Astronomy Picture of the Day——月球南极

Southern Moonscape Image Credit & Copyright: Tom Glenn


Explanation: The Moon's south pole is near the top of this detailed telescopic view. Looking across the rugged southern lunar highlands it was captured from southern California, planet Earth. At the Moon's third quarter phase the lunar terminator, the sunset shadow line, is approaching from the left. The scene's foreshortened perspective heightens the impression of a dense field of craters and makes the craters themselves appear more oval shaped close to the lunar limb. Below and left of center is sharp-walled crater Tycho, 85 kilometers in diameter. Young Tycho's central peak is still in sunlight, but casts a long shadow across the crater floor. The large prominent crater to the south (above) Tycho is Clavius. Nearly 231 kilometers in diameter its walls and floor are pocked with smaller, more recent, overlaying impact craters. Mountains visible along the lunar limb at the top can rise about 6 kilometers or so above the surrounding terrain.


月球南极


在这幅望远镜拍摄的照片中,位于顶部的是月球南极。这幅照片是在美国南加利福尼亚拍摄的,可以看出月面南部的崎岖地貌。此时正当下弦月,图像中还能看到分布十分密集的撞击坑。由于投影效应,靠近边缘处的撞击坑呈现为椭圆形。靠近照片中心左下方的是直径85千米的第谷环形山,环壁十分陡峭。年轻的第谷中央峰沐浴在阳光下,但在环形山底投下了长长的阴影。第谷环形山以南,也就是上方是巨大而明显的克拉维乌斯环形山,它的直径达231千米。它的环壁和环形山底叠加上了很多更小、更新的撞击坑。在最顶部的月面边缘处的山峰比其周围的地面高出约6千米。