Mars Was Once a World of Rain

Mars Was Once a World of Rain

Mars today is a frozen, barren world where liquid water can briefly appear on its surface but evaporates almost instantly in the thin atmosphere, unable to persist in any meaningful quantity. But a handful of pale, bleached rocks spotted by NASA's Perseverance rover are telling a very different story about the planet's past, one of tropical downpours, sodden landscapes, and conditions that might once have been hospitable to life.