dv said:
Bubblecar said:
Assuming there’s no life down there, I wonder how easy it would be to establish terrestrial marine life in such an environment.
The liquid is quite deep and we can expect it to be anoxic and cool. Contemporary macroscopic live on earth tends to like oxidated environments. There are extremophiles (Archae) on earth that could deal with such an environment but not fish or molluscs etc.
There exists beneath the water a rocky core and there is considerable dispute about its temperature. If it is warm then perhaps there exist the equivalents of our “black smokers” and other warm vents that could provide a stream of nutrients, warmth and high oxidation-state compounds: that might be a better bet than the shallower, colder water, but I am not an expert.
I’m going to agree and disagree. First of all, there cannot be any dispute about temperature because the transition from liquid to solid occurs at a temperature that is almost completely independent of pressure. That means that the top of the liquid ocean is going to be close to 2 degrees C, suitably cold for most types of oceanic life on Earth. The bottom of the ocean in Enceladus is going to be much hotter than 100 degrees C, so every form of oceanic life on Earth could find a comfortable temperature zone in Enceladus ocean. P.S. I cave already calculated these temperatures for all the solar system objects likely to or known to have subsurface oceans.
As for oxidation state, that hadn’t occurred to me, and it doesn’t matter much. We know that carbon-based life can only be abiologically generated in a reducing environment, so you are MUCH more likely to find living organisms in a reducing environment than in an oxidising environment. The first blue-green algae got an enormous competitive advantage by polluting its environment with oxygen, killing off almost all of its competitors. Anaerobic archaea and bacteria still haven’t recovered from that toxic atmospheric oxygen pollution.
I agree that black smokers near the bottom of Enceladus ocean may be producing sulphur rich water that single and multicellular lifeforms could live off. But I’m firmly of the opinion that we don’t know yet whether the probability of formation of life in that environment is more like 100% or one in 10 to the power minus 5 million. (See Topic 13 of “Topics in astronomy”).
I expect Enceladus ocean to have no life in it, in which case we could export an ecosystem there – it would have a much better chance of permanent survival than on the surface of Mars. But in some cases (such as humans in scuba gear) it would take a while for exported lifeforms to acclimatise to the very high pressures.
The ocean of Enceladus would survive the expansion of the Sun into a red giant. The ocean of Earth definitely would not.