Schumacher is a lunar crater that lies in the northeast part , just to the north of the larger walled plain Messala. The two formations are separated by a rough strip of terrain less than 10 kilometers across, and bisected by a pair of small, co-joined craters. The northern member of this pair lies across the southern rim , and intrudes into the interior floor. The rim of this crater forms an eroded ring that is broken along the western side by the flooded crater Schumacher B. (wikipedia entry)