1989: Voyager 2 makes its closest encounter with Neptune, passing just 3,000 miles above the cloud tops of the most distant planet in our solar system.
The Voyager 2 space probe has been our most productive unmanned space voyage. It visited all four of the outer planets and their systems of moons and rings, including the first visits to previously unexplored Uranus and Neptune.
What did the space probe discover about Neptune?
Originally it was thought that Neptune was too cold to support atmospheric disturbances, but Voyager 2 discovered large-scale storms, most notably the Great Dark Spot. It turned out to have a much shorter duration than Jupiter’s persistent Great Red Spot. Neptune not only has storms, it happens to have the fastest winds in the solar system.
The space probe was plotted to perform a close encounter with Triton, the larger of Neptune’s originally known moons. Along the way, Voyager 2 found six new moons (.pdf) orbiting the planet.
Voyager 2 found four rings and evidence for ring arcs, or incomplete rings, above Neptune. That means all four of the gas giants in our solar system have rings. Neptune’s, however, are very meager compared to the magnificent rings around Saturn.
