In 1977, NASA launched Voyager 1 carrying a map that uses 14 pulsars to pinpoint Earth’s exact position in the Milky Way—a cosmic roadmap designed for curious aliens that some modern astrophysicists, including Stephen Hawking, later argued was a terrifying mistake that we can never take back.

On September 5, 1977, NASA launched a spacecraft that nobody expected to ever come back. Voyager 1 was built to fly past Jupiter and Saturn, beam home some pictures, and then keep going forever. Once the planetary work was done, the probe would slip out of the Solar System into the great cold dark between