A not very big house in Karlova Street, close to Charles Bridge, has a plate hanging on its wall commemorating that it was here where Johannes Kepler lived while staying in Prague. The majority of passers-by don’t pay much attention to this reminder of the prominent mathematician and astronomer, and the museum which has been recently opened in the house will probably not change much on this respect. It is a small place, the entrance fee is very reasonable and it is likely to attract better-informed visitors by and large. It is without doubt an attractive place.

UNESCO, OSN and Galilean telescope

The year 2009 was declared International Year of Astronomy by UNESCO and the United Nations. The move was partially initiated by the Italians who suggested honouring the 400th anniversary of the first use of a Galilean telescope for systematic astronomic observations. The International Year of Astronomy 2009, IYA 2009 - www.astronomy2009.org, www.astronomie2009.cz) is coordinated by the International Astronomical Union and virtually every Praguer is proud of the fact that its 26th congress was held in the Czech capital city in 2006.
Every state contributes to the world astronomical celebration according to its means. Czechs soon realised that apart from the first use of a Galilean telescope for systematic astronomic observations, another event significant for Prague happened 400 years ago. Johannes Kepler, who at this time belonged to the Emperor Rudolph’s court, published his excellent, and by astronomers still highly appreciated book, called the Astronomia nova, which contains two of his famous laws.

From this discovery it was only a small step to reach the decision to organise the international scientific conference entitled Kepler’s Heritage in the Space Age (http://www.astro.cz/clanek/3912).

Ceremonial opening in spite of pitfalls

Even though the idea to found the Kepler Museum is not new, it wasn’t so easy to carry it out. The Museum of the Founder of Celestial Mechanics, as Kepler is sometimes called, was supposed to be opened as early as 14th May. The celebration had to be postponed due to insufficient finances. Fortunately, the organisers didn’t give up and made a resolution that the Museum had to be open to mark the International Year of Astronomy as this is a unique occasion. Eventually they succeeded and the place was opened to the public on 27th August, marking the end of the Prague’s international conference dedicated to Johannes Kepler’s work.

Talking about the conference, we should also mention that its participants didn’t only visit Prague but also made a trip to nearby Benátky nad Jizerou, where Kepler would often travel to visit his teacher Tycho de Brahe, and they also ventured to the Austrian town Linz, where Kepler lived at one point of his life.

What is on offer in the museum?

The small 20 m2 space of the historical building in Karlova Street offers visitors several information boards and a few unique animations such as the recording of a snowflake’s growth, which was a source of great fascination to Kepler. Visitors will also be able to look at and try out a model of a gear pump invented by Kepler.  Other exhibits include replicas of tools used by the astronomer in his work, and children can look forward to a few surprises.

Legends describing individual exhibits will be in Czech and English. The Museum is meant for a wide public, school groups, college and university students and international visitors. Purchase of souvenirs is also possible in the building.

The three circles in the Kepler Museum’s logo stand for Mars, the Earth and the Sun - celestial bodies that Kepler investigated while living in Prague. The logo was designed by Kateřina Kerelová.

Tickets have an original design as well. They are composed from the design on the dial of Prague's Astronomical Clock, showing the exact time when the museum was entered, in Old Czech and Babylon signs as well as in the sideral time. There is a part of the Renaissance star sky map printed on the other side of the ticket, and the whole map can be assembled from 12 tickets. The tickets were designed by  Vojtěch Sedláček.

Opening hours:

daily except Monday, from 10 a.m. until 6 p.m.


30 czk adults

20 czk children, teachers and seniors older than 70 years

free entry - children younger than 7 years and members of the Czech Astronomical Society

Who was Johannes Kepler

He was a pioneer of many things that were studied or carried out many decades later, said Antonín Švejda from the National Technical Museum about Kepler.

Johannes Kepler was born on 27.12.1571 in Weil der Stadtu, and died on 15.11.1630 in Regensburg.  He studied at the university in Tubingen. After his graduation in 1593, he worked as a teacher at the college in Graz, between 1594 and1600. In 1600, Kepler arrived in Prague to become an assistant of Tycho de Brahe. At this time he was a mathematician influenced by Copernicus’ teaching. As a member of the group of astronomers around Tycho de Brahe he participated in processing Brahe’s measurements of the exact orbit of the planet Mars. When Tycho de Brahe died a year later, Kepler became the Emperor’s mathematician and astronomer.

The tolerant atmosphere of Rudolphine Prague enabled Kepler to carry out intensive scientific research.  Between 1600 and 1609, Kepler worked in Prague on his fundamental work, the Astronomia nova. At the end of 1608, the Emperor granted the last financial support, and in 1609 Kepler published his book. The Astronomia nova records the discovery of the first two of three principles known today as Kepler’s laws of planetary motion. Ten years later his book Harmonices mundi, which contains the third law, was published in Linz. Kepler’s laws specified the foundation of astronomy, and became a starting point for the new stage of the development of human knowledge influencing several scientific disciplines as well as the overall philosophical perception of the world. Jiří Grygar said that "Kepler’s laws became the Bible of astronomy. “  More at: http://fyzweb.cz/materialy/aplety_hwang/KeplerovyZakony/Kepler_cz.html

In 1612, Kepler left for Linz and in 1626 moved to Ulm. According to some biographers, Kepler was unable to make any observations when he was of advanced age, because he was short-sighted and allegedly wasn’t able see the stars at all.

Source: Czech Astronomical Society and others