Published on Monday, 21 July 2008 19:00 | | 
Two studies based on data from NASA's Mars Reconnaissance Orbiter have revealed that the Red Planet once hosted vast lakes, flowing rivers and a variety of other wet environments that had the potential to support life.
One study, published in the July 17 issue of Nature, shows that vast regions of the ancient highlands of Mars, which cover about half the planet, contain clay minerals, which can form only in the presence of water.
By Dwayne Brown