A 7,000-year-old village may have practiced a haunting skull ritual that left bodies behindApollo astronauts trying to rest on the way to the Moon kept noticing the same thing in the dark. With the cabin lights down and their eyes adjusted, they saw brief flashes and streaks of light, dots and lines that no one else could see and that were not there in any ordinary sense. The cause, worked out over the missions that followed, was cosmic rays from deep space passing through the visual system. The broad cause is now well supported, even if the exact biophysics of how a passing particle turns into a flash of light is still not fully pinned down.
The flashes are an example of a phosphene, a sensation of light produced by something other than light entering the eye.
In this case, the something was radiation.
The reports began on Apollo 11. After a period of dark adaptation, with eyes open or closed, crew members saw flashes they described as pinpoints, thin streaks, or small clouds of light. They were almost always colourless. They came at a rate of roughly one-half to two a minute, often enough to be a distraction when someone was trying to sleep.
This was not confined to one crew or one flight. Flashes were reported across the Apollo missions, and later by astronauts on Skylab, on Mir, and on the International Space Station. The phenomenon even had a kind of forecast. As early as 1952, the biophysicist Cornelius Tobias had suggested that people exposed to cosmic radiation in space might see exactly this sort of thing, and the team that investigated the Apollo reports traced them back to that idea.
Suspecting a cause and demonstrating it are different tasks. To test whether the flashes really were caused by particles passing through the head, the Apollo 16 and 17 crews carried a device called the Apollo Light Flash Moving Emulsion Detector, worn on the head during the coast to and from the Moon. It used stacked photographic emulsion to record the tracks of charged particles, so that the path of a particle could be matched against the moment an astronaut reported a flash.
The numbers were small but telling. The detector was worn for about an hour on each of the last two Apollo missions. On Apollo 17, seventeen flashes were reported during the session, and two of them were matched to heavy cosmic-ray nuclei passing through an eye. Combined with the geometry of the eye and statistical modelling, that was enough for the investigators to attribute the flashes to cosmic rays. Ground experiments pointed the same way: when volunteers had their dark-adapted eyes exposed to beams of heavy ions, they saw comparable flashes.
The confirmed part is that cosmic rays cause the flashes. The unconfirmed part is the step in between, the biophysics of how a single fast particle produces a perceived point of light. Several mechanisms have been proposed, and more than one may contribute.
The leading idea is that the particle ionises tissue directly in the retina, stimulating the light-sensing cells or the neurons behind them as it passes through. This fits the ground experiments, where heavy ions produced flashes at intensities too low for any light to have been generated. A second idea is Cherenkov radiation: a particle moving through the clear jelly of the eye faster than light moves through that medium emits a faint glow, real photons generated inside the eye itself. The trouble is that Cherenkov light should look bluish and diffuse, and most astronauts described sharp white dots and streaks, which do not match. A third possibility is that some flashes come from particles striking the optic nerve or the visual centres of the brain, bypassing the eye altogether.
Decades on, reviews of the phenomenon still describe the specific mechanism as undefined, and note that the effects on the different parts of the visual system have not been fully separated.
The cause is well established; the wiring is not.
On Earth’s surface, we are mostly shielded from this by the atmosphere and the magnetic field. In low Earth orbit the shielding is reduced but not gone, which is why astronauts on stations such as Mir and the ISS have also reported the effect. The Apollo crews saw the flashes more strongly still because they left that protection behind, travelling beyond the magnetosphere. The flashes were, in effect, the radiation environment of deep space made briefly visible inside a human head.
That is why they are treated as more than a curiosity. They are a perceptible sign that high-energy particles are passing through the body, the brain included, and the same radiation is a serious concern for long missions beyond Earth. On the International Space Station, experiments have used the visual system as a way to study how cosmic radiation affects the central nervous system. For a crew bound for Mars, who would spend months outside the magnetosphere, the dose to the brain over that time is one of the open problems of the trip.
