Follow this link to skip to the main content
National Aeronautica and Space Administration
+ NASA Homepage
+ NASA en Español
+ Marte en Español
Search Mars
Go Search
NASA's Mars Exploration Program
Overview Science Technology Missions People Features Events Multimedia All About Mars
Mars for Kids
Mars for Students
Mars for Educators
Mars for Press
+ Mars Home
Mars Atlas
Latest Images
Global Views of Mars
Mars Artwork
Polar Ice Caps
Water Features
Martian Terrain
Dust Storms
Sand Dunes
Mars Atlas

(largest volcano in the solar system!)
Click for larger view 3-D view of Olympus Mons

The largest of the volcanoes in the Tharsis Montes region, as well as all known volcanoes in the solar system, is Olympus Mons. Olympus Mons is a shield volcano 624 km (374 mi) in diameter (approximately the same size as the state of Arizona), 25 km (16 mi) high, and is rimmed by a 6 km (4 mi) high scarp. A caldera 80 km (50 mi) wide is located at the summit of Olympus Mons. To compare, the largest volcano on Earth is Mauna Loa. Mauna Loa is a shield volcano 10 km (6.3 mi) high and 120 km (75 mi) across. The volume of Olympus Mons is about 100 times larger than that of Mauna Loa. In fact, the entire chain of Hawaiian islands (from Kauai to Hawaii) would fit inside Olympus Mons!

Click for larger view
Olympus Mons compared to Arizona
Click for larger view
Caldera at the summit
Click for larger view
MOC image of Olympus Mons

Why is Olympus Mons so big?

Olympus Mons Hawaiian Islands The main difference between the volcanoes on Mars and Earth is their size; volcanoes in the Tharsis region of Mars are 10 to 100 times larger than those anywhere on Earth. The lava flows on the Martian surface are observed to be much longer, probably a result of higher eruption rates and lower surface gravity.

Another reason why the volcanoes on Mars are so massive is because the crust on Mars doesn't move the way it does on Earth. On Earth, the hot spots remain stationary but crustal plates are moving above them. The Hawaiian islands result from the northwesterly movement of the Pacific plate over a stationary hotspot producing lava. As the plate moves over the hotspot, new volcanoes are formed and the existing ones become extinct. This distributes the total volume of lava among many volcanoes rather than one large volcano. On Mars, the crust remains stationary and the lava piles up in one, very large volcano.

For more on Olympus Mons:
3-D image of Olympus Mons (you'll need 3-D glasses!)
Earth and Space Network
University of Michigan

JPL Image Use Policy

Credits Feedback Related Links Sitemap