The 2026 Nobel Prize in physiology or medicine has been awarded to three scientists – Karl Deisseroth, Peter Hegemann and Georg Nagel – for their work developing a technique to decode the inner workings of the brain.

Every winter, Antarctica roughly doubles in size as sea ice locks into place over the ocean. Typically, Breid Bay in East Antarctica is entirely covered in a frozen crust from July through August. But in August 2024, satellite images revealed a massive hole in the ice, formally known as a polynya, which is a region of open seawater surrounded by sea ice. It's something scientists have never seen before at that time of year. At its largest, the hole reached an area of 89,121 square kilometers, which is only slightly smaller than the entire landmass of Portugal. According to a research team from India led by earth scientist Jeebanjyoti Swain, the hole was the result of a series of extreme weather conditions, including a series of intense atmospheric rivers and marine heatwaves. Swain and team have published their findings in _Geophysical Research Letters._ (a) Polynya event captured by NASA Worldview satellite, (b) Bathymetry of the Breid Bay, (c) Daily sea‐ice concentration showing the evolution of the open‐ocean polynya. The magenta contour denotes the 30 percent sea ice concentration threshold, and the dashed black rectangle highlights the same polynya region (16–31°E, 65–68°S) shown in panel (b) and (c). (Swain et al., _Geophysical Research Letters,_ 2026) "A series of intense atmospheric rivers, commonly known as 'rivers in the sky,' transported large amounts of moisture from lower latitudes into the Antarctic region, accompanied by a persistent southward flow that drove sea‐ice poleward," the authors write. Six atmospheric rivers carrying warm moist air occurred from July 2024 through August. The scientists note these specific atmospheric rivers are among the strongest mid-winter moisture transport events on record. "Together, they produced enhanced downwelling long-wave radiation, atmospheric warming, warm snowfall, and positive heat flux into the ocean, which collectively suppressed sea‐ice growth," the authors explain. "At the same time, strong winds induced Ekman suction, bringing warmer subsurface water toward the surface and contributing to upper‐ocean warming, with sustained marine heatwaves further inhibiting sea‐ice freezing." Ekman suction is a phenomenon that occurs when large volumes of surface water are displaced by the friction of wind blowing across the ocean. In this case, the Ekman suction carried upper circumpolar deep water to the surface, which is relatively warmer and more turbulent than the surface water usually is at that time of year, slowing and preventing freezing. Swain and team predict we will be seeing more of these Antarctic polynyas in the future, as climate change strengthens atmospheric rivers, produces more frequent and persistent heat waves in both air and sea, and heats up the upper layers of the Southern Ocean. "The low sea‐ice conditions and polynya formation may become frequent in regions where sea‐ice has historically remained stable," the team writes. This year, Antarctica reached its third-lowest level of winter sea ice extent on record. All four of the lowest winter sea ice records have occurred within the past four years, with 2023 being the record minimum, and 2024 (the year the massive hole appeared at Breid Bay) in second. In June this year, a large area of the Bellingshausen Sea (on the west side of the Antarctic Peninsula) failed to freeze over, leaving an area of ocean roughly the size of France exposed, which would usually have been covered by sea ice. Sea ice comes and goes throughout the year, and it floats, so it's not directly involved in changes to sea level. But it creates a buffer around the ice shelves and glaciers that do have the potential to accelerate sea level rise. Without a wide skirt of sea ice through the winter, more of Antarctica's ice sheet will be exposed to the increasingly warm ocean water, which is what scientists are really concerned about. Sea ice is also very important to Antarctic ecosystems: food webs that feed much of the world's oceans hinge on the ice's regular return. There's clear evidence that these changes to our global climate are the result of human activities: primarily, burning fossil fuels. This also means we can change the trajectory of these concerning trends. The research has been published in _Geophysical Research Letters_. This article was fact-checked by Fiona MacDonald and edited by Fiona MacDonald. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.

Robots and rovers in deep space sometimes need to make their own decisions

Half of our genome is made of transposons — snips of DNA that can move and copy themselves. But they’re more than parasites or genetic junk.

