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The USNO websites aa.usno.navy.mil, ad.usno.navy.mil, aristarchus.usno.navy.mil, maia.usno.navy.mil, rorf.usno.navy.mil, and toshi.usno.navy.mil are undergoing modernization efforts. The expected completion of the work and return of service is estimated as 30 April 2020. Please submit a requirements form to the USNOPAO if the information you are seeking is not accessible via other means.
 

The USNO's Mission

NOTICE

This US Naval Observatory Website is undergoing modernization and will be offline starting Thursday, 24 October 2019.   The expected completion of work and return of service is estimated as 30 April 2020.  Please visit usno.navy.mil and submit a Requirements Form to the USNO PAO if the information you are seeking is not accessible via another means.

 
USNO strengthens national security and critical infrastructure by serving as DoD’s authoritative source for the positions and motion of celestial bodies, motions of the Earth, and precise time. USNO provides tailored products, performs relevant research, develops leading edge technologies and instrumentation, and operates state of the art systems in support of the U.S. Navy, DoD, Federal Agencies, international partners, and the general public.
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