The American astronomer Clyde Tombaugh (1906–1997), who humbly described himself as a “farm boy amateur astronomer without a university education,” was working at the Lowell Observatory when the search for a suspected “Planet X” was started. Tombaugh’s job was to continue the demanding task of photographing the area of the sky where this planet was believed to exist. Tombaugh became a celebrity for his momentous discovery of Pluto in 1930, winning a college scholarship for his work. He went on to a distinguished career as an astronomer.