Most have heard of the "Goldilocks Zone", where a planet orbits at just the right distance from its star to allow liquid water, widely believed a requirement for the abiotic origin of carbon-based life forms. Since those with a solid knowledge of chemistry almost always accept carbon as the only primary element capable of giving rise to life, we will presume this determination as fact.
Technically, the temperature range of the Goldilocks Zone largely depends on atmospheric pressure (discounting dissolved solids). On earth's surface, this Zone is 1 C to 99 C. Below this, you have solid water, and above this you generate its gaseous state. It is not reasonable to believe that the chemistry to evolve life will behave in the way required for abiogenesis outside this range. It is the liquidity of water that makes such things happen!
However, there is likely a more narrow range for the true Goldilocks Zone due to the reactivity and moderate stability of many biochemicals. Some would say this Zone is on the low end of the scale, perhaps from ca. 15 C to 50 C. Others have suggested it may be much higher since thermophilic bacteria on earth live in very hot water, some as high as 120 C ((in water at extreme oceanic depths, which prevents boiling). It seems more likely however that such organisms had their origins at much lower temperatures, and then evolved to occupy higher temperature niches. This is almost certainly true of all extremophiles.
The lower end to any "real" Goldilocks Zone is likely to be substantially above freezing, providing sufficient energy for molecules to interact and become self-replicating. Certainly some lower limit is suggested as it seems unlikely that life would arise from lifeless chemicals in the "slow-motion" chemistry encountered at temperatures close to freezing.
So, is there a "Abiogenesis Zone" within the Goldilocks Zone where life is most likely to arise? And, aside from all the required elements found in life on earth, are there any other absolute requirements other than liquid water to allow for the origin of life, as on earth? Some would think there must be.
Technically, the temperature range of the Goldilocks Zone largely depends on atmospheric pressure (discounting dissolved solids). On earth's surface, this Zone is 1 C to 99 C. Below this, you have solid water, and above this you generate its gaseous state. It is not reasonable to believe that the chemistry to evolve life will behave in the way required for abiogenesis outside this range. It is the liquidity of water that makes such things happen!
However, there is likely a more narrow range for the true Goldilocks Zone due to the reactivity and moderate stability of many biochemicals. Some would say this Zone is on the low end of the scale, perhaps from ca. 15 C to 50 C. Others have suggested it may be much higher since thermophilic bacteria on earth live in very hot water, some as high as 120 C ((in water at extreme oceanic depths, which prevents boiling). It seems more likely however that such organisms had their origins at much lower temperatures, and then evolved to occupy higher temperature niches. This is almost certainly true of all extremophiles.
The lower end to any "real" Goldilocks Zone is likely to be substantially above freezing, providing sufficient energy for molecules to interact and become self-replicating. Certainly some lower limit is suggested as it seems unlikely that life would arise from lifeless chemicals in the "slow-motion" chemistry encountered at temperatures close to freezing.
So, is there a "Abiogenesis Zone" within the Goldilocks Zone where life is most likely to arise? And, aside from all the required elements found in life on earth, are there any other absolute requirements other than liquid water to allow for the origin of life, as on earth? Some would think there must be.
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