Smithsonian Astrophysical Observatory


Established in 1890, the Smithsonian Astrophysical Observatory was one of the earliest observatories to practice the "new astronomy," or astrophysics. Originally located behind the Smithsonian Institution Building, the Castle, in 1955, the Observatory moved to Cambridge, Massachusetts. Today, the Harvard-Smithsonian Center for Astrophysics has observing stations in Arizona, Hawaii, and Massachusetts.

Fred Lawrence Whipple Observatory, Arizona, 2007
Smithsonian Astrophysical Observatory, Fred Lawrence Whipple Observatory in Arizona, view of ridge.
Smithsonian Astrophysical Observatory in the South Yard
Astrophysical Observatory in Castle South Yard, 1899
Buildings in the South Yard behind the Smithsonian Institution Building, include a building located on the southeast built for use by the Smithsonian Astrophysical Observatory, established on March 1, 1890. The United States Department of Agriculture Building is in the background.
Secretary Charles G. Abbot with Bolometric Apparatus
Abbot with Bolometric Apparatus, 1900
Charles Greeley Abbot, then Acting Director of the Smithsonian Astrophysical Observatory (SAO), pictured with bolometric apparatus, was one of a team of Smithsonian scientists who traveled to Wadesboro, North Carolina, to study an eclipse of the sun in 1900. Abbot later became director of the SAO and Fifth Secretary (1928-1944) of the Smithsonian.
Secretary Samuel P. Langley, by Unknown, 1901, Smithsonian Archives - History Div, 2002-12172.
Langley Observing Birds in Flight on National Zoo Grounds, 1901
Secretary Samuel P. Langley studying and photographing birds in flight from a tower on the grounds of the National Zoological Park. Secretary Langley (third Secretary of the Smithsonian, 1887-1906), in establishing the Zoo in Rock Creek Park, had remarked on the suitability of the isolated spot for his astrophysical observatory. Although that arrangement never came to fruition, in 1901 he directed that two towers be erected in the park for flight observation experiments. During the years leading up to 1903, when Langley attempted flight with the aerodrome he designed, the Secretary was intently studying birds in flight.
Sumatra Eclipse Expedition, by Unknown, 1901, Smithsonian Archives - History Div, 94-12603.
Sumatra Eclipse Expedition, 1901
Photograph of the members of the Sumatra Eclipse Expedition in 1901: (l-r) Jewell, Eichelberger, Dr. Mitchell, Littell, Dr. Humphries, Peters, Professor Barnard, Dinwiddie, Paul A. Draper, Astrophysicist Charles Greeley Abbot (Aid Acting in Charge of the Smithsonian Astrophysical Observatory (SAO), later to become the Director of the SAO and Fifth Secretary of the Smithsonian, 1928-1944), and Professor Skinner. The men are standing on a deck of a ship in a harbor, all wearing suits, ties, and hats.
SAO Station Atop Mount Whitney, by Unknown, 1909, Smithsonian Archives - History Div, SIA2008-3163.
Observing Station on Mount Whitney, California, 1909
Plate 3, Smithsonian Institution Annual Report for the Year 1909, opposite p.66. In 1909, using a grant from the Thomas George Hodgkins Fund, the Smithsonian Astrophysical Observatory erected a shelter atop Mount Whitney, California, for astrophysical researchers. Smithsonian Secretary Samuel Pierpont Langley (1834-1906) had been at the site in 1881 and deemed it the best location in the country for meteorological and atmospheric observations. SAO Director (1906-1918) Charles Greeley Abbot, later fifth Secretary of the Smithsonian from 1928-1944, began observations at the site in 1909 and secured the construction of the stone building. Abbot worked with W. W. Campbell, director of the Lick Observatory, in completing the field station. Lick Observatory is part of the University of California Observatories of the University of California on Mt. Hamilton, California.
Secretary Charles G. Abbot's Solar Cooker at Mt. Wilson, CA
Abbot’s Solar Cooker, c. 1920s
Astrophysicist Dr. Charles Greeley Abbot's solar cooker, which cooks food by solar energy, at Mount Wilson, California. Dr. Abbot was the fifth Smithsonian Institution Secretary from 1928 to 1944, and director of the Smithsonian Astrophysical Observatory from 1907-1944. From 1905 through the 1930s, the Astrophysical Observatory used the telescopes at Mount Wilson.
Mt. Harquahala, Arizona, by Unknown, 1924, Smithsonian Archives - History Div, 78-6571.
Mount Harquahala, Arizona, Observing Station, 1924
Buildings erected by the Smithsonian Astrophysical Observatory (SAO) at the Harqua Hala, Arizona (Mt. Harquahala) observatory which was in use from 1920 to 1926.
