There is a limit on how many times a mammal can be cloned before suffering "mutational meltdown," Japanese scientists have discovered, after making 1,200 clones over two decades that started off with a single mouse.

The 58th generation of mice did not survive, establishing for the first time that mammals cannot be cloned an infinite number of times, the scientists said in a study published on Tuesday.

It had been hoped that this method, which involves making clones of other clones, could have a range of uses in the future, including saving endangered species or mass-producing animals for their meat.

"We had believed that we could create an infinite number of clones. That is why these results are so disappointing," the study's senior author Teruhiko Wakayama of the University of Yamanashi told AFP.

Every time two black holes collide somewhere in the universe, they send ripples through the fabric of spacetime itself. We call these ripples gravitational waves. The problem is detecting them since they are almost impossibly faint by the time they reach Earth. LIGO, the Laser Interferometer Gravitational-Wave Observatory, solves that problem with a 4 kilometre laser tunnel so sensitive it can measure a change in distance a thousand times smaller than a proton. But what if there was another way to measure such changes?

Researchers at Stockholm University, Nordita, and the University of Tübingen think there might be. Their new theoretical study, published in Physical Review Letters, suggests that gravitational waves leave detectable fingerprints in the light emitted by atoms and that a cloud of atoms just a few millimetres across might one day serve as a gravitational wave detector.

Some of the longest, most important migrations of species on Earth are happening beneath the surface of the world's rivers and many are rapidly collapsing, according to a major new assessment by the Convention on the Conservation of Migratory Species of Wild Animals (CMS), an environmental treaty of the United Nations.

The Global Assessment of Migratory Freshwater Fishes, being launched at the CMS 15th Meeting of the Conference of the Parties (COP15) in Brazil, finds that migratory freshwater fish—a group of species that maintain river health, underpin some of the world's largest inland fisheries, and sustain hundreds of millions of people—are among the most imperiled wildlife on the planet.

The Assessment identifies hundreds of migratory fish needing cross-border action, presenting authoritative evidence that species whose life cycles depend on connected rivers across national borders face accelerating declines driven by dam construction, habitat fragmentation, pollution, overfishing, and climate-driven ecosystem changes.

The analysis identifies 325 migratory freshwater fish species as candidates for coordinated international conservation efforts, highlighting a largely overlooked biodiversity crisis unfolding across the world's shared river basins.

Researchers at the University of St Andrews have unveiled two breakthrough techniques for chemically recycling and upcycling nitrile‑rubber products, such as disposable gloves, seals, and industrial parts, into new materials that are also capable of capturing carbon dioxide.

The development of sustainable methods for the upcycling of plastic waste is one of the most important challenges in achieving a circular economy and can play a significant role in tackling the climate crisis.

Among various plastics that need to be recycled, nitrile butadiene rubber (NBR) has received comparatively little attention, despite a large market of 36 million tons or $2.5 billion globally per year. NBR has wide applications ranging from disposable gloves to hoses, seals, and circular seals used to prevent leaks.

NBR is challenging to recycle due to its thermoset nature, with less than 2% currently recycled, often through low-value downcycling.

However, in a paper published in Angewandte Chemie, researchers from the School of Chemistry at St Andrews introduce two new ways to chemically recycle NBR and turn it into useful new materials.

The body depends on vitamin B2, also called riboflavin, but it cannot make the nutrient itself. That means it has to come from food, including dairy products, eggs, meat, and green vegetables. Inside cells, riboflavin is converted into helper molecules that support metabolism and protect against oxidative damage.

That sounds entirely beneficial, but researchers have now uncovered a troubling tradeoff. The same vitamin-linked system that helps protect healthy cells can also help cancer cells stay alive.

Scientists at the Rudolf Virchow Centre (RVZ) at Julius-Maximilians-Universität Würzburg (JMU) have found that this protective role has an unexpected downside. The same mechanism can also help cancer cells survive.

“Vitamin B2 plays a crucial role in protecting cancer cells from ferroptosis, a special form of programmed cell death,” says PhD student Vera Skafar. She is a member of the research group led by José Pedro Friedmann Angeli, Professor of Translational Cell Biology. The results have been published in the renowned journal Nature Cell Biology.

It seems like every day a new study finds tiny plastic particles called microplastics where they should not be: in our bodies and our food, water and air.

Yet finding and identifying microplastics is extremely challenging, especially given their small size. One microplastic can range from as large as a ladybug to as small as an eighth of a red blood cell.

In addition, it can be hard for researchers to avoid unintentionally contaminating their samples, because these plastics are practically everywhere. As a result, much of this research may be overestimating the number of microplastics.

In a new study published in March 2026, our team found that, even when following established protocols, using certain methods to measure environmental microplastics can potentially contaminate the results.

When you reach into a bucket of ice, open your front door on a snowy day, or feel the tingle of menthol toothpaste, a protein in your nerve cells called TRPM8 springs into action, opening like a tiny gate to send a "cold" signal to your brain. Now, UC San Francisco researchers have discovered how TRPM8 changes its shape when exposed to cool temperatures. The work, published in Nature, could one day be used to help treat pain that is triggered by cold. It also answers a long-standing question about why birds—which also have TRPM8 in their nerve cells—are far less cold sensitive than mammals.

