I've often wondered about this. Do Catholics believe in 'alien' lifeforms? Well, DO THEY?
"When he was asked about the possibility of extraterrestrial life, the Director of the Vatican Observatory (Fr. Funes) responded that "it is possible, even if until now, we have no proof. But certainly in such a big universe this hypothesis cannot be excluded."
Asked is he sees a contradiction between the Catholic faith and believing in aliens, he said, "I think there isn't (a contradiction). Just as there is a multiplicity of creatures over the earth, so there could be other beings, even intelligent (beings), created by God. This is not in contradiction with our faith, because we cannot establish limits to God's creative freedom. To say it with St. Francis, if we can consider some earthly creatures as 'brothers' or 'sisters', why could we not speak of a 'brother alien'? He would also belong to the creation."
Aren't you glad I asked?