" ) >> dryuan: it's so great. >> cooper: why "johnny b. goode"? >> dryuan: to me, "johnny b. on, of moving, getting to someplace you've never been before and the odds are against you, but you want to go. that was "voyager." >> cooper: do you imagine the extra-terrestrials who discover this, tapping their feet to "johnny b. goode?" >> dryuan: that was the joke on "saturday night live" when "voyager" was launched. you know, they broke in and said, "this just in from the extra-terrestrials..." >> steve martin: ...send more chuck berry. >> cooper: the voyagers haven't found any extra-terrestrials so far, but they have contributed to the search for life in space. their observations of jupiter's moon, europa, suggested there might be an ocean beneath its icy surface, which was later confirmed by another spacecraft, "galileo." "voyager 2" also sensed that something unusual was happening on saturn's moon, enceladus. many years later, the "cassini" spacecraft discovered geysers of water shooting above its surface. so, on europa and enceladus, you found water, which means potentially, t