In Memoriam: The Royal Greenwich Observatory, 1675–1998

The Royal Greenwich Observatory, the most famous observatory in the world, was closed by the British government on 31 October 1998. This appalling act of scientific and cultural vandalism marked the end of the Observatory's 323-year role as a pioneer of British astronomical research.

Among the great astronomical nations of the world — France, Germany, Russia, Spain, the United States, Japan — only Britain no longer has a national observatory.

The Observatory was founded by King Charles II in 1675 to answer the mostpressing scientific question of the time: how to navigate ships on the high seas. The first Astronomer Royal, John Flamsteed, was charged "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."

For more than 200 years, the main work of the Observatory was to compile the annual volumes of The Nautical Almanac. Since its first edition in 1767, The Nautical Almanac has given the precise positions of the Sun, Moon and planets to allow mariners to determine their position at sea from sightings made with a sextant.

To ensure the accuracy of the data published in The Nautical Almanac, the Observatory made many thousands of measurements of the positions of celestial bodies using telescopes on the top of Greenwich Hill. The Observatory also sent out expeditions to the four corners of the world to observe rare events such as total solar eclipses and transits of Venus which could be used to measure the scale of the solar system. The expeditions of Captain Cook, better known nowadays as voyages of discovery, were in fact sent out to observe transits of Venus.

With the rise of astrophysics, the Observatory gained a new role as a focus for research in astronomy. Following its move to Herstmonceux Castle in Sussex after the Second World War, it became the home of the Isaac Newton Telescope, a 2.5-metre reflector which offered British astronomers access to a very large telescope for the first time.

In the mid-1970s, the Observatory was a key player in the creation of the Observatorio del Roque de los Muchachos on the island of La Palma in the Canaries. The ORM, situated at an altitude of 2400 metres on the rim of an extinct volcano, is acknowledged to be one of the best optical observatories in the world. British astronomers can use several world-class telescopes: the 1-metre Jacobus Kapteyn Telescope, the 2.5-metre Isaac Newton Telescope and the 4.2-metre William Herschel Telescope, which together make up the Isaac Newton Group.

The Isaac Newton Group was designed and installed by the staff of the Royal Greenwich Observatory. For 20 years the RGO provided expert technical support for the telescopes, including optics, mechanical engineering, electronics, computing, development of new detectors and the twice-yearly round of allocating and scheduling observing time to researchers from British universities.

Thanks to the skill and dedication of the staff of the Royal Greenwich Observatory, British astronomers have ready access to some of the best optical telescopes in the world.

From its founding in 1675 to its destruction in 1998 for short-sighted financial reasons, the Royal Greenwich Observatory has led the world in astronomy.

Shortly before the closure of the RGO, its archivist, Adam Perkins, wrote this valedictory to his colleagues:

We are the inheritors of the Greenwich of George Airy and have carried his spirit forward. We have done the work we have been asked to do, each in our separate but important ways. We are all Astronomers Royal.

David Harper
(H.M. Nautical Almanac Office, Royal Greenwich Observatory, November 1996 to October 1998.)