In the summer of 1977, NASA sent Voyager 1 and Voyager 2 on an epic journey into interstellar space. Each of the Voyager probes carries a golden record, a compilation of images and sounds meant to represent our planet to any distant civilisations that should encounter them. ‘The launching of this bottle into the cosmic ocean says something very hopeful about life on this planet,’ said Carl Sagan, the golden record’s co-creator. Sagan met and fell madly in love with his future wife Ann Druyan while working on the golden record. The project became their love letter to humankind and to each other.