Effelsberg radio telescope. This 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, Germany, and is part of the Event Horizon Telescope. 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.