Olympus Mons is an extremely large volcano located on the planet mars, which is measured at a height of nearly 22km. This makes Olympus Mons the largest known mountain on any planet in the solar system and the second largest mountain known to man, after Rheasilvia Mons on the asteroid 4 Vesta. Olympus Mons was identified by Astronomers in the late 19th century and was known as the albedo feature Nix Olympica (Latin for Olympic snow). Although it was predicted to be a mountain, space probes later confirmed suspicions that it was a mountain, naming it Olympus Mons.