nineteen day moon

At the midpoint of the terminator, the eastern edge of the Mare Tranquillitatis has been overtaken by darkness. Beyond its northern shore by about its length, close to the terminator, class 1 Hercules stands in strange isolation, its companion Atlas hidden by the advancing nightside.

One Humorum width below the southern shore of the Mare Tranquillitatis, the incomplete bright ring of class 5 Gutenberg marks the southern end of the slender remnant of the Mare Fecunditatis, and the northern end of what remains of the Pyrenees Mountains, which in turn run along much of the eastern edge of the Mare Nectaris.

Roughly due south of the Mare Nectaris at a distance about equal to its length, class 1 Piccolomini, with its prominent central peak, is very striking. Due south by the same distance again, close to the terminator, are class 2 Metius and, to its south-west and tangent to it, Fabricius, also class 2. Fabricius occupies the north-eastern quarter of the much older and larger walled plain Janssen. Its huge but eroded outline can be seen well with the Sun at this low angle.