General definition of exobiology is the study of life in the Universe. More precisely it includes:
- the study of conditions and processes which have lead to the emergence of life in our planet, or which could have lead to it somewhere else
- the study of the evolution of organic matter from soimple to more complex structures in the Universe
- the research on the distribution of life under any form it could appear, and its evolution in the Universe

Recent developments in astronomy (discovery of extra solar planets, space exploration...) are at the origin of this new interdisciplinary field of research and we will present what could be the trails to follow to try to understand the origin of life.