National Geographic : 2013 Sep
OLYMPUS MONS 81,100 feet Mars MAUNA KEA 32,696 ft Hawaii, U.S. MOUNT EVEREST 29,035 ft China-Nepal border MAXWELL MONTES 38,300 ft* Venus MARS Olympus Mons EARTH Mauna Kea Mount Everest VENUS Maxwell Montes 20,000 40,000 60,000 80,000 100,000 Feet Sea level at Mauna Kea Airliners’ average cruising height, about 35,000 ft ACTUAL PROPORTIONS Mauna Kea Olympus Mons Maxwell Montes Mount Everest 96 national geographic • September 2013 Space Mountains Until Galileo came alonG in the early 1600s, people thought the moon was an unblemished sphere. His crude telescope revealed shifting shadows, which the astronomer correctly interpreted as mountains, craters, and valleys. As it turns out, mountains appear all over the solar system. Spacecraft orbiting the inner planets have sent back images and bounced laser beams and radar waves off their surfaces to measure heights. In the early 1970s Apollo astronauts even sampled rock on lunar highlands. Unmanned missions to the outer planets show giant peaks on the asteroid Vesta and the moons of Jupiter and Saturn (the planets themselves are mostly giant balls of gas). The origins of extraterrestrial mountains offer clues to the solar system’s turbulent history. THE NEW AGE OF EXPLORATION | A GRAPHIC LOOK talleSt moUntainS in tHe SolaR SYStem Earth’s most famous peak, Everest, is of modest height compared with some of the solar system’s highest mountains— a term used to describe a variety of features on planets and moons, from volcanoes and ridges to crater rims. *The height of Maxwell Montes is determined by measuring the distance from its summit to the center of Venus, then subtracting the average radius of the planet.