Gaithersburg Latitude Observatory

Gaithersburg Latitude Observatory
Gaithersburg latitude observatory
LocationDeSellum Ave., Gaithersburg, Maryland
Coordinates39°8′12″N 77°11′57″W / 39.13667°N 77.19917°W / 39.13667; -77.19917
Area2.3 acres (0.93 ha)
Built1899 (1899)
Built bySmith, Edwin
NRHP reference No.85001578
Significant dates
Added to NRHPJuly 12, 1985
Designated NHLDecember 20, 1989

The Gaithersburg Latitude Observatory is a historic astronomical observatory on DeSellum Avenue in Gaithersburg, Maryland. It was established in 1899 as part of a system of six International Latitude Observatories to precisely measure the wobble of the Earth's rotating axis. The observatory building and adjacent monuments were designated a National Historic Landmark in 1989 as a testament to international scientific cooperation. The observatory was taken out of service in 1982 after automation eliminated the need for human observations; the property is now owned by the city.