A day or two short of the full moon, depending on the libration, on the northwest terminator of the moon you will find a remarkable crater that catches the eye. This is Pythagoras (133km dia.) with beautifully terraced walls and a central peak that casts great shadows across the western side of the crater and the west wall. The extreme near limb presentation of this magnificent crater gives us the opportunity to see just how shallow craters are. When on the terminator near the center of the moon, they look like deep wells but in this case the depth is only 4.8 km or 3.75% of the diameter! Shallow indeed! You can see this for yourself by making a 100mm diameter crater that is only 4mm deep.
The large non-circular crater in front of Pythagoras is Babbage (148km) and to it’s left is Oenophiles (70km) and further on is the smaller Markov (43km). To the lower right of Pythagoras is Anaximander (also 70km) and further right is Carpenter (61km). Above Carpenter is the shadow filled Pascal (109km) seen well at this libration.
Below Anaximander is a large shallow circular depression that is the remnant of a once tremendous crater, J. Herschel (160km). On its southern border is Horrebow (26km) and to the left of the the great crater is Robinson (also 26km). Lastly, at the very bottom of this image is the crater Harpalus (41km). Between this crater and Babbage is a squarish area that is named South (111km). Babbage, South, Herschel and Anaximander are the oldest craters in this image being of Pre-Nectarian age, possibly as old as 4.55 billion years. while Harpalus and Carpenter are the youngest being Copernican as old as 1.1 b.y. This is a region worthy of your study on those bright moonlit nights!
