http://www.dailymail.co.uk/sciencetech/article-1284013/Scientists-hint-life-Saturns-moon-Titan.html
Question:
Hydrogen is the lightest element on the periodic table and would float above the atmosphere, even in a methane/hydrocarbon soup like Titan. How can Hydrogen precipitate out of the atmosphere and "fall" to where the little microbugs can ingest it and make it disappear?
I understand that acetylene would be more dense than methane... but not hydrogen.
Part of the "hydrogen escape" mechanism is heat. The warmer a planet is, the more energy gas molecules have to bounce around etc. and eventually reach escape velocity. Also is the ability of UV light to crack the hydrogen atoms out of other hydrogen bearing molecules like water. And the solar wind plays a role as well.
And for heat, UV, and solar wind Saturn is roughly 20x farther out from the sun than the Earth is, give or take an AU or two. I can't recall if Titan has a significant magnetosphere which is what protects Earth from solar wind stripping (and why Mars suffers from it) but the gas giant Saturn itself certainly does which could protect Titan further.
I agree with the notion of scientific conservatism. If I were to bet on it, I'd lay my money on it being complex hydrocarbon chemistry we just don't understand as of yet, than actual life. However I certainly agree it bears further study.
If we find so much as fossil bacteria on Mars or living organisms eking out a meager existence in the permafrost, or Earthly ocean trench analogues under the ice on Europa, it'll be ground breaking and tell us a great deal about the probable existence of life in the entire Universe, seeing as it arose more than once just in our own star system.
Although in both cases, while they'd be "extremophiles", they'll likely be examples of "life as we know it", with similar cousins in our own Antarctic, or the sea floor.
If there's "Methane based life" on Titan, that will be truly ground-breaking. As that would mean the arena for life to develop is even wider than we first thought. For every 'warm' place like Earth, Mars, or under the ice of Europa, there's hundreds more 'cold' ones like Titan.