Which major storm did Voyager 2 discover on Neptune?

Voyager 2 discovered Neptune’s Great Dark Spot during its 1989 flyby.

The Great Dark Spot was a huge, dark, anticyclonic storm in Neptune’s southern hemisphere. It looked superficially like Jupiter’s Great Red Spot, but the two storms differ: Neptune’s feature appeared relatively cloud-free and was observed to be far less permanent.

Voyager 2 also saw a second, smaller storm called the Small Dark Spot, along with bright methane-ice clouds known as “Scooter.” The spacecraft’s images revealed powerful winds and a dynamic atmosphere on a planet more than 4 billion kilometres from Earth at the time of the encounter.

When the Hubble Space Telescope observed Neptune in 1994, the original Great Dark Spot had disappeared. This helped show that Neptune’s dark vortices can form and dissipate over comparatively short periods. The Great Red Spot is the famous storm on Jupiter, not Neptune, while Dragon Storm is associated with Saturn’s moon Titan.