Dark matter is an enigmatic form of matter not expected to emit light, yet it is essential to understanding how the rich tapestry of stars and galaxies we see in the night sky evolved. As a fundamental building block of the universe, a key question for astronomers is whether dark matter is smooth or clumpy, as this could reveal what it is made of. Since dark matter cannot be observed directly, its properties can only be determined by observing the gravitational lensing effect, whereby the light from a more distant object is distorted and deflected by the gravity of the dark object.

"Hunting for dark objects that do not seem to emit any light is clearly challenging," said Devon Powell at the Max Planck Institute for Astrophysics and lead author of the study. "Since we can't see them directly, we instead use very distant galaxies as a backlight to look for their gravitational imprints."

Europe must quickly get its own reusable rocket launcher to catch up to billionaire Elon Musk's dominant SpaceX, European Space Agency director Josef Aschbacher told AFP in an interview.

While the US company has an overwhelming lead in the booming space launch industry, a series of setbacks, including Russia's withdrawal of its rockets, left Europe without an independent way to blast its missions into space.

That year-long hiatus ended with the first launch of Europe's much-delayed Ariane 6 rocket in July 2024. But the system is not reusable, unlike SpaceX's Falcon 9 workhorse.

"We have to really catch up and make sure that we come to the market with a reusable launcher relatively fast," Aschbacher said at AFP's headquarters in Paris.

"We are on the right path" to getting this done, he added.

'Paradigm shift'
The ESA has already announced a shortlist of five European aerospace companies bidding to build the continent's first reusable rocket launch system.

That number will be narrowed down to two—or even one—at the agency's ministerial council in the German city of Bremen next month, Aschbacher said.

"Ariane 6 is an excellent rocket—it's very precise," Aschbacher said. "We have now had three launches," with two more expected before the year's end, he added.

Despite finally getting Ariane 6 and the new, smaller Vega C launcher off the ground, the ESA has decided on a "paradigm shift," Aschbacher said.

Marking a defining moment in the “historic shift” away from fossil fuels, renewable energy surpassed coal to become the world’s largest source of electricity in the first half of 2025.

The latest report from Ember shows that solar and wind power grew faster than global electricity demand, with solar alone covering 83 percent of the increase and shattering records worldwide. Amidst this global rise, output from renewables overtook coal for the first time on record for the first six months of this year. 

“We are seeing the first signs of a crucial turning point,” Małgorzata Wiatros-Motyka, Senior Electricity Analyst at Ember, said in a statement. “Solar and wind are now growing fast enough to meet the world’s growing appetite for electricity. This marks the beginning of a shift where clean power is keeping pace with demand growth.”

Solar power is growing faster than ever, with a record 31 percent increase in the first half of 2025. China accounted for 55 percent of this growth, followed by the US (14 percent), the EU (12 percent), India (5.6 percent), and Brazil (3.2 percent), while the rest of the world contributed just 9 percent. 

Nevertheless, several countries set new records in terms of solar power. Among the top 20 solar producers, seven nations – including Hungary, Greece, the Netherlands, Pakistan, Spain, Australia, and Germany – generated at least 20 percent of their electricity from solar in the first six months of 2025.

Fungi are best known for returning dead, organic matter to the Earth, but materials scientists are exploring whether they could someday help our bodies repair, in the form of special hydrogels.

To play a role in biomedical settings, a hydrogel needs a multilayered structure like our own skin, cartilage and muscles. While some engineers are working on synthetic versions that mimic biology, University of Utah scientists have found a hydrogel that literally has a life of its own.

Marquandomyces marquandii is a common species of soil mold, and a promising candidate for the job. This fungus has had a bit of an identity crisis, being misclassified as Paecilomyces marquandii until it was reassigned to its own genus in 2020. Soon, it may be able to add the role of 'bio-integrated hydrogel' to its resume.

Bio-integrated hydrogels are created from organisms that we know form crosslinked, intricate network structures that may be capable of standing in for our own soft tissues.

"Hydrogels are regarded as a promising alternative for applications in tissue regeneration and engineering, cell culture scaffolds, cell bioreactors, and wearable devices, owing to their ability to closely mimic the viscoelastic properties of soft tissues," writes lead author Atul Agrawal, an engineer at the University of Utah, and his collaborators.

Sometimes the best families are the ones you make for yourself—this elephant has formed a herd of her own with a group of buffalo who have learned to understand her. 🐘

The brain seems to “rescue” weak memories when they are tied to a significant or surprising experience. This new understanding of how emotion shapes recall could lead to better memory treatments and smarter learning strategies.

