On Aug. 25, 1989, NASA's Voyager 2 spacecraft made a close flyby of Neptune, giving humanity its first close-up of our solar system's eighth planet. No other spacecraft has visited Neptune since.
This picture of Neptune was produced by images taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the "Great Dark Spot" — a storm in Neptune's atmosphere — and the bright, light-blue smudge of clouds that accompanies the storm.
Thirty-one years later, the RTG-powered Voyager 2 spacecraft is about 11.5 billion miles from Earth--one-way light time is more than 17 hours. Voyager 1 is even further.
To know exactly where the twin spacecraft are, visit Where Are the Two Voyagers Now?
To see all images of Neptune, visit the Voyager Gallery.