Effelsberg radio telescope. Composite image of a coloured radio image of the Milky Way (upper frame) and the Effelsberg radio telescope (lower frame), which was used to obtain the data. The 100-metre telescope was inaugurated in 1972 and is one of the world's largest fully steerable radio telescopes. It operates at wavelengths from about 7 millimetres to 90 centimetres. It is operated by the Max Planck Institut fur Radioastronomie at the University of Bonn in Germany and has been used in several astronomical surveys. For nearly 30 years it was the largest fully steerable radio telescope until the opening of the Green Bank Telescope in Green Bank, West Virginia, USA, in 2001.