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Endymion Triple Sunset Ray August 15, 2003

Mojo spotted a triple sunset ray on the terminator 8/14/03, an 18 day old waning moon night where the near full moon rose at about 10:30 p.m. just to the left of Half Dome. We were at Glacier Point, Yosemite with the San Francisco Amateur Astronomers. Telescope: 7.1 inch f/9 Astro-Physics Starfire refractor. We couldn't figure which crater it was, so I sketched this rough sketch of the whole terminator from Mare Crisium down (north) to the triple sunset ray. The next morning, I worked my way, crater by crater, over the terminator with my trusty Rukl Atlas. This sketch shows the various craters along the terminator along with the Rukl Atlas map reference. I just noticed that I have Endymion identified as on Rukl 6 but it is actually on Rukl 7.

Sunset Terminator with craters and Rukl references

I sketched the sunset ray at 11:03 PDT 8/14/03. That's 6:03 UT on 8/15/03. The ray was first spotted at 10:45 p.m. by Mojo and it was still visible at 11:10 p.m. Longitude 119W Latitude 37N, elevation 7200 feet. Seeing 5/10 and transparency 2/6. I was mostly sketching Mars on this trip. So I was really glad Mojo noticed this amazing triple ray!

Endymion Sunset Ray

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