>>9334975Sure.
Ammonia. Methane. Magma. Carbon tetrachloride.
We don't see them every day because the temperature's not right -- fortunately for us!
Hydrogen and oxygen happen to be very common atoms so water is a common substance in the universe. And water is quite stable over a large temperature range. It may boil but doesn't dissociate easily as various organic (carbon) compounds would.
It also has the happy (and rare) property that its solid state is less dense than its liquid. Ice floats and forms an insulating barrier over a liquid sea, hindering further freezing.
A methane ocean would freeze from the bottom up until it was entirely solid.
