In keeping with the International Year of Astronomy, the two-parter "Faszination Universum" traces important stages in the exploration of our solar system and the universe. 400 years ago Galileo Galilei looked for the first time through a telescope in the sky. For the first time he saw the crater landscape of the lunar surface, he saw planets that were otherwise only seen as points of light in the sky. In the same year Johannes Kepler published his calculations about the planetary orbits. He wanted to make observations in clear formulas and understand the laws of the processes in the sky. The year 1609 marks the beginning of astrophysical research. So UNESCO declared 2009 the International Year of Astronomy. (Text: ZDF, translated from German)