Short and painless:
Based on the location and time, we calculate the constellation of the stars visible to you. Since the earth rotates around itself and in the course of a year around the sun, the starry sky changes depending on place and time. With the help of thousands of data from the European Space Agency (ESA), we can show you not only past starry skies, but also constellations of stars in the future.

For all those who want to know more:
The information for our maps comes from the Hipparcos Catalogue (HIP) of the European Space Agency (ESA). It is a high-precision star catalogue measured by the Hipparcos astrometry satellite. The results established a new era in astrometry and its measurement of more than one hundred thousand stars now renews the image of our cosmic environment. For further information: www.sci.esa.int/hipparcos. The star map shows all stars (magnitude 6) theoretically visible to the human eye under a dark sky. You can compare your Star Map with any open source planetarium software. We recommend Stellarium.org for this. From a human perspective, the relationship between the stars and our solar system is changing incredibly slowly. Therefore, already in ancient times people could see the same known constellations that we still admire today. Nevertheless, the starry sky visible to us changes every night, every week and every year as the Earth revolves around itself and the Sun.