A surprising stress-related signal may help the brain repair itself after injury. Researchers found that myelin-producing precursor cells rapidly release the stress hormone CRH near damaged brain tissue, helping control how those cells mature and rebuild protective nerve insulation. The same system also influences brain development and the thickness of myelin later in life. The findings could offer new clues about how early-life stress contributes to psychiatric disorders.

A tiny superconducting engine has successfully converted heat near absolute zero into useful work, demonstrating the first cyclic quantum heat engine of its kind. Future versions could operate autonomously inside quantum computers, potentially eliminating huge numbers of costly, noise-producing microwave cables.

Nuclear reactors may go dark, but their fuel continues producing a faint antineutrino “glow” long after shutdown. Researchers have now detected that residual signal for the first time, finding it closely matched predictions of radioactive decay inside the reactor and nearby spent-fuel pools. The breakthrough suggests antineutrino detectors could eventually monitor reactors even when they are offline.

Scientists have discovered that the aging human brain may be far less isolated from the rest of the body than once believed. Stanford researchers found that large numbers of immune cells from the blood begin entering the brain as early as middle age, where they can transform into microglia, the brain’s specialized immune cells. The finding overturns a long-standing assumption that these cells remain largely separate from the body’s immune system throughout life.

Scientists have found that the AMOC may be far more vulnerable to rapid warming than to temperature alone. When warming happens slowly, the ocean can adapt, but at faster rates similar to today’s, the massive Atlantic circulation could reach a tipping point at much lower temperatures.

Simply choosing the stairs could have surprisingly big benefits for your heart and longevity. A large analysis involving more than 480,000 people found that regular stair climbers were 39% less likely to die from cardiovascular disease and 24% less likely to die from any cause than people who rarely took the stairs. They also had lower risks of heart attack, stroke, and heart failure.

Women who used estrogen-only hormone therapy later in life were less likely to develop dementia and showed fewer signs of Alzheimer’s disease in their brains, according to a large study of more than 21,000 participants. Hormone therapy use was linked to 39% lower odds of a dementia diagnosis and 35% lower odds of Alzheimer’s-related brain changes at autopsy, including amyloid plaques and tau tangles. Biomarker tests also suggested less amyloid buildup among hormone therapy users.

A large study of more than 5,500 adults over 50 found a striking combination of risk factors: abdominal obesity paired with vitamin D deficiency was linked to a 123% higher risk of death over six years. Each condition was associated with increased risk on its own, but together they appeared to create a dangerous feedback loop, with belly fat reducing the amount of vitamin D available in the bloodstream while low vitamin D may worsen inflammation and other health problems.

Orange juice may have a much bigger effect on the body than scientists once realized. Drinking it regularly appears to influence genes tied to inflammation, blood pressure, metabolism, and blood sugar control, while studies have also found improvements in cholesterol and blood vessel health. Researchers suspect natural citrus compounds such as hesperidin may be partly responsible. Even the gut microbiome may benefit.

JWST has uncovered surprising clues that Neptune’s strange inner moons may be the wreckage of an ancient cosmic catastrophe. Researchers detected clay-like minerals on Larissa, Galatea, and Neptune’s rings that form in the presence of liquid water—yet the moons themselves show no obvious water ice. The material likely came from deep inside much larger icy moons that were shattered when Triton was captured by Neptune, destroying much of the planet’s original satellite system.

Astronomers have released more than three million new spectra in a sweeping expansion that, for the first time, brings SDSS-V optical observations to the Southern Hemisphere. The data reveal everything from rare stars and glowing nebulae to hundreds of thousands of X-ray sources and supermassive black holes changing over time.

Astronomers using the James Webb Space Telescope have discovered a bizarre object from just a few hundred million years after the Big Bang that looks like an enormous star but shines far too brightly to actually be one. The mysterious red object, dubbed a “black hole star,” may contain a black hole about 100,000 times the mass of the Sun wrapped inside a dense, star-like cocoon of hydrogen roughly the size of our solar system.

Scientists may have uncovered evidence that a mammal ancestor was giving birth to live young 236 million years ago. A fossilized cynodont showed a neonatal growth line and an unusually large birth size that closely match patterns seen in modern mammals. The discovery could push the evolution of live birth back by up to 95 million years. It also raises the possibility that many supposedly “modern” mammalian traits evolved surprisingly early.

A protein inside appetite-controlling brain cells may play an important role in preventing overeating and obesity, particularly when high-fat foods are readily available. Unexpected differences between males and females could also help explain why obesity risk—and responses to weight-loss drugs—can vary.

Why do we keep making the same choices even when better options are available? Researchers found that simply repeating a decision can reshape what we prefer, causing familiar choices to feel better than alternatives. Instead of weighing every option from scratch, the brain often remembers what it chose before and repeats it. That shortcut may help explain many everyday habits and seemingly irrational decisions.

A single human brain cell may be far more powerful than scientists once realized. Researchers found that cortical neurons can perform remarkably complex computations, giving them capabilities more like tiny biological computers than simple on-off switches. This could help explain why the human brain supports abilities such as language, imagination, and mathematics.

Researchers have discovered that a gene linked to congenital heart disease acts like an architect for the heart cell’s DNA. Losing just one copy of TBX5 can cause the genome’s carefully folded 3D structure to unravel, disrupting the genes needed to build a healthy heart. The effects can vary from cell to cell, which may help explain why people with the same mutation develop different heart defects. The same hidden mechanism could also play a role in other birth defects.

NASA’s Perseverance rover caught a striking first from Mars: Earth disappearing behind the tiny moon Phobos. Seen from nearly 195 million miles away, our planet was reduced to a single point of light before briefly vanishing behind Phobos. The rare alignment created an unusual cosmic portrait of Earth as seen from another planet.

Researchers have found a striking new way to potentially eliminate HIV soon after infection using a one-time combination of three therapies. In newborn nonhuman primates treated within three days of exposure, the regimen—standard antiretroviral drugs, broadly neutralizing antibodies, and the experimental antibody leronlimab—completely cleared the virus, even though none of the treatments could do so alone.

Researchers have found strong evidence that original collagen can survive inside dinosaur fossils for tens of millions of years, overturning a long-standing assumption about fossilization. The discovery could unlock hidden molecular clues about dinosaur biology, evolution, and how ancient proteins managed to survive for so long.