💾 Archived View for gem.librehacker.com › gemlog › starlog › 20221230-1.gmi captured on 2023-01-29 at 03:34:27. Gemini links have been rewritten to link to archived content
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The sky appeared to be clear when I peeked outside about 8pm AKST, and there was a bright waxing moon, just a little past first quarter, so it seemed like a good opportunity for moongazing. I used the 60AZ-M telescope, and tried out the 25mm, 12.5mm, and 6mm eyepieces, along with the neodymium filter. The view was mostly good, except there was a noticeable amount of rippling and some occasionally blurriness. I'm not sure if that was turbulence in the upper atmosphere, or maybe turbulence inside the telescope since I hadn't given it much time to reach thermal equilibrium. The 25mm and 12.5mm eyepieces worked pretty well, but the refraction (color bending) was very noticeable when using the 6mm.
My wife bought me a neat little book called the National Audubon Society Field Guide to the Night Sky (ISBN 978-0-679-40852-9). The material is a bit old (1991) but it includes some great maps of the lunar surface, with a map for each phase along with a matching photo.
I focused on an interesting feature which was three craters, near the (also interesting) junction between Mare Imbrium and Mare Serenitatis. I've tried to center on it in this Stellarium screenshot:
The three large craters are (biggest to smallest) Archimedes, Aristillus, and Autolycus. The shadows on the ridges around Mare Imbrium and Mare Serenitatis were much more pronounced in my telescope than they are on the screenshot, and they seemed to pinch down sharply on that little valley in-between the two.
NASA indicates that Archimedes crater (the largest of the three) is 83 km (52 miles) in diameter and is flooded with mare basalt (cooled lava) making it geologically interesting.
