Clementine data offers compositional information of the upper microns of the lunar surface. The only way to get information about the deep crust is to have a drill core. Without a mission to return to the Moon and bring back drill cores, researchers must rely upon a natural means of excavation. Impact craters excavate rocks from the interior of the crust. The diameter of the crater is proportional to the depth of excavation of material in the crater ejecta, walls, and central peak. Therefore studying craters of various sizes yields information about the three-dimensional composition of the lunar crust.