Voyager 2’s closest approach to Neptune came on August 25, 1989, at just under 5,000 kilometres from the cloud tops. It revealed Neptune as a dynamic world rather than a cold, featureless sphere. To scientists’ astonishment, Voyager 2 discovered the ‘Great Dark Spot’, a massive storm system comparable in scale to Earth. Winds were clocked at 2,100 kilometres per hour, the fastest recorded anywhere in the Solar System.
