HISTORY

P luto is the ninth planet from the Sun as well as the smallest and most remote planet known in the solar system. It was named for the Greek god of death and of fertility. The astronomer Percival Lowell, at his private observatory in Flagstaff, Arizona initiated a search for another planet. This eventually resulted in the discovery of Pluto by Clyde W. Tombaugh on Feb. 18, 1930.

C haron, Pluto's grayish satellite, was discovered by American astrophysicist James W. Christy on June 22, 1978. Its average orbital path lies 19,000 km (11,800 miles) from the center of Pluto. Charon completes one revolution in 6.39 days, the same as Pluto's rotation period. The two objects may be relics of the early days of the solar system.