United States Naval Observatory
![An aerial view of the United States Naval Observatory in 2004](https://upload.wikimedia.org/wikipedia/commons/1/14/United_States_Naval_Observatory.aerial_view.jpg)
The observatory is located in Northwest Washington, D.C. at the northwestern end of Embassy Row. It is among the few pre-20th century astronomical observatories located in an urban area. In 1893, in an effort to escape light pollution, it was relocated from Foggy Bottom near the city's center, to its Northwest Washington, D.C. location.
The USNO has conducted significant scientific studies throughout its history, including measuring the speed of light, observing solar eclipses, and discovering the moons of Mars. Its achievements including providing data for the first radio time signals, constructing some of the earliest and most accurate telescopes of their kind, and helping develop universal time. The Naval Observatory performs radio VLBI-based positions of quasars for astrometry and geodesy with numerous global collaborators (IERS), in order to produce Earth orientation parameters and to realize the celestial reference system (ICRF).
Aside from its scientific mission, since the 1970s the Naval Observatory campus hosts the official residence of the vice president of the United States. Provided by Wikipedia
1
Published: 1876
2
Published: 1983
3
Published: 1980-
4
“...United States Naval Observatory...”
5
“...United States Naval Observatory...”
6
“...United States Naval Observatory...”
7
“...United States Naval Observatory...”
8
Published: 1871
Superior document: Washington observations : Appendix 1869,1
9
Published: 1912-
10
Published: 1862-1885
11
Published: 1906-1911
12
Published: 1895-1899
13
Published: 1887-1893