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
Custer Observatory Custer Observatory Custer Observatory is an astronomical observatory owned and operated by Custer Institute. Located in Southold, New York (US), facing Peconic Bay and Shelter Island, Custer's location boasts some of the darkest skies on Long Island. Long Island's oldest public observatory, Custer Institute was founded in 1927 by Charles Wesley Elmer (co-founder of the Perkin-Elmer Optical Company), along with a group of fellow amateur-astronomers. The name was adopted to honor the hospitality of Mrs. Elmer, the Grand Niece of General George Armstrong Custer. In 1942, the Custer Institute was incorporated as a non-profit educational corporation in the State of