It’s all relativeIn “Earth is young at heart” (SN: 6/25/16, p. 5), Emily Conover reported that Earth’s core is more than two years younger than the planet’s surface, according to new calculations. Thanks to the effect of gravity on the passage of time, a clock placed at Earth’s core will tick fractions of a second […]
Out-of-reach nutrients could help explain why life on Earth took so long to bounce back from the worst extinction of all time. Analyzing the chemical changes that followed the Permian extinction 252 million years ago, geologists propose that hot sea surface temperatures led to conditions that trapped nitrogen far below the ocean’s sunlit, life-filled layers. […]
If you have an appetite for cosmic destruction, there’s an app for that. NOVA Black Holes, a free iPad game developed by the PBS series NOVA, lets you hurl a star at other celestial objects while navigating an increasingly complex minefield of stars, planets and black holes. Each level presents a new target and a […]
Call it exoplanet fatigue. The historic detection of an exoplanet just 4.2 light-years from Earth, featured on our cover, was big news. It attracted a lot of media buzz. But outside the office, I heard little about it. No questions from other parents at the playground, including those who had been eager to chat about […]
A Swedish scientist is gene editing healthy human embryos, and he is probably not alone, researchers say. Chinese researchers have twice reported editing genes in human embryos that are unable to develop into a baby (SN Online: 4/6/16; SN Online: 4/23/15). But developmental biologist Fredrik Lanner of the Karolinska Institute in Stockholm is the first […]
Rosetta is no more. The comet orbiter touched down on the surface of comet 67P/Churyumov–Gerasimenko at 7:19 a.m. Eastern and immediately shut down, bringing to an end a nearly 26-month mission in orbit around the comet. “I hereby declare mission operations ended,” said Rosetta mission manager Patrick Martin. The landing site has been dubbed Sais, […]
For the first time, researchers have grown eggs entirely in a lab dish. Skin-producing cells called fibroblasts from the tip of an adult mouse’s tail have been reprogrammed to make eggs, Japanese researchers report online October 17 in Nature. Those eggs were fertilized and grew into six healthy mice. The accomplishment could make it possible […]
Textbook drawings of the cell’s largest organelle might need to be updated based on new images. Super-resolution shots of the endoplasmic reticulum reveal tightly packed tubes where previous pictures showed plain flat sheets, scientists report in the Oct. 28 Science. The finding helps explain how the endoplasmic reticulum, or ER, reshapes itself in response to […]
SALT LAKE CITY — Dinosaur smarts may be a mystery, but their brains, at least, are now more concrete. A chunk of petrified brain tissue discovered in a tidal pool in southern England is the first reported from a dinosaur, researchers claim. The roughly 133-million-year-old fossil preserves the brain’s wrinkled topology, said paleontologist David Norman, […]
Ecologist Linda Geiser works her way through thick undergrowth on the steep hills of the Bull Run Watershed just outside of Portland, Ore. Every step in her heavy boots is deliberate. It would be easy to break an ankle here, or worse. A dense sea of ferns and berry bushes hides deep pits and sharp […]