Greenwich Observatory
Greenwich
Observatory, astronomical observatory, east central England,
located at Cambridge University's Institute of Astronomy.
The original site of the observatory in Greenwich
was arbitrarily established in 1884 as longitude 0°. A plaque in the original
structure marks the zero point from which longitude is calculated. Because the London haze had made accurate astronomical observations
almost impossible, the observatory equipment was slowly moved (1946-l953) to Herstmonceux Castle
in East Sussex, about 97 km (about 60 mi) southeast of Greenwich. Primarily for budgetary reasons,
all operations of Greenwich Observatory were transferred (1986-90) from
Herstmonceux to Cambridge
University.
The observatory was
founded in 1675 by Charles II, king of England, to keep accurate tables of
the position of the moon for the calculation of longitude by English ships. In
1750 publication of the tables was begun in the Astronomical Observations,
which were published annually after 1838. Meridian observations of the sun,
stars, and ets were also made at the observatory. Photographs of the sun
were taken daily, conditions permitting, and a continuous photographic record
of sunspots was kept, starting in 1873. Faint satellites of the ets Neptune
and Uranus were discovered by the British astronomer William Lassell in 1846
and 1851, respectively, using the 24-in (61-cm) Newtonian reflector telescope.
Another discovery made at the observatory was that of the eighth satellite of
Jupiter. The observatory, officially known as the Royal Greenwich Observatory,
is managed by the Science Research Council. Its director is called the
Astronomer Royal. Famed Astronomers Royal have
included Edmund Halley and Nevil Maskelyne.
