On a large asteroid named Vesta, mysteriously curved gullies and fan-shaped deposits may have formed from short-lived flows of saltwater, a new study reports — a discovery that's quite surprising because Vesta shouldn't really have any water at all.
Vesta, the second biggest member of the asteroid belt between Mars and Jupiter, has existed for 4.5 billion years with an utter lack of atmosphere — so, any water the asteroid harbored on its surface should have long escaped into space. Yet, close-up images of the asteroid, captured by NASA's Dawn spacecraft over a decade ago, showed narrow gullies and canyons carved into impact craters on the object. Puzzlingly enough, that led scientists to conclude that liquid water probably flowed on its surface relatively recently.
