Lowell Observatory Lowell Observatory Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, and was designated a National Historic Landmark in 1965. In 2011, the Observatory was named one of "The World's 100 Most Important Places" by TIME. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh. The observatory was founded by astronomer Percival Lowell of Boston's Lowell family and is overseen by a sole trustee, a position historically handed down through the family. The
Percival Lowell Planet X. Lowell started a search program in 1906 using a camera in aperture. The small field of view of the reflecting telescope rendered the instrument impractical for searching. From 1914 to 1916, a telescope on loan from Sproul Observatory was used to search for Planet X. Lowell did not discover Pluto but later Lowell Observatory (observatory code 690) would photograph Pluto in March and April 1915, without realizing at the time that it was not a star. In 1930 Clyde Tombaugh, working at the Lowell Observatory, discovered Pluto near the location expected for Planet X. Partly in recognition of