I set up to sketch Rupes Recta on the floor of Mare Nubium. From the eastern edge of Mare Nubium you can see the triplet craters, Thebit (57 km), A and L. Next moving westward is the Imbrian escarpment Rupes Recta , not a true wall in the usual sense but on one side standing more than 300 meters high at some locations and 114 km in length. The scarp face would be visible from the rim of young crater Birt’s (17 km) to the west of “straight wall” if you could get there. Touching the rim of Birt to the east is Birt A.
For this sketch I used: black Canson paper (8” x 10”), white and black pastel pencils, assorted erasers, and blending stumps
Telescope: 13.1” f/6 Dobsonian working at 222X (9mm ocular)
Date: 11-22-2012 01:00-02:45 UT Temperature: 12°C (54°F)
Hazy, slightly breezy
Seeing: Antoniadi III
Colongitude 10.1 °
Lunation 8.1 days