The southern region of Pluto’s Sputnik Planum contains newly discovered ranges of mountains that have been informally named Hillary Montes (Hillary Mountains) and Norgay Montes (Norgay Montes) for Sir Edmund Hillary and Tenzing Norgay, the first two humans to reach the summit of Mount Everest in 1953. These mountains are made of water ice, which is hard as rock at Pluto’s low temperature. Credit: NASA/JHUAPL/SWRI