Posts Tagged ‘United States Naval Observatory’


The Naval Observatory Clock

In their debut album in 1969, the rock band “The Chicago Transit Authority” (later shortened to “Chicago”) asked the musical question, “Does anybody really know what time it is?”  Well, if anybody can answer that question, it would be the people at the United States Naval Observatory (USNO), located in Northwest D.C. at 3450 Massachusetts Avenue (MAP), at the Northwestern end of Embassy Row.  And outside the gate to the USNO compound is a display for the Master Clock that serves as the official time in the United States.  So if you’re out for a bike ride in D.C. and you really need to know what time it is, I recommend riding by.

The USNO is one of the oldest scientific agencies in the United States.  Its headquarters was established in D.C. in 1894 as an astronomical observatory.  It was originally located in a more urban area of the city before the light pollution thrown off by the growth in the city’s center diminished its effectiveness.  It was subsequently moved to its current location on a 2000-foot circle of land atop Observatory Hill overlooking the city.  Today, the observatory’s primary observational and positioning work is done away from any urban areas at a higher elevation station near Flagstaff, Arizona.

Today, the USNO’s primary mission is to produce positioning, navigation and timing for the U.S. Navy and the U.S. Department of Defense and its contractors.  As part of that mission, the Naval Observatory is specifically responsible for standard time, time interval, and radio-frequency standards, and operates the primary Master Clock facility at its site in D.C.  However, if it’s not possible for you to stop by the facility in Northwest D.C., the USNO also provides public time service via servers on the Internet, such as, and via telephone voice announcements by calling 202-762-1401.

Aside from its scientific mission, since 1974, the official residence of the Vice President of the United States is Number One Observatory Circle, a house on the grounds of the Naval Observatory.  It has also been speculated that the residence houses a bunker-like room that serves as the “secure, undisclosed location” where Vice Presidents are taken and remain under protection during times of national emergency, such as after the 9/11 terrorist attacks.  In a 2009 interview, Vice President Biden described the bunker.  However, a short time later the Vice President’s press office issued a statement denying the bunker report, suggesting that Biden had instead been describing “an upstairs workspace”.