Sunshine (Danny Boyle film from a couple of years ago). The distress beacon from the Icarus 1 which stalled near the surface of the sun 7 years earlier. http://www.youtube.com/watch?v=N-r4pPrHarw
Talk about your favourite sounds from sci-fi films/programs/whatevs. Stuff that you hear and get a weird unearthly shiver from. Add links too if you can be arsed. I'm riding a geek wave at the minute and would like some more input.
A top example is the horn sound made by the Tripods in War of the Worlds.