Geological Chronicle
Mendel is a large lunar impact crater spanning 139.65 kilometers in diameter across the far side of the Moon. It sits in the southern fringe of the huge skirt of ejecta surrounding the Mare Orientale impact basin, with the even larger crater Lippmann to its south-southwest. Mendel also marks the western margin of the 630-kilometer-wide Mendel-Rydberg Basin, an expanse named jointly for Mendel and the smaller crater Rydberg to the east.
Dating to the Pre-Nectarian period, the crater is worn and eroded, with several small craters along its rim. Along parts of the inner wall, worn, terrace-like features have become rounded with time. Mendel J is attached to the southeastern edge and shares part of the rim, while the small Mendel B lies across the northeastern rim and a pair of small craters crosses the western rim.
The interior floor of Mendel displays deposits and depressions that may have formed from Mare Orientale ejecta. The crater is named for Austrian biologist Gregor Johann Mendel.