By Clara Moskowitz The two Voyager spacecraft launched in 1977 are now the farthest man-made objects from Earth, at more than 19.5 billion and 16 billion kilometers away, respectively. In 2012 Voyager 1 became the first spacecraft to leave the solar system and enter interstellar space—and its sister spacecraft is not far behind. Both probes were the first to visit the solar system’s giants, Jupiter and Saturn, and Voyager 2 flew by the other outer planets; they changed our understanding of those worlds profoundly. The Voyagers also carry “golden records” packed with recordings of sounds, songs and pictures to communicate a sense of life on Earth to any extraterrestrials that might encounter them. Arizona State University planetary scientist Jim Bell recounts the story of the Voyagers in his new book The Interstellar Age: Inside the Forty-Year Voyager Mission (Dutton, 2015). Bell spoke to Scientific American about the impact of the spacecraft and how scientists decided what human facts and achievements to put on the golden records. Transcript of the conversation via Scientific American.