Why Smaller Worlds Have Much Taller Mountains Than Earth

Is Olympus Mons on Mars really the Solar System’s highest mountain, or do other planetary bodies hold taller peaks?

How tall is Olympus Mons compared to Earth mountains?

Olympus Mons on Mars reaches an astonishing 21.3 km, or 70,000 feet, as measured by the Mars Orbital Laser Altimeter. That height accounts for 0.65% of Mars’s total radius. By comparison, Mount Everest on Earth stands at 8.849 km, or 29,032 feet, above sea level. While Everest represents the highest point above sea level on Earth, Mauna Kea reaches an impressive 9.33 km in dry prominence from base to peak, rising 4,205 meters above the ocean while sinking another 5,000 to 6,000 meters to the sea floor.

What factors allow Mars to grow such massive volcanoes?

Olympus Mons grew to its colossal size due to specific physical conditions on Mars. The planet lacks continental drift. Mars features a lower gravity compared to Earth, which allows volcanic structures to pile higher.

Which other moons and asteroids host extreme peaks?

Lesser-mass worlds across the Solar System support surprisingly dramatic topography. Jupiter’s moon Io features the southern peak of Boösaule Montes, which reaches between 17.5 and 18.2 km from base to peak, representing about 1% of Io’s total radius. Saturn’s moon Iapetus features an equatorial ridge rising 20 km high, accounting for 2.7% of its radius, though its origin remains an open question with theories including a destroyed moon that fell back to the surface. Ceres, the largest world in the asteroid belt, contains a cryovolcanic mountain named Ahuna Mons that rises 4 km from base to tip.