Measuring Lunar North and South Polar Regions

The lunar polar regions are high-priority targets for scientific investigation and exploration. To aid these endeavors, we produced enhanced altimetry data from the Lunar Orbiter Laser Altimeter for the north polar region, from which we computed new maps of surface height and slope as well as topographic roughness on horizontal baselines of 100–1600 m. We also produced a new map of permanently shadowed regions (PSRs) that contains fewer artifacts and is higher resolution than previous maps. These new maps were then compared to an analogous set previously produced for the south polar region. Generally, in both polar regions, more steeply sloped terrain is rougher at baselines ≲200 m and has a bluer roughness spectrum, a behavior hypothesized to be due to downslope mass transport. Roughness in the polar regions is also correlated with regolith temperature, and we discuss several possible causes including surface ice in unresolved cold traps, subsurface ice outside cold traps, and changes ... Read full article.