Water on terrestrial planets of the Solar System Water on terrestrial planets of the Solar System The origin and development of water on terrestrial planets, Venus, Earth, Mars, and the closely related Earth's Moon, varies with each planetary body, with the exact origins remaining unclear. Additionally, the terrestrial dwarf planet, Ceres is known to have water ice on its surface. A significant amount of surface hydrogen has been observed globally by the Mars Odyssey GRS. Stoichiometrically estimated water mass fractions indicate that—when free of carbon dioxide—the near surface at the poles consists almost entirely of water covered by a thin veneer of fine material. This is reinforced by
Olympus Mons three large Martian shield volcanoes, collectively called the Tharsis Montes (Arsia Mons, Pavonis Mons, and Ascraeus Mons). The Tharsis Montes are slightly smaller than Olympus Mons. A wide, annular depression or moat about deep surrounds the base of Olympus Mons and is thought to be due to the volcano's immense weight pressing down on the Martian crust. The depth of this depression is greater on the northwest side of the mountain than on the southeast side. Olympus Mons is partially surrounded by a region of distinctive grooved or corrugated terrain known as the Olympus Mons aureole. The aureole consists of