This artist's concept shows NASA's Voyager spacecraft against a field of stars in the darkness of space.
Our longest-living and farthest-reaching spacecraft, Voyager 1 and 2, are celebrating 40 years of space exploration this August and September. Each spacecraft carries the Golden Record of earth sounds, pictures and messages.
Today, Voyager 1 is almost 13 billion miles from Earth as it travels northward through interstellar space. Voyager 2 is almost 11 billion miles from Earth, traveling south, and will enter interstellar space within the next few years.