Tharsis Montes Tharsis Montes The Tharsis Montes are three large shield volcanoes in the Tharsis region of the planet Mars. From north to south, the volcanoes are Ascraeus Mons, Pavonis Mons and Arsia Mons. Mons (plural "montes") is the Latin word for mountain; it is a descriptor term used in astrogeology for mountainous features in the Solar System. The three Tharsis Montes volcanoes are enormous by terrestrial standards, ranging in diameter from (Pavonis Mons) to (Arsia Mons). Ascraeus Mons is the tallest with a summit elevation of over , or base-to-peak. For comparison, the largest volcano on Earth, Mauna Loa in Hawaii,
Ahuna Mons on the opposite side of Ceres, fracturing the outer layers of the area and facilitating the movement of high viscosity cryovolcanic magma (consisting of muddy water ice softened by its content of salts) that was then extruded onto the surface. Crater counts suggest that formation of the mountain continued into the last several hundred million years, making this a relatively young geological feature. Ahuna Mons Ahuna Mons is the largest mountain on the dwarf planet and asteroid Ceres. It protrudes above otherwise smooth terrain, it is not an impact feature, and it appears to be the only mountain of its