Royal Observatory, Greenwich

The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to <a href="/facts/Herstmonceux/tnvmUfPt">Herstmonceux</a>) is an <a href="/facts/Observatory/y0FVg7vS">observatory</a> situated on a hill in <a href="/facts/Greenwich_Park/QwAUx18u">Greenwich Park</a> in south east London, overlooking the <a href="/facts/River_Thames/XnQWN52L">River Thames</a> to the north. It played a major role in the history of <a href="/facts/Astronomy/0ArJVM1p">astronomy</a> and <a href="/facts/Navigation/sGGAJ0AQ">navigation</a>, and because the <a href="/facts/Prime_meridian_(Greenwich)/5dhcewNL">Prime Meridian</a> passed through it, it gave its name to <a href="/facts/Greenwich_Mean_Time/JpSIdWsn">Greenwich Mean Time</a>, the precursor to today's <a href="/facts/Coordinated_Universal_Time/2EnjfSyu">Coordinated Universal Time</a> (UTC). The ROG has the <a href="/facts/IAU/cbnG5Ccz">IAU</a> observatory code of 000, the first in the list. ROG, the <a href="/facts/National_Maritime_Museum/C8kWrTSQ">National Maritime Museum</a>, the <a href="/facts/Queen%2527s_House/U2S7XP8P">Queen's House</a> and the <a href="/facts/Clipper_ship/2tHzxph3">clipper ship</a> <a href="/facts/Cutty_Sark/X8k10c7r">Cutty Sark</a> are collectively designated <a href="/facts/Royal_Museums_Greenwich/NU5KaNgV">Royal Museums Greenwich</a>.
The observatory was commissioned in 1675 by <a href="/facts/Charles_II_of_England/Acc7cFtF">King Charles II</a>, with the <a href="/facts/Foundation_stone/atoU4fhN">foundation stone</a> being laid on 10 August. The old hilltop site of <a href="/facts/Greenwich_Castle/DlnVx8mI">Greenwich Castle</a> was chosen by <a href="/facts/Sir_Christopher_Wren/yKSh7QUa">Sir Christopher Wren</a>, a former <a href="/facts/Savilian_Professor_of_Astronomy/6MYUzWSX">Savilian Professor of Astronomy</a>; as <a href="/facts/Greenwich_Park/QwAUx18u">Greenwich Park</a> was a royal estate, no new land needed to be bought. At that time the king also created the position of <a href="/facts/Astronomer_Royal/GTCk0QaQ">Astronomer Royal</a>, to serve as the director of the observatory and to "apply himself with the most exact care and diligence to the rectifying of the tables of the motions of the heavens, and the places of the fixed stars, so as to find out the so much desired longitude of places for the perfecting of the art of navigation." He appointed <a href="/facts/John_Flamsteed/hptRt6IK">John Flamsteed</a> as the first Astronomer Royal. The building was completed in the summer of 1676. The building was often called "Flamsteed House", in reference to its first occupant.
The scientific work of the observatory was relocated elsewhere in stages in the first half of the 20th century, and the Greenwich site is now maintained almost exclusively as a museum, although the <a href="/facts/Annie_S._D._Maunder/SHXkQ1UR">AMAT telescope</a> became operational for astronomical research in 2018.

Royal Observatory, Greenwich open-in-new

Royal Observatory, Greenwich