1905-1973

Dutch-born American astronomer best known for discovering Uranus's fifth satellite, Miranda (1948), and Neptune's second satellite, Nereid (1949). Kuiper confirmed the existence of an atmosphere around Saturn's satellite Titan. He discovered methane bands on Uranus and Neptune, and deduced the existence of frozen water at Mars's polar caps. Kuiper was active in the United States space program, especially the Ranger and Mariner programs. He also helped select lunar landing sites for the Apollo missions.