Originally posted by sonhouse
I would imagine the cold temps are far too extreme. I know there are some microbes that live in extreme cold, but I doubt they could've been formed under cold temperatures.
According to the link, Earth's early temperature of 3.7 billion years ago was likely able to sustain temperatures above freezing due to evidence of enough CO2 being around at that time to keep temps above freezing.
If this is the case, the microbes in the colder places on earth first lived in less extreme cold, and probably evolved over time to be able to sustain colder and colder temperatures. I doubt any planets on Jupiter or Saturn would have life, since life (as we know it) would have even more extreme temperatures than earth's, and probably never had a point (unless you guys evidence to contrary) where their temps were moderate enough to sustain life...especially since (according to the article) the sun was more faint (weaker) than it is now.