[fractionalhare]

Triton is a nitrogen saturated, frozen wasteland colder than Pluto. Perhaps you're thinking of Titan? Titan is also an icy hellscape at nearly -200 C, but you can look forward to an ocean of ammonia once you manage to break through the surface.

Europa has liquid water, but the average surface temperature is still colder than the worst ever recorded on Earth. The speculative oceans you seek would be encased under miles of solid ice, just like Titan's. Europa is likewise catastrophically radioactive.

These places are all extremely small, extremely far away and extremely deadly. They make Mars seem pleasant.

[xvilka]

Right, I mixed both.