But as astronomers continue to discover additional planets in the cosmos -- including some that seem to be able to sustain life -- the question gains new intensity, and not just for scientific reasons but also for theological concerns.
As this BBC piece notes, the potential discovery of other life in the cosmos "would raise a series of questions that would exceed the bounds of science. For example, when we ask, 'What is life?' are we asking a scientific question or a theological one? Questions about life’s origins and its future are complicated, and must be explored holistically, across disciplines. And that includes the way we respond to the discovery of aliens.
"This is not just an idle fantasy: many scientists would now argue that the detection of extraterrestrial life is more a question of when, not if."
In several faith traditions, including Christianity, there tends to be a myopic view of life that suggests humans are not only at the top of the chain but that there are no other possible forms of life anywhere else that could match our wonderfulness.
A few years ago, for instance, science writer John Gibbon made something like that argument in his book Alone in the Universe: Why Our Planet is Unique.
It's a seductive argument, but it doesn't prepare us theologically for the possibility that life of some sort might be found beyond Earth. What might be the theological implications of that, especially for Christianity, which teaches that God so loved humanity that God became incarnate in a human being, Jesus of Nazareth?
Would we have to imagine Jesus becoming incarnate on the planet Tralfamadore out of love of the Tralfamadorians if such a place populated by such beings is found?
If so, what does that do to the essential tenets of Christianity, if anything?
This conversation can drift easily into strange fantasy and away from our responsibilities to live compassionately here on Earth, but if it challenges our too-small notions about God, perhaps it's worth it.
(The photo you see here today is one of a series of clouds I've taken from airplanes. But in this case, the lens is pointed mostly toward Earth, not toward the mysteries of outer space, where other life might or might not exist.)
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MAYBE ANNE FRANK'S FAMILY WASN'T BETRAYED AT ALL
Speaking of old questions, one from World War II is about who might have revealed to authorities the hiding place of Anne Frank and her family. There are lots of theories about the discovery of the young Jewish girl who left a now-world-famous diary. But as this Washington Post piece reports, researchers now think there may have been no betrayal at all. It might just have been coincidence. In any case, let's remember the point that Alvin H. Rosenfeld makes in his book The End of the Holocaust: The Holocaust was a whole lot bigger than Anne Frank, and Anne herself was more complex than the one quote often repeated from her about her not losing hope in humanity.