Geological Chronicle
Piccolomini is an impact crater situated in the southeastern sector of the Moon, with the crater Rothmann to the west-southwest and Stiborius to the south. The lengthy Rupes Altai begins at its western rim and curves toward the northwest. Measuring 87.58 kilometers across and 4,500 meters deep, the crater formed during the Upper Imbrian period between 3.8 and 3.2 billion years ago.
The crater rim has not been severely worn by impacts, and the inner wall possesses wide terraces. These structures have been somewhat smoothed by landslips and erosion, most likely induced by seismic activity, while an influx of material has entered across the northern rim, flowing down toward the base.
The crater floor is relatively smooth, broken only by minor hills and small impact craters. In the middle sits a complex central peak surrounded by lesser mounts, with the main peak rising 2.0 kilometers above the floor. Infrared spectra have identified the signature of pure crystalline plagioclase across this rise.
The crater is named after sixteenth-century Italian archbishop and astronomer Alessandro Piccolomini. The International Astronomical Union formally adopted the designation in 1935.