分类： science

After six months of unexplained silence from its pioneering Martian orbiter, NASA announced this Wednesday that it is formally bringing the Mars Atmosphere and Volatile Evolution (MAVEN) mission to a close. Over its 11 years of unplanned extended operations, the probe rewrote scientific understanding of the Red Planet, leaving a legacy that will shape planetary research for decades to come.

Launched with an initial projected lifespan of just one to two years, MAVEN slipped into orbit around Mars in September 2014, tasked with answering a longstanding cosmic question: how and why Mars lost most of its thick early atmosphere, transforming from a warm, wet world capable of hosting liquid water on its surface into the cold, arid desert we see today. It continued to beam back invaluable data and support surface operations far longer than mission planners ever dared to hope, until contact was abruptly lost with the spacecraft in December 2024.

Though NASA confirms MAVEN is believed to still remain in a stable orbit around Mars, repeated attempts to reestablish contact over the past six months have gone unanswered. The agency has officially acknowledged the loss of the craft, though it will launch a full formal review to pinpoint the root cause of the communications failure, according to statements released Wednesday.

For scientists who spent years working on the mission, MAVEN’s contributions extend far beyond its original mandate. Shannon Curry, an astrophysics professor and key MAVEN mission researcher, called it “the best Mars mission ever” in comments to reporters Wednesday. The probe’s measurements gave planetary scientists an unprecedented look at atmospheric escape—the process through which gases in a planet’s atmosphere leak out into interplanetary space. Currey noted that “We now have a better understanding of atmospheric escape at Mars than at any other planet, including Earth.” This body of data has turned Mars into an unparalleled natural laboratory for studying atmospheric evolution on rocky planets throughout the solar system and beyond, she added.

Tiffany Morgan, head of NASA’s exploration programs, echoed that praise, emphasizing that MAVEN “profoundly advanced our understanding of Mars’s atmosphere, climate history, and habitability.” Beyond its core scientific work, MAVEN filled a critical secondary role: it served as a reliable communications relay, relaying data and commands between Earth and NASA’s fleet of rovers and landers operating on the Martian surface. With MAVEN now offline, that responsibility will be transitioned to other operational orbiters currently circling the Red Planet to maintain uninterrupted contact with surface missions.

In a collective rebuke of growing commercial overstatement of artificial intelligence’s capabilities in pure mathematics, more than 150 mathematicians from leading academic institutions across Europe, Japan, the United States and other regions have put their names to a public statement calling on the global mathematics community to push back against the trend of AI developers leveraging the discipline to inflate their products’ reputations.

The statement, dubbed the Leiden Declaration, arrives amid a wave of aggressive claims from major AI corporations about their systems’ supposed breakthroughs in mathematics — including supposed solutions to long-unresolved open problems in the field and strong performances in high-level competitive mathematics challenges. The signatories specifically urge governments and research funders not to fall for the overblown marketing surrounding AI’s current mathematical competencies.

Ulrike Tillmann, vice-president of the International Mathematical Union (IMU), offered her public backing for the declaration, noting that while AI has unlocked intriguing new opportunities for mathematical inquiry, the risks and ethical questions it introduces demand rigorous, critical examination. “The future of mathematical research must be guided by human judgment, fair and transparent practices, and the shared values of the global mathematical community, Tillmann emphasized in her endorsement.

The declaration itself calls out the core conflict of interest driving the current hype: AI developers operate under intense commercial pressure to overstate what their tools can do, as hundreds of billions of dollars in venture capital and public investment hang in the balance. Unlike peer-reviewed mathematical research, which advances at a deliberate, verification-focused pace, AI development and publicity is driven by market timelines. This leads to misleading framing, the declaration argues, where narrow performance on specific mathematical tasks is incorrectly presented as proof of general reasoning ability in commercial AI models.

Michael Harris, a Columbia University professor and co-author of the declaration, explained the high-stakes dynamic at play to AFP. “There is a competition to the death on the part of the main labs… they are trying, using mathematics… to attract investment so that each of them will be left standing, Harris said. This scramble for funding comes as the AI industry is in a period of major market expansion: in recent weeks, Elon Musk’s SpaceX, which owns AI developer xAI, and AI startup Anthropic have both moved forward with plans for initial public offerings, with industry leader OpenAI widely expected to follow suit shortly.

The declaration also pushes back against recent high-profile endorsements of AI’s research potential from leading mathematicians. Just one week before the declaration’s release, OpenAI shared a social media video featuring Terence Tao, a UCLA professor and former Fields Medal winner — the highest honor in pure mathematics — praising the company’s AI tools for their ability to support mathematical research. Harris acknowledged Tao’s immense contributions to the global mathematics community but argued that it is unhealthy for the field to consistently hold up a single mathematician as the official voice endorsing commercial AI tools.

