Sky with Ocean Joined: Scaling the Stars at the US Naval Observatory, 1830 to Present

USNO is one of the oldest scientific agencies in the country. It was established in 1830 as the Depot of Charts and Instruments. Its primary mission was to care for the U.S. Navy’s chronometers, charts and other navigational equipment.
In 1844, as its mission evolved and expanded, the Depot was reestablished as the U.S. Naval Observatory and was located on a hill north of where the Lincoln Memorial now stands in Washington’s Foggy Bottom district. For nearly 50 years significant scientific studies were carried out, such as speed of light measurements, the phenomena of solar eclipses, and transit of Venus expeditions. Publication of its annual American Ephemeris and Nautical Almanac started in 1852 and continues to the present day. In 1877, using the recently-completed 26-inch Alvan Clark “Great Equatorial” refractor, astronomer Asaph Hall discovered Phobos and Deimos, the two satellites of Mars.
After years of suffering the increasingly deteriorating environment in Foggy Bottom the Observatory moved to its present location in upper Georgetown in 1893. Over the course of the next century USNO astronomers developed the instruments and techniques that made it what it is today: the world’s foremost authority in the fields of astrometry and precise time determination and distribution.
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.
Biography:
Geoff Chester has recently retired from his position as Public Affairs Officer and Historian after over 27 years at USNO. By a curious quirk of history, he is the great-grandson of the Observatory’s 15th Superintendent, Rear Admiral Colby Chester. Prior to coming to USNO he spent 19 years working in various capacities for the Einstein Planetarium at the Smithsonian’s National Air & Space Museum. He is a past president of the National Capital Astronomers, and is an active member of the American Astronomical Society, the Northern Virginia Astronomy Club, the Association of Lunar and Planetary Observers, DarkSky International, and the Alliance of Historic Observatories.

[@mdbssn]

Great presentation! A fascinating overview of some history of astronomy, timekeeping, the USNO, and our local astronomical institutions from a very practical and observation-focused perspective.

[@tomlucia6143]

you mentioned that you remelted the mirror..was it still just as effective as before.

[@tomlucia6143]

does it have a clock for predicting eclipses