Why Some Memories Stick While Others Fade
Some memories come rushing back with vivid clarity, as if they happened only moments ago. Others feel distant and incomplete, like faint outlines on a page, while some remain completely inaccessible, no matter how hard we try to remember. Why does the brain preserve certain experiences so firmly while allowing others to fade away?

Researchers at Boston University may have uncovered an explanation. Their new study suggests that ordinary memories become more durable when they are linked to a meaningful or emotionally charged event—something unexpected, rewarding, or intense. For instance, if you suddenly realize your Powerball numbers have won, you are likely to recall the mundane details of what you were doing just before that moment. The findings, published in Science Advances, could pave the way for new methods to help people with memory impairments and even improve how students retain challenging information.

Stabilizing Fragile Memories Through Emotion
“Memory isn’t just a passive recording device: Our brains decide what matters, and emotional events can reach back in time to stabilize fragile memories,” says Robert M.G. Reinhart, a BU College of Arts & Sciences associate professor of psychological and brain sciences. “Developing strategies to strengthen useful memories, or weaken harmful ones, is a longstanding goal in cognitive neuroscience. Our study suggests that emotional salience could be harnessed in precise ways to achieve those goals.”

In their paper, Reinhart and his team illustrate this idea with a scene from Yellowstone National Park: a hiker unexpectedly encountering a herd of bison. According to the researchers, the awe of that experience can help preserve not just the extraordinary sight itself but also the smaller, seemingly insignificant details surrounding it—like noticing a rock on the trail or catching a glimpse of an animal in the brush.

“The question is, What are the mechanisms for that?” says Reinhart, who’s also a College of Engineering associate professor of biomedical engineering and a faculty member at the BU Center for Systems Neuroscience. “That’s what we tried to uncover, how the brain selectively strengthens those fragile memories.”

Betelgeuse, the brilliant red star marking Orion's shoulder, has long been suspected of harbouring a secret. I have to confess, Betelgeuse holds a special place in my heart as the first star I ever looked at through a telescope as a child, so learning that astronomers theorised this massive supergiant wasn't alone made it even more intriguing. Proving it, however, required catching a fleeting alignment and deploying some of our most powerful space telescopes in a race against time. Now, researchers from Carnegie Mellon University have finally confirmed what many suspected, Betelgeuse does indeed have a companion star, though not quite the type anyone expected.

The challenge of detecting anything near Betelgeuse cannot be overstated. The star is roughly 700 times larger than our Sun and thousands of times brighter, making it extraordinarily difficult to spot nearby objects. It's rather like trying to photograph a firefly hovering next to a car headlight, perhaps worse! The brightness difference between Betelgeuse and its tiny companion is, as Anna O'Grady, a McWilliams Postdoctoral Fellow at Carnegie Mellon, put it, "absolutely insane."

The breakthrough came during a critical observational window around 6th December, when the companion, affectionately nicknamed "Betelbuddy," reached its maximum separation from the supergiant before disappearing behind it for another two years. The timing demanded swift action. O'Grady and her team secured Director's Discretionary Time on both NASA's Chandra X-ray Observatory and the Hubble Space Telescope, reserved time typically granted only for the most exceptional research opportunities. Having two such proposals accepted simultaneously speaks to the significance of the discovery.

Using Chandra's X-ray observations, the deepest ever taken of Betelgeuse, O'Grady's team searched for evidence of accretion, the telltale signature of compact objects like neutron stars or white dwarfs pulling material from their surroundings. They found nothing. No accretion signature appeared in the data, ruling out these possibilities. Instead, the findings published in The Astrophysical Journal point to something more ordinary yet equally fascinating, a young stellar object roughly the size of our Sun.

Glaciers appear to be resisting the effects of climate change by cooling the air that comes into contact with their icy surfaces. But this natural defense may not last much longer. Researchers from the Pellicciotti group at the Institute of Science and Technology Austria (ISTA) have assembled and reanalyzed an extensive global dataset of glacier observations, offering new insight into this temporary phenomenon.

According to their study, published in Nature Climate Change, glaciers are expected to reach the height of their self-cooling ability within the next decade. After that point, near-surface temperatures are projected to climb more rapidly, leading to faster melting and retreat.

Postdoctoral researcher Thomas Shaw vividly recalls a summer day in August 2022 that marked one of his key field experiences. Working under Francesca Pellicciotti at ISTA, Shaw stood atop Switzerland’s Glacier de Corbassière, 2,600 meters above sea level, gathering crucial data about the glacier’s condition. The weather was deceptively mild, with clear skies and a temperature of 17 degrees Celsius, unusual for someone standing on a glacier.

