Geological Chronicle
Positioned near the eastern limb of the Moon southwest of Mare Smythii, Kästner measures 116.07 kilometers across and belongs to the category termed a walled plain. Just to its northwest lies the walled plain Gilbert, with the prominent crater Ansgarius positioned to the south and La Pérouse situated toward the southwest.
The crater has a worn, irregular outer wall overlaid by several small craters, including a small break along the north-northeast. Along its northeastern rim is Kästner B, and to the southwest is the small crater Kästner E, while a shallow unnamed crater is attached to the southern rim. Within the rim, the interior floor is relatively level and featureless, marked only by a few small craters and minor ridges.
The crater name was approved by the International Astronomical Union in 1961 in honor of German mathematician and physicist Abraham Gotthelf Kästner. Satellite craters in the area carry notable naming histories: Kästner F was renamed Black by the IAU, while names on some older maps—Defoe for Kästner B, Chekhov for Kästner R, and Cellini for Kästner S—were never approved by the IAU.