A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2018 Jan 30, 13:52 -0800
Peter, you wrote:
"Just to chime in with another small correction on top of all these: the physical oblateness of the Moon, 1/800 or so."
I don't believe in that number. Like the small displacement of the Moon's visual center from its center of mass, I feel it's an artifact of the analysis. At this scale the overall "lumpiness" of the Moon wins out. And that's the next thing to consider if you want to get into corrections to lunars at the scale of one arcsecond: the wobbly limb profile. It's a little flat here, a little rounder there on the scale of one arcsecond. Fortunately near-perfect limb profiles are now available from orbital missions in the past decade. I've looked into it, but set it aside as "rather pointless".