The people who travel back to lunar distance under Artemis and later missions will almost certainly see the flashes again. They will also carry better instruments and a sharper reason to use them. Pinning down how the flashes are produced would be a small result. Understanding what months of that radiation does to the brain behind the eye is the one that matters.
The post Apollo astronauts trying to sleep on the way to the Moon kept seeing flashes and streaks in the dark, and the cause turned out to be cosmic rays from deep space passing straight through their eyes. appeared first on Space Daily.
The Apollo astronauts who tracked Moon dust back into their cabin kept filing the same odd report. Fresh lunar dust, they said, smelled like spent gunpowder. The impression was immediate, and it was reported by multiple crews. Yet the smell never survived the trip home. By the time the samples were opened in laboratories on Earth, they no longer smelled like gunpowder, and more than fifty years later there is still no settled account of what the astronauts were smelling up there.
The puzzle is real, but it is narrower than it sounds. A good deal is known about why lunar dust is chemically strange. What is missing is the specific link between that chemistry and the smell.
The descriptions are unusually consistent, and unusually specific. Harrison Schmitt, the geologist on Apollo 17 and the only trained scientist to walk on the Moon, said the instant impression was of spent gunpowder, not something metallic or acrid. He even noted the timing: about seven minutes passed between the start of repressurising the lander and his first remark about the smell.
Gene Cernan, his crewmate, reached for the same comparison. Buzz Aldrin, on Apollo 11, described it a little differently, closer to burnt charcoal, or wet ashes from a fireplace. John Young, on Apollo 16, went further than smelling it and reported that it did not taste half bad.
One detail matters for what follows. The astronauts were careful to say burnt gunpowder, the smell after firing, not the smell of the powder itself. The two are not the same.
The most useful clue is the disappearance. There are hundreds of kilograms of lunar material in the curation lab at NASA’s Johnson Space Center in Houston, and it does not smell of gunpowder. Gary Lofgren, a NASA geologist who has handled the dusty rocks directly, sniffed them and reported plainly that they do not smell like gunpowder.
The astronauts were not imagining it. The accepted reading is that the dust was, in the word researchers use, pacified. Whatever produced the smell was a reaction that happened once, when the dust first met the air inside the cabin, and was finished long before the samples reached Earth. A smell that depends on a one-time reaction cannot be bottled and shipped.
The reason fresh lunar dust reacts at all comes down to where it has been. The surface of the Moon has no air and no weather. For billions of years its dust has been broken down by micrometeorite impacts and bombarded by the solar wind, producing extremely fine grains with fresh, raw surfaces and, in many of them, tiny specks of metallic iron embedded in glassy coatings. Surfaces like that are chemically hungry. They carry what chemists call dangling bonds, unsatisfied bonds left exposed because the dust has never had air to react with.
Bring that dust into a cabin filled with oxygen and a little moisture, and those surfaces oxidise quickly. The reaction is a slow form of burning, too gradual for smoke or flame, and it is the most popular candidate for the smell. Schmitt himself guessed as much at the time, suspecting his nose was responding to unsatisfied bonds of the kind found in both fresh dust and just-fired gunpowder.
This is a hypothesis with broad support, not a proven result. No instrument sampled the cabin air, so the actual molecules responsible were never identified. The gunpowder comparison is an association in the human nose, not a statement about shared chemistry. Other ideas have been raised over the years, including sulphur-bearing minerals in the dust and volatiles implanted by the solar wind. None has been confirmed, because the evidence that would settle it evaporated, in effect, during the flight home.
The smell is a footnote.
The reactivity behind it is not.
The same properties that may have produced the odour, the abrasive shape of the grains and their reactive surfaces, make lunar dust a serious problem for people and equipment. It clings to everything, works its way through seals, and is fine enough to be inhaled deep into the lungs. Dust that got into the Apollo cabins left crews with eye, nose and throat irritation, an effect NASA came to call lunar hay fever, with Schmitt’s reaction the best documented. Reviews of lunar dust as a hazard link its reactive surfaces and iron content to the way it interacts with human tissue.
