Square Kilometre Array Sited in Africa
In May 2012, the members of the Square Kilometre Array (SKA) Organisation decided to split the world's most ambitious radio astronomy project between two sites in the southern hemisphere. South Africa won the larger share, including the planned array of mid-frequency dishes, while Australia, together with New Zealand, was awarded the low-frequency antennas. The decision mattered because it placed a major share of a flagship global science facility in Africa for the first time, and because it ended years of competition between the two bidders.
The SKA idea emerged in the early 1990s, when radio astronomers began discussing a telescope with a collecting area of roughly a square kilometre, far more sensitive than anything then existing. Such an instrument could probe the early universe, the formation of the first stars and galaxies, the nature of gravity, and possibly cosmic magnetism. A site needed very low levels of radio interference, which meant remote, sparsely populated land. By the late 2000s, the shortlist had narrowed to southern Africa and Western Australia. South Africa's bid centred on the semi-desert Karoo region in the Northern Cape, with additional stations planned in several African partner countries.
To strengthen its case, South Africa built a precursor instrument, MeerKAT, a 64-dish array in the Karoo, while Australia constructed its own pathfinder, the Australian SKA Pathfinder. Both demonstrated technical capability and local expertise. The 2012 decision was a compromise: rather than choosing one winner outright, the organisation divided the telescope by frequency range. Reports at the time suggested the choice reflected both scientific and political considerations, and the exact weighting of those factors is not public in detail.
The consequences have been significant for African science. South Africa invested in training programmes, bursaries and engineering capacity, and eight partner countries, including Botswana, Ghana, Kenya, Madagascar, Mozambique, Namibia and Zambia, joined in the effort. MeerKAT was inaugurated in 2018 and has since produced widely noted images, including detailed views of the centre of the Milky Way. It was later incorporated into the first phase of the SKA project.
The wider SKA programme has evolved since 2012, with design changes, rescoping and a formal intergovernmental organisation, the SKA Observatory, established in 2021. Construction began in the early 2020s, and full operation is expected later in the decade. Whatever discoveries follow, the 2012 siting decision marked a turning point, signalling that cutting-edge astronomy could be built and led from the African continent.