The U.S. Naval Observatory is one of the oldest scientific agencies in the USA. 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. Its most important task was the calibration of ship's chronometers, which was accomplished by timing the transit of stars across the meridian.
Today, the U.S. Naval Observatory is the preeminent authority in the areas of time keeping and celestial observing; determining and distributing the timing and astronomical data required for accurate navigation and fundamental astronomy.