Astrobiology is the study of life in the universe in general sense. It covers several scientific domains such as prebiotic and interstellar chemistry, micropaleontology, limits of life, habitability, biosignature detection… The AB1 session is a general session where every scientist involved in one of these fields is welcome to present his work. Note however that there are other astrobiology sessions that are concerned with specific topics, such as: “Planetary Habitability in the Solar System and Beyond” for session AB2, “Organic molecules in the Solar System and beyond” for session AB3, and “The importance of organic matter evolution from the Interstellar medium to planetary systems” for session AB4.