This image provided by NASA shows shows a Martian rock outcrop near the landing site of the rover Curiosity thought to be the site of an ancient streambed, next to similar rocks shown on earth. Curiosity landed in a crater near Mars' equator on Aug. 5, 2012, on a two-year mission to study whether the environment could have been favorable for microbial life.
The stones inside the rock are too big to have been moved by wind, Curiosity scientist Rebecca Williams, with the Planetary Science Institute in Tucson, Arizona, told reporters on a conference call.
"The consensus of the science team is that these are water-transported gravel in a vigorous stream," she said. (Photo Source: NASA/chinanews.com)