Once Upon a Water Planet NASA Science

Today the Red Planet is dry and barren, but what about tomorrow? New data suggest that the long story of water on Mars isn’t over yet. Mars was once wet, but now it is dry. Spacecraft photos of Mars reveal signs of ancient rivers, lakes and maybe even an ocean. They might have been filled with water billions of years ago, but something happened — no one knows what — and the planet became a global desert. Wherever the moisture went, new data suggest it might not be gone for good. Indeed, water may have flowed on Mars literally as recent as “yesterday or last year,” declares James Garvin, Chief Scientist for Mars exploration at NASA headquarters. Evidence is mounting that water lies beneath the Martian terrain, he says. Furthermore, every few centuries weather conditions might become clement enough for that water to “come and go” on the surface as well.