Ammonius (crater)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Ammonius crater AS16-P-5381.jpg
Slightly oblique view from Apollo 16, facing east
Coordinates 8°30′S 0°48′W / 8.5°S 0.8°W / -8.5; -0.8Coordinates: 8°30′S 0°48′W / 8.5°S 0.8°W / -8.5; -0.8
Diameter 9 km
Depth 1.9 km
Colongitude 1° at sunrise
Eponym Ammonius Hermiae
Oblique view from Apollo 14, facing west

Ammonius is a bowl-shaped lunar impact crater with a slightly raised rim and is named after It is located on the floor of the walled plain Ptolemaeus, about 30 kilometers northeast of the crater midpoint.

Just to the north on the lava-flooded floor of Ptolemaeus is a relatively prominent "ghost" crater: the discernible buried rim of a pre-existing crater. The diameter of this ghost crater is nearly double that of Ammonius, and is currently identified as Ptolemaeus B.


The crater is named after Ammonius Hermiae. In the past this crater was identified as Ptolemaeus A, before being named by the IAU in 1976.[1] Before it was called Ammonius, the crater was planned to be called Lyot proposed by Hugh Percy Wilkins and Patrick Moore, instead, Lyot would be named in the Moon's southeastern limb.


  1. ^ Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN) Ammonius

External links[edit]