Launched in 1977 , Voyager 1 was part of a twin-spacecraft mission on a multi-planet tour . But in 2013 , NASA made the groundbreaking announcement that Voyager 1 had left the heliosphere -- a magnetic boundary `` bubble , '' if you will , which scientists use to explain the separation of our solar system from the rest of the galaxy . A rare planetary alignment let the mission travel past Jupiter , Saturn , Uranus , Neptune . The two Voyagers have provided unparalleled insight into our solar system . Comment:
Launched in 1977 , Voyager 1 was part of a twin-spacecraft mission on a multi-planet tour . A rare planetary alignment let the mission travel past Jupiter , Saturn , Uranus , Neptune . The two Voyagers have provided unparalleled insight into our solar system . Comment: