Scientists say the rocks found by the Mars Curiosity rover look like they've been moved by water
Mars rover Curiosity found rocks on the Martian surface that are too big to be carried by wind, so researchers suppose water must have existed on Mars at one time. Over the next two years, Curiosity will continue its search for signs of ancient microbial life on Mars.
The NASA rover Curiosity has beamed back pictures of bedrock that suggest a fast-moving stream, possibly waist-deep, once flowed on Mars — a find that the mission's chief scientist called exciting.
There have been previous signs that water existed on the red planet long ago, but the images released Thursday showing pebbles rounded off, likely by water, offered the most convincing evidence so far of an ancient streambed.
By Alicia Chang, Associated Press