According to estimates, the universe contains several 100 billion stars and, thus, many planetary systems. With the support of the FWF, astrophysicist Manuel Güdel is exploring on which of these life would be possible. Güdel's interest in astronomy was first awakened by the mission Apollo 11, the spaceflight that first landed humans on the Moon. Having learned a great deal about the development of planetary systems since, he has realised just how fragile our home planet Earth is. "We should take good care of it," the researcher warns in this portrait.