In 1977 (the same year we opened up shop), the twin spacecraft Voyager 1 & 2 were launched, and aboard them was the 'Golden Record', a gold plated copper disc carrying music, speech, Earth sounds and encoded images as a form of time capsule and possible introduction to any aliens that might chance upon it.
It's the coolest record ever made, at once a blast from the past and a beacon into the future. Voyager 1 has now left the solar system, carrying the record into interstellar space, and Voyager 2 will follow it soon.
What's on the record
The contents of the record were selected for NASA by a committee chaired by Carl Sagan. Dr. Sagan and his associates assembled 115 images and a variety of natural sounds, such as those made by surf, wind and thunder, birds, whales, and other animals.
To this they added musical selections from different cultures and eras, and spoken greetings from Earth-people in fifty-five languages, and printed messages from President Carter and U.N. Secretary General Waldheim. There are also 115 images encoded in analog form.
Each record comes with a cartridge and a needle. Instructions, in symbolic language, explain the origin of the spacecraft and indicate how the record is to be played:
Hear the recordings
NASA has now put the recordings onto SoundCloud so you can hear them just as the aliens will (provided they can find a turntable!).
Check them out below: