Ammonius (aka Lyot) (on the floor of Ptolemaeus)

(formerly Ptolemaeus A)

Lat: 8.5°S, Long: 0.8°W, Diam: 8 km, Depth: 1.86 km, Rükl: 44

Images

Ptolemaeus A (Ammonius) was captured on Ranger 8's Frame P002 (third photograph in this frame, at lower left).
One of Apollo 12's orbital Hasselblad photographs of Ammonius is included in the book Full Moon by Michael Light and Andrew Chaikin. This photograph (AS12-51-7506, as Plate 43) looks almost the same as AS12-51-7507. Both photographs show the bowl-shaped crater Ammonius in the foreground, while the lunar module (LM Intrepid) is seen near the lunar horizon.
Research Ranger 8 and Apollo 12 photography: Danny Caes

Ammonius is the most prominent crater on the floor of Ptolemaeus.

Depth data from Kurt Fisher database
- Westfall, 2000: 1.86 km
- Viscardy, 1985: 1.85 km
Included in ALPO list of bright ray craters.
Included in ALPO list of banded craters

Named for Ammonius (unkn.-c. A.D. 517-526), a Greek philosopher.
The name Ptolemaeus A was part of the original IAU nomenclature of Blagg and Müller (Catalog Entry 2963). The name is attributed to Mädler.
This replacement name for a formerly lettered crater was provisionally introduced on LTO-77D2 (Oct. 1974), for which it served as the chart title. It was approved in 1976 (IAU Transactions XVIB). - Jim Mosher
Hugh Percy Wilkins and Patrick Moore proposed calling this crater Lyot, but the I.A.U. did not approve the name. The name Lyot was later used for a crater near the Moon's southeastern limb.

Ptolemaeus A ("Lyot"): THE MOON by H.P.Wilkins and P.Moore.