"Just like there is an abundance of creatures on earth, there could also be other beings, even intelligent ones, that were created by God. That doesn't contradict our faith, because we cannot put boundaries to God's creative freedom. As saint Francis would say, when we consider the earthly creatures to be our "brothers and sisters", why couldn't we also talk about a "extraterrestrial brother"? He would still be part of creation."
If there is intelligent life out there, will they be Catholic? Will they believe that they too were created in God's image? Will they be tolerant of our Catholics' version of worship? I already know the flip side of those questions. Let's hope that ET is better at spiritual charity than we are.