premise: Mars is the site of Olympus Mons.
hypothesis: Alba Mons ( formerly known as Alba Patera , a term that has since been restricted to the volcano 's summit caldera ) is an immense , low-lying volcano located in the northern Tharsis region of the planet Mars . Mars . Mars is the site of Olympus Mons , the largest volcano and second-highest known mountain in the Solar System , and of Valles Marineris , one of the largest canyons in the Solar System . Olympus Mons ( [ pronəˌlɪmpəs_ˈmɒnz , _ oʊ - , _ - ˈmɒns ] Latin for Mount Olympus ) is a very large shield volcano on the planet Mars .