August 5, 2010
Same Old Story
image by Gari Arrillaga, Salou, Spain
No reputable scientist believes it anymore, but I still worry. From the general idea in the 18th, 19th and early 20th centuries that the Moon was largely made by volcanism, to the post Apollo 16 thought that impact cratering may have caused everything, volcanism has been relegated to pretty much just the maria. But when I see images like this one by Gari of Pitiscus and Hommel, I wonder. Notice that most of the terrain between craters has a rough texture made up of small ridges and craters. Except for the smooth surface near the center left margin, just north of Asclepi. Here it looks like three or four ancient craters have been filled with smooth material, but outside the remnant rims the texture is complex. If, as the standard story goes, the smooth material is fluidized ejecta from the formation of the Orientale Basin, it seems that all the surrounding terrain would be similarly veneered. But it ain't.
01-07-2010 23:25. See image margin for more.
Rükl plate 75