Founded in 1830 as the U.S. Navy Depot of Charts and Instruments, the United States Naval Observatory (USNO) is recognized as the world’s foremost authority on spatial and temporal reference frames. USNO is headquartered in Washington, D.C., and operates a dark-sky observing station near Flagstaff, Arizona (NOFS). It also has a small detachment activity, the Alternate Master Clock facility (AMC), located at Schriever Space Force Base in Colorado Springs, Colorado. The Observatory provides a wide range of astronomical data and products, and serves as the official source of time for the U. S. Department of Defense, and the standard of time for the entire United States.
The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the two moons of Mars and the largest moon of Pluto. Its achievements including providing data for the first radio time signals, constructing some of the earliest and most accurate telescopes of their kind, playing a key role in discovering one of the coolest ever known brown dwarf objects, and helping the development of universal time. Under our current mission, the U.S. Naval Observatory serves as the authoritative source for the positions and motion of celestial bodies, motions of the Earth, and precise time. USNO provides tailored products, performs relevant research, develops leading edge technologies and instrumentation, and operates state of the art systems in support of the U.S. Navy, Department of Defense, Federal Agencies, international partners, and the general public.
While touring the Flagstaff station you may view the 40-inch telescope. After seeing “first-light” in Washington in 1934, this telescope was moved to Flagstaff in 1955 due to the extensive light pollution in the DC area. Designed by George Willis Ritchey, the Ritchey-Chretien telescope design has since become the de facto optical design for nearly all major telescopes, including the famed Keck telescopes and the space-borne Hubble Space Telescope. This instrument was used in 1963 by astronauts Jim Lovell, Pete Conrad, and John Young, to view the Moon and Mars during their extensive training for their Apollo missions.
Also available is the 1.3-meter telescope, the historic 6-inch Clark transit of Venus telescope, and the 8-inch transit telescope that is mounted on a double pier and depends on the rotation of the Earth for pointing.
Solar observing will be available weather permitting. Civilian staff members from the Celestial Reference Frame Department, the Earth Orientation Departimet, and our Information Technology Department will be available for questions. Short presentations on the history of the Observatory and the important impact of light pollution will be presented. Additional science related talks may be presented if weather conditions make a walking tour impossible. This is a walking tour and will cover up to one mile of walking over the 1.5-hour visit.
Board member, Adam Marsh, and lead paleontologist at Petrified National Forest, works with a team of scientists to uncover an approximately 300 million-year-old fossil skeleton discovered at Canyonlands National Park in Utah (June 2024)