The search for life outside the Earth has been one of the biggest quests of mankind. We have reached a level in technology that allows the first steps towards a scientific investigation. The aim of this workshop was to take an interdisciplinary look at the signatures that would be indicative for past or present life on another planet, to compare them to biosignatures on Earth, and to discuss state-of-the-art in-situ instruments that are envisioned to search for these signatures in the exploration of the solar system as well as concepts for the search for habitable planets around other stars.