The scope of this session includes, but is not limited to, investigations concerning the interior structure, the surface morphology, geology, geochemisty 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 TP12/SB4 ("Phobos, Deimos, and Other Small Solar System Satellites"). Contributions to Martian phyllosilicates can be submitted also to session TP2.1 ("Phyllosilicates on Mars as Indicators of Aqueous Processes and Geochemical Environments").