This is a false-color image of the surface of Mars as taken by the Mars Orbiter Laser Altimeter, an instrument aboard NASA's Mars Global Surveyor and released on May 27, 1999. It is the first 3D imagery of the Red Planet. This high-resolution map represents 27 million elevation measurements gathered in 1998 and 1999. The massive Hellas impact basin in the Southern Hemisphere, lower left, is nearly 6 miles deep and 1,300 miles across, and is surrounded by a ring of material that rises 1.25 miles and stretches 2,500 miles from the basin center. Photo courtesy of NASA