Microsoft General Counsel talks about protecting customer data Mars rover Curiosity has found definitive proof that water once ran across the surface of Mars, US space agency NASA announced. There is earlier evidence for the presence of water on Mars, but this evidence -- images of rocks containing ancient streambed gravels -- is the first of its kind. NASA scientists presented their findings of the former streambed on Mars at a news conference Thursday Scientists are studying the images of stones cemented into a layer of conglomerate rock, reported Xinhua. The sizes and shapes of stones offer clues to the speed and distance of a long-ago streams flow. "From the size of gravels it carried, we can interpret the water was moving about three feet per second, with a depth somewhere between ankle and hip deep," said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. "This is the first time were actually seeing water-transported gra...