Zeiss Planetarium Jena

The projection planetarium was invented at the Zeiss works in Jena in the early 1920s: Walther Bauersfeld designed a projector that threw stars onto a dome from inside, and to build the dome he developed a lightweight steel lattice sprayed with concrete, which was itself a construction innovation. The first was demonstrated in Munich in 1923, and Jena's own building opened in July 1926; it has run since and is the oldest continuously operating planetarium in the world. The dome is about twenty-three metres across. Modern digital projection has been added alongside the optical instrument, and the programme includes music shows as well as astronomy.

What you actually see

• The 1926 building - the world's oldest planetarium still in operation.
• The dome construction - a steel lattice and sprayed concrete technique invented for it.
• The optical projector - a Zeiss star projector alongside digital systems.
• The mixed programme - astronomy shows and music presentations.

When to go

Year-round; shows run to a published timetable and popular ones sell out, so booking is advisable. There is nothing to see outside show times.

Honest expectations

Entry is by show only, not general admission. Most programmes are in German. Shows sell out at weekends.

Nearby

The Leuchtenburg lies south; Weimar is west.