What is "sirsalis"

Sirsalis is a relatively young lunar impact crater located near the western lunar limb, to the southwest of the Oceanus Procellarum. The crater lies across a ridge that runs in a north–south direction. It has a sharp edge and a low central peak. The crater overlaps the slightly larger and older Sirsalis A to the west-southwest, and the two form a distinctive feature.

To the east is a rille system named the Rimae Sirsalis. The longest of these rilles follows a line running approximately north-northeast to south-southwest, just clearing the southeastern rim of Sirsalis by about 10 kilometers. This long rille runs 330 kilometers from the shore of Oceanus Procellarum until it crosses the crater Darwin A and intersects the Rimae Darwin to the east of Darwin.