The Lunar-X Files: A Fleeting Vision near the Crater Werner

摘要

Every month — or to be more precise, every 29.530589 days — the Moon cycles through its phases and alternately reveals and hides the features on its surface. As experienced lunar observers know, the appearance of a particular surface feature depends on the relief of the feature (that is, the height of the feature above or below the surrounding terrain) and the angle of the illumination of the Sun. The interplay of these two parameters leads to countless lunar landscape views, luring dedicated observers back time and time again to observe, sketch, and photograph the Moon.