Personally, I think that this is one of the greatest science fiction movies I have seen, because it's a little refreshing to see aliens who aren't here to suck our brains out through our noses or colonize the planet, and government organizations that don't shoot said aliens etc. It is also pretty successful at capturing the awe and mystery of events like those in the movie.

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"Sometimes you get the bear, and sometimes the bear gets you."
-Commander Riker, USS Enterprise