Posted on Monday 5 January 2004

This false-color, detailed, topographical map of the Mars Orbiter Laser Altimeter data shows in blue the area an enormous complex of lakes that are thought to have existed over three and a half billion years ago in the southern highlands of Mars. As the largest lake spilled over the low point in its boundary a torrential flood would have moved north, along the direction indicated by the arrow, carving the sinuous Ma'adim Vallis. At the north end of Ma'adim Vallis, the flood waters would have poured into large, round Gusev Crater. Standing bodies of surface water are thought to be favorable for ancient martian microbial life.

Over the weekend, NASA landed a probe at the bottom of the Gusev Crater.

(adapted from APOD)