researchers at the National Aeronautics and Space Administration (nasa) say that water flowed on Mars for a million years. The present findings support the theory that life existed on Mars. According to Wesley Huntress, nasa 's associate administrator for space science, recent photographs from the Mars Global Surveyor orbiting Mars show an ancient riverbed at the bottom of a 2.5-kilometre wide canyon called "Nanedi Vallis' near the planet's equator.

The twisting, winding canyon