Chapter 7 - Habitability in the Solar System beyond the Earth and the search for life

Abstract

In contrast to exoplanets, all the worlds of our Solar System are accessible for a direct in situ investigation for life and sample return to Earth laboratories. This makes these worlds of particular interest in the search for a second genesis of life beyond the Earth. To organize the search for life in the Solar System, we need to first determine the habitability of these targets and then the possibilities of accessing evidence of life on these worlds. In this chapter, I review our current knowledge of the habitability of current target locations for life detection missions. This review concludes that of all the worlds in our Solar System, three can be listed as suitable targets based on our current knowledge: Mars, Enceladus, and Titan. Missions to the surface of Europa or the clouds of Venus are not suitable because there are no known habitable environments at these locations. Other targets suggested to be of possible astrobiology interest for which present or past habitability remains an open question include Ceres, Vesta, the clouds of Jupiter, Triton, Pluto, and even the Moon.