Observatory at Mt. Montezuma, Chile
Mount Montezuma, Chile, Observing Station, c. 1920
Solar observation instruments outside the entrance to the instrument tunnel at the Smithsonian Astrophysical Observatory in use from 1920 to 1955 at Mt. Montezuma, Chile. A man stands in the entrance holding a cord while another man works on the instruments.
Telescope at Mt. Wilson Observatory
Mount Wilson, California, Telescope, c. 1931
The Great Hooker 100-inch telescope used at the Mt. Wilson, California Observatory, which served as a Smithsonian Astrophysical Observatory station from 1905 to the mid 1930's.
Observatory on Mount St. Katherine, Egypt
Mount St. Katherine, Egypt, Observing Station, c. 1933
A solar observing station of the Smithsonian Astrophysical Observatory located at Mt. St. Katherine, Egypt, from 1933 to 1937. This view shows the observatory (top) and living quarters at the site.  
Laboratory of Division of Radiation and Organisms, SIB
Johnston in Division of Radiation and Organisms Lab, c. 1940s
The Division of Radiation and Organisms, located in the basement of the Smithsonian Institution Building. Shown here is apparatus for studying phototropism (bending toward light) of seedlings, in connection with experiments to determine effects of wave lengths of light on growth. Photo shows Earl S. Johnston at work.
Tyrone Solar Station, Burro Mountain, NM
Instrument Tunnel at Tyrone Solar Station, New Mexico, c. 1940s
Outside the instrument tunnel at the Smithsonian Astrophysical Observatory's Tyrone Solar Station (in use from 1938 to 1946), Burro Mountain at Silver City, New Mexico, are solar observing instruments.
Moonwatch Volunteers, 1965, by Unknown, 1965, Smithsonian Archives - History Div, 96-960.
Moonwatch Volunteers, 1965
Volunteer satellite trackers in Pretoria, South Africa, for Smithsonian Astrophysical Observatory's Moonwatch Network, one of more than 100 teams worldwide. Volunteers used the "fence method" of observing the sky. Each observer covered a small, overlapping portion of a specific sky quadrant, and watches for the passage of the satellite in his telescope. The instrument used was the Moonwatch Apogee Scope, a 20 power telescope with a 5-inch objective lens. The Moonwatch teams backed up an optical network of 12 Baker-Nunn tracking cameras.
Corbitt, Whipple & Udall at Mt. Hopkins Observatory
Gamma Ray Collector at Mount Hopkins Observatory, Arizona, 1968
(Left to right) Tucson mayor James Corbitt, Smithsonian Astrophysical Observatory Director Dr. Fred Whipple (1955-1973) and Rep. Morris K. Udall (D-AZ) stand in front of a 34-foot gamma-ray collector at the Smithsonian Astrophysical Observatory, Mt. Hopkins, Arizona, October 23, 1968. The large surface light collector, really a mosaic of 252 polished glass mirrors, searches for sources of gamma-ray radiation in the heavens, a feat never attempted before from a ground-based observatory.
Installation of Multiple Mirror Telescope
Building the Multiple Mirror Telescope, 1978
One of the six cells, designed to hold the 72-inch mirrors of the Multiple Mirror Telescope (MMT), is lowered into place at the Smithsonian Astrophysical Observatory, located on top of Mt. Hopkins, Arizona. The MMT is some 8,500 feet above the Santa Cruz Valley.
Narrow Dirt Road to Whipple Observatory
Aerial View of Fred L. Whipple Observatory, Arizona, 1984
A winding, single-lane, dirt road 18 miles long connects the Smithsonian Astrophysical Observatory's Whipple Observatory atop Mount Hopkins in Arizona with the outside world. In 1984, a 1.5-mile section of the road at the very top, between the 8,550-foot summit and the 7,600-foot ridge was paved.
Harvard-Smithsonian Center for Astrophysics
Harvard-Smithsonian Center for Astrophysics, c. 1985
The Harvard College Observatory located in Cambridge, Massachusetts where SAO's scientific headquarters in Washington, D.C., moved after fhe Smithsonian Astrophysical Observatory (SAO) and Harvard College Observatory established a relationship between the two observatories in 1955. By moving the SAO to the Harvard College Observatory, the Smithsonian would gain access to the network of solar research stations operated by Harvard. On July 1, 1973, the Smithsonian Astrophysical Observatory merged with the Harvard College Observatory to become the Harvard-Smithsonian Center for Astrophysics, or CFA.
Multiple Mirror Telescope at Mount Hopkins
Multiple Mirror Telescope at Fred L. Whipple Observatory, Arizona, 1989
Multiple Mirror Telescope (MMT), a joint facility of the Smithsonian and the University of Arizona, rises above the Arizona desert on the summit of Mount Hopkins in southern Arizona.