Global topography of Mars

Global topography of Mars

Fig. 8.13 . By measuring the round-trip time of laser pulses bounced off the surface of Mars, the laser altimeter aboard the Mars Global Surveyor orbiter measured the altitude with a vertical accuracy of about 1 meter, providing this topographical map of Mars between latitudes of 65 degrees south (bottom) and 65 degrees north (top). The locations of five landing sites are labeled with the names of the landing spacecraft. This map portrays the great elevation difference between the northern, low-lying plains and the cratered southern highlands, and records the downhill direction that liquid water would flow. The red areas in the southern hemisphere are high regions, about four kilometers above the average surface height, and the blue regions of the northern hemisphere are low places, about four kilometers below the average height. The North Polar Basin, or Borealis Basin, is the large blue, low-lying area at the top of this topographical map; it covers about 40 percent of the planet. The map also shows the Tharsis bulge that lies near the Martian equator in the east longitude from 220 to 300 degrees. The bulge includes several major shield volcanoes, such as Olympus Mons. The huge Valles Marineris canyon system extends to the west of Tharsis. The giant the Hellas impact basin, at 45 degrees south and 70 degrees east, is about 3,000 kilometers across and lies about 9 kilometers deep. (Courtesy NASA/JPL/GSFC.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University