The Sparrow, by Mary Doria Russell
This is one of those books I've heard fantastic things about for ages, and bought at least a couple of years ago, but have only gotten around to reading just now.
I should have done so sooner.
The Sparrow makes me wish I were still teaching, so I could put together a class on science-fictional anthropology/xenology. I would use this, and Ursula Le Guin's The Telling, and Orson Scott Card's Speaker for the Dead, and Ruth Nestvold's Looking Through Lace, and it would be fabulous.
But of course most people probably aren't reading it for its anthropological delights, at least not primarily. Fortunately, it has other things to offer, most notably a full set of fantastic characters and one of the most well-executed religious meditations I've ever seen. The religious part is Christian, specifically Catholic, specifically Jesuit, but the questions it grapples with are a lot more universal than that, and deeply compelling -- mostly, I think, because the characters are so well-drawn. If this were just about the idea, and not the people living it, I would not have cared half so much.
You may be asking yourself what, exactly, Jesuits are doing in a story about alien contact. Well, a radio transmission is received on Earth -- music from Alpha Centauri -- and while the rest of the world is dithering about what to do, the Society of Jesuits (in its typically efficient and hard-ass fashion) quietly organizes a mission, in the non-evangelical sense of the word. Of the four priests sent on the journey, not one of them attempts to convert the aliens they find on the other end, which I found refreshing, even if I'm not sure real Jesuits would show such restraint. Anyway, as one of the reviews on the back of my copy puts it, they send off "four Jesuits priests, a young astronomer, a physician, her engineer husband, and a child prostitute turned computer expert," for reasons that amount to either random chance or divine providence, depending on your point of view. This motley group loads themselves onto an asteroid and jets off to Alpha Centauri to find the Singers who made such beautiful music.
What they find strikes that delicate balance of being humanly comprehensible and inhumanly strange. But you know from the start that it will all go very wrong: the book unfolds in two parallel tracks, one giving the story of the mission's background and execution, the other detailing the aftermath, when the Jesuit Emilio Sandoz has returned to Earth, the sole (and mutilated) survivor of the expedition. This is not what you would call a happy book. Sandoz is a wreck in every possible way, from his soul to his almost completely non-functional hands. The question is what happened -- and, more importantly, why.
It took me a little while to get into this book. The early stages of the Jesuit inquiry into the mission are unproductive in the extreme, while the background half of the plot spends a lot of time setting up the characters in a non-linear fashion, before it gets to the alien signal and the plans that result from it. As a result, you're quite a ways in before you start to have any sense of the what, let alone the why, of the disaster. Curiosity was strong enough to lead me onward, though, and the payoff was worth it. And if the characters adapted a little too easily to life on an alien world, well, I'm okay with that; by the time the story got that far, it would have taken a lot more to make me put it down. It's a thought experiment, in a lot of ways, a narrative laboratory test designed to explore the way a human being might react to certain physical, emotional, and spiritual trials.
I've said before that I don't like idea-driven SF, and yet in a lot of ways, that's exactly what this is. I suppose the difference is the kind of idea. Technology? I could care less. The Sparrow makes a nod toward some kind of weird asteroid drive, and the Wolverton tube used to generate food for the passengers on their eight-month voyage, but those are there just to make the plot possible. The real ideas here are religious and xenological, and I'll happily curl up with those until the alien cows come home. It's rare for me to think up an "if you like X, you'll like Y" comparison, but I suspect any fans of Le Guin would be well-matched with this book.