Siding Spring Observatory

Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a collection of other telescopes owned by the Australian National University, the University of New South Wales, and other institutions. The observatory is situated 1,165 metres (3,822 ft) above sea level in the Warrumbungle National Park on Mount Woorat, also known as Siding Spring Mountain. Siding Spring Observatory is owned by the Australian National University (ANU) and is part of the Mount Stromlo and Siding Spring Observatories research school. There are currently 12 telescopes on site.

The original Mount Stromlo Observatory was set up by the Commonwealth Government in 1924. After duty supplying optical components to the military in World War II, the emphasis on astronomical research changed in the late 1940s from solar to stellar research. Between 1953 and 1974, the 74-inch (1.9 m) reflecting telescope at Mount Stromlo was the largest optical telescope in Australia.

Already in the 1950s, the artificial lights of Canberra had brightened the sky at Mount Stromlo to such an extent that many faint astronomical objects had been overwhelmed by light pollution. The Siding Spring site was selected by the ANU in 1962 from many other possible locations because of the dark and cloud-free skies. By the mid-1960s the ANU had set up three telescopes, together with supporting facilities, such as sealed roads, staff accommodation, electricity and water. In 1984, the Prime Minister, Bob Hawke, opened the ANU's largest telescope, the low-cost and innovative 2.3 m aperture telescope, housed in a simple, co-rotating cuboid dome.

Since the 1950s, and quite independently of developments at Siding Spring, the Australian and British governments had been negotiating about the construction of a very large telescope. When these negotiations finally came to fruition in 1969, the infrastructure of Siding Spring Observatory was already in place, and it was the obvious site at which to locate the 4-metre aperture Anglo-Australian Telescope (AAT).

During the constructions of the AAT in the early 1970s, the British Science Research Council also built the UK Schmidt Telescope, 1 km to the NE of the AAT dome. The considerably wider field of view of the Schmidt optical design complements the narrower field of the AAT, in that larger areas of sky may be surveyed more quickly. Interesting objects so discovered are then studied in greater detail on the larger instrument. In 1987, the Schmidt Telescope was amalgamated with the AAT.

Siding Spring Observatory also houses telescopes from Korea, Las Cumbres Global Telescope Network and the University of New South Wales. In 1990, the earth-satellite tracking facility of the Royal Greenwich Observatory was closed down after 10 years of operation.