Jansen (crater)

Jansen is a lunar crater in the north part of the Mare Tranquillitatis. It is located to the east-southeast of the crater Plinius. The rim of Jansen is low and narrow, with a notch along the western edge. The interior is relatively level, which may indicate it has been covered by lava. To the south-southwest a small but prominent crater lies on the crater floor, halfway between the center and the rim.

To the northwest of the rim is a rille named Rima Jansen, and to the east are wrinkle ridges in the mare surface. A low ridge runs from near the southeast rim in a southeasterly direction.