Mars rover Curiosity sees key water indicator
12 March 2013 Last updated at 22:54 GMT
The US space agency (Nasa) has reported that its Curiosity rover has made another significant discovery on Mars.
The robot has drilled into a rock that contains clay minerals - an indication of formation in, or substantial alteration by, neutral water.
Scientists say the find is one more step towards showing conditions on the Red Planet in the distant past could have supported life.
Pallab Ghosh reports