So, are glaciers “keeping their cool” a little too well? While average global temperatures continue to rise, glacier surfaces appear to warm more slowly. In the Himalayas, some of the world’s largest glaciers even send frigid air cascading down their slopes, forming cold winds that help protect their ecosystems. Yet scientists caution that this self-cooling process does not signal long-term resilience. Instead, it may be a fleeting response to a warming world.

A new study led by Shaw demonstrates that this reaction of glaciers is likely to reach its peak in the 2030s. “The more the climate warms, the more it will trigger the glaciers to cool their own microclimate and local environments down-valley,” says Shaw. “But this effect will not last long, and a trend shift will ensue before the middle of the century.” From then on, the glaciers’ melting and fragmentation due to human-caused climate change will intensify, and their near-surface temperatures will rise more rapidly, hastening their decline.

For roughly one in every hundred people, even tiny amounts of gluten can trigger severe symptoms and pose serious health risks.

While a domino effect of immunological reactions can be traced back to their genetic roots, multiple contributing factors make it hard to map the precise chain of events that causes celiac disease.

Using transgenic mice, an international team led by scientists from McMaster University in Canada has pinpointed a crucial role played by the gut's lining cells, a major stepping stone that could lead to new therapies.

Check out the new trailer for esa's proposed Ramses mission! 🍿📽️

Ramses would escort the cruise-ship-sized asteroid Apophis through its safe but exceptionally rare flyby of Earth in 2029: esa.int/ESA_Multimedia…

During the Cretaceous period, Earth experienced intense volcanic eruptions, widespread depletion of oxygen in the oceans, and multiple mass extinction events. Fossils from this time have been preserved and still provide scientists with valuable insights into what the climate may have been like in different parts of the world.

A group of researchers in China has now analyzed a remarkable set of these fossils: dinosaur eggs discovered at the Qinglongshan site in the Yunyang Basin in central China. For the first time, scientists successfully applied carbonate uranium-lead (U-Pb) dating to determine the age of dinosaur eggs. Their findings were recently published in Frontiers in Earth Science.

“We show that these dinosaur eggs were deposited roughly 85 million years ago, in the Late Cretaceous period,” said corresponding author Dr Bi Zhao, a researcher at the Hubei Institute of Geosciences. “We provide the first robust chronological constraints for these fossils, resolving long-standing uncertainties about their age.”

It's official: we no longer live on a planet with temperatures that can sustain warm-water coral reefs.

This is the first of many fragile Earth systems set to topple as human activities continue to stoke our planet's fever, the 2025 Global Tipping Points Report warns.

Mass reef dieback occurs at an estimated 1.2 °C warming above preindustrial averages, a point the report – involving 160 scientists across 23 countries – confirms we're well beyond.

"I recognize that engaging with tipping points and talking about these risks is emotionally challenging," University of Oslo sociologist Manjana Milkoreit, who contributed to the report, told ScienceAlert. "Maybe the most important but also most difficult thing anybody can do is not to turn away and ignore this problem."

Earth's most vibrant underwater gardens, from the Great Barrier Reef in Australia to Florida's Sombrero Reef, are being annihilated by human-caused global warming. Four global coral bleaching events have now been recorded, with two of these occurring in the last decade. In this time, the Great Barrier Reef alone bleached in 2016, 2017, 2020, 2022, 2024, and 2025.

"The world has just spent much of the last two years at 1.5 °C warming, and the resulting marine heatwaves have caused unprecedented bleaching of 80 percent of the world's reefs," University of Exeter earth system scientist Tim Lenton told ScienceAlert.

These repeat mass bleaching events are now occurring too close together for reefs to recover, triggering the mass death of corals we're now witnessing and threatening the myriad of creatures that call these once-thriving ecosystems home.

"Half-a-billion people depend on these reefs for their livelihoods, including fishing and coastal protection, and the ecosystem services the reefs provide are valued at over US$2 trillion per year," explained Lenton.

"Reefs can bounce back, but only if we manage to cool things back down again."

In honor of National Fossil Day, we're highlighting this mouse deer fossil found in the Abocador de Can Mata, a garbage dump in Spain that has been the source of more than 70,000 fossils from the Miocene era—about 11.2 million to 12.5 million years ago—over the last two decades.

Researchers at Science Tokyo have identified two separate stem cell lineages responsible for forming tooth roots and the alveolar bone that anchors teeth in the jaw.

By using genetically modified mice and lineage-tracing methods, the team uncovered how specific signaling pathways direct stem cells to specialize during tooth development. Their findings provide valuable insight that could help advance the field of regenerative dentistry in the future.

