For centuries, Mt. Everest has inspired explorers here on Earth. But there are other mountains to be found in our solar system. In fact, the largest known mountain is found on the planet Mars. “Olympus Mons” is a shield volcano measuring over 370 miles in diameter (see the size comparison to the state of Arizona).
At a height of 16 miles, it is an imposing feature on the Martian landscape. Even before modern spacecraft imaged Mars, astronomers theorized about the size of Olympus Mons. This was primarily because of the prominence of Olympus Mons above the many dust storms on the Red Planet. Incidentally, the red color of Mars comes from high concentrations of iron in the terrain. While the planet may look “hot”, Mars is actually colder than Earth due to its greater distance from the sun.