How to Form Io's Mountains? Just Squeeze!

On Earth, mountains form along tectonic boundaries, but Io, Jupiter's volcanic moon, is awash with molten rock and dotted with solitary mountains -- how did they form?

May 20, 2016
12:28 PM EDT
A close-up of Mongibello Mons at sunset. The mountain is about 8.6 kilometers (5 miles) high. Io has mountains that are as high as 10 miles above the plain, which is taller than Earth mountains. | NASA/JPL/University of Arizona
The south polar region of Io as seen by Voyager 1. This includes the mountain Haemus Mons, which is 10 kilometers (32,000 feet) high. It is visible at bottom. | NASA/JPL/USGS