Coulomb is a lunar impact crater that lies behind the northwestern limb, on the far side. It is located to the west-southwest of the large crater Poczobutt, and northeast of Sarton. The rim of this crater is mildly eroded, but still retains a well-defined edge and displays some old terracing on the wide inner walls. The exterior of the crater also retains something of an outer rampart, extending for about a third of crater diameter. (wikipedia entry)