Neptune, the farthest known planet, was last visited by Voyager 2 in the 1980s. The Arcanum mission is designed to orbit Neptune and land on Triton, giving insight into both objects of interest in ...
Space photo of the week: 1st-ever close-up of Neptune is Voyager 2's final portrait of a planet —Elon Musk said he's 'definitely going to be dead' before humans go to Mars — and you probably ...