Tombaugh, Clyde

Tombaugh, Clyde (William) (1906–  ) astronomer; born in Streator, Ill. In 1930, while at the Lowell Observatory in Flagstaff, Ariz.—and before he had earned his bachelor's degree—he found the ninth planet, Pluto, the existence of which had been predicted by Percival Lowell. He would also discover a globular star cluster, hundreds of asteroids, and a supercluster of galaxies. After stints at Arizona State College (1943–45), the University of California: Los Angeles (1945–46), and the White Sands Missile Range (1946–51), he settled at New Mexico State University where he concentrated on studying the planet Mars.