ancient mars

NASA's Curiosity Rover Sharpens Paradox of Ancient Mars

NASA's Curiosity Rover Sharpens Paradox of Ancient Mars

Mars scientists are wrestling with a problem. Ample evidence says ancient Mars was sometimes wet, with water flowing and pooling on the planet’s surface. Yet, the ancient sun was about one-third less warm and climate modelers struggle to produce scenarios that get the surface of Mars warm enough for keeping water unfrozen.