section_path: Targets of exploration/Neptune
section_name: Neptune
paragraph_text: Neptune
  
  The exploration of Neptune began with 25 August 1989 Voyager 2 flyby, the sole visit to the system as of 2024. The possibility of a Neptune Orbiter has been discussed, but no other missions have been given serious thought.
  
  Although the extremely uniform appearance of Uranus during Voyager 2 ' s visit in 1986 had led to expectations that Neptune would also have few visible atmospheric phenomena, the spacecraft found that Neptune had obvious banding, visible clouds, auroras, and even a conspicuous anticyclone storm system rivaled in size only by Jupiter's Great Red Spot. Neptune also proved to have the fastest winds of any planet in the Solar System, measured as high as 2,100 km/h. Voyager 2 also examined Neptune's ring and moon system. It discovered 900 complete rings and additional partial ring "arcs" around Neptune. In addition to examining Neptune's three previously known moons, Voyager 2 also discovered five previously unknown moons, one of which, Proteus, proved to be the last largest moon in the system. Data from Voyager 2 supported the view that Neptune's largest moon, Triton, is a captured Kuiper belt object.