A full moon in the Southwest is a great time to paint outside. It's not as diffucult as it sounds. On a night where there is a full moon you can see a lot of strong contrast between light and dark. Edges past the foreground are a lot softer because of the dark, but the foreground can have a lot of variety because of the strong light.
I start with two booklights that I bought at Barnes and Noble. One clipped on top of the easel to shine on the painting and one down below shining on the palette. The light from the moon is a bluish-green so I replace ultramarine blue with prussian blue. Also the lights appear cooler with the blue-green light and the shadows recede and become very dark and appear warmer or more red. I work small, 8 x 10, or 6 x 8 and I work fast because it can get a little creepy out in the desert at night when the nocturnal animals begin to roam. You can't see what's out there, but you can sure hear them. Frank Tenney Johnson handled nocturnal painting very well. Presently, Bill Anton does nice work. My painting above is of San Xavier, "Evening Journey." I enjoy this challenge, you might too.