Ptolemaeus
Location: ·
Leader of the grand trio of ancient walled plains lining the Moon's central meridian.
Type
Crater
Diameter
154 km
Position
9.2°S 1.8°W
Name approved
1935
The floor of Ptolemaeus is not mare basalt. It is light plains material of the Cayley type, smooth and about as reflective as the highlands around it, most likely emplaced as basin ejecta rather than erupted.
Under a low Sun the floor shows the outlines of several buried craters, rims just high enough to catch the light and invisible at any other illumination. These ghost craters put the fill at a few hundred metres at most.
Sunrise
Sunset
Sunrise and sunset on Ptolemaeus
| Event | Time | Lit |
|---|---|---|
| Computing… | ||
- Sunrise / Sunset: at the feature's centre (IAU Gazetteer of Planetary Nomenclature).
- Lit: the illuminated fraction of the Moon's disc at that moment.
Named after
Claudius Ptolemy, Greco-Roman astronomer and geographer (c. 87–150).
Further info
Official record from the IAU Gazetteer of Planetary Nomenclature: Ptolemaeus
Wikipedia: Ptolemaeus (lunar crater)