Habitability of natural satellites is the measure of a
natural satellite's potential to sustain
life. It is an emerging study which is considered important to
astrobiology for several reasons, foremost being that natural satellites are predicted to greatly outnumber planets and that it is hypothesized that habitability factors are likely to be similar to
those of planets. There are, however, key environmental differences which have a bearing on moons as potential sites for
extraterrestrial life.