Royal Greenwich Observatory

Royal Greenwich Observatory (RGO)

An astronomical institute in the UK, which was first established at Greenwich near London in 1675 by King Charles II.
In the seventeenth century, the major problem facing navigators was the establishment of longitude at sea. In principle, this could be done by observing the position of the Moon, and Charles II set up a Royal Commission in December 1674 to examine the idea. The Commission sought the advice of the astronomer John Flamsteed, who pointed out many practical difficulties. The King then appointed Flamsteed first Astronomer Royal, with the job of solving the problem. The site in Greenwich Park for the new Royal Observatory was suggested by Christopher Wren.
The Observatory has played an important role in positional astronomy throughout its history. The Washington Conference of 1884 fixed the meridian through Greenwich as the zero point of longitude.
In the twentieth century, the emphasis in the Observatory's work changed to include more astrophysics. The difficulty of observing in London led to a move to Herstmonceux Castle, Sussex, in 1948. By the 1970s, it was clear that first-class observational work could no longer be done at any site in Britain, and a decision was made to move all observational work to La Palma in the Canary Islands. In 1990 the administrative offices of the Observatory were moved to Cambridge.