Beyond the problem of co-opting mathematics for commercial marketing, the signatories outline a host of deeper risks to the discipline itself. AI systems can generate logically plausible but fundamentally incorrect mathematical proofs that are extremely difficult for human researchers to verify, they note. The technology also erodes clear attribution for the foundational human research that AI models are built on.

Longer-term harms to research culture are also a major concern: widespread adoption of AI in mathematics could push more researchers to chase trendy, AI-aligned problems at the expense of exploring less hyped but equally important lines of inquiry. It could also weaken traditional peer review systems and reorient academic research to serve the priorities of commercial AI developers, rather than the open, self-directed inquiry that has long defined university-based mathematics.

The declaration also highlights broader societal harms tied to unregulated AI development, including risks of weaponization for warfare, expansion of mass surveillance, political interference, and increased environmental damage from energy-intensive AI model training. In closing, the statement urges all practicing mathematicians to carefully assess the ethical implications of any AI-related work they take on, and to step away from projects that cause undue harm.

CHARLESTOWN, Nevis — A small Caribbean island nation has entered the global space research landscape with a groundbreaking achievement: the successful deployment of the first space life sciences experiment originating from the entire Caribbean region. This milestone marks a defining moment for science, education, and cross-border innovation in the Federation of St Kitts and Nevis, placing the country alongside a expanding cohort of nations advancing international space exploration.

The experiment lifted off on May 31, 2026, as part of the SSC SubOrbital Express SIX-5/M17 mission, launching from Esrange Space Center in Kiruna, Sweden. The historic project was brought to fruition through a groundbreaking multilateral collaborative partnership, bringing together Nevis’ Ministry of Education, the University of Zurich (UZH), and the Center for Space and Aviation Switzerland and Liechtenstein (CSA).

In an official statement following the launch, the government of St Kitts and Nevis emphasized that the mission carries historic significance far beyond Nevis’ borders. For the entire Caribbean, it proves that small island developing states are fully capable of making meaningful contributions to cutting-edge scientific inquiry and global technological progress.

At its core, the experiment is designed to address a longstanding gap in space biology research: understanding how altered gravitational conditions alter the behavior of human immune cells. Researchers will analyze how both microgravity, the near-weightless environment of space, and hypergravity, an environment with greater gravitational pull than Earth, impact gene expression and core cellular functions. Any insights generated from the mission are expected to directly inform global research into protecting human health during long-duration spaceflight, a critical area of study as nations plan deeper exploration missions beyond low-Earth orbit.

A core defining feature of the initiative is its focus on building local scientific capacity, rather than relying solely on external researchers. Four experienced science educators from Nevis were selected to participate directly in the project, working side-by-side with leading international space scientists to develop the experiment’s design and support its implementation. This opportunity gave the local educators first-hand, practical experience in space research and advanced scientific research techniques that they can bring back to their classrooms.

Government officials explained that the collaboration has already delivered lasting benefits to education and research infrastructure across the federation. Local teachers and students have gained unprecedented access to real-world, global scientific research practices, while new purpose-built laboratory facilities and expanded research capabilities have been established locally. The initiative has also transformed STEM (Science, Technology, Engineering, and Mathematics) education across Nevis by creating tangible, direct connections between standard classroom learning and high-profile global scientific exploration.

This mission, officials noted, showcases the transformative impact of strategic international academic and government partnerships, while highlighting the untapped potential of Nevisian educators and students to contribute to cutting-edge scientific innovation on the global stage.

As researchers begin the process of collecting and analyzing data from the experiment, educators and students across Nevis will continue to participate in every step of the research process. The findings generated will not only advance global understanding of human biology in altered gravitational environments, but also serve as a powerful inspiration to cultivate the next generation of scientists, engineers, and innovators across the entire Caribbean region.

A rogue meteor barreling toward Earth broke apart in the upper atmosphere over the northeastern United States on Saturday, triggering shockwaves loud enough to rattle homes and leave local residents unsettled, NASA has confirmed. The explosive disintegration of the extraterrestrial object occurred at 2:06 p.m. local time, with the fireball fragmenting over a cross-border region spanning northeastern Massachusetts and southeastern New Hampshire, according to agency representative Jennifer Dooren, NASA’s Deputy News Chief, in an official comment to AFP.

