Radio Astronomy – Listening to the Invisible Sky

The night sky isn't only the pinpricks of starlight we see with our eyes — it's also quietly broadcasting on wavelengths we can't see at all, and for the last century a small community of scientists has been learning to listen. This episode traces radio astronomy from an accidental discovery of cosmic static at a telephone company, through the giant dishes and continent-spanning arrays used to hear it properly, to two of Australia's flagship instruments in the outback of Western Australia and New South Wales.

You'll come away understanding what radio waves are and why they reveal things visible light physically cannot, how Karl Jansky stumbled onto cosmic radio noise while chasing a phone-line problem, how a radio dish and an interferometer actually work, what the 21 centimetre hydrogen line lets astronomers map, what pulsars and fast radio bursts are, and why Australia's dish at Parkes and the Square Kilometre Array in the Western Australian outback occupy such a special place in this science.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: CSIRO – Parkes (Murriyang) radio telescope and ASKAP public science pages; ICRAR (International Centre for Radio Astronomy Research); SKA Observatory – public information on the Square Kilometre Array; NASA – Imagine the Universe, radio astronomy overview.