AdvertisementLOOK: Map Of Mars' Gravity Illuminates Planet's InteriorMarch 21, 2016Merrit KennedyfacebookEmailA Martian gravity map shows the Tharsis volcanoes and surrounding flexure. The white areas in the center are higher-gravity regions produced by the massive Tharsis volcanoes, and the surrounding blue areas are lower-gravity regions that may be cracks in the crust (lithosphere). (MIT/UMBC-CRESST/GSFC via NASA)