This image provided by NASA and taken by a camera aboard NASA’s Mars Reconnaissance Orbiter shows the equatorial plains region known as Elysium Planitia on Mars. Using a radar instrument aboard the spacecraft, scientists made a 3-D map of flood channels below the surface of Mars, apparently created by past flooding. The findings were reported online, March 7, in the journal Science. The face of Mars is dotted with a maze of channels, pointing to possible ancient megaflood episodes. Now scientists peering below the surface have uncovered the first evidence of underground channels apparently created by flooding — a finding that's expected to further illuminate the role of water in Mars' history. Using a ground-piercing radar sensor aboard the Mars Reconnaissance Orbiter, a team of scientists created 3-D maps of an equatorial region known as Elysium Planitia and the channels that run underneath the plains. Besides the contributions from rovers and landers, "