海王星的夜晚

海王星的夜晚

Neptune at Night
Image Credit & Copyright: Voyager 2, NASA

Explanation: Ice giant Neptune is faint in Earth’s night sky. Some 30 times farther from the Sun than our fair planet, telescopes are needed to catch a glimpse of the dim and distant world. This dramatic view of Neptune’s night just isn’t possible for telescopes in the vicinity of planet Earth though. Peering out from the inner Solar System they can only bring Neptune’s day side into view. In fact this night side image with Neptune’s slender crescent next to the crescent of its large moon Triton was captured by Voyager 2. Launched from planet Earth in 1977 the Voyager 2 spacecraft made a close fly by of the Solar System’s outermost planet in 1989, looking back on Neptune at night as the robotic spacecraft continued its voyage to interstellar space.

Tomorrow’s picture: Valles Marineris

海王星的夜晚
影像提供与版权: Voyager 2, NASA

说明: 在地球的夜空中，冰寒的巨行星海王星是个很昏暗的天体。它与太阳的间距要比地球的日距大约30倍，需要动用望远镜才得以一窥这颗昏暗遥远行星的面貌。然而，像这样戏剧性的海王星夜晚，却是地球附近的望远镜无法见到的景观。从太阳系内围看出去，地面望远镜只能看到海王星的白昼面。事实上，这幅呈现海王星夜晚、有纤薄蛾眉相大卫星海卫一同框的影像，拍摄者为旅行者2号航天器。旅行者2号于1977年从地球发射启程，并于1989年近距离掠过这颗太阳系最外围的行星。当这艘无人航天器持续航向星际空间时，回眸眺望了海王星。

明日的图片: Valles Marineris