This story appears in the May 2019 issue of National Geographic magazine.
Our fleshly forms evolved to work within the tug of gravity. Without it, the clockwork of bodily functions doesn’t run smoothly. One recent study in the New England Journal of Medicine raises concern for a particularly vital organ: the brain. By scanning 10 cosmonauts’ craniums before and after six months in space, scientists found that their gray matter—responsible for things like muscle control, memory, and sensory perception—became compressed by an increase in the cerebrospinal fluid that cushions it. Returning to Earth helped the gray matter mostly bounce back but seemed to cause shrinkage in white matter, which connects parts of the brain. More study is needed, but the find suggests life among the stars may be hard on Earthlings. —Maya Wei-Haas
California gold rush–era mining sites hold hidden treasure: rare heirloom fruits and nuts. Scientists hope to learn from the mountain orchards, which have survived drought, diseases, and pests without human help for more than 150 years. “They’re growing in an environment that may be more like environments we’re going to have in the future … hotter, drier,” says Charlie Brummer, director of UC Davis’s Plant Breeding Center. —Maryn McKenna
Researchers have created sensors small enough for bumblebees to wear and still fly. While the bees buzz around, the devices collect data such as humidity and temperature, which can be used to better understand plant and insect biology—and benefit agriculture. —Douglas Main