June 2, 2013
Cookie Dough Domes
image by Jim Phillips
This is an updated view of a classic area. At least it is classic to anyone who loves lunar domes. Arago Alpha (top) and Beta (left of Arago) are the most famous large lumpy domes on the Moon. Their shapes and surface roughness differ from the flattened hemispheric domes such as those at Hortensius. The hemispheric domes look like they were made of relatively fluid lavas spread across the surface like pancake batter (you can tell I am looking forward to breakfast). By contrast the Arago domes are more like a pasty cookie dough (maybe I need a snack). Presumably the Arago dome lava was more viscous, or equivalently, erupted at a lower rate so that it piled up rather than flowing away. Using LRR QuickMap I find Alpha to be about 32 km wide and 350 m high, and Beta about the same width and maybe 50 m taller. No one has clearly explained why these massive, lumpy domes are near the edge of this basin.
May 30, 2013. 20" F/3.3 Starmaster with Lockwood Quartz mirror.
Rükl plate 35
21st Century Atlas chart 7.
Yesterday's LPOD: Gravity Man
Tomorrow's LPOD: Half a Globe is Better Than a Flat Image