Two frame composite showing the Copernicus - Erastosthenes area taken in excellent seeing. There is a lot to see in this area. Most prominent, of course, is Copernicus at 93km in diameter. It is estimated from dated Apollo samples to be 800 million years old, which makes it relatively young for craters on the moon. It has a prominent ray structure - here contrast enhanced to show its details. Rays like this form when lighter colored materials from under the surface are ejected as part of the impact and distributed over darker/older mare areas. Also prominent is the extensive secondary cratering to Copernicus' right in this image. Erastosthenes is to the lower right and has a field of very small shallow secondary craters to its upper right. In the upper left near the crater Hortensius there is a field of five volcanic domes some of which (if you look carefully) have summit craters. Just to the left of Erastosthenes is the ghost crater Stadius almost completely filled with lava with only a hint of the original crater rim visible.