That has turned an Apollo-era anecdote into a present-day engineering requirement. For NASA’s Artemis programme, and for the commercial missions intending to operate on the surface for more than a few days, dust handling is now a standing line item: cabin filtration, suit design, airlock procedures, and medical monitoring all have to account for a material whose chemistry was barely understood when the first samples came home.
The next people to bring Moon dust into a sealed cabin will arrive with instruments the Apollo crews did not have, and with reason to use them. Whether anyone finally captures the cabin chemistry, and identifies what the astronauts were smelling, is one of the smaller questions Artemis could answer. The larger one, how to live and work in the stuff without it harming lungs and hardware, is the reason the answer would be worth having.
The post The Apollo astronauts who carried lunar dust back into the cabin kept making the same strange report — fresh Moon dust smelled like spent gunpowder — yet the smell never survived the trip home, and more than fifty years later no one has fully explained what they were breathing in up there. appeared first on Space Daily.
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Across the stories today, a common thread emerges: the tension between revelation and rescue—moments when new understanding drives urgent action, even as time runs short.
Beneath our feet, scientists have mapped fungal networks stretching nearly a billion times the distance to the sun, revealing an underground web of connection that dwarfs anything visible above ground. It’s a reminder that the natural world operates on scales both microscopic and cosmic, with systems we’re only beginning to understand. This same spirit of discovery appears in unexpected places—from the ghostly earthshine illuminating the moon’s dark side to the arrival of a tropical western reef heron in Wales, likely pushed northward by changing climate patterns.
The day’s coverage points to growing momentum around what happens when scientific insight meets conservation urgency. In Mozambique, nine female white rhinos completed their journey to establish the country’s first viable breeding population in generations—a decade-long effort finally bearing fruit. Meanwhile, Australian researchers at PlantBank work like modern-day ark builders, preserving seeds before species disappear forever. On Palau’s Ulong Island, the simple act of removing invasive rats triggered rapid ecological recovery across both land and marine environments, challenging assumptions about how long nature needs to heal.
Yet revelations don’t always bring good news. China’s power sector emissions fell for the first time in a decade, a historic milestone, but a coal surge threatens to reverse that progress. Trees may store less carbon than scientists hoped, according to new research examining growth patterns across 137 forest sites. And Antarctica is missing sea ice equivalent to France’s size, with winter temperatures soaring 20°C above normal—numbers that feel abstract until you consider their global implications.
It’s a reminder that progress and pressure often arrive together. Lake Mead approaches the critical threshold that will slash Hoover Dam’s electricity production, while thousands of marine animals die in fishing nets annually through bycatch. For the 58-year-old Kenyan fisherman Mohamed Mwazigona, returning to shore with just 2 kilograms of fish, these aren’t statistics—they’re the reality of dwindling catches that threaten coastal livelihoods.
Behind the numbers are real communities adapting in real time. Eight volunteers used ropes and pulleys to rescue a 172-pound loggerhead turtle named Bowser from a Florida pier—the kind of hands-on conservation that makes the difference between survival and loss. In Albania, protesters dubbed the “Flamingo Revolution” emerged after bulldozers illegally destroyed protected wetlands for a luxury resort, showing how environmental destruction can galvanize public resistance.
The stories also reveal how legal frameworks struggle to keep pace with environmental challenges. A federal judge ruled the Trump administration’s cancellation of environmental justice grants illegal, while Australia’s climate chief outlined plans to transform the country from fossil fuel exporter to renewable energy leader. Meanwhile, environmental laws were waived to enable border wall construction through Big Bend National Park, illustrating how political priorities can override conservation concerns.
What emerges is a picture of a planet under pressure, but also of human ingenuity rising to meet unprecedented challenges. As commercial satellites threaten the night sky that has guided humanity for millennia, conservationists celebrate osprey chicks hatching in Wales and sengi pups born in captivity. Progress isn’t linear, and solutions often come from unexpected directions—underground fungal networks, community rescue efforts, and the patient work of seed preservation.
