wanted to approach the problem from the perspective of analytical geometry rather than dynamical simulations, so they essentially mapped the corners, edges, and faces onto a sphere and simulated how gravity would act upon such objects as they fell and came to rest.

The ultimate objective was to estimate the probability distribution over the possible range of resting configurations using just geometry. They ran multiple computer simulations of seven weirdly shaped designs for dice and then created physical 3D-printed versions to test them experimentally, tossing each die between 100 and 1,000 times.

They tweaked each shape until the experimental resting positions were within 3 or 4 percent of the predicted probability outcomes. These designs included a single die simulating two rolling six-sided dice (D6+D6); two binomial dice simulating flipping two and three fair coins, respectively; and three versions of a single die with three equally likely outcomes, shaped like a kitten, an armadillo, and a dragon. They also analyzed a talus-shaped model, similar to the sheep’s knuckles or “astragali” used as dice in antiquity for gambling or divination. Baktash recalled playing with such objects as a child growing up in Iran.

“These irregular dice were in a way similar to the ones we’ve designed, in that they don’t have even probabilities—like 1/4, 1/4, 1/4, 1/4—but rather depend on the very particular shape of the knuckles,” said Crane. “People bet on different outcomes, using past experience to build up their intuition about which sides are most likely. Hossein’s tool can do this much more directly: By just looking at the shape, it can directly give you some pretty accurate probabilities. If we were able to time travel back and gamble in ancient Greece, we might be able to make a lot of money (in BC-adjusted dollar).”

The algorithm efficiently and robustly computed the probability of all resting configurations (in 3 ms) of the pig model from the popular game Pass the Pigs. Keenan Crane

So one day soon, gamers might be able to choose from a wide selection of exotically shaped dice for future play—and even 3D print their own designs. (You can already 3D print the team’s designs since Baktash posted the STL files.) The new tool might also prove useful for creating natural-looking arrangements of geometry or adjusting a design so that an object is better able to stand upright, akin to the “Daruma doll,” a traditional Japanese toy that is hollow and weighted at the bottom so that it always returns to an upright position when tilted over. “Our approach makes it possible to bake this property into the geometry of the shape itself,” said Crane.

As for more “serious” applications, Crane points to underwater construction, “where the low-momentum assumption is very realistic and it’s important for things to land in the proper orientation,” he said. “Alternatively, if you imagine each little grain of sand or soil is a rigid particle, the statistics of how they land might help understand things like how soil settles and compacts. The exciting thing about putting research like this out in the world is that, a few years later, other folks inevitably find use cases for it that we never could have imagined.”

There are some inevitable tradeoffs. Oklahoma State University mathematician Henry Segerman told New Scientist that the method isn’t “necessarily a silver-bullet solution to designing weird dice, because it ignores friction, bouncing, and other real-world momentum effects. It’s more like they are—very efficiently—predicting where a die ends up if you put it down with a random orientation on a non-slip surface in low gravity. It slowly falls over and rolls down to land, without slipping or bouncing.”

Crane and his co-authors acknowledge as much in their paper. “On the one hand, [critics] are absolutely correct that our model does not make perfect predictions from the perspective of idealized geometry and physics,” said Crane. “On the other hand, if your goal is to literally make dice for tabletop games, it’s perfectly reasonable to make these kinds of approximations.”

still of one of the STL files used to 3D print the dice. — You can 3D print these unusually shaped dice using the STL files. Credit: Hossein Baktash

That’s partly because of the nature of statistics. “If you flip a coin or roll a die only a few times, it can be very hard to tell whether it’s fair or not,” said Crane. “Suppose I roll a 6-sided die just once, and it comes up with a ‘5.’ Is it fair, or not? Impossible to say. Likewise, if I play Settlers of Catan, I might roll the dice only about 100 times in the whole game. Even if the dice are actually fair, the distribution of rolls I see throughout this short game might vary quite a bit from the idealized distribution—I might just happen to roll a lot more nines that game than usual. So, in a real game, there may not be a huge practical difference between using fair dice and dice that have a small bias. The signal-to-noise ratio is so low that the practical effect over a short game is pretty small.”