From urban seagulls to snorkeling penguins.

Voting starts September 22 with a final winner crowned on September 29.

If you’ve felt a complete sense of exhaustion lately, join the club. New research from the Centers for Disease Control and Prevention shows that fatigue is running rampant in the good ol’ U.S. of A. CDC scientists examined nationally representative data of Americans across the country. Nearly three-quarters of people over 18 reported they felt fatigued in the past three months, they found, while over 15% felt fatigued most or all of the time. People with frequent fatigue were also substantially more likely to have other health problems, including depression. “This report provides a unique look at the prevalence and distribution of fatigue symptoms that are not condition-specific in the general U.S. population,” the authors wrote in their paper, published this month by the CDC’s National Center for Health Statistics. ## The fatigued states of America Though everyone feels tired from time to time, fatigue is a state of extreme exhaustion that doesn’t necessarily improve with rest or sleep. It can be the primary sign of a persistent medical issue, as with myalgic encephalomyelitis (also known as chronic fatigue syndrome), or a symptom of acute, self-limiting illnesses like the flu. According to the CDC researchers, studies looking at the prevalence of fatigue have typically focused on smaller groups of people with specific medical conditions, such as cancer. For this study, the researchers wanted to measure fatigue more broadly in the general public. To do so, they turned to data from the 2024 version of the National Health Interview Survey, a long-running survey of Americans’ reported medical conditions, health care use, and other health-related behaviors conducted by the U.S. Census Bureau. The researchers defined fatigue in this study as people saying yes when asked if they had felt “very tired or exhausted.” In 2024, a total of 71.5% of respondents said they were fatigued in the preceding three months. Of these, 54.9% said they had fatigue some days, 10.7% said it was most days, and 5.9% felt it every day. A majority of people with frequent fatigue said they felt it most (34.5%) or all of the day (20.2%). Based on the overall U.S. adult population, that would amount to about 190 million people who have recently experienced at least some fatigue. As often the case with health problems, the risk of fatigue wasn’t evenly distributed in the population. Women were more likely to report frequent fatigue than men (20% compared to 13%), for instance, as were the youngest adults (roughly 19% of people ages 18 to 34 compared to 13% of people over 65). Indigenous populations had the highest rates of frequent fatigue compared to other racial demographics; people in the southern U.S. had the highest regional rates; the poorest Americans had the highest rates compared to other wealth groups; and people in rural areas had higher rates than those living in large and medium-sized cities. ## The burden of fatigue Unfortunately, people with frequent fatigue often face other challenges, the authors note. Nearly 90% reported having trouble in at least one out of nine areas related to healthy functioning, for instance, such as difficulty concentrating, being unable to take care of their basic needs like washing or dressing themselves, or mental health symptoms like depression and anxiety. More than half said they had trouble in three or more of these areas, compared to about 17% of adults without frequent fatigue who said the same. About 29% of frequent fatigue sufferers also reported having limitations participating in social activities, and 36% reported having workplace limitations. The findings are based on people’s self-reported feelings of fatigue, which can be subjective. Also, this study is cross-sectional, meaning it only looked at a snapshot of people’s current health. As such, it’s not possible to tell which factors might be contributing to people’s fatigue, or vice versa. Some people’s fatigue might worsen their pre-existing depression symptoms, for instance, or a separate condition might be responsible for a person’s fatigue and their other issues (the authors cite the example of a person recovering from a stroke). What this study does show is that fatigue is a widespread problem among Americans and that frequent fatigue can be especially disruptive to a person’s life.

“The numbers are just really mind-boggling."

