I seem to remember reading long ago that it takes a shallow impact angle of less than 20 degrees for an oblong crater to result. I bet Kurt can locate (or already knows) the actual critical angle. 2009/1/7 Jim Gibson <jimgibson00@yahoo.com>
I was just checking out the moon while my optics cooled. Thought I might check out a few doubles tonight which is about all I can do with the moon the way it is.
I was cursing the Southern Highlands when I notices this long looking crater south of Tycho a ways. I thought it was actually round but only looked oval because of it's location. Turns out that it is the crater Schiller; 71 km wide and 179 km long. Interesting since over 90% of the creators are more round than oval. I am guessing that the impact that created Schiller must have been quite oblique. No spray visible though like there is on Tycho.