Naval Observatory, United States, is the country’s oldest national observatory. It was founded in 1830 and is operated by the U.S. Navy. It is headquartered in Washington, D.C.
The United States Naval Observatory is responsible for measuring the positions and motions of the sun, moon, planets, and stars, and for monitoring the position of the earth. It also maintains the U.S. reference for precise time. The observatory distributes its data through such means as almanacs and related publications, electronic data links, and satellites. Information from the observatory is used by U.S. and international civilian and scientific agencies, primarily for navigation and scientific research.
In 1978, this instrument was used to discover Pluto’s satellite Charon. The instrument, a reflecting telescope with a diameter of 61 inches (155 centimeters), is in Flagstaff, Arizona. A 26-inch (66-centimeter) refracting telescope, now located in Washington, D.C., was used to discover the two moons of Mars in 1877.
