Peaks of Eternal Light: Lunar Polar Solar Siting

At the Moon's poles the Sun never climbs far above the horizon and never truly sets over a lunar day — so whether a spot on a crater rim is lit depends almost entirely on the shape of the ground around it, not the clock. This simulator renders an irregular polar crater rim as a heightfield of instanced columns and ray-marches the terrain's skyline toward the current sun azimuth to test each point for line-of-sight to a grazing, low-elevation Sun. Select any column to see it flagged lit or shadowed in real time, its year-round illumination swept across a full rotation at the season's worst sun elevation, and the live count of rim points that clear your candidate threshold — the same topographic-shadowing method used to locate real "peaks of eternal light" for continuously solar-powered lunar outposts.