The phrase "water is life" is true – water makes all known life on Earth possible. It's also a key component in lubricating the super-slow movement of Earth's mantle layer, hydrating those rock layers enough for them to ooze and slide past each other. This is important to the tectonic cycle, which in turn helps regulate climate over geological time. That water also allows for important recycling of rocks and volatile compounds through the mantle. "Liquid water is the key component of Earth's habitability," geoscientist Alfred Wilson from the University of Leeds in the UK writes in a commentary accompanying a new study about Earth's interior waters. How did that water get into the mantle? One model suggests asteroids brought the water to Earth, and it stayed hydrated as the planet formed. Or maybe the water came later, hydrating a previously dry mantle. Where exactly that water is currently located within the miles-deep mantle layer of the planet's interior hasn't previously been well understood. The new research suggests the water is likely located near the boundary between the mantle and its liquid outer core, where seismic tests have shown there are mysterious "ultralow velocity zones." The lower mantle extends from about 660 to 2,900 kilometers (373–1,802 miles) beneath the surface. Its most abundant minerals, including bridgmanite and ferropericlase, are thought to be largely dry. Other minerals can hold water at depth, but many either need unusual compositions to remain stable or break down at the high temperatures found in the deepest mantle. So the researchers went looking for another possibility. They used laser-heated diamond anvil cells – devices that squeeze tiny samples between two diamond tips just a paper-thickness-width apart, while lasers blast them with heat – to recreate high temperatures and pressures. Pressure–temperature conditions for the formation of iron oxyhydroxides. (Yuan et al., _Nature Geoscience_ , 2026) Under those conditions, the scientists have identified two previously unknown iron oxyhydroxides (Fe5O12Hx and Fe7O12Hx), that could lock away enormous amounts of water. The experiments show that these phases can exist under deep-mantle conditions, but do not directly demonstrate that they are present inside Earth. "Identifying these iron oxyhydroxides is important because they are seemingly stable, dense phases that capture and retain water across a wide range of lower-mantle conditions," writes Wilson in his commentary. These minerals formed even when water was scarce. In some experiments, the starting material contained less than 0.1 percent water, yet even those trace hydrogen concentrations were enough to stabilize the new phases. That's important because Earth's deep interior isn't like some giant underground ocean. Any water stored there would have to be incorporated into minerals, often under conditions where free water is essentially absent. These new minerals appear unusually well suited to the job. They are both stable at the extreme conditions of the lowermost mantle and substantially denser than surrounding mantle rock. That means that when a primordial molten "basal magma ocean" cooled and crystallized early in Earth's history, these water-bearing minerals could have formed and then sunk toward the core-mantle boundary. frameborder="0″ allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen> This hidden water may not necessarily stay hidden, because as water-bearing material is dragged upward by mantle circulation, decreasing pressure could destabilize the minerals, releasing their water into other mantle phases. Eventually, some of that water could, and probably does, make its way back toward the surface through mantle plumes and volcanism. The discovery also sheds light on a previous mystery. A mineral known as the "H-phase," observed in earlier high-pressure experiments, appears to match one of the newly identified oxyhydroxides. The researchers suggest that hydrogen contamination from trace moisture – rather than an entirely new dry mineral – may have helped produce the puzzling phase in earlier experiments. "Apparently, even very small amounts of hydrogen are sufficient to stabilize these highly hydrated iron compounds," says mineral physicist and crystallographer Leonid Dubrovinsky from the University of Bayreuth. **Related:Colossal 'Anomalies' in Earth's Mantle Aren't What We Thought** There are still big unanswered questions, and the picture is "incomplete" according to Wilson. Exactly how much water these minerals contain needs to be determined, and what happens when they reach the core-mantle boundary remains uncertain. It is also unclear how easily and over what time periods water stored in these deep minerals can ultimately return to the surface. Still, the discovery suggests that Earth's water cycle may extend all the way to the edge of the core, and according to Wilson, these newly identified minerals "represent a breakthrough in the mystery of how the Earth obtained and retained its water." The research is published in _Nature Geoscience_. This article was fact-checked by Rebecca Dyer and edited by Rebecca Dyer. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.

The Indian and Pacific oceans have been climatically linked for centuries, but scientists say that connection is now breaking down in an exceptional way. Ancient climate records suggest volcanoes disrupted the relationship in the past, while today human-caused warming appears to be driving a much more unusual shift.

