Radio Astronomy

Radio astronomy uses radio waves to study regions of space. Radio waves are a form of electromagnetic radiation - like visible light waves only with much longer wavelengths. Visible light waves are oscillating electromagnetic signals with wavelengths of less than one millionth of a metre, whereas radio waves have wavelengths in the range of a few millimetres to several metres. Radio telescopes gather and concentrate the radio waves from an astronomical source. The signal received …

…of a metre, and so collecting mirrors are large enough compared to a wavelegth of light that they can resolve the details of objects observed. However, radio waves have wavelengths of roughly one tenth of a metre and so even large radio telescope dishes produce blurry images. A single radio dish would have to be many kilometres across to achieve a sharp image at radio wavelengths and such telescopes have been too difficult to build.