Young Mars would have been a staggering place to explore. The Red Planet was covered in flowing rivers of both water and lava. At the time, a series of four volcanoes — Olympus Mons and the three peaks of Tharsis Montes — were all growing taller than any mountain on Earth.
Each of these peaks is impressive. But Olympus Mons stands above the rest, reaching an astonishing height of 16 miles (26 kilometers), or around three times as tall as Mount Everest. That makes Olympus Mons the largest volcano in the solar system.
A 3-D image of Mars' massive volcano, Olympus Mons, which is the largest in the solar system. (Credit: NASA)
