The Round Tower in Copenhagen is Europe’s oldest functioning astronomy observatory. It was used by the University of Copenhagen until 1861 and nowadays it’s used regularly by amateur astronomers. The tower was built as a university observatory in 1642 due to Tycho Brahe’s influence although he died in 1601 so he didn’t live to see it. His close colleague Longomontanus was the first head of this new institution. The tower is in the centre of Copenhagen rounded by cafes, shops and restaurants so it is a building which can be found very easily:
From the ground floor to the top of the tower there is a spiral path which ascends you to the terrace where you can enjoy a beautiful view of Copenhagen:
As you are ascending to the top there are some visitable rooms with some references to Astronomy and Tycho Brahe:
Before arriving at the terrace, we find the Planetarium:
The planetarium in the Round Tower is a three-dimensional model of the solar System with the Sun at the centre, orbited by the six innermost planets. Copied from Bayer’s early 17th-century work, the background depicts the starry sky of the North. It was mounted in 1928 as a replacement for the original 1740 model.
The original planetarium showed both the Copernican system, with the Earth orbiting around the Sun, and Tycho Brahe’s divergent system, with the Earth at its centre.
The Planetarium was not installed until 1697, but it was built by Ole Romer, astronomy professor and head of the Round Tower observatory, as early as the 1670s.
We also find another plane model of the solar system…
which is a reproduction of another one found in one of the rooms of the tower: