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.

Thirty years ago, 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. Marking the end of the Voyager ...

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When you buy through links on our articles, Future and its syndication partners may earn a commission. What it is: One of the final photographs of Neptune taken by NASA's Voyager 2 probe Where it is: ...