<Tr> <Th> Discoverer </Th> <Td> Mariner 9 </Td> </Tr> <Tr> <Th> Eponym </Th> <Td> Latin--Mount Olympus </Td> </Tr> <P> Olympus Mons (/ əˌlɪmpəs ˈmɒnz, oʊ -, - ˈmɒns /; Latin for Mount Olympus) is a very large shield volcano on the planet Mars . By one measure, it has a height of nearly 25 km (13.6 mi or 72,000 ft). Olympus Mons stands about two and a half times as tall as Mount Everest's height above sea level . It is the second tallest mountain and the tallest planetary mountain in the Solar System . It is the youngest of the large volcanoes on Mars, having formed during Mars's Hesperian Period . It is currently the largest volcano discovered in the Solar System and had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain . </P> <P> The volcano is located in Mars's western hemisphere at approximately its big 18 ° 39 ′ N 226 ° 12 ′ E ﻿ / ﻿ 18.65 ° N 226.2 ° E ﻿ / 18.65; 226.2, just off the northwestern edge of the Tharsis bulge . The western portion of the volcano lies in the Amazonis quadrangle (MC - 8) and the central and eastern portions in the adjoining Tharsis quadrangle (MC - 9). </P>

What is the height of olympus mons on mars