Effelsberg 100-m Radio Telescope

The Effelsberg 100-m Radio Telescope is a large dish antenna in Bad Münstereifel that receives electromagnetic radiation from space and is used to observe stars, galaxies, and clouds of gas. The white parabolic reflector rests on a rotating steel base and can tilt upward to an elevation of nearly 90 degrees.

After opening in 1972, this facility remained the largest fully steerable radio telescope in the world for nearly three decades. It was built by the Max Planck Institute for Radio Astronomy in Bonn and continues to operate under the same institution.

Effelsberg takes its name from the ridge south of Bad Münstereifel where the facility sits in a wooded valley that shields it from unwanted radio noise. Visitors can walk onto the grounds and approach the enormous dish from close range, watching it pivot slowly toward different sections of the sky.

Anyone visiting the site should turn off mobile phones and electronic devices during observation periods because even faint signals can interfere with the measurements. The access road passes through forest and low hills, with the telescope becoming visible only during the final stretch of the approach.

The entire mirror support structure was designed by computer so that the parabolic shape remains perfect at all observation angles, even though the weight of the construction acts differently depending on its position. This technique was new at the time of construction and made it possible to build a much larger moving telescope.