I was pondering this idea about life existing without water. it lead me to this conclusion. Humans only know what is needed to sustain human life, not alien life. it is quite possible, that on other planets in nearby galaxies, there is intellegent life that is sustained by other things. it is possible that we havent seen these life forms here because our atmosphere could be deadly to them, and they havent found ways to "breathe" on class-m planets. the scientific ego still has this belief that we are the "only" intellegent life in our solar system. the truth of the matter is, we are probably too primitive to other worlds, they might not want to interfere and break their "prime directive" of not dealing with primitive life forms, for fear they might overwhelm us. my next statement may offend someone, so i apologize in advance, but look at the history of ancient cultures, and look at different events in the bible, as well as the accounts of the sumerians, the first civilization. it was clear that there was alien life her on earth, some even theorize that we were put here on earth by an alien for a purpose( read the history of the sumerians, akkadians, and mesopotaimians), so the idea that the vatican acknowledging aliens could exist is not a big surpise. if you ask me, they knew all along.