In a strategic retreat in the fight against climate change, the United Nations has acknowledged that Earth has lost its chance to prevent some of the worst of global warming's harms. So now the world must figure out how to get temperatures below the danger zone and back to safety, officials say.

NASA rovers Curiosity and Perseverance have photographed some pretty strange objects on the surface of Mars. From human-like heads and femur-like bones, to 'mushrooms' and suspiciously geometric structures, these objects are generally ultimately determined to be something Mars has in abundance. Yep, you got it – rocks. In an image snapped by Curiosity in 2023, and newly doing the is-there-life-on-Mars rounds, however, the explanation is a little more unusual. On the far left of an otherwise normal picture of a Martian landscape is a strange dark shadow that looks a little like the silhouette of a jellyfish with tentacles dangling down – or, more appropriately, a Martian Tripod straight out of H.G. Wells' _War of the Worlds_. Obviously, this feature is not as easy to explain away as a rock – but, equally as obviously (or it should be), nor are there alien jellyfish drifting about in the atmosphere of Mars. Instead, the mysterious smudge is likely far more cosmic in origin – a charged particle raining down from space and smacking into the silicon detector of Curiosity's NavCam. A close-up of the glitch. (NASA/JPL-Caltech) In fact, there's an easy way to be fairly confident that whatever it is we're looking at is not actually an ominous "jellyfish" perched on a Martian ridge. Curiosity routinely takes multiple images of a target, and this is a good illustration of why. The eerie jellyfish shot was taken on 20 August 2023 at 22:27:46 UTC. It also took photographs of the exact same scene using the exact same instrument, 13 seconds and 25 seconds earlier. Neither of the two earlier images shows even a hint of a negative-space jellyfish. Two frames taken seconds apart. (NASA/JPL-Caltech) Nor is this the first time a strange, fleeting smudge has appeared in one of Curiosity's images. Cosmic rays are high-energy particles that constantly rain down from space. Here on Earth, we don't generally have to worry about them – our planet's magnetic field deflects many, while those that get through tend to smash into particles in our thick atmosphere, producing showers of secondary particles high overhead. Mars isn't nearly so well defended. It has no global magnetic field, and its atmosphere has just 0.5 percent of the mass of Earth's, leaving Curiosity comparatively exposed to the energetic particles hammering down from space. So it's actually not unusual for cosmic-ray artifacts to show up in Curiosity images. These charged particles routinely strike the detectors of cameras operating beyond Earth's protective magnetic field and atmosphere. When they do, they can leave behind glitches in the resulting images. For Curiosity's photos, these often look like bright white patches, as though someone has hit the camera from afar with a tiny laser pointer, or bright white streaks and staticky speckles. They can take a few different forms. "In the thousands of images we've received from Curiosity, we see ones with bright spots nearly every week," imaging scientist and systems engineer Justin Maki of NASA's Jet Propulsion Laboratory said in 2014. A similar black artifact caused by a cosmic ray. (NASA/JPL-Caltech) But cosmic ray artifacts don't have to be bright white, as they are often described. In a video recorded using Curiosity's Hazcam in 2023, a "small black artifact" is noted as originating from a cosmic ray striking the sensor. These events are brief, usually visible in just a single frame – exactly the sort of behavior seen in Curiosity's mysterious "jellyfish". That doesn't mean we can definitively blame a cosmic ray for this particular apparition. Without analysis from the Curiosity imaging team, other camera or processing artifacts can't be ruled out. **Related:****Mysterious Structure on Mars Looks Uncannily Like an Ancient Egyptian Pyramid** But the images themselves make one thing pretty clear: Whatever produced the jellyfish was almost certainly happening in the camera, not lurking on the surface of Mars. Mars doesn't need jellyfish, or severed heads, or weird pyramids to be interesting. The reason we see those things is interesting enough: We have robots exploring an entire other planet on our behalf – one whose geology throws up some bonkers rocks, and which leaves rovers sitting ducks to be bopped on the head by particles that may have traveled half the cosmos to get there. This article was fact-checked by Michael Irving and edited by Michael Irving. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know.