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Welcome to the web pages of the Astronomical Applications Department of
the U.S. Naval Observatory
Our products - almanacs, software, and web services - provide
precise astronomical data for practical applications, serving the
defense, scientific, commercial, and civilian communities.
Sun and Moon rise and set times, Moon phases, eclipses, seasons, positions of solar system objects, and other data
Background information on common astronomical phenomena, calendars and time, and related topics
Astronomical and navigational almanacs, special publications, research reports
Computer almanac for PCs and Macs, and more
Information about the department and its history