Spreading across the continent: the Astronomical Society of Australia 1966–2023

Australian astronomy has undergone huge changes since the middle of the twentieth century, when astronomers generally only had access to the observing facilities of their own institution. In this paper, we look at the changes in the context of the membership of the Astronomical Society of Australia (ASA), since its formation in 1966. Initially, the dominant institutions were the Australian National University, the University of Sydney and the CSIRO, with each of these having more than twice the members of any other Australian institution. Access to world-class national facilities provided by the Anglo-Australian Telescope (AAT, an optical telescope) from 1975 and the Australia Telescope Compact Array (ATCA, a radio telescope) from 1991, led to increases in astronomer numbers at institutions other than the three dominant ones. More recently, to stay internationally competitive, astronomers need access to even larger observing facilities. One of these facilities is the Square Kilometre Array project (SKA). This radio telescope is to be split between Southern Africa and Australia with SKA-Low, observing in low frequency radio waves, to be sited at a remote location in Western Australia. That plan, and two new SKA precursor instruments, has boosted the number of astronomers in the state, making Western Australia one of the major centres of astrophysical research in Australia.