Why it's so special: Only one spacecraft has ever visited the eighth and most distant planet from the sun. On Aug. 25, 1989, NASA's Voyager 2 spacecraft took the first-ever close-up images of Neptune.

But Webb's observations didn't just provide new pretty pictures of the ice giant planet's greenish-blue splotches. It revealed how odd Neptune's auroras are compared to other planets', glowing over ...

Voyager 2's image of Neptune released shortly after the flyby in 1989 (left) with the newly reprocessed version in true colour (right). A new study suggests that Neptune and Uranus are a similar shade ...