Olympus Mons

Olympus Mons (Latin, "Mount Olympus") is the tallest known mountain in our solar system, located on the planet Mars at approximately {{coor d|18|N|226|E|globe:Mars}}. In the days before space probes revealed its identity as a mountain, Olympus Mons was known to astronomers as the albedo feature, Nix Olympica ("Snows of Olympus").

General description

The central edifice stands 27 kilometres (88,600 feet) high over its base (about three times the height of Mount Everest above sea level and three times the height of Mauna Loa above its base); it reaches 25 km above the mean surface level of Mars, since it stands in a two-kilometre-deep depression. It is 540 km (335 miles) in width, flanked by steep cliffs, and has a caldera that is 85 km (53 miles) long, 60 km (37 miles) wide, and up to 3 km (1.8 miles) deep with six overlapping pit craters. Its outer edge is defined by an escarpment up to 6 km (4 miles) tall unique among the shield volcanoes of Mars.

Related Topics:
27 kilometres - Mount Everest - Mauna Loa - 540 km - Caldera - Escarpment

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The size of Olympus Mons is so great (roughly the size of the American state of Missouri) that a person standing on the surface of Mars would be unable to view the profile of the volcano even from a distance as the curvature of the planet would obscure such detail. The only way to view the mountain properly is from orbit. Similarly, if one were to stand on the highest point of its summit, the slope of the volcano would extend all the way to the horizon.

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An occasional misconception is that the top of Olympus Mons is above the Martian atmosphere. The atmospheric pressure at the top is about 2% that of average Martian surface pressure; by comparison the atmospheric pressure at the summit of Mount Everest is about 25% of that at sea level. Even so, airborne martian dust is still present and high altitude carbon dioxide-ice cloud cover is still possible at the peak of Olympus Mons, though water-ice clouds are not. Although the Martian average atmospheric pressure is less than 1% of that seen on Earth, the much lower gravity on Mars allows its atmosphere to extend much higher.

Related Topics:
Atmosphere - Mount Everest - Carbon dioxide - Cloud

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