Earthman tried as beast, forced to recant
The narrator reaches the moon by a fireworks-driven machine and finds its inhabitants walking on four legs. Because he walks upright, they treat him as a curious animal, keep him as a pet alongside a stranded Spaniard, and have their scholars debate whether he can reason at all. When he insists the moon he came from (Earth) is a real world, lunar priests condemn it as heresy and force a public recantation, a parody of Galileo's trial with the human now the specimen being classified.