Part of Basin Schiller – Zucchius

Part of Basin Schiller – Zucchius
Sketch and Details by Frank McCabe

After 12 cloudy days and nights I was anxious to get out under a clear sky to make an attempt at sketching a lunar target of opportunity. Before selecting a target I noticed the moon was moving through the Pleiades and created a very interesting binocular target. With the moon at 12.5 days into the lunation, the waxing gibbous phase was showing me the Schiller – Zucchius basin very nicely. I centered on two craters to one side of this 3 ringed basin. First the young Copernican period crater Zucchius (65 km.) with its terraced inner walls and shadowed floor looked deeper than its 3.3 km. measured depth because of the light and shadow. Sharing a common wall with this crater is the ancient and similar sized Segner (68 km.). This pre-Nectarian crater looked old and worn. Its rim was low and had nothing in the way of central peaks just a small nearly centered crater Segner H. Extending from the north side of crater Segner’s outer rim is a ridge which is a short wall segment of the second basin ring. What looks much like a shallow depression and measures about the same size as these two craters is the central ring of the basin and can be seen at the lower left (Northeast) in the sketch.
A photo of this entire basin credited to Gary Seronik can be seen on LPOD for October 17, 2004
http://www.lpod.org/archive/LPOD-2004-10-17.htm
I found myself sketching quickly in the cold air which was rapidly dropping in temperature as I sketched. After about an hour I considered the sketch finished and returned to the indoor warmth to thaw out.

Sketching:

For this sketch I used: black Canson paper 9″x 12″, white and black Conte’
pastel pencils , and Conte’crayons, a blending stump, plastic and gum erasers. Brightness was not altered but contrast was increased +2 using the scanner for this sketch
Telescope: 10 inch f/ 5.7 Dobsonian with 6mm (241x) eyepiece
Date: 12-29-2009 4:45-5:45 UT
Temperature: -8°C (18°F)
Clear, calm
Seeing: Antoniadi IV
Co longitude 60.6°
Lunation 12.7 days
Illumination 90.7%

Frank McCabe