When Voyager 1 and Voyager 2 were launched in 1977, their mission was to explore the outer solar system, and they did so in the following decade.
The two spacecraft returned an enormous amount of imagery and information about the four gas giants, Jupiter, Saturn, Uranus, and Neptune, using an 8-track tape memory system and onboard computers thousands of times weaker than the phone in your pocket.
However, NASA anticipated that once the planetary tour was completed, the Voyagers would continue on a path toward interstellar space, having gained enough velocity from Jupiter’s gravity to eventually escape the sun’s grasp. NASA scientists decided that because the Voyagers will be orbiting the Milky Way for the foreseeable future, they should carry a message from their creator.
Carl Sagan, a well-known astronomer and science popularizer, was commissioned by the Voyager team to write that message. Sagan’s committee chose a copper phonograph LP as their medium, and over the course of six weeks created the “Golden Record”: a collection of sounds and images that will most likely outlast all human artifacts on Earth.