The final supermoon of 2025, the Cold Moon of December was the last of three consecutive supermoons this year (October, November, December). The Moon’s surface material, known as regolith, has subtle color differences dictated by the mineral composition in any particular area. This mineral distribution on the lunar surface was mapped in great detail by the US Clementine probe in 1994, but you can post-process images of the Moon showing these colors without having to launch a spacecraft to do so – which is exactly what I did here!!
Motivated by the “Moon Illusion” to capture the image…
As I was driving home from work on 4 December, at about 16:40MST, I experienced the Moon Illusion as I crested the hill on Palmer Park Blvd. The full moon rising filled my windshield! I couldn’t very well stop in the middle of traffic to capture that image (and it wouldn’t have looked the same in my cell phone anyway). Shortly after I got home, I set up my camera on the front patio and captured a few images (and was disappointed to see that they didn’t fill up the sensor of my camera – guess it wasn’t tricked by the “moon illusion” optical illusion effect!)
For a description of what I’m talking about when I say “moon illusion” see the Fun Facts section of the lunar gallery at: https://beersastrophotography.com/gallery/cold-supermoon/
Inspired by Ann Chavtur in processing it…
I decided that I would use the mineral moon processing that Ann Chavtur introduced me to last year (see November 2024’s Beaver Supermoon at https://beersastrophotography.com/gallery/beaver-supermoon-as-mineral-moon/), so I pulled up last year’s journal and started with that process. (A combination of the processing techniques described in a BBC Sky at Night article (https://www.skyatnightmagazine.com/astrophotography/astrophoto-tips/create-a-mineral-moon-astrophoto) and SarahMaths Astro YouTube video (https://www.youtube.com/watch?v=4TZH_4Lx_mQ)).
I discovered that evening, when I thought I would “just quickly process” the image I’d captured after dinner before I headed to bed, that you can’t follow the same process for a different image exactly – or you make a mess of it! So, I walked away that evening (I did have to work on Friday); took it up again on Friday evening, walked away again; then finally finished the processing on Saturday morning (with one “walk away” for my run with Danielle in-between processing versions).
The “rest of the story” including some interesting information and a link to more details on moon geology is in the gallery post at: https://beersastrophotography.com/gallery/cold-supermoon/