Square Kilometre Array (SKA)

The SKA is a multi radio telescope project, designed to be built in Australia, New Zealand, and South Africa. Once built, it will have a collecting area of roughly one square kilometre. It will operate over a wide range of frequencies, and it will be 50 times more sensitive than any existing radio telescope. It will be able to survey the sky 10,000 times faster than ever before.

Artist's impression of the central core of antennas of the SKA
Credit: SKA

The science goals of the SKA are:

  • to test models of general relativity and gravity
  • to map a billion galaxies out to the edge of the observable universe
  • to search for extraterrestrial life on exoplanets

Unlike optical astronomy, radio astronomy can be done during the daytime as well as at night. A radio telescope is a specialised antenna and radio receiver, in a large dish. Radio astronomy suffers interference with signals from many manmade electronic devices, including radios, TVs, cars, and aeroplanes. This is why many radio telescopes are located far away from cities and towns.

The SKA telescope is an interferometer. Interferometers use a network of antennas, over a wide area, to simulate a much larger single antenna. This achieves a very high resolution. In the SKA, there will be radio receivers as distant as 3000 km from the central core. The SKA will be built in the southern hemisphere, where the view of the Milky Way is best, and where radio interference is minimised.