The shadowed portion of the crater was imaged with the Terrain Camera of the Japanese SELENE spacecraft using the illumination of sunlight reflected off the rim . The interior of the crater consists of a symmetrical 30 ° slope that leads down to a 6 @.@ 6 km diameter floor . The handful of craters along the interior span no more than a few hundred meters . The bottom is covered by an uneven mound @-@ like feature that is 300 to 400 m thick . The central peak is about 200 m in height .