The Siding Spring Survey (SSS) was a near-Earth object search program that used the 0.5-metre Uppsala Southern Schmidt Telescope at Siding Spring Observatory, New South Wales, Australia. It was the southern hemisphere counterpart of the Catalina Sky Survey (CSS) located in the Santa Catalina Mountains on Mount Bigelow, near Tucson, Arizona, USA. The survey was the only professional search for dangerous asteroids being made in the Southern Hemisphere.