eighteen day moon

Just above the midpoint of the terminator, the last remnant of the Mare Crisium appears as a smooth bite taken out of the Moon's edge.

North-west of Crisium, class 1 Macrobius appears as a sharp circle. About two Humorum lengths northwards, at about the same distance in from the terminator, class 5 Atlas and its close neighbour to the west, class 1 Hercules, making a final appearance together, also show strongly.

The larger dark area to the south of the Mare Crisium is the Mare Fecunditatis. At its north-west, where it merges with the Mare Tranquillitatis, stands class 5 Taruntius. Its flooded floor matches the surrounding dark Mare, so it appears as a thin, bright ring. At roughly the same distance from the terminator and about one Humorum length south from the southern edge of Fecunditatis is class 1 Santbech, and continuing south much the same distance again is the similarly sized class 1 Rheita. The south-west quadrant of its rim partly obliterates a long, irregular gouge which curves south-east towards the terminator. This is the Rheita Valley. It has a strange shape, and is now generally thought to be a series of craters which have run together.