But then look at the description of chemosynthesis there – using the oxidation of inorganic compounds. Where do they get an oxidizing agent? Usually it’s oxygen, or else ions like nitrate or sulfate formed from it. Our oceans have these in constant supply because of photosynthesis at the surface, and otherwise they’d have been used up billions of years ago. It doesn’t address the question for Europa.
The amount of energy you can capture from a thermal gradient is relatively small, and something would have to be huge to actually experience a noticeable gradient from tidal heating. In theory it could power some kind of geological activity, like hydrothermal vents…but then see above.
I don’t know, I’d feel a lot more optimistic if someone ever explained how this could possibly work, instead of giving analogies to Earth ecosystems that aren’t nearly as isolated as people portray.
