When NASA’s Voyager 2 spacecraft flew by the strange world of Neptune’s largest moon, Triton, three decades ago, it imaged a world as stunning as it was puzzling, revealing massive, dark plumes of icy material spraying out from its surface, a captured Kuiper Belt object that evolved, a potential ocean world with active plumes, an energetic ionosphere and a young, unique surface. Voyager 2 is the only spacecraft ever to have flown past Neptune, leaving a trail of intriguing, unanswered questions that NASA hopes to answer.
