Its rim is split by a long, linear rille Rima Hyginus that branches to the northwest and to the east-southeast for a total length of 220 kilometers. Together the crater Hyginus and Rima Hyginus form a distinctive and prominent feature in an otherwise flat surface. Smaller craterlets can also be discerned along the length of this rille, possibly caused by a collapse of an underlying structure. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.
