Both these craters are roughly equidistant from Ulugh Beigh, although Aston appears much closer due to the oblique viewing angle.

The interior floor of this crater has been resurfaced by lava, leaving a dark surface with the same albedo as the neighboring mare.

The northern part of the crater has a higher albedo than this dark surface, matching the appearance of the terrain to the west of the mare.

This is a merged formation with a smaller crater lying across the southwest rim of the larger, and the two sharing a common dark floor.

By convention, these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Ulugh Beigh.