Mars sketched by Tom Sarna using a 10-inch f/4.5 reflector at 140x, August 6, 1988, from Downers Grove, Illinois.
David J. Eicher library
To learn more about astronomical sketching, Astronomy magazine subscribers can access my Astronomy.com video "Sketching from the telescope" and read Glenn Chaple's Observing Basics column "Sketching 101."
See the rest of the Sketching at the telescope series.