As the week unfolds, all eyes will be on how these parallel stories of discovery and rescue continue to intersect, shaping our understanding of what’s possible when knowledge meets action.
The post China’s Coal Surge Threatens Historic Emissions Drop, Hoover Dam Faces Massive Power Cut as Lake Mead Hits Critical Low — Today’s Environmental Briefing for Sat, Jun 13 2026 first appeared on EnviroLink Network.
London's mayor praised the beavers, who are already having a noticeable impact.The humble bird may help scientists understand how experts learn to see disease.
Scientists have often wondered how the brain can take in new experiences without erasing stored memories. However, a new study in Nature now identifies a circuit-level mechanism that may help answer this question—and it may also offer clues for improving artificial intelligence.
Researchers at NYU Langone Health recorded the activity of hundreds of neurons simultaneously across several brain regions in mice. By tracking how signals move from the hippocampus to the neocortex, where long-term memories are kept, they found that a subset of hippocampal neurons appears to participate in routing information between regions in distinct patterns. These cells participate in both incoming and outgoing signaling, but do so using distinct patterns of activity.
The study focused on a series of interconnected brain regions: CA3, which processes rapidly changing information; CA1, which serves as a central hub; and the retrosplenial cortex, which is important for navigation and spatial memory. About one in four CA1 neurons receives most of the signals from CA3. When these same neurons send signals to the retrosplenial cortex, they fire in a different pattern, creating a separate outgoing channel using the same cells.
Rather than using new neurons, the brain separates these channels by changing how the same neurons fire together. The researchers suggest this arrangement may help reduce interference between new learning and more stable cortical memories.
“Our findings help explain how memory can be both moldable and enduring,” said co-lead author Joaquín Gonzalez, PhD, a postdoctoral fellow in the Department of Psychiatry at NYU Grossman School of Medicine. “By changing how the same cells fire together instead of turning on new cells, the brain can keep information organized and protect older memories.”
The CA1 neurons involved in learning during the day also stay active at night. The researchers found that these cells remain busy during sleep events called sharp-wave ripples, which are bursts of activity the hippocampus uses to replay and strengthen memories from the day.
Since overlapping neurons are recruited during both waking activity and sleep replay, the same circuit elements appear to participate in both learning and consolidation. This theoretically allows the brain to use a single system for both learning and storing memories, without the two processes interfering with each other.
“Our study shows how learning and memory consolidation can coexist in the same network,” said co-lead author Mihály Vöröslakos, MD, PhD. “Our discovery was made possible because for the first time, we were able to record hundreds of individual neurons across all the key regions simultaneously in animals that were moving around naturally.”
The system identified in this research may help explain how memory disorders begin. In Alzheimer’s disease, for example, the hippocampal circuits examined here are some of the earliest to deteriorate. These networks are essential for sorting and organizing new experiences.
“Our discovery of a ‘memory switchboard’ deep in the hippocampus may provide clues as to how memory circuits fail in Alzheimer’s disease,” said co-senior author Zhe S. Chen, PhD, a professor in the Departments of Psychiatry and Neuroscience at NYU Grossman School of Medicine.
Artificial intelligence systems have a hard time holding onto what they’ve already learned when faced with new tasks, a problem researchers call catastrophic forgetting. The human brain appears able to update memories without catastrophic forgetting by altering the use of existing neural circuits. By studying how our brains pull this off, scientists hope to design AI that can keep learning new things without forgetting the old.
“By showing how the mammalian brain can safeguard memories during learning, our research may offer a biological blueprint for designing next-generation AI technology that can update itself continuously without overwriting what it has already acquired,” said co-senior author György Buzsáki, MD, PhD, the Biggs Professor of Neuroscience at NYU Grossman School of Medicine.
The researchers plan to investigate whether similar switchboard-like channels exist in other memory circuits. The authors caution that their findings in mice under controlled conditions do not yet allow conclusions about the human brain.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.
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