"Everyone always wants to know how temperature sensing works, but it turns out to be a very technically challenging question to answer," said co-senior author David Julius, Ph.D. "So, to finally have insight into this is really very exciting."

Julius is the Morris Herzstein Chair in Molecular Biology and Medicine, chair of Physiology, and recipient of the 2021 Nobel Prize in Physiology or Medicine. He won the prize for discovering TRPV1, which enables nerves to sense capsaicin, the spicy heat of chili peppers.

A key to the cold discovery was being able to see proteins in motion.

"For decades, structural biology has focused on capturing proteins in stable, frozen states. This work shows that to truly understand how a protein functions, you also have to understand how it moves," added Yifan Cheng, Ph.D., professor of biochemistry and biophysics and an investigator at the Howard Hughes Medical Institute (HHMI) who co-led the work.

Researchers at Aarhus University are challenging long-standing assumptions about the immune system. Their findings suggest that a small organ, once thought to stop working early in adulthood, continues to influence cancer risk, cardiovascular disease, and how well patients respond to modern cancer therapies.

That organ is the thymus, located behind the breastbone. It may now take on a more prominent role in how scientists understand immunity, cancer treatment, and heart disease risk.

The thymus is responsible for maturing T cells, which are essential for fighting infections and disease. It gradually shrinks with age, and scientists have long believed it becomes inactive in early adulthood, producing no new T cells after that point. However, two new studies from Aarhus University, published in Nature, challenge that idea.

Nicolai Birkbak, a professor at the Department of Clinical Medicine at Aarhus University and the Department of Molecular Medicine at Aarhus University Hospital, and one of the researchers behind the studies, explains: “This is significant and potentially paradigm-shifting new knowledge. It challenges the prevailing view that the thymus has no importance in adult life. On the contrary, our studies show that a healthy thymus may be crucial both for disease risk and for how well you respond to cancer treatments.”

A scientist who pioneered the modern food processing safety standards used around the world was awarded this year's World Food Prize, the organization announced Wednesday, crediting his work for averting millions of cases of foodborne illness and reducing food waste.

Huub Lelieveld of the Netherlands earned the award after six decades spent advancing ways to improve food safety and advocating for trade regulations that allow safe food to get around the world more easily.

"I just did what I thought was right," Lelieveld said in an interview with The Associated Press. "I want everybody to have enough food but … it should also be safe."

Lelieveld began his career as a food researcher at Unilever at a time when mechanisms for manufacturing safe food products were, to him, "illogical," he said.

Food was often sterilized or chemically preserved after production, and equipment needed to be shut off once or twice each day to be cleaned, which was both difficult and time consuming. The processed food also required heavy use of preservatives, salt, sugar and acids to reduce the risk of contamination, which detracted from flavor and nutrition.

"I realized very soon that they did things in the wrong way, in my view," Lelieveld said. "From the beginning, I've been working on … convincing people that you should do it in a different way."

Lelieveld worked with colleagues to develop hygienic production methods and equipment, making food manufacturing more efficient and less reliant on chemicals.

Having scaled the processes at Unilever and shown that they worked, Lelieveld said the company gave him permission to publish the research for dissemination and use globally.

"My philosophy was: You should not compete on food safety," Lelieveld said. "Spreading the technology, the hygienic technology, was very important."

Scientists are working to understand how magnetic currents from the sun spread beneath Earth's crust when the northern lights dance across the sky. Their goal is to tame its "dark twin" and prevent damage to our power grid.

The activity on the sun is at its strongest right now. Periods of such intense activity occur about every 11 years and follow a well-known cycle.

But it's not the colors in the sky that captivate the scientists. While the northern lights splash their colorful displays across the sky, scientists are studying its dark twin: geomagnetic storms.

The magnetic storms that come from the sun induce strong voltage fluctuations, "shaking" their way underground and outward. The induced currents can cause trouble for some transformer stations, but not all, just a few. Some stations are located in more sensitive locations than others. Why is that?

This is one of the questions that researchers are seeking answers to. To that end, they are studying how magnetic storms induce electrical currents in the ground.

The magma reservoir of the largest volcanic eruption of the Holocene is refilling. This Kobe University insight on the Kikai caldera in Japan allows us to understand giant caldera volcanoes like Yellowstone or Toba more generally and gets us closer to predicting their behavior, too.

Some volcanoes erupt so violently, ejecting more magma than could cover all of Central Park 12 km deep, that all that's left is just a wide and rather shallow crater, a so-called "caldera." Examples of such supervolcanoes are the Yellowstone caldera, the Toba caldera and the mostly underwater Kikai caldera in Japan, which last erupted 7,300 years ago in what was the largest volcano eruption in the current geological epoch, the Holocene.

It is known that these volcanoes can and do reerupt but very little is known about the processes that lead up to an eruption and are therefore ill-equipped to make predictions.

"We must understand how such large quantities of magma can accumulate to understand how giant caldera eruptions occur," says Kobe University geophysicist Seama Nobukazu.

