Anglo-Australian Telescope. Time-lapse image of the dome of the Anglo-Australian Telescope (AAT), showing star trails in the night sky. This 3.9m optical telescope is part of the Anglo-Australian Observatory on the summit of the 1200m high Siding Spring mountain in New South Wales, Australia. Since completion in 1974 the AAT has enabled observation of many objects and regions only visible from the Southern Hemisphere, for example the centre of our own Milky Way Galaxy. The Anglo- Australian Observatory also operates the UK Schmidt Telescope. The Observatory is funded and run jointly by the United Kingdom and Australia.