The elevation measurements were collected by the Mars Orbiter Laser Altimeter (MOLA), an instrument aboard NASA's Mars Global Surveyor spacecraft, during the spring and summer of 1998.
It has also scanned the surface of the planet using Mola (Mars Orbiter Laser Altimeter), which beams an infrared laser pulse towards the surface of the Red Planet 10 times a second.
MOLA, which works by bouncing beams of light off the planet's surface, has found mountains twice as high as Everest, a crater ten kilometres deep, and huge valleys carved by more water than scientists believed had ever existed on Mars.