The challenge of true tooth regeneration
The ability to regrow lost teeth and their surrounding bone structures remains one of the most sought-after goals in dental science. For many years, tooth replacement has relied on artificial substitutes such as dental implants and dentures. Although these solutions can effectively restore function and appearance, they cannot fully replicate the natural feel, biological integration, or structural complexity of real teeth.

This limitation has motivated researchers to explore how natural tooth formation occurs, in hopes of developing regenerative treatments that could restore lost teeth more completely.

However, tooth and bone formation is an extraordinarily complex process. It depends on the coordinated activity of multiple tissues, including the enamel organ, dental pulp, and jawbone cells. These components must communicate through finely tuned signaling networks to control the formation of the tooth crown, root, and the alveolar bone that supports the tooth. Despite decades of study, many aspects of these interactions remain poorly understood.

How does your brain recognize when it’s time to take a breath, when your blood pressure has fallen, or when your body is fighting an infection? The key lies in interoception, a little-known process through which the nervous system constantly monitors and interprets internal signals to keep essential body functions stable.

Researchers from Scripps Research and the Allen Institute have been awarded the National Institutes of Health (NIH) Director’s Transformative Research Award to develop the first comprehensive map, or atlas, of this internal sensory network.

The project will be led by Nobel Prize–winning neuroscientist Ardem Patapoutian, in collaboration with Li Ye, the N. Paul Whittier Chair in Chemistry and Chemical Biology at Scripps Research, and Bosiljka Tasic, Director of Molecular Genetics at the Allen Institute. Xin Jin, Associate Professor at Scripps Research, will serve as co-investigator and head the genomic and cell-type identification portion of the project. The initiative is supported by $14.2 million in NIH funding over the next five years.

“My team is honored that the NIH is supporting the kind of collaborative science needed to study such a complex system,” says Patapoutian, the Presidential Endowed Chair in Neurobiology at Scripps Research.

Decoding the Signals Within
Patapoutian, who shared the 2021 Nobel Prize in Physiology or Medicine for discovering cellular sensors of touch, will use the NIH award with his team to decode interoception.

“We hope our results will help other scientists ask new questions about how internal organs and the nervous system stay in sync,” adds Ye. Like Patapoutian, he’s also a Howard Hughes Medical Institute Investigator.

NASA astronaut Don Pettit has helped YouTuber Steve Mould with the final step in his "weird chain theory": testing the idea in space.

In 2013, YouTuber and science communicator Steve Mould brought the "chain fountain", an unsolved problem in physics, to the attention of the wider public. The effect, sometimes referred to as the "Mould effect" for his work on it, is strange to see. Simply put, place a long chain in a container, pull one end out, and let it fall to the floor. Now watch as the whole chain seems to jump up out of the glass, before falling towards the floor: Watch video

The effect, though independently found by Mould, was known about before, even if it was unexplained. Since the effect was popularized by Mould, he, Mehdi Sadaghdar of YouTube channel ElectroBOOM, and several academic studies have attempted to explain it. Mould has also set the record for the biggest chain fountain.

SpaceX closed out a dramatic chapter in the development of its super-heavy-lift Starship launch system with a successful flight test that mostly followed the noscript for the previous flight test.

The 11th test flight began with the ascent of Starship’s Super Heavy booster from SpaceX’s Starbase launch pad in South Texas at 6:23 p.m. CT Oct. 13 (11:23 p.m. UTC). It was that particular pad’s last liftoff. An upgraded Pad 2 is being prepared to accommodate a more powerful Starship Version 3, with the first launch expected next year.

Starship V3 will feature an upgraded version of SpaceX’s methane-fueled Raptor engines and larger propellant tanks that are capable of in-orbit refueling.

The Super Heavy booster and its second stage, known as Ship, are being designed for missions in Earth orbit and beyond — and V3 is the version that’s meant to get SpaceX to that level.

NASA is counting on SpaceX to provide a modified version of Starship for landing astronauts on the moon by as early as 2027. SpaceX founder Elon Musk is counting on Starship to carry robots and humans to the moon and Mars, in accordance with his vision of making humanity a multiplanet species.

Standing a little more than 400 feet tall (122 metres), Starship is considered the world’s most powerful rocket, with liftoff thrust of 16.7 million pounds (7.5 million kg). That’s more than twice the oomph achieved by the Saturn V rocket during the Apollo era’s heyday.
Watch launch video

A strange new phase of ice has been discovered during experiments with the world's largest X-ray laser. Meet ice XXI, a bizarre phase that forms at room temperature, under extreme pressure.

The solidified water we're most familiar with here on Earth is technically known as ice I, but it's just the tip of the iceberg – for instance, aliens on Neptune could be dropping ice XVIII in their drinks. Exposing plain old H2O to different temperature and pressure conditions could result in more than 20 different phases of the stuff, in fact.

