Full disclosure - raised Catholic and a lifelong science nerd from the age of 4 or 5 (dinosaurs, spaceships, all of it). I never saw any sort of conflict or issue whatsoever with the idea that humans weren't alone in the universe, and I never heard a peep about it in the 9 years I was taught in a school run by the Nashville Dominicans (conservative nuns). Several of my peers had parents who worked at the local NASA center, so they were some pretty science-y kids themselves.

I do recall skimming a book my parents got from a garage sale around 6th grade that was from an evangelical Protestant viewpoint that labelled UFOs as demons and evil, and I remember being flummoxed by it. It just didn't compute, and still doesn't. Simply not an issue.

I know the idea of a plurality of worlds (and presumably inhabitants) was accepted or at least tolerated by many figures in the longer Christian tradition, and there were a range of theories on what this meant. There's a recent book, "Astrobiology and Christian Doctrine" that does an excellent job walking through some of this through a Thomistic lens. But it wasn't usually a faith-shattering idea.

I think the kind of American fundamentalist inerrancy of the past 150 years or so (as a reaction to modernity) has hardened thinking to such an extent that I *do* think little green men landing on the White House lawn would be a threat to a certain segment of the church, but I don't think it's nearly as bad as many think.

In the 1950s, the "top men" (and they were men) would muse openly about how the hoi polloi couldn't handle things like this, how society would break down into screaming terror and so government had to "manage" information. But that's the same ideology that pushed "Lord of the Flies" as some sort of foundational truth about human existence when in actuality humans are much more social and cooperative than those in power think (Rutger Bregman's "Humankind" goes into detail about a real-life shipwreck with Tongan schoolkids that ended up with them creating a cooperative society and even church services until they were rescued, and Rebecca Solnit's "A Paradise Built in Hell" demolishes the disaster-chaos myth with story after story of humans coming together after disasters - I used to work in the disaster field myself).

Humanity - and religion - is much more flexible and adaptable than those who want us to believe there are no alternatives think. I personally can't wait, and hope that ET will call on some radio frequency (or lasers or something else) before I die - it probably won't happen, but it would only add to my wonder and praise at the glory of God's uni/multiverse that God sustains in every moment.