Though Voyager 2 was the first spacecraft to fly by Neptune, detect its auroras in infrared, and snap a picture of the majestic ... Neptune's auroras are unlike Earth's, Jupiter's, and Saturn's ...

The perception of Neptune as much darker and bluer than Uranus was "cemented" when pictures were sent back by the Voyager 2 probe after it flew by the two planets in 1986 and 1989, said The Times.