Smithsonian Astrophysical Observatory

The Smithsonian Astrophysical Observatory is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory to form the Harvard–Smithsonian Center for Astrophysics .HistoryThe SAO was founded in 1890 by Samuel Pierpont Langley, the Smithsonian's third Secretary, primarily for studies of the sun. Langley is remembered today as an aeronautical pioneer, but he was trained as an astronomer and was the first American scientist to perceive "astrophysics" as a distinct field. Langley invented the bolometer and discovered infrared radiation from the sun.In 1955, the SAO moved from Washington, D.C. to Cambridge, to affiliate with HCO and to expand its staff, facilities, and most importantly, its scientific scope. Fred Whipple, the first director of SAO in this new era, accepted a national challenge to create a worldwide satellite-tracking network, a decision that would establish SAO as a pioneer and leader in space science research.Smithsonian and the USAF Project Space Track shared observations and ephemerides throughout the early days of satellite tracking, 1957–1961.In 1973, the ties between Smithsonian and Harvard were strengthened and formalized by the creation of the joint Harvard-Smithsonian CfA.