Ice XXI is the latest to join the ranks. It has a tetragonal crystal structure with fairly large repeating units consisting of 152 water molecules, which makes it distinct from all other known phases of ice.

Don't expect to whip up a few fancy cubes of ice XXI in your freezer at home, though. Or any kind of freezer for that matter.

The researchers used a diamond anvil cell at the European XFEL facility in Germany to squeeze water to pressures of up to 2 gigapascals (about 20,000 times the air pressure at sea level) within 10 milliseconds.

They then released the pressure relatively slowly – over a leisurely period of one second – before repeating the process. The whole time, the X-rays captured a million images per second to see how the crystal structure changes.

Human embryo models capable of synthesizing their own blood have been developed, in an advance that could lead to new treatments for blood disorders as well as the production of stem cells for transplants.

The 3D structures, named “hematoids”, are similar to embryos but differ in several important ways. They don’t have the capacity to continue to develop into a fetus – they lack essential tissues and would also require a yolk sac and placenta. However, what the study demonstrates is that they can effectively simulate processes that happen during the early stages of embryo growth.

The hematoids self-assemble from human pluripotent stem cells, which can be nudged down any development pathway to become any type of human tissue. On only the second day of development, the team observed that the hematoids had arranged themselves into the three layers that lay the foundation for the human body plan: the ectoderm, mesoderm, and endoderm.

On the eighth day, some of the hematoid cells were beating – the precursors to a heart.

And after around two weeks of development in the lab, the scientists observed the first tell-tale signs that they’d begun producing blood.

“It was an exciting moment when the blood red colour appeared in the dish – it was visible even to the naked eye,” said co-first author Dr Jitesh Neupane, of the University of Cambridge’s Gurdon Institute, in a statement.

In normal embryogenesis, this stage corresponds to around four or five weeks of development. It’s not possible to observe this directly in a living human because the embryo would have implanted into the uterus wall by then, so these models are our only chance to study these processes in detail.

“Our new model mimics human foetal blood development in the lab. This sheds light on how blood cells naturally form during human embryogenesis, offering potential medical advances to screen drugs, study early blood and immune development, and model blood disorders like leukaemia,” said Neupane.

Co-first author Dr Geraldine Jowett added, “Hematoids capture the second wave of blood development that can give rise to specialised immune cells or adaptive lymphoid cells, like T cells, opening up exciting avenues for their use in modelling healthy and cancerous blood development.”

Academics at the University of Oxford and the University of Pennsylvania have conducted the most comprehensive review of evidence on the effectiveness on carbon offsetting to date and concluded the practice is ineffective and riddled with "intractable" problems. The review is published in the Annual Review of Environment and Resources.

Carbon offsets are projects that generate credits meant to represent the reduction, avoidance, or removal of greenhouse gas (GHG) emissions from the atmosphere. The first carbon offset was generated in 1989. The authors call for the phasing out of most credits except those generated by permanent carbon dioxide removal.

"We must stop expecting carbon offsetting to work at scale. We have assessed 25 years of evidence and almost everything up until this point has failed," says co-author Dr. Stephen Lezak, researcher at the Smith School of Enterprise and the Environment. "The present market failures are not due to a few bad apples but rather to systematic, deep-seated problems, which will not be resolved by incremental changes."

"We hope our findings provide a moment of clarity ahead of COP30: These junk offsets—the ones not backed by permanent carbon removal and storage—are a dangerous distraction from the real solution to climate change, which is rapid and sustained emission reductions," says lead author Dr. Joseph Romm, Senior Research Fellow at the Penn Center for Science, Sustainability and the Media.

The most severe issues uncovered by the research are nonadditionality (generating credits without reducing emissions), impermanence, leakage, double counting, "perverse incentives," and the "gameability" of crediting systems, where bad actors have been able to routinely circumvent even well-designed rules. Far from solving these problems, Article 6 of the Paris Agreement, which was finalized at COP29, simply restated "long-ignored tenets of carbon market development, with the specious expectation that this time the outcomes might differ significantly," the authors say.

"Despite efforts to implement safeguards, carbon offset projects continue to face documented cases of weak accountability, risking the perpetuation of neocolonial patterns of appropriation. While nature-based projects can deliver local benefits, these should be financed through mechanisms other than carbon credits, such as contribution claims where projects are financed while still ensuring that purchasing entities are responsible for reducing their own emissions," says co-author Amna Alshamsi, a doctoral researcher at the University of Sussex's School of Global Studies.

Previous research has shown how offset programs routinely overestimate their climate impact, in many cases by as much as a factor of 10 or more.