Astrobiology: Future Perspectives

Abstract

Because of the paucity of geologic samples dating back to the early Earth, trying to unveil the nature of the prebiotic terrestrial environment is as frustrating as it is fascinating. An understanding of the characteristics of this period in our planet’s history is, however, crucial to studies of the origin of Life. Recent progress in astrophysics, geochemistry and simulation of planetary accretion provide some new and precious constraints but also question some of the previously admitted facts . The aim of this chapter is to highlight some of the important open-ended questions about the environment of the prebiotic Earth (for a more comprehensive review, see Kasting and Catling, 2003). The implications of recent theories of terrestrial planets formation on the origin and early evolution of the atmosphere are discussed, in particular, along with the various influences of our faint but active young Sun during this period.