Smithsonian Astrophysical Observatory (SAO)
A research establishment founded by the US Smithsonian Institution in 1890. Initially it had modest facilities in Washington, DC. In 1955, under the directorship of Fred Whipple, its headquarters were moved to the grounds of Harvard College Observatory (HCO) in Cambridge, Massachusetts, and its activities were expanded. In 1967, an observatory was established at Mount Hopkins in Arizona, now known as the Fred Lawrence Whipple Observatory. In 1973, the Harvard-Smithsonian Center for Astrophysics was formed by combining the resources of the SAO and HCO under one director, George Field.