The observatory was founded in 1925 on the initiative of Cuno Hoffmeister by the town of Sonneberg with the support of the Carl-Zeiss-Stiftung.

To this end the sky is monitored continuously through photography, resulting in one of the largest archives of astronomical plates.

[4][5][6] The original observing programme was the Sonneberg Field Patrol, which was begun in 1924 by Cuno Hoffmeister and ran until 1995.

In 1960 and 1961, two quad-lens astrographs were commissioned and the survey was extended to 81 fields, which then included higher galactic latitudes.

[4][5] The observatory has a notable library, containing text books, monographs, conference proceedings etc., as well as periodicals and publications from other institutes and organisations.

There are tours of the observatory and meteorite collection as well as weekly public observing sessions.

This was removed to the Soviet Union after the Second World War, but replaced in 1960/1961 with two astrographs, funded, resp., by Zeiss Jena and Hoffmeister.

[2] In 1962 the new survey station began operation, which could photograph the whole sky to −35° declination on a nightly basis with B as well as V filters.

He had been removed from his position as teacher in 1933 by the Nazi regime because of his membership in the Social Democratic Party of Germany.

Although the town was bombarded by the US Air Force in April 1945, just days before the area was occupied by the US Army, the observatory suffered no direct damage.

However, the 400 mm astrograph and two survey cameras were removed to the Soviet Union as World War II reparations.

However, after the Berlin Wall was built in 1961, the Sonneberg Observatory found itself inside the restricted border area.

[4] In 1967 a reform of the academy resulted in the dismissal of Hoffmeister as director and the observatory becoming part of the Zentralinstitut für Astrophysik in Potsdam.

The closure of the site was scheduled for 1969, research into variable stars was to end, staff was to move to Potsdam.

The head of the observatory, Wolfgang Wenzel, managed to avert closure and then ignored a ban on using the large instruments until it was rescinded two years later.

Instead, Sonneberg in 1992 became part of the state observatory Thüringer Landessternwarte Tautenburg; it hence transferred from Brandenburg to Thuringia.

161 held in Potsdam adopted a resolution emphasising the importance of the plate archive and calling on the authorities not to close the observatory.

[note 2][4][2] In 1997 the Astronomy Museum was set up, operated by the Freunde[2][6] and a dedicated association Astronomiemuseum e.V.

Science outreach work, including operation of the Astronomy Museum, is delegated to the Freunde.

[4][6][2] In 2007 the plate archive, library and instruments changed ownership from the state of Thuringia to the Zweckverband.