Geological Chronicle
Casatus lies near the Moon’s southern limb. Its north-northeast rim overlies part of the slightly larger crater Klaproth, though Casatus has the higher walls. On the western side, Casatus A intrudes somewhat into the interior, producing an inward-bowing rim. Newton lies to the southeast.
The outer rim is old and worn, with tiny impacts along the rim and inner wall. Its height reaches 6,500 m on the western side and 5,500 m in the east. Casatus J lies across the south-southeastern rim. Where Casatus divides from Klaproth, the rim is lower and forms a rounded ridge.
The interior floor is nearly level. Several tiny ghost-crater rims project above it, with a pair of clefts in its southern part. In the northern half, the small, bowl-shaped impact crater Casatus C forms a prominent feature. No central peak is present at or near the midpoint of the interior.
Casatus is named for Paolo Casati, the Italian Jesuit mathematician. Giovanni Battista Riccioli added the name to lunar nomenclature in 1651; the International Astronomical Union officially adopted the designation in 1935.