As the Voyager spacecraft continue their missions onwards into interstellar space, it seems hard to believe that it has already been 30 years since the encounter of Voyager 2 with Neptune: the last planetary stop of an unexpectedly long voyage. Despite the passage of a three decades, the scientific study of Voyager’s Neptune encounter data continues to this day. Including Voyager 2’s findings from Uranus, these data constitute our only close up observations of these ice giants, which are now recognized as playing a key role in the early history of our solar system. Combined with the recent realization that Neptune-size planets are an important class of objects in other planetary systems, the study of Neptune seems more important today than it did when the Voyager mission was first contemplated nearly half a century ago.
Diagram showing the trajectories of Voyager 1 and 2 through the outer solar system. Click on image to enlarge. (NASA)
Getting to Neptune
The origins of the Voyager mission to Neptune can be traced back to work originally performed by a NASA summer intern. In 1965, Gary Flandro discovered that as a result of a rare alignment of the outer planets that occurs ...