In 1989, Voyager 2 measured winds up to 2,100 kilometres an hour circling an Earth-sized storm on Neptune. By 1994, when Hubble looked again, the storm had simply vanished, unlike Jupiter’s Great Red Spot, which has raged for more than a century. Scientists named it the Great Dark Spot. Around its edges, Voyager measured winds reaching 2,100 kilometres an hour, among the fastest ever recorded anywhere in the solar system. A second, smaller storm nearby got the far less poetic name Dark Spot 2.