In a key clarification, Dooren emphasized the incoming object was a fully natural cosmic body unrelated to any ongoing annual meteor showers. It was not, she confirmed, leftover debris from an out-of-date satellite or discarded human-made space hardware re-entering Earth’s atmosphere. Scientists calculated the total energy released during the meteor’s breakup to match the detonation of roughly 300 tonnes of TNT — the force behind the deep, resonant booms reported across a wide swath of the region.

At the moment it shattered, the meteor was moving at a blistering speed of more than 75,000 miles per hour (over 120,000 kilometers per hour), and was cruising at an altitude of approximately 40 miles above Earth’s surface. The unexpected loud blasts triggered widespread alarm among local communities, with hundreds of social media users sharing accounts of the noise strong enough to shake the foundations and windows of residential buildings.

The Saturday event draws a sharp contrast to one of the most damaging meteor events in recent history. Back in 2013, a far larger house-sized fireball exploded over Chelyabinsk, Russia, at an altitude of just 14 miles. That blast packed a force equivalent to 440,000 tonnes of TNT, shattered windows across a 200-square-mile area, and left more than 1,600 people injured, most hurt by flying broken glass. Unlike the 2013 incident, the US event caused no reported injuries or structural damage due to its higher altitude and far smaller size.

A groundbreaking new experimental study published Thursday in the *Journal of Experimental Biology* has upended long-held assumptions about how the world’s most widely used insect repellent, DEET, works against disease-carrying mosquitoes. The research, led by an international team of scientists, demonstrates that mosquitoes can be conditioned to associate the scent of DEET with the promise of a food source — even learning to prioritize biting human skin that has been treated with the repellent.

Lead researcher Claudio Lazzari, an emeritus professor at the University of Tours’ Insect Biology Research Institute in France, was quick to clarify that these surprising lab results, collected under highly controlled experimental conditions, do not undermine DEET’s proven track record as the global gold standard for mosquito bite prevention. Developed in the 1940s in the United States, DEET has been credited with saving millions of lives by reducing transmission of life-threatening mosquito-borne illnesses, and it remains the go-to repellent recommended by the World Health Organization for disease control.

Despite DEET’s success, Lazzari noted that the scientific community has long lacked a full understanding of why the compound deters mosquitoes in the first place. Researchers have debated for decades whether DEET is toxic to the blood-feeding insects, blocks their ability to track human scent, or simply produces an odor that mosquitoes find naturally unpleasant. To answer this question, the team turned to a classic conditioning experiment modeled after Ivan Pavlov’s famous dog studies, which first demonstrated how animals can learn to link unrelated stimuli to rewards.

For their tests, the researchers focused on *Aedes aegypti* mosquitoes — the species responsible for spreading dangerous pathogens including dengue fever, Zika, yellow fever, and chikungunya. In initial trials, mosquitoes were placed in mesh enclosures and presented with warm sheep’s blood, which the insects immediately fed on, as expected. When DEET scent was introduced alone, mosquitoes predictably moved away from the food source, consistent with DEET’s repellent properties.

The conditioning phase followed: over three repeated trials, scientists gave mosquitoes access to warm blood for 20 seconds, releasing DEET scent during the final 10 seconds of feeding. After this training, mosquitoes were re-exposed to DEET scent with no blood present. Astonishingly, more than 60% of the trained mosquitoes still attempted to bite the test fabric, conditioned to link the DEET scent with food. To confirm the result, a researcher offered the trained mosquitoes a choice between two bare hands: one untreated, and one covered in DEET. The insects overwhelmingly chose the DEET-coated hand. The team repeated the experiment using sugar instead of blood (to reflect mosquitoes’ natural diet of plant nectar in the wild) and observed the same outcome.

Co-author Clement Vinauger, a researcher at Virginia Tech in the United States, explained that the study challenges the long-standing paradigm that DEET repels mosquitoes purely through its inherent chemical properties. “What we are showing is that the mosquito’s brain can rewrite that response based on experience,” Vinauger said. “What the insect has learned matters just as much as what the chemical does. That, I think, is a paradigm shift.” Lazzari added that the repellent effect does not stem from DEET being toxic to mosquitoes; instead, mosquitoes’ innate avoidance of the compound is a learned response to how their brains interpret the chemical scent, which can be reshaped by experience.

Lazzari emphasized that this learned preference for DEET is extremely unlikely to occur in natural settings, as the specific controlled conditions of the lab experiment are not easily replicated in the wild. He reiterated that the public should continue to follow product instructions for DEET-based repellents, which remain a critical tool for preventing mosquito-borne disease. The findings, however, point to an urgent need for continued research into new repellents that are more effective, more eco-friendly, and less likely to trigger allergic reactions in human users, building on this new understanding of mosquito behavior.