BBC News reports that NASA's rover Curiosity has discovered traces of water flowing on Mars.

Pictures sent by Curiosity show images of rounded off pebbles and sand, which NASA scientists say indicate the water was moving about one meter per second at a depth between ankle and hip deep. They also said there were signs of erosion.

There have been signs that water existed on the planet by other satellites, but this is the first time evidence was found on the surface of the Red Planet.

Over the next two years, curiosity will investigate whether microbes could have survived in the environment surrounding the area where water apparently once flowed.