Please Note: The Library Hall and current exhibition is closed as we prepare the coming exhibition “Light Echoes”, opening on October 2nd.
Open 10-20.

The Observatory

The Observatory

The Round Tower is the oldest functioning observatory building in Europe. King Christian IV erected the tower to enable astronomers from the University of Copenhagen to gaze at the stars far above the lights and the smoke of the city. For centuries, it was the centre of Danish astronomy and the point of departure for meteorological observations and surveying.

The Round Tower was originally known as “Copenhagen’s Royal Star Castle”. The Observatory at the top has undergone several changes throughout history. Over the centuries, a number of different structures have stood atop the tower to house its astronomical instruments.

The present-day Public Observatory dates from 1929. The same year the refracting telescope arrived, allowing a magnification between 80 and 450 times. The Observatory is open throughout the Round Towers normal opening hours, where you can look inside, letting your thoughts wander across the Universe.

During the winter months, it is staffed for skygazing Monday and Tuesday evenings, allowing all visitors to observe celestial objects through its telescope, weather permitting.

What Can You See in the Night Sky?

Below is an overview of the celestial objects we expect to be able to observe through the telescope on each evening – provided that the weather is clear and not rainy or overcast:

Oct 5 Saturn

Okt 6 Saturn

Oct 12 Saturn

Oct 13 Saturn

Oct 14 Saturn

Oct 15 Saturn

Oct 16 Saturn

Oct 19 The Moon, Saturn

Oct 20 The Moon, Saturn

Oct 26 The Moon, Saturn

Oct 27 The Moon, Saturn

Nov 2 Saturn

Nov 3 Saturn

Nov 9 Saturn

Nov 10 Saturn

Nov 16 The Moon, Saturn

Nov 17 The Moon, Saturn

Nov 23 The Moon, Saturn

Nov 24 Full Moon, Saturn

Nov 30 Saturn

Dec 1 Saturn

Dec 7 Saturn

Dec 8 Saturn

Dec 14 The Moon, Saturn

Dec 15 The Moon, Saturn

Dec 21 The Moon, Saturn

Dec 22 The Moon, Saturn

Dec 28 Saturn, (Jupiter)

Dec 29 Saturn, (Jupiter)

Jan 4 (Jupiter), Saturn

Jan 5 (Jupiter), Saturn

Jan 11 (Jupiter), Saturn

Jan 12 The Moon, (Jupiter), Saturn

Jan 18 The Moon, (Mars), (Jupiter), Saturn

Jan 19 The Moon, (Mars), (Jupiter), Saturn

Jan 25 (Mars), (Jupiter), Saturn

Jan 26 (Mars), (Jupiter), Saturn

Feb 1 (Mars), (Saturn), Jupiter

Feb 2 (Mars), (Saturn), Jupiter

Feb 8 (Mars), (Saturn), Jupiter

Feb 9 The Moon, (Mars), (Saturn), Jupiter

Feb 15 The Moon, Mars , Jupiter, (Saturn)

Feb 16 The Moon, Mars , Jupiter, (Saturn)

Feb 22 Mars, Jupiter, (The Moon), (Saturn)

Feb 23 Mars, Jupiter, (Saturn)

Mar 1 Mars, Jupiter, (Saturn)

Mar 2 Mars, Jupiter, (Saturn)

Mar 8 Mars, Jupiter, (Saturn)

Mar 9 Mars, Jupiter, (The Moon), (Saturn)

Mar 15 Mars, Jupiter, The Moon, (Saturn)

Mar 16 Mars, Jupiter, The Moon, (Saturn)

Mar 22 Mars, Jupiter, (The Moon)

Mar 23 Mars, Jupiter

Mar 29 Mars, Jupiter

Mar 30 Mars, Jupiter

What’s on

The Observatory through time

The Round Tower is Europe’s oldest working observatory building. However, the Observatory at the top has changed appearance several times throughout its history. Discover the story of the Round Tower Observatory here

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Siegfried Wagners buste af Tycho Brahe

Tycho Brahe Was Not Here

Tycho Brahe has never set foot in the Round Tower, which was not finished until long after the world-famous Danish astronomer had died in exile in Prague. Yet there is a direct line from Tycho Brahe to the Observatory at the top of the tower.

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One of the almanacs from 1700 with the royal cipher of Christian V

Almanac

For nearly 200 years, the Round Tower figured on the front cover of the University of Copenhagen's almanac as a as a token of the university vouching for the authenticity of the content. But you should not believe everything you read.

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The bombardment of Copenhagen 1807. Museum of Copenhagen

Rocket Science Seen from the Round Tower

The British bombardment of Copenhagen in 1807 was not just a catastrophe for the city. The rain of bombs, grenades and rockets also led to what has been called the world's first example of rocket-based astronomy - with the Round Tower in an important role.

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View from the Round Tower

The Elements of Wind and Weather

From 1751 onwards, astronomers made daily systematic observations of the weather at the top of the Round Tower. They did it for the first time in Denmark and had a very specific purpose. For what if you could predict rain, snow, lightning and thunder for years to come?

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The Observatory with the Greenlandic flag

The Universe in Greenlandic

The Danish Astronomer G. F. Ursin disliked the Greenlanders thinking of the Sun as a Greenlandic woman and the Moon as a Greenlandic man. But he himself had no problems imagining life in space.

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