Astronomical objects emit energy in the form of electromagnetic waves in the entire wavelength spectrum. They emit high-energy, very short-wave gamma and X-ray radiation as well as longer-wave and hence lower-energy radiation such as visible light, even longer-wave infrared and microwave radiation and even lower-energy radio radiation.
Radio radiation gets its name from the fact that humans use electromagnetic radiation in this wavelength range for radio transmission.
The Earth's atmosphere absorbs or scatters the electromagnetic radiation emitted by astronomical objects. The physical processes responsible for this vary in strength depending on the wavelength. Gamma radiation, for example, is absorbed in the upper atmosphere and does not reach the earth's surface. For visible light, short-wave infrared radiation and long-wave radiation in the radio wave range, on the other hand, the Earth's atmosphere is relatively well permeable, as the following figure shows well. Astronomical objects can be observed particularly well through these "atmospheric windows".
The 3 meters large radio telescope of the Hans Haffner observatory opens thus for pupils and students besides the optical atmospheric window a further window into space.
In 2013, plans began to expand the observatory to include the radio telescope. After the financing of the radio telescope had been ensured thanks to the generous support of the Wilhelm and Else Heraeus Foundation, the planning of the necessary extension could be tackled, the financing of which was secured through the support of the Klett Foundation.
The practical implementation of this project was realized in the same way as the construction of the observatory: through the extraordinary, tireless efforts of numerous students and with the great support of local companies and craftsmen.