Alba Mons Alba Mons 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. It is the largest volcano on Mars in terms of area, with volcanic flow fields that extend for at least from its summit. Although the volcano has a span comparable to that of the United States, it reaches an elevation of only at its highest point. This is about one-third the height of Olympus Mons, the tallest volcano on the planet. The flanks of
Olympus Mons unaware of standing on a very high mountain, as the slope of the volcano would extend far beyond the horizon, a mere 3 kilometers away. The typical atmospheric pressure at the top of Olympus Mons is 72 pascals, about 12% of the average Martian surface pressure of 600 pascals. Both are exceedingly low by terrestrial standards; by comparison, the atmospheric pressure at the summit of Mount Everest is 32,000 pascals, or about 32% of Earth's sea level pressure. Even so, high-altitude orographic clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present. Although the average