Even when Earth was locked in its most extreme deep freeze, the planet’s climate may not have been as silent and still as once believed. New research from ancient Scottish rocks reveals that during Snowball Earth — when ice sheets reached the tropics and the planet resembled a giant snowball from space — climate rhythms similar to today’s seasons, solar cycles, and even El Niño–like patterns were still pulsing beneath the ice.

A new clinical trial suggests that changing when you eat could make a meaningful difference for people living with Crohn’s disease. Researchers found that time-restricted feeding, a form of intermittent fasting that limits meals to an 8-hour daily window, reduced disease activity by 40% and cut abdominal discomfort in half over 12 weeks. Participants also lost weight and showed healthier inflammation and immune markers, even though they did not reduce calories or change what they ate.

Life may have started in sticky, rock-hugging gels rather than inside cells. Researchers suggest these primitive, biofilm-like materials could trap and concentrate molecules, giving early chemistry a protected space to grow more complex. Within these gels, the first hints of metabolism and self-replication may have emerged.

For millions of years, a frozen wanderer drifted between the stars before slipping into our solar system as 3I/ATLAS—only the third known interstellar comet ever spotted. When scientists turned NASA’s Swift Observatory toward it, they caught the first-ever hint of water from such an object, detected through a faint ultraviolet glow of hydroxyl gas. Even more surprising, the comet was blasting out water at a rate of about 40 kilograms per second while still far from the Sun—much farther than where most comets “switch on.”

Swapping just an hour of TV a day for something more active could significantly lower the risk of developing major depression—especially in middle age. A large Dutch study tracking more than 65,000 adults over four years found that replacing 60 minutes of TV with other activities cut depression risk by 11% overall, and by nearly 19% in middle-aged adults. The more time people reallocated—up to two hours—the greater the benefit, with risk dropping as much as 43% in midlife.

A six-week study from the University of Nottingham suggests that pairing fermented kefir with a diverse prebiotic fiber mix may deliver a powerful anti-inflammatory boost. This “synbiotic” combination outperformed omega-3 supplements and fiber alone, leading to the broadest drop in inflammation-related proteins in healthy adults. By feeding beneficial microbes and helping them produce compounds like butyrate, the combo appeared to improve overall immune balance and metabolic health.

Three major reviews commissioned by the World Health Organization find that GLP-1 drugs including tirzepatide (sold as Mounjaro and Zepbound), semaglutide (Ozempic and Wegovy), and liraglutide (Victoza and Saxenda) can lead to substantial weight loss in people with obesity. But while the results are impressive, researchers caution that most trials were funded by drugmakers, long term safety data are still limited, and side effects such as nausea are common.

For the first time, deadly H5N1 bird flu has been confirmed as the cause of a wildlife die-off in Antarctica, killing more than 50 skuas during the 2023–2024 summers. Researchers on an Antarctic expedition found the virus ravaging these powerful seabirds, with some suffering severe neurological symptoms—twisted necks, circling behavior, and even falling from the sky. While penguins and fur seals were examined, skuas emerged as the primary victims, especially on Beak Island, where a mass die-off occurred.

Deep inside a nearby galaxy cloaked in thick clouds of gas and dust, astronomers have uncovered a surprising treasure trove of organic molecules using the James Webb Space Telescope. Peering through the cosmic veil in infrared light, researchers detected an extraordinary mix of carbon-rich compounds — including benzene, methane, and even the highly reactive methyl radical, never before seen outside the Milky Way.

A simple brain-training program that sharpens how quickly older adults process visual information may have a surprisingly powerful long-term payoff. In a major 20-year study of adults 65 and older, those who completed five to six weeks of adaptive “speed of processing” training — along with a few booster sessions — were significantly less likely to develop dementia, including Alzheimer’s disease, even two decades later. Participants who received the boosted speed training had a 25% lower dementia risk compared to those who received no training, making it the only intervention in the trial to show such a lasting protective effect.

A distant star system with four super-sized gas giants has revealed a surprise. Thanks to JWST’s powerful vision, astronomers detected sulfur in their atmospheres — a chemical clue that they formed like Jupiter, by slowly building solid cores. That’s unexpected because these planets are far bigger and orbit much farther from their star than models once allowed.

Avian malaria is spreading across Hawaiʻi in a way scientists didn’t fully grasp until now: nearly every forest bird species can help keep the disease alive. Researchers found the parasite at 63 of 64 sites statewide, revealing that both native honeycreepers and introduced birds can quietly pass the infection to mosquitoes—even when carrying only tiny amounts of it. Because infected birds can remain contagious for months or even years, transmission keeps simmering almost everywhere mosquitoes exist.

Hundreds of millions of years ago, the first animals to crawl onto land were strict meat-eaters, even as plants had already taken over the landscape. Now scientists have uncovered a 307-million-year-old fossil that rewrites that story: one of the earliest known land vertebrates to start eating plants. The animal, named Tyrannoroter heberti, was a stocky, football-sized creature with a skull packed with specialized teeth designed for crushing and grinding vegetation.

A cooler bedroom might be better for older sleepers than previously thought. Researchers found that keeping nighttime temperatures at 75°F reduced stress responses and helped the heart work more efficiently during sleep. Hot nights usually force the heart to work harder, interfering with recovery. As climate change drives warmer nights, this small adjustment could make a big difference.

Depression in older adults may sometimes signal the early stages of Parkinson’s disease or Lewy body dementia. Researchers found that depression often appears years before diagnosis and remains elevated long afterward, unlike in other chronic illnesses. This suggests depression may reflect early brain changes rather than emotional distress alone.

Your cat’s purr may say more about who they are than their meow ever could. Scientists discovered that purrs are stable and uniquely identifiable, while meows change dramatically depending on context. Domestic cats, in particular, have evolved highly flexible meows as a way to communicate with humans. The purr, meanwhile, stays constant—making it a reliable marker of individual identity.

Blood vessels twist, branch, narrow, and balloon in ways that dramatically affect how blood flows — but most lab models have long treated them like straight pipes. Researchers at Texas A&M have now built a new kind of “vessel-chip” that mirrors the real complexity of human blood vessels, from aneurysms to dangerous constrictions.

Why does the same virus barely faze one person while sending another to the hospital? New research shows the answer lies in a molecular record etched into our immune cells by both our genes and our life experiences. Scientists at the Salk Institute have created a detailed epigenetic map of human immune cells, revealing how inherited traits and past exposures—like infections, vaccines, or even environmental chemicals—shape immune responses in different ways.

Autism has long been thought of as a condition that mostly affects boys, but a massive study from Sweden suggests that idea may be misleading. Tracking nearly 3 million people over decades, researchers found that while boys are diagnosed more often in childhood, girls steadily catch up during their teenage years. By early adulthood, autism diagnoses among males and females are nearly equal.

Methane levels in Earth’s atmosphere surged faster than ever in the early 2020s, and scientists say the reason was a surprising mix of chemistry and climate. A temporary slowdown in the atmosphere’s ability to break down methane allowed the gas to linger, while unusually wet conditions boosted emissions from wetlands, rivers, lakes, and rice fields around the world. Pandemic-related changes in air pollution played a key role, indirectly weakening the atmosphere’s natural “clean-up” process.