One thing I have discovered (to my surprise) is how shocked some folks get when I express my opinion that we humans are never getting off the earth in any serious way.

Oh sure, we might get a couple of people to Mars to walk around. Maybe a long-term space station with more than a handful of astronauts in near-Earth orbit. Maaaaaaaybe a moon station.

But we’re never, I think, going to colonize the planets. And we’re most emphatically never going to go to another star. This earth is pretty much it. We must learn to face the fact that the frontier period is past and we ain’t going anywhere.

These are not, by the way, religious opinions.

They are opinions based not on my theological views, but on cold, practical considerations about things like “what it takes to get there.” I’ll be willing to change my opinion when we establish a thriving metropolis in Antarctica, which is infinitely easier than establishing a serious, self-supporting colony on Mars or the Moon.

Similarly, to devotees of the search for extraterrestrial intelligence and the quest for “space, the final frontier,” I say my mind is strongly persuaded by a book called Rare Earth that the assumption of a densely populated cosmos is all wet and that intelligent (or even multi-cellular) life is a lot rarer than you’d think from watching “Star Trek.”

In short, I think that we are, for all practical purposes, all alone. If there’s somebody out there, we’ll never know it, because the odds are that intelligent physical life is so remote from us — if it exists at all — that we can’t hear it if it is broadcasting electromagnetic signals.

Again, I say this, not due to my theological views, but because science is on my side.

As Rare Earth demonstrates, more than 20 factors all have to line up just so in order to even have a shot at intelligent life arising on a planet. The odds against all those factors working out with such fine tuning are extremely slight. So the odds of life existing in most of our galaxy are likewise extremely slight.

Indeed, the vast majority of stars in the Milky Way cannot have inhabitable planets, since they are concentrated in the center, where stellar radiation makes the chemical conditions of life impossible.

Why this digression on science?

Because while my views are not theological, what I discover is that the faith in extraterrestrials and our eventual trek to the stars is deeply theological with many people.

Very typical of what I mean is the remark made to me by a friend a few years ago: “As thought experiments go, speculation about extraterrestrials has been (for me, anyway) a devotional exercise.” And not just for him. Note this weirdly Eucharistic anecdote about science fiction writer Kim Stanley Robinson from the Chicago Tribune:

“In the middle of writing Blue Mars, [Robinson] recalled, he took a small Martian meteorite he had purchased from a dealer and climbed to the roof of his home. At sunset, he popped the tiny stone into his mouth and swallowed it, hoping that having a piece of Mars inside him would enhance his creative process.”

Communing with the real presence of our great god and savior, Mars/Ares. Nope. Nothing religious going on here.

This is why the longer I live, the more persuaded I become that aliens fill, in a secular age, the imaginative and emotional niche that was once occupied by angels and demons just as our destiny in space fills what used to be the Christian hope of our destiny in heaven.

It is, I think, a profound illustration of the fact that our hearts are God-shaped vacuums, sucking in whatever comes to hand in the search for God or his nearest approximation.

Some will argue that Christians “fear” the notion of contact with extraterrestrials because it will definitively remove us from our “privileged” position and show that we are but one of many intelligent species throughout the cosmos.

But this simply goes to prove my point about the way in which angels and demons have receded from popular imagination and left a void. For the trouble with this criticism is that the Christian revelation already tells us there are myriad intelligent beings throughout Creation. That is, after all, what angels and demons are.

So I see no reason that finding extraterrestrials should trouble us as Christians. I merely think that there is plenty of scientific — not theological — reason to think that such biological creatures will never be found.

Colonization of the stars and contact with extraterrestrials (sort of) fills the void left by modernity’s abandonment of the true eschatological hope of the return of Christ.

Sooner or later, it will become evident to secularists that this hope is as chimerical as the Marxist hope of the “withering away of the state.”

I wonder whether that will prompt a return to Christian hope or simply lead to final despair?

Mark Shea is senior content editor

for www.CatholicExchange.com.