First flyby of Neptune
Who
Voyager 2
What
0 first
Where
Not Applicable ()
When

On 25 August 1989, Voyager 2 made its closest approach to Neptune after a three-and-a-half year cruise from Uranus. The probe came within 4,800 km above the cloud tops of the planet’s north pole.

This was the closest Voyager 2 had been to any planet since it left Earth in 1977. Its discoveries include the Great Dark Spot in Neptune’s atmosphere, the nature of the winds on Neptune, four complete rings as well as evidence for incomplete ring arcs, and six small moons. The most spectacular discovery of the encounter was of active cryovolcanism on Neptune’s largest moon, Triton.