Radio telescopes detect and amplify radio waves from space, turning them into signals that radio astronomers use to enhance our understanding of the Universe.
All astronomy is about observing waves of light. Stars, galaxies and gas clouds in space emit visible light as well as light from other parts of the electromagnetic spectrum in the form of radio waves, gamma rays, X-rays, and infrared radiation.
The Circinus galaxy as seen at different wavelengths: cold hydrogen gas (coloured blue), the fuel for star formation, was mapped using one of CSIRO’s radio telescopes; the warm dust of space (coloured red) and stars (shown in green) were mapped using data from mid-infrared instruments. When combined, these three images reveal gas and stars in the inner disk and spiral arms of the galaxy. ©The Royal Astronomical Society (from For, Koribalski & Jarrett (2012))
The Circinus galaxy as seen at different wavelengths: cold hydrogen gas (coloured blue), the fuel for star formation, was mapped using one of CSIRO’s radio telescopes; the warm dust of space (coloured red) and stars (shown in green) were mapped using data from mid-infrared instruments. When combined, these three images reveal gas and stars in the inner disk and spiral arms of the galaxy. ©The Royal Astronomical Society (from For, Koribalski & Jarrett (2012))
Optical telescopes – telescopes that collect visible light – show us shining stars, glowing gas and dark dust but this doesn't give us the whole picture of what's happening in space. Telescopes tuned to different parts of the electromagnetic spectrum can reveal hidden objects in space; the resulting images can then be combined to give a more complete picture.
Radio waves from space were first detected in the 1930s but little was done to follow them up until after the Second World War. In the post-war period CSIRO scientists and engineers were among the pioneers of radio astronomy.
In much the same way that you tune the radio to a particular station, radio astronomers can tune their telescopes to pick up radio waves millions of light years from Earth. Using sophisticated computer programming, they can unravel signals to study the birth and death of stars, the formation of galaxies and the various kinds of matter in the Universe.
In its simplest form a radio telescope has three basic components:
Radio telescopes can be used both night and day, and CSIRO's telescopes are operated around the clock.
Radio astronomers process the masses of information collected by a telescope. To help make sense of the strings of numbers, they convert the numbers into pictures. Each number represents information from a specific point in space. Often they have colours assigned to the numbers corresponding to the amount of information they represent. Astronomers then combine the colours to make a picture, visualising the information to reveal some of the characteristics of objects in the Universe.
Radio astronomy has changed the way we view the Universe and dramatically increased our knowledge of it, for example:
The science and engineering behind radio astronomy can also benefit our everyday lives, for instance: