The Copernican Abyss

The Copernican Abyss

I managed to witness a sunrise on crater Copernicus just after nightfall. This was a sketching opportunity I did not want to pass up. Copernicus crater at 90 plus kilometers in diameter and 800 million years old is one of the showpiece craters of the moon whenever it is visible.
The rim of Copernicus at this observation was coming under full illumination while the crater floor remained in cold darkness.
A pair of 7x binoculars is all that is need to show this crater to the observer. As the moon approaches full phase the ray system of this crater can be seen to best advantage.

Sketching:

For this sketch I used: white sketching paper 12”x 10”, HB, 4B, 6B graphite pencils, a blending stump, Artgum eraser and brush. After scanning, Brightness was decreased (-2) and contrast increased (+2) using Microsoft Office Picture Manager.

Telescope: 10″ f/5.7 with 9mm ortho. eyepiece for 161x
Date: 8-19-2010, 1:00 – 1:30 UT
Temperature: 22° C (72° F)
Partly cloudy, calm, 60% humidity
Seeing: Antoniadi III
Colongitude 20.4°
Lunation 8.9 days
Illumination 73 %

Frank McCabe