I've always wondered if the Earth could have existed in a binary with a larger, habitable planet; if the Moon, for instance, was habitable. How much of an exploratory incentive would it have been to our species if we could see another Earth with seas and forests staring down at us every night?

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I think fish is nice, but then I think that rain is wet, so who am I to judge?

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.