Post #414030

The presence of atmospheric pressure and an ecosystem are explainable by it being the interior of a living being. We don't know anything about its biology but it's presumably evolved to have mynocks living inside it, like we have bacteria inside us. We assume that the Falcon tells Han that there's sufficient pressure that they'd only need breathing masks. The only issue then is why he isn't more suspicious of this, but in a universe like SW's this sort of thing might be not unheard of.