This newly created map of Mars shows the variations in thickness of the planet’s crust from new mapping pulled from Mars’ gravitational effects on orbiters (NASA’s Mars Global Surveyor, Mars Odyssey and Mars Reconnaissance Orbiter) passing over each location on the planet.
The global map shows portions of the planet that include tall volcanoes on the left and the deep Valles Marineris canyon just right of center. Color coding indicates calculated thickness of the crust, from dark blue for approximately 6 to 12 miles (10 to 20 kilometers) to white for approximately 56 to 62 miles (90 to 100 kilometers).
If Mars were a perfectly smooth sphere of uniform density, the gravity experienced by the spacecraft would be exactly the same everywhere. But like Earth, Mars has both a bumpy surface and a lumpy interior. As the spacecraft fly in their orbits, they experience slight variations in gravity caused by both of these irregularities, variations which show up as small changes in the velocity and altitude of the three spacecraft.