explore-blog:

The spin axis of the Moon is tilted by only 1.54 degrees (vs. Earth’s 23.5 degrees), leaving some areas near the poles in permanent shadow and making others sunlit for the majority of the year.

NASA used 1,700 wide-angle images taken with their Lunar Reconnaissance Orbiter  over a six-moth period, or six lunar days, then converted each into a binary image to differentiate between sunlit and shadowed regions. All the binary images were then stacked, and a calculation was made for each pixel to determine what percentage of the time during six months that spot was illuminated. The result is this striking  South Pole illumination map.