Odd O'blography

Outward and Upward

In previous posts, I presented alternate perspectives on the highest height:

"How High is Up?" 

"How Up is High?" 

But should a discussion of the highest mountain be limited only to earthly heights? The same urge that impels us to climb trees and conquer peaks also drives us to reach for the heavens. There are eight planets in our solar system to be considered, and dozens of moons and dwarf planets, some of them as large as Mercury (we'll disregard moons smaller than Everest is tall).

There are at least ten peaks higher than Everest in our known celestial neighborhood. One is on Venus (35,000 ft), five are found on moons orbiting the gas giants (up to 65,000 ft), and four are found on the red planet. Mars boasts a truly astonishing peak, Olympus Mons, that rises more than 13 miles above the surrounding terrain. Olympus Mons may have been the last gasp from a once active volcanic core. Its enormous base covers an area the size of Arizona, and its symmetrical cone rises to 72,000 feet.

We have an accurate picture of Olympic Mons thanks to the Mars Global Surveyor spacecraft which reached Mars orbit in 1997. It used infrared laser pulses to measure the distance of the MGS spacecraft to the Martian surface. The data sent back to earth was used to create precise topographic maps in preparation for the more recent Mars rover missions.

So, is Olympus Mons the highest mountain in our solar system? Yes, but the asteroid Vesta has a 'peak' that rises almost as high from the center of an impact crater at its south pole. The height of this feature was revealed in photographs taken by the Hubble telescope and confirmed by NASA in 2011 with the Dawn spacecraft. Whether this prominent feature even qualifies as a mountain is a matter of opinion. Vesta isn't very round at 342 by 287 miles, and the floor of the enormous crater is more than 50,00 feet deep. And it certainly wouldn't pose much of a challenge for a climber. Vesta has a gravity only 2% that of Earth. An athletic person could easily leap hundreds of feet on Vesta.

From the perspective of a mountaineer, I'd suggest Olympus Mons is the ultimate challenge in our solar system. Mars gravity is only 38% that of Earth, but the thin Martian atmosphere and extreme cold would require protection similar to a space suit. Climbing with the encumbrance of protective gear would largely offset the lower gravity. And a 13-mile elevation gain is equivalent to doing a vertical half-marathon.