"ഗെയാ സിദ്ധാന്തം" എന്ന താളിന്റെ പതിപ്പുകൾ തമ്മിലുള്ള വ്യത്യാസം

[[File:The Earth seen from Apollo 17.jpg|thumb|The study of planetary habitability is partly based upon extrapolation from knowledge of the [[Earth]]'s conditions, as the Earth is the only planet currently known to harbour life (''[[The Blue Marble]]'', 1972 [[Apollo 17]] photograph)]]