NASA/JPL-CalTech

This animation shows the terrain of Mars as the planet rotates. The data were taken using the Mars Orbiter Laser Altimeter (MOLA) onboard the Mars Global Surveyor. The instrument transmits infrared laser pulses to the Martian surface and measures the time of flight to compute the range of the spacecraft to the surface. These measurements are then used to construct a precise topographic map of Mars.

The Martian Terrain

The information from MOLA gives scientists some of the most detailed information about the surface of Mars. The first pictures of the surface from space came in 1965 from the Mariner 4 spacecraft. In the 1970s, the Viking spacecraft landed on the surface and returned detailed information about the soil composition. Mars is divided into two main types of terrain: ancient cratered areas and younger, volcanic regions. Ancient cratered terrain is found mainly in the southern hemisphere. The volcanic plains are mainly in the northern hemisphere and lie several kilometers below the southern uplands. Mars has the largest volcano in the Solar System, Olympus Mons, which is 25 kilometers above the surrounding plains and 500 kilometers in diameter. Mars also has runoff channels, where the runoff of ancient rainstorms once flowed.

Ellen Cohen