"Galileo Galilei...supported Copernicus’ view that the Earth orbited the Sun, a “heliocentric” theory which the Church declared contrary to Scripture... Giordano Bruno not only supported the heliocentric view, he also claimed there are multiple worlds beyond Earth, each orbiting their own sun.... The idea of aliens and multiple worlds is not new for the Church.... The Vatican even sponsored an astrobiology workshop in 2009.
"Philosophers have been grappling with the implications of alien life for hundreds of years, if not longer. But until aliens are found, says (Vatican astronomer Brother Guy) Consolmagno, these issues will remain in the realm of science fiction instead of religion or science. “I think that’s a very important role that science fiction has to play, because at this point we’re just playing with ideas,” says Consolmagno. “We’re just exploring the space where the ideas could be. We don’t know – we don’t have the answers. That’s why it’s so much fun!”