Listen to this - http://www.nasa.gov/123163main_cas-skr1-112203.wav - it is a radio signal from Saturn that has been shifted into audible frequencies by NASA. Sounds like something from an old episode of Blakes Seven.
http://www.nasa.gov/mission_pages/cassini/multimedia/pia07966.html
Drat - the sound card on my computer went phut a while ago and I haven't got around to fixing it! :-?