by wrongc0ntinent on 5/17/16, 8:25 PM with 13 comments
by deepnet on 5/18/16, 9:30 AM
Urey & Miller terrestrial biogenesis happened during the Hadean / Archean transition and their pre-biotic soup had a different chemistry than today.
James Lovelock developed the homeostatic biosphere theory that life shapes its enviroment at JPL, when hunting for Martian Methane.
From Lovelock and Margulis's Giai paper: "3.2 x 10^9 years, that life has been present on Earth, the physical and chemical conditions of most of the planetary surface have never varied from those most favourable for life" [1]
by datashovel on 5/18/16, 12:29 AM
I don't think they were trying to assert this necessarily (that the current conditions of Europa were necessary and sufficient for life to exist there), but I just wonder this every time I read about space exploration and the fact that scientists are seeking planets that have an earth-like atmosphere.
Personally I'd want to know (a) what conditions caused life to begin on earth, then and only then (b) which planets have, presently or in the past, similar conditions.
All the talk about looking for earth-like planets to find extraterrestrial life could be a big waste of time if we eventually learn that present-day conditions on Earth are not conducive to creating the fundamental building blocks for life, no matter how good it has been at sustaining it.
UPDATE: Sorry, just noticed I mention atmosphere in my comment. That's a mistake. I was thinking 'earth-like conditions' (which is more or less what's mentioned in the article), but I typed atmosphere.
by ck2 on 5/17/16, 10:51 PM
It has less gravity than earth's moon.
(I love how google can now tell me gravity of planets and moons)
by headcanon on 5/17/16, 9:31 PM