So in the end of season three I think, when Thrace comes back and says 'I found Earth', the ending zooms out of the galaxy, zooms back in, and I could have sworn I saw Florida, the continental United States, and the gulf of Mexico, all while hearing 'I found Earth and I will take you there'. So when they finally get to the (nuked out) fake-Earth, that is presumably the planet.
So, why does fake-Earth have a Florida and Mexico? (We know the final-Earth was found because in the end when they arrive, we clearly see Africa and Arabia).