Habitability and Atmospheric Biosignatures in an Exoplanetary Context

Abstract

The extent of habitable conditions beyond the Solar System and the potential range of atmospheric biosignatures are central issues in exoplanetary science. We are currently at a fascinating juncture where the characterization of specific objects such as Proxima Centauri-b is an emerging theme for favored targets which lie in the habitable zone. It is the task of a new generation of atmospheric models and planned instruments to determine the climate and atmospheric compositions of these fascinating objects. This chapter reviews factors affecting planetary habitability and discusses the various definitions of the habitable zone. It also provides a brief overview of exoplanetary atmospheric biosignatures and their spectral signals.