It has been 55 years since Clyde Tombaugh, a young assistant at the Lowell Observatory in Flagstaff, Arizona, found a smudge of light on a photographic plate that moved from night to night. That smudge was Pluto, the ninth and most mysterious member of the sun’s family.
Articles with Pluto
The images that led to the discovery of Charon in 1978 • U.S. Naval Observatory