In 2020, astronomers using NASA’s Hubble Space Telescope watched a mysterious dark vortex wider than the Atlantic Ocean on Neptune abruptly steer away from a “likely death” on the giant ice planet, some 30 years after NASA’s Voyager 2 probe flew past in 1989 after a nearly 3-billion-mile odyssey, snapping images of two giant storms brewing in Neptune’s southern hemisphere. NASA scientists dubbed the storms “The Great Dark Spot” and “Dark Spot 2.” Five years later, Hubble revealed both the Great Dark Spot and the smaller Dark Spot 2 had vanished.
Or so they thought
Hubble first observed he formation of a Great Dark Spot on Neptune in 2018. Like Jupiter’s 350-year-old Great Red Spot, Neptune’s Great Dark Spots are storms that form in areas of high atmospheric pressure. Scientists have seen a total of six dark spots on Neptune over the years. Voyager 2 identified two storms in 1989. Since Hubble launched in 1990, it has viewed four more of these storms.