One of the Mars Rover's main goals on its current mission was to find a site on the planet that could have supported life. Ding, ding, ding. NASA says the rover Curiosity actually landed on what looks to be an ancient streambed, reports the Washington Post. Rounded pebbles and other telltale signs suggest that a fast-moving stream ran as high as hip-deep across the planet.
“Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them,” says a professor on the team. “This is the first time we’re actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it.” (Read more Mars rover stories.)