NASA has lost contact with one of its three spacecraft orbiting Mars, the agency announced Tuesday. Meanwhile, a second Mars orbiter is perilously close to running out of fuel, and the third mission ...

It's not the heat. It's the humidity.

A thin atmosphere and other factors have left Mars' soil in rough shape, but the quest continues for signs of life, even if it's extinct. NASA/JPL-Caltech/MSSS What if we aren’t alone in the universe?

Add Yahoo as a preferred source to see more of our stories on Google. Artist concept of Mars's warm southern interior. Mars's southern mantle may be 200 to 400°C hotter than the north, revealing a ...