Mountains of Eternal Light
Earlier selenographers and selenodesists referred to the mountains of the moon or high crater rims near the north and south poles as mountains of eternal light , the tips of which are almost always in sunlight .
At the South Pole they are partly identical to the Leibniz Mountains , but also include some more distant mountain ranges “behind” the large Manzinus and Moretus craters . At the North Pole, there are crater edges and peaks in the area of the lunar craters Byrd , Peary , Nansen and Hermite.
The mountains of eternal light are particularly noticeable with a narrow crescent moon , where they already appear in small telescopes as bright points beyond the shadow border ( terminator ), i.e. clearly stand out from the still dark surroundings.
With medium-sized telescopes (from about the eight-inch) individual crater rim or mountain peaks can be seen. For some time now, astronomers have been planning to build an observatory in these regions that is not disturbed by terrestrial stray light and radio traffic. It would be cheapest on the edge of the back of the moon , but then telemetry would have to be done via lunar satellites . Solar energy is a good source of energy .
The valleys between the laterally lit heights are constantly in the shade, which also promises interesting outcrops. Between 1996 and 1999, radar and spectrometer measurements by the lunar probes Clementine and Lunar Prospector proved the existence of water ice on both poles. The ice is presumably contained in the regolith on the lunar surface, but it could also form small ice lenses at a depth of around 50 cm. Both possibilities would be of great interest for space travel .