Voyager Golden Record cover uses pulsars to show Sun's location and launch time

The Voyager spacecraft, launched in 1977, carry a Golden Record intended to communicate with any extraterrestrial intelligence that might encounter it. The cover of the record is etched with a diagram that points to 14 pulsars, whose precise spin rates serve as a cosmic map. These pulsars act like celestial clocks, revealing both the location of Earth and the approximate time of the spacecraft's departure. The design deliberately avoids reliance on any single human language, making it a universal message.

The diagram is meant to help any intelligent being decode the record's contents. By measuring the pulsars' spin frequencies, an alien civilization could triangulate the Sun's position within the Milky Way. The relative timing of the pulses also indicates the epoch when Voyager left Earth. This approach ensures the instructions are understandable without shared linguistic or cultural references.

The Golden Record itself contains sounds, music, and images representing life on Earth. The cover's pulsar map is a key part of this message, providing the coordinates for finding our solar system. The 14 pulsars were chosen because their spin rates are unique and stable over long periods, though they do slow down very gradually. The diagram includes a binary representation of the spin periods, allowing for precise identification.

The Voyager spacecraft are now in interstellar space, beyond the influence of the Sun. The Golden Record is expected to last for billions of years, drifting through the galaxy. While the chance of it being found is extremely small, the pulsar map ensures that if it is, the finder could theoretically locate Earth. The record serves as a time capsule of humanity, with the cover providing the key to its origin.