Washington DC National Observatory

Find the Right Attraction with our DC Family Travel Guide
	Washington DC for Families Travel Guide NEW! In 3 clicks you'll know all the kid friendly hotels, attractions, hotels, monuments, restaurants and more with our Washington DC with KidsTravel Guide. Includes Bonus maps. Get it now.

Location: 3450 Massachusetts Ave., NW, Washington, DC

Washington DC The U.S. Naval Observatory is one of the oldest scientific agencies in the country. 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.

Today, the U.S. Naval Observatory is the preeminent authority in the areas of Precise Time and Astrometry, and distributes Earth Orientation parameters and other Astronomical Data required for accurate navigation and fundamental astronomy.

The U.S. Naval Observatory serves as the official source of time for the Department of Defense and the standard of time for the United States. The atomic clock timescale of the Observatory is based on an ensemble of cesium-beam frequency standards and hydrogen masers.