Lowell Observatory

Lowell Observatory was founded in 1894 by Percival Lowell on Mars Hill in Flagstaff, at an elevation of 7,250 feet (2,210 m), and is one of the oldest observatories in the United States. In 1930, Clyde Tombaugh discovered Pluto here using the Pluto Discovery Astrograph. The observatory has been a National Historic Landmark since 1965. The 24-inch Clark refractor of 1896 is still used for public viewing today. The Lowell Discovery Telescope (4.3 m / 14 ft, first light in 2012) stands near Happy Jack and is a research instrument.

For visitors, besides the Clark telescope there is the Giovale Open Deck Observatory (since 2019) for public observing nights. More than 150,000 people visit each year. Allow two to three hours if you also want to observe in the evening. Because of the elevation, evenings can be cool, so a warm jacket is a good idea. Check the evening observing program in advance.