American astronomer

Clyde W. Tombaugh, an astronomer and master telescope maker, spent much of his career performing a painstaking photographic survey of the heavens from Lowell Observatory in Flagstaff, Arizona. This led to the discovery of Pluto (1930), the ninth planet in the solar system. Although Tombaugh is best known for this early triumph, he went on to make other contributions, including his work on the geography of Mars and studies of the distribution of galaxies. Tombaugh also made valuable refinements to missile-tracking technology during a nine-year stint at the U.S. Army's White Sands Proving Grounds in New Mexico.

Clyde William Tombaugh, the eldest of six children, was born to Muron Tombaugh, a farmer, and Adella Chritton Tombaugh. He spent most of his childhood on a farm near Streator, Illinois. In 1922, the family relocated to a farm in western Kansas. Tombaugh glimpsed...