2012 is another exciting year for Mars science: Three orbiters are still active, and the Mars Exploration Rover, Opportunity, has reached the rim of Endeavour crater, which displays outcrops of phyllosilicates. New data from Mars come in on an almost daily basis, and the Mars Science Laboratory rover, Curiosity, is expected to land in Gale Crater in August. The session will address results from all previous and current missions. Contributions are encouraged that cover the interior and the surface (the Martian atmosphere will be covered by session TP7: “Atmospheres of Terrestrial Planets”). The scope of this session includes, but is not limited to, investigations concerning the interior structure, the surface morphology, geology, geochemistry and mineralogy, and surface-atmosphere interactions. The session also welcomes studies that address the potential past and present habitability of the Martian surface and subsurface. Note that investigations of the Martian moons, Phobos and Deimos, will be covered by session TP5/SB12 ("Phobos, Deimos, and Other Small Solar System Satellites").