Regarding exemplary science fiction

This is exemplary for a number of reasons.

Most importantly is the context of the piece. This is written in a context of wonder. Discovery, curiosity, committment, education - all these values are implicit in the piece.

It doesn't flinch away from detail explanation of the biochemisty of a Titanian raindrop because it IS fascinating. Mr Swanwick doesn't say: The raindrop fell and Lizzie caught it. No. He describes it for a reason.

The reason seems to be that the writer is saying something very significant to the reader. He is expressing a value, saying that you SHOULD be fascinated by the composition of a raindrop from Titan.

Why? Well the answer to that question is the essence of what makes good science fiction work - we are fascinated by that raindrop not because of what it is but because of who we are.

On an entirely different level, this is excellent because of the stateliness and pacing of the phrasing (the opening contrasts long slow sentences with short, action-based sentences; read it again!), the delicate admixture of scientific diction with everyday ("Dianocytelene condensed... until it was one shard in a cloud of millions"), and the understated tone of exaltation that subtly colors the words ("...it was only a breath away from hitting the surface.") and makes them rereadable . That's right, this is literature because you want to reread it.

Visually this can compete with the opening of an early Spielberg movie, building up from delightfully layered micro-details that pave the way for the story to unfold. But instead of simply quoting more lines from it, I encourage you to reread it now. It doesn't get much better than this.