U.s. Naval Observatory
Naval Observatory)
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The official seal of the U.S. Located in Northwest Washington, D.C., it is one of the few observatories located in an urban area; at the time of its construction, it was far from the light pollution generated by the (then-smaller) city center.
History
Aerial view of the U.S.
Naval Observatory.
Established in 1830 as the Depot of Charts and Instruments, it was made into a national observatory in 1842 via a federal law. James Melville Gilliss was put in charge of the project.
The observatory's primary mission was to care for the United States Navy's marine chronometers, charts, and other navigational equipment.
It calibrated ships' chronometers by timing the transit of stars across the meridian. Initially located downtown in Foggy Bottom (near the Lincoln Memorial), the observatory was moved to its present location in 1893, atop Observatory Hill overlooking Massachusetts Avenue, amidst perfectly circular grounds.
The first superintendent was Navy Commander Matthew Fontaine Maury.
It was the first timeball in the United States, and the 12th in the world. When the timeball was dropped, a flag was mechanically raised letting all ships and civilians know the exact time.
Thus, time was kept not only for Washington, D.C., but, through the use of the telegraph, also for every state in the Union. Time was also "sold" to the railroads and was used in conjunction with railroad chronometers to schedule American rail transport.
Early in the 20th century, the Arlington Time Signal broadcast this service to wireless receivers.
The names "National Observatory" and "Naval Observatory" were both used for 10 years, until a ruling was passed to use only the term "Navy Observatory".
President John Quincy Adams, who signed the bill for the creation of a national observatory just before leaving presidential office, had intended for it to be called the National Observatory. He spent many nights at the observatory with Maury, watching and charting the stars, which had always been one of Adams' hobbies.
In November 1913, the Paris Observatory, using the Eiffel Tower as an antenna, exchanged sustained wireless (radio) signals with the United States Naval Observatory, using an antenna in Arlington, Virginia to determine the exact difference of longitude between the two institutions.
The modern United States Naval Observatory continues to be a major authority in the areas of time-keeping and celestial observation.
In collaboration with the Rutherford Appleton Laboratory, it determines the timing and astronomical data required for accurate navigation and fundamental astronomy, and distributes this information in the Astronomical Almanac.
Number One Observatory Circle, official home of the Vice President of the United States
Perhaps it is best known to the general public for its highly accurate ensemble of atomic clocks and its year 2000 Timeball replacement. The site also houses the largest astronomy library in the United States.
Since 1974, Number One Observatory Circle, a house situated in the grounds of the observatory (formerly the residence of its superintendent, and later the home of the Chief of Naval Operations), has been the official residence of the Vice President of the United States.
According to a May 15, 2009 blog posting by Newsweek's Eleanor Clift, Vice President Biden recently revealed the existence of what Clift described as a bunker-like room in the residence.
The bunker is believed to be the secure, undisclosed location former Vice President Dick Cheney remained under protection in secret after the 9/11 attacks. According to Clift's report:
"Biden said a young naval officer giving him a tour of the residence showed him the hideaway, which is behind a massive steel door secured by an elaborate lock with a narrow connecting hallway lined with shelves filled with communications equipment."
Biden's press office subsequently issued a statement denying the bunker report, suggesting that Biden had instead been describing "an upstairs workspace".
The USNO service also maintains an observatory near Flagstaff, Arizona.
Time service
Atomic clock ensemble at the U.S.