Discovered the planet Pluto on Feb. 18, 1930; the official public
announcement was made March 13, 1930. Dr. Tombaugh was the first
American astronomer to discover a planet. Dr. Tombaugh likened his
discovery of Pluto, named after the Roman god of the underworld due to
the fact it dwells in almost perpetual darkness, to finding a needle in
a haystack.
