One of the most moving and beautiful astronomy and space books of all time was Carl Sagan's "Murmurs of Earth", an account of the Voyager 1 space mission and the gold record that was attached to signal to anyone who might find it eons in the future that WE WERE HERE. This gold record had symbols impressed upon it that would convey who had made it and where they lived. The record itself had tracks that were audio recordings of sounds from our planet. Yes, it was an audio analogue record, basically an LP pressed out of gold. It just goes to show how much technology has changed in the last 50 years. There were no images or videos on it, at the time (September 5, 1977) a technology beyond what was then capable.
Voyager 1 has now left the confines of our solar system and travels in interstellar space, much as Elvis has left the room, the first and only Earthling-made object to have achieved that distinction. But it lives on, still sending data back to us, long after it was to have ceased operating. Now you can listen to the tracks on the gold record, courtesy of the World Wide Web. How ironic that the first voice on it is of the hidden Nazi, Kurt Waldheim, at the time Secretary-General of the UN. Message to future aliens: If you came looking for us and we weren't here, it was because of what institutions like the UN became and what men like Kurt Waldheim were - mass murderers posing as guardians of humanity. Tell us , Oh Aliens, are you as barbaric as some of us were or have you solved that problem? Well....assuming you are there to listen.