Two eyes on the Black Eye Galaxy!

Data from Hubble and NASAWebb combine in this new image of the Black Eye Galaxy, also known as Messier 64.

Astronomers used Hubble and Webb to study this galaxy to learn more about star formation in nearby galaxies: go.nasa.gov/4bALYih

Dark matter, a type of matter that does not emit, reflect or absorb light, is predicted to account for most of the matter in the universe. As it eludes common experimental techniques for studying ordinary matter, understanding the nature and composition of dark matter has so far proved very challenging. One hypothesis is that it is made up of hypothetical particles known as quantum chromodynamics (QCD) axions. These are theoretical elementary particles that would interact very weakly with ordinary matter and are predicted to be extremely light, highly stable and electrically neutral.

While several large-scale studies have searched for small signals or effects that would indicate the presence of these particles or their interaction with ordinary matter, their existence has not yet been confirmed experimentally. In a paper recently published in Physical Review Letters, researchers at Perimeter Institute, University of North Carolina, Kavli Institute and New York University have introduced a new approach to search for QCD axions using a class of materials that generate electric fields when deformed, called piezoelectric materials.

In a major advance applying insights from quantum physics to the inner workings of biology, a team of WashU researchers has successfully implanted quantum sensors in living cells to measure shifts in magnetism and temperature. The measurements could offer new insights into the efficiency of cellular metabolism in health and disease.

"We were able to accurately measure quantum-level properties within our nanodiamond sensors in living cells," said Shakil Kashem, a graduate student in physics in Arts & Sciences at Washington University in St. Louis and co-lead author of a preprint posted to bioRxiv. The other lead author is Stella Varnum, a recent WashU immunology Ph.D. graduate.

The measurements focused on mitochondria, the energy-producing organelles within cells. "This approach could help us better understand mitochondrial function in health and in diseases linked to mitochondrial dysfunction, such as heart failure, Type 2 diabetes and metabolic diseases."

There's more evidence that water once flowed on Mars with the discovery of an ancient river delta deep below the surface. NASA's Perseverance rover found it more than 35 meters beneath Jezero Crater using ground-penetrating radar. Perseverance was launched in 2020 to search for signs of ancient life on the red planet. Since landing in February 2021, it has been exploring Jezero Crater and collecting rock samples.

The crater, which is approximately 45 kilometers (28 miles) in diameter, lies north of the Martian equator and was formed by an asteroid impact almost 4 billion years ago. NASA chose this spot to explore because numerous geological features suggest that water once flowed here and may have supported ancient life, specifically, a part of the crater called the Margin Unit. This area is packed with carbonates, which on Earth, usually form in stable aqueous environments, such as shallow seas or lakebeds.

The new research is published in the journal Science Advances and is based on data from 78 traverses of the area from September 2023 to February 2024.

Small changes to aircraft flight paths to avoid the atmospheric conditions that create condensation trails—known as contrails—could reduce aviation's global warming impact by nearly half, a new study suggests. The study, led by researchers at the University of Cambridge, suggests that changing cruising altitude by a few thousand feet, either up or down, could prevent contrails from forming. Reducing or avoiding contrail formation in this way would also be faster and cheaper than other climate mitigation measures for the aviation industry, since the practice can be adopted with existing aircraft and fuel.

However, the researchers say that time is of the essence, and that the sooner airlines adopt contrail avoidance policies, the bigger the positive climate impact will be. Their results are reported in the journal Nature Communications.

Slightly larger than Earth, the exoplanet LHS 3844b circles a small red dwarf star called LHS 3884, about 48.5 light-years away. Unlike Earth, it does not experience sunrise or sunset. The planet is tidally locked, so one hemisphere always faces its star while the other remains in permanent darkness. This creates an extreme split: one side is relentlessly heated, while the other plunges toward temperatures where molecular motion nearly stops, a condition known as absolute zero (zero Kelvin).

At first glance, such a world seems completely inhospitable. Yet scientists are beginning to question that assumption.

Daisuke Noto, a postdoctoral researcher in Hugo Ulloa’s Penn GEFLOW Lab at the University of Pennsylvania, has been investigating whether these stark conditions truly rule out life. “Just looking at the extreme temperatures on the day and night sides like 1,000-2,000 Kelvin on the day side and absolute zero on the night side might lead one to conclude these exoplanets are too harsh for life. But,” says Noto, “life might find a way.”

The amount of heat trapped by Earth reached record levels in 2025, with the consequences of such warming feared to last for thousands of years, the UN warned Monday.

The 11 hottest years ever recorded were all between 2015 and 2025, the United Nations' WMO weather and climate agency confirmed in its flagship State of the Global Climate annual report.

Last year was the second or third hottest year on record, at about 1.43 Celsius above the 1850-1900 average, the World Meteorological Organization said.

"The global climate is in a state of emergency. Planet Earth is being pushed beyond its limits. Every key climate indicator is flashing red," said UN Secretary-General Antonio Guterres.

"Humanity has just endured the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to act."

For the first time, the WMO climate report includes the planet's energy imbalance: the rate at which energy enters and leaves the Earth system.