Geological Chronicle
Zeeman is a 186.56-kilometer impact crater on the lunar far side near the south pole. Positioned between the craters Numerov to the northwest and Ashbrook to the southeast, the formation dates to the Nectarian period on the lunar geologic timescale. It is not directly visible from Earth.
The outer rim of Zeeman is eroded irregularly, with considerable variation in the width of its inner slopes. The crater Zeeman Y lies across the northern wall, reaching nearly to the relatively flat interior floor, while a small crater and a connecting gash cut through the western rim. On the floor, a low central rise sits offset to the southeast of the midpoint, where infrared spectra identify pure crystalline plagioclase.
An unnamed massif in the northwestern rim rises about 4.0 kilometers above adjacent crests and 7.57 kilometers above the crater floor. Its height is unusual, and its formation does not appear explainable simply by the impact that excavated the crater. Zeeman is named for Dutch physicist and Nobel laureate Pieter Zeeman.