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A compilation of stories, telescopes, internship resources, and other things radio astronomy.

In the heart of the Eifel: das Radioteleskop Effelsberg

Scoping out Radio Astronomy

A blog dedicated to telling the history of radio astronomy: its evolution, its discoveries, and its telescopes

In the heart of the Eifel: das Radioteleskop Effelsberg

Olivia Wilkins

The Radioteleskop Effelsberg is one of the largest fully-steerable radio telescopes in the world, second only to the GBT. Its parabolic reflector dish has a diameter of 100 meters, which can be seen towering over the trees in the Eifel just 1.3 kilometers northeast of the village of Effelsberg in Nordrhein-Westfalen.

The radio telescope is operated by the Max-Planck-Institut für Radioastronomie (MPIfR), which began operations in 1966 in Bonn, 40 kilometers northeast of Effelsberg. After an application to build the 100-m diameter telescope was submitted to the Volkswagen Foundation, it was agreed that the site of the telescope would be in a valley to protect against radio frequency interference (RFI), which in the 1960s came mostly from nearby air bases. The Effelsberg valley was ultimately chosen because it opens to the south, making the center of the Milky Way accessible for observations. Construction commenced in 1967.


Since achieving first light in 1972, the Radioteleskop Effelsberg has been continuously improved and upgraded to become one of the most advanced modern telescopes globally. Upgrades have included everything from a new dish surface to better receivers to obtain higher-resolution data. The telescope has also been equipped with extremely low noise electronics, minimizing the interference in data, which is especially important for such a sensitive telescope. Although data collected at Effelsberg is not protected by a radio quiet zone, the trees and mountains of the Eifel help shield the rural instrument from rogue radio frequency interference.

In addition to being used as a single-dish telescope, the Radioteleskop Effelsberg has been part of several interferometry projects, collaborating with the Green Bank Telescope (USA), the Lovell Telescope (UK), Parkes Observatory (Australia) and Spektr-R (Russia).