A Sculptural Sketch

This is a “sculptural sketch” created at the eyepiece of my telescope. It started as a flattened rectangular slab of modeling clay about 1/4” inch thick and 11” by 13” in size. As I observed, I laid down thin strips of clay to form the glacis around each crater. I then used a butter knife to excavate the crater floors. I tried to keep in mind the true topographical relief of each feature. For example, Aristillus, the deepest crater is merely 5/16” deep from rim crest to floor. I “normalized” the sculpture by imagining what these features would look like if I were to see the view from directly above the area. The next morning, I sanded white and black dry pastels into a powder that was blended and applied by sponge to approximate the albedo features. What really surprised and delighted me was that despite the shallowness of the surface details, when the light source was adjusted to approximate the phase, the highlights and shadows created a very realistic scene. As I was working, I remembered Nasmyth and Carpenter’s beautiful plaster sculptures of the Moon for their classic The Moon: Considered as a Planet, a World, and a Satellite (1885); page 114 shows their exquisite sculpture of this area.

Sculptural sketch details:

Subject: Archimedes and environs Rukl: 12, 22
Date: 7-31-09 Time: 0540-0730 UT
Location: Jacumba, California
Antoniadi III Weather: Clear and calm
Telescope: 12” Meade LX200 SCT with UHTC
Binoviewer: Denkmeier Model DII SCT 2X
Eyepieces: Pentax 20mm XW
Magnification: 152X and 305X
Medium: Modeling clay sculpture with dry pastel powder
Sculpture size: 11” x 13”