Very distant galaxies have surprisingly little dark matter, the invisible stuff thought to make up the bulk of matter in the universe, new observations suggest. Stars in the outer regions of some far-off galaxies move more slowly than stars closer to the center, indicating a lack of dark matter, astronomer Reinhard Genzel and colleagues report […]

This rainbow pinwheel of mouse placentas isn’t just an eye-catching, award-winning image. The differences in color also provide researchers with new clues to how a mother’s immune system may affect her or her baby’s health during pregnancy. The work could lead to earlier diagnosis and treatment of preeclampsia, a common pregnancy complication. Suchita Nadkarni, an […]

Ever since she was a baby, my older daughter has periodically endured massive nosebleeds. When she was 10 months old, I walked into her room to pick her up after her nap. There, I was greeted with a baby happily standing in what appeared to be a sea of ruby red blood. Her busy little […]

Kids can have virtual out-of-body experiences as early as age 6. Oddly enough, the ability to inhabit a virtual avatar signals a budding sense that one’s self is located in one’s own body, researchers say. Grade-schoolers were stroked on their backs with a stick while viewing virtual versions of themselves undergoing the same touch. Just […]

Stone Age dentists didn’t drill and fill cavities. They scraped and coated them. Two teeth from a person who lived in what’s now northern Italy between 13,000 and 12,740 years ago bear signs of someone having scoured and removed infected soft, inner tissue. The treated area was then covered with bitumen, a sticky, tarlike substance […]

Saturn’s icy moon Enceladus packs snacks suitable for microbial life. Data from the Cassini spacecraft show that the vaporous plume shooting out of the moon’s southern pole contains molecular hydrogen. It is probably generated when water in the moon’s subterranean ocean reacts with rock in its core, researchers report in the April 14 Science. Such […]

Last week, I wrote about how powerfully protective whooping cough vaccines can be when babies receive their first dose before even being born, from their pregnant mothers-to-be. As I was looking through that study, another of its findings struck me: Babies didn’t seem to get any extra whooping cough protection when their moms were vaccinated […]

An ancient tomb in southern China has provided the oldest known examples, in scaled-down form, of revolutionary weaving machines called pattern looms. Four immobile models of pattern looms illuminate how weavers first produced silk textiles with repeating patterns. The cloths were traded across Eurasia via the Silk Road, Chinese archaeologists report in the April Antiquity. […]

Researchers have pinpointed a gene that keeps important brain cells in mice from crossing their wires, providing a possible link between brain wiring and mood disorders like depression. Without the gene, called Pcdhαc2, mice acted more depressed, researchers report April 28 in Science. Nerve cells, or neurons, that produce the chemical messenger molecule serotonin extend […]

Fossils of a humanlike species with some puzzlingly ancient skeletal quirks are surprisingly young, its discoverers say. It now appears that this hominid, dubbed Homo naledi, inhabited southern Africa close to 300,000 years ago, around the dawn of Homo sapiens. H. naledi achieved worldwide acclaim in 2015 as a possibly pivotal player in the evolution […]