Alphonsus is an ancient impact crater on the Moon that dates from the pre-Nectarian era. It is located on the lunar highlands on the eastern end of Mare Nubium, west of the Imbrian Highlands, and slightly overlaps the crater Ptolemaeus to the north. To the southwest is the smaller Alpetragius. The crater name was approved by the IAU in 1935.
The crater area in a Selenochromatic format Image (Si)
Alphonsus crater appears in the right half of this image taken by Ranger 7. NASA photo.
Oblique view of the five small named craters: C = Chang-Ngo, R = Ravi, M = Monira, J = Jose, S = Soraya. Facing south with sun illuminating from left. North on the photo is on the bottom
Ranger 9 image showing rilles on the floor of the crater
Ptolemaeus (lunar crater)
Ptolemaeus is an ancient lunar impact crater close to the center of the near side, named for Claudius Ptolemy, the Greco-Roman writer, mathematician, astronomer, geographer and astrologer. It measures approximately 154 kilometers in diameter.
Ptolemaeus from Apollo 16. NASA photo.
The crater area in a Selenochromatic format Image (Si)
The Apollo 12 lunar module Intrepid flies over Ptolemaeus and the smaller Ammonius within it. Herschel lies to the right. NASA photo.
Ptolemaeus crater in Weinek's Lunar Atlas from 1897, on the photo, north is downwards
