Method for Identifying Lava Tubes Among Pit Craters Using Brightness Profile Across Pits on the Moon or Mars

Caves can serve as major outposts for future human exploration of the Moon and Mars. In addition, caves can protect\udpeople and electronic equipment from external hazards such as cosmic ray radiation and meteorites impacts and serve\udas a shelter. Numerous pit craters have been discovered on the Moon and Mars and are potential entrances to caves; the\udprincipal topographic features of pit craters are their visible internal floors and pits with vertical walls. We have devised two\udtopographical models for investigating the relationship between the topographical characteristics and the inner void of pit\udcraters. One of our models is a concave floor void model and the other is a convex floor tube model. For each model, optical\udphotographs have been obtained under conditions similar to those in which optical photographs have been acquired for\udcraters on the Moon and Mars. Brightness profiles were analyzed for determining the profile patterns of the void pit craters.\udThe profile patterns were compared to the brightness profiles of Martian pit craters, because no good-quality images of\udlunar pit craters were available. In future studies, the model profile patterns will be compared to those of lunar pit craters,\udand the proposed method will likely become useful for finding lunar caves and consequently for planning lunar bases for\udmanned lunar expeditions