The Full Moon

The Moon at full phase, when the Sun is almost directly behind the observer and shadows nearly vanish, flattening the relief but showing surface composition clearly. The dark grey plains are the maria, basins flooded by basaltic lava more than three billion years ago; the brighter, heavily cratered terrain is the older highland crust. The bright streaks radiating from Tycho in the south and Copernicus near the centre are ray systems, material thrown out by impacts and scattered across the surface.