Then there is the human factor: Even assuming perfect dice, how people handle them is imperfect and unpredictable; even fair coins don’t yield 50/50 odds because of that. “There will always be some kind of ‘dice handling bias’ due to the way that people pick up, shake (or not shake!), and toss dice,” said Crane. “If you wanted to make dice that exhibit perfect statistics in practice, rather than just in theory, you might need to take an interdisciplinary approach that incorporated not just geometry and physics, but also ideas from psychology, design, and so on.”

“I think the reality is that if we wanted more perfect statistics, we would just ask a computer to generate a random number,” Crane concluded. “The reason people use dice for tabletop games is because it’s tactile and fun. I think Hossein’s approach does a great job of making dice rolling even more fun—while still remaining grounded on some solid mathematical principles.”

Your next gaming dice could be shaped like a dragon or armadillo Read More »

Enigmatic hominin species studied using 2 million-year-old proteins

ancient proteins, Biology, evolution, human evolution, mass spec, paleontology, proteins, Science / Tim Belzer / May 30, 2025

The absence of AMELY suggests that a sample is female, but it isn’t definitive. That’s both because it’s impossible to rule out some problem with identifying the protein in samples this old, and in part because some rare males (including at least one Neanderthal) carry deletions that eliminate the gene entirely.

Another key aspect is that some of the 425 amino acid locations differ between hominin species, and even individual members of Paranthropus. Thus, they can potentially serve as a diagnostic of the relationships between and within species and help address some of the confusion about how many species of Paranthropus there were and their relationship with other hominins. While it’s difficult to say too much with only four samples, the researchers found some suggestive evidence.

For example, they tested whether you might see the sort of amino acid variation found among these samples if they all belonged to the same species. This was done by randomly choosing four human genomes and examining whether they had a similar level of variation. They concluded that it was “plausible” that you’d see this level of variation among any four individuals that were chosen at random, but the population of modern humans is likely to be larger than that of Paranthropus, so the test wasn’t definitive.

Among the 425 different amino acids were 16 that had species-specific variations among hominins. Somewhat surprisingly, Paranthropus robustus is the most closely related species to our own genus, Homo, based on a tree built from these variations. Again, however, they conclude that there simply isn’t enough data available to feel confident in this conclusion.

But that should really be an “isn’t enough data yet.” We heard about this paper from regular Ars reader Enrico Cappellini, who happens to be its senior author and faculty at the University of Copenhagen’s Globe Institute. And a quick look over his faculty profile indicates that developing the techniques used here is his major research focus, so hopefully we’ll be able to expand the data available on extinct hominin species with time. The challenge, as noted in the paper, is that the technique destroys a small part of the sample, and these samples are one-of-a-kind pieces of the collective history of all of humanity.

Science, 2025. DOI: 10.1126/science.adt9539 (About DOIs).

Enigmatic hominin species studied using 2 million-year-old proteins Read More »

China extends its reach into the Solar System with launch of asteroid mission

asteroids, china, launch, long march 3b, sample return, Science, solar system, Space, tianwen, tianwen 2 / Rejus Almole / May 29, 2025

Comet 311P/PanSTARRS was observed by the Hubble Space Telescope in 2013 with a set of six comet-like tails radiating from its main body. This object, also called P/2013 P5, is known as an active asteroid. Credit: NASA, ESA, and D. Jewitt (UCLA)

Tianwen-2’s mothership, with 11 scientific instruments, will commence the second phase of its mission after dropping off the asteroid specimens at Earth. The probe’s next journey will bring it near an enigma in the asteroid belt, named 311P/PanSTARRS, in the mid-2030s. This object is one in a rare class of objects known as active asteroids or main-belt comets, small worlds that have tails and comas like comets but loiter in orbits most commonly associated with asteroids. Tianwen-2 will be the first mission to see such an object up close.

