Challis (crater)
 Challis is a lunar crater that is located in the northern regions of the Moon's near side close enough to the limb to appear significantly foreshortened when viewed from the Earth. It is joined to the crater Main through a break in the northern rim and is close to Scoresby along the southeast side.The rim of this crater has been damaged and eroded by a history of impacts with the most intact portion located along the southeastern half.