Voyager 1 is a one of two unmanned space probes launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and interstellar space beyond the Sun's heliosphere. It's currently over 24 billion kilometers away, making it the farthest human-made object from Earth. Onboard the space probe is a gold-plated audio-visual disk that contains information about Earth and its inhabitants should it ever be discovered by intelligent extraterrestrial lifeforms.