Habitats of life

Abstract

There are four principal habitats in which life may exist - the surface of a planetary body, its subsurface, its atmosphere and space. From our own experience we know that life does exist on the surface of a planet, in its subsurface and transiently at least in the atmosphere. Where it is present, it exists in a surprising diversity and in a variety of microhabitats, from deep caverns (Hose et al. 2000; Melim et al. 2001) to hydrothermal fluids and hot springs of various chemistries (Jannasch 1995; Rzonca and Schulze-Makuch 2002), to the frozen deserts of Antarctica (Friedmann 1982; Sun and Friedmann 1999). In this chapter we will elaborate on the principle habitats, the constraints they impose on life, and the possibilities they provide. © Springer-Verlag Berlin Heidelberg 2008.