It turns out that the Catholic Church has not ruled out the possibility of extraterrestrial life. Moreover, if a science fiction story features space travel then there’s a 90% chance it will involve interactions with sapient extraterrestrials.
Assuming we humans encounter extraterrestrials at some point in the future (and that the Catholic church is willing to let them join, and that at least some of them want to join), I am curious as how the sacraments will be adapted for non-humans.
For instance, how will baptism work for a sapient alien that has to spend his entire life submerged in water? What about one who can not physically come into contact with water without dying?
If a sapient alien is photosynthetic, how would he be able to celebrate the Eucharist?
If there’s a sapient alien species that reproduces via autogamy, how would the church’s rules on sex, marriage, and gender apply to them?
I know we haven’t actually found aliens in real life; these questions are mostly thought experiments.