A Martian lake that could harbor life
Scientists have found a 12-mile-wide lake beneath an ice cap on Mars—a major discovery that increases the chances of finding microbial life on the Red Planet. It has long been known that large bodies of liquid water once existed on Mars, because its surface is laced with ancient dry river valleys and lake beds. But this is the first sign that the planet still holds at least one stable body of liquid water, reports The New York Times. An Italian team examined three years of data collected by the European Space Agency’s Mars Express orbiter, which scanned the planet’s southern polar ice cap with ground-penetrating radar. In one patch, the radar signals that bounced back looked similar to those from lakes beneath Greenland and Antarctica. Sitting about a mile beneath the surface, the lake’s water must be extraordinarily salty not to have frozen in the minus 90 degree cold. High salt levels, which lower a liquid’s freezing point, make for a deeply inhospitable environment—but bacterial life has been found living in salty Antarctic lakes that are sealed under ice. “There are all the ingredients for thinking that life can be there,” says Enrico Flamini, who oversaw the research. Confirming that there’s a lake, and looking for life there, will require NASA to send a deep-drilling robot.