Stepping into the Solar System

Until the last few years, China’s space program has primarily centered on the Moon as a destination for scientific exploration. The Moon remains the main target for China’s ambitions in space, with the goal of accomplishing a human lunar landing by 2030. But the country is looking farther afield, too.

With the Tianwen-1 mission in 2021, China became the second country to achieve a soft landing on Mars. After Tianwen-2, China will again go to Mars with the Tianwen-3 sample return mission, slated for launch in 2028.

Tianwen, which means “questions to heaven,” is the name given to China’s program of robotic Solar System exploration. Tianwen-3 has a chance to become the first mission to return pristine samples from Mars to Earth. At the same time, NASA’s plans for a Mars Sample Return mission are faltering.

China is looking at launching Tianwen-4 around 2029 to travel to Jupiter and enter orbit around Callisto, one of its four largest moons. In the 2030s, China’s roadmap includes a mission to return atmospheric samples from Venus to Earth, a Mars research station, and a probe to Neptune.

Meanwhile, NASA has sent spacecraft to study every planet in the Solar System and currently has spacecraft at or on the way to the Moon, Mars, Jupiter, a metal asteroid, and to interstellar space. Another US science mission, Dragonfly, is scheduled for launch in 2028 on a daring expedition to Saturn’s moon Titan.

But NASA’s science division is bracing for severe budget cuts proposed by President Donald Trump. In planetary science, the White House’s budget blueprint calls for canceling a joint US-European Mars Sample Return mission and several other projects, including the DAVINCI mission to Venus.

China extends its reach into the Solar System with launch of asteroid mission Read More »

We now have a good idea about the makeup of Uranus’ atmosphere

Science / Rejus Almole / May 28, 2025

Uranus, the seventh planet in the Solar System, located between Saturn and Neptune, has long been a mystery. But by analyzing observations made by NASA’s Hubble Space Telescope over a 20-year period, a research team from the University of Arizona and other institutions has provided new insights into the composition and dynamics of the planet’s atmosphere.

Information about Uranus is limited. What we know is that the planet is composed mainly of water and ammonia ice, its diameter is about 51,000 kilometers, about four times that of the Earth, and its mass is about 15 times greater than Earth’s. Uranus also has 13 rings and 28 satellites.

In January 1986, NASA’s Voyager 2 space probe successfully completed what has been, to date, the only exploration of the planet, conducting a flyby as part of its mission to study the outer planets of the Solar System.

Uranus in 1986 — This image of Uranus was taken by NASA’s Voyager 2 space probe in January 1986. Credit: NASA/JPL

But thanks to this new research, we now know a little more about this icy giant. According to the research, which assessed Hubble images taken between 2002 and 2022, the main components of Uranus’ atmosphere are hydrogen and helium, with a small amount of methane and very small amounts of water and ammonia. Uranus appears pale blue-green because methane absorbs the red component of sunlight.

This image of Uranus, taken by NASA’s James Webb Space Telescope, shows nine of the planet’s 28 satellites and its rings. Credit: NASA/ESA/CSA/STSCI

The research has also shed light on the planet’s seasons.

Unlike all of the other planets in the Solar System, Uranus’ axis of rotation is almost parallel to its orbital plane. For this reason, Uranus is said to be orbiting in an “overturned” position, as shown in the picture below. It is hypothesized that this may be due to a collision with an Earth-sized object in the past.

Uranus orbiting the Sun. It can be seen that Uranus’ axis of rotation is almost parallel to its orbital plane. Credit: NASA/ESA/J. Feild (STSCI)

The planet’s orbital period is about 84 years, which means that, for a specific point on the surface, the period when the sun shines (some of spring, summer, and some of fall) lasts about 42 years, and the period when the sun does not shine (some of fall, winter, and some of spring) lasts for about 42 years as well. In this study, the research team spent 20 years observing the seasons.

We now have a good idea about the makeup of Uranus’ atmosphere Read More »