Posidonius (crater)

Posidonius is a lunar impact crater that is located on the north-eastern edge of Mare Serenitatis, to the south of Lacus Somniorum.

The rim of Posidonius is shallow and obscured, especially on the western edge, and the interior has been overlain by a lava flow in the past.

[2] On the Mare Serenitatis surface near Posidonius is a notable system of wrinkle ridges that parallel the nearby shore.

Posidonius Gamma was first observed by the lunar cartographer Julius Schmidt in 1867, who noted the similarity to the bright patch surrounding the crater Linné.

[3] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Posidonius.

Selenochromatic Image (Si) of crater area
Oblique view of Posidonius from Apollo 15 . A tightly convoluted sinuous rille crosses the raised floor of the crater, turns back, and follows the rim to a low point in the western rim.
Part of the sinuous rille in Posidonius ( LRO image).
Oblique view of Posidonius from Apollo 17 . Note that the lava which flooded the crater reached its rim and is clearly above the mare plain to the west (left).
The hill Posidonius γ with the crater Posidonius Y ( LRO image).