A super realistic, gently glowing moon lamp for decoration or education
I like astronomy, and when I ran across these files generated from high resolution NASA data of the moon, I knew I needed a moon globe. Created by Thingiverse user moononournation, the thickness of the globe’s skin varies with the surface color of the full moon. Darker areas are thicker, so that it looks extremely realistic when lit from inside.
I have an Ender 3 Pro, modified with a direct drive extruder. It should print fine with the standard extruder too. I picked the six inch globe — the 8 inch should just fit if it’s scaled down just a touch to allow for support. I printed it in white PETG. It took a long time — about a day and a half, sliced in Cura with tree support.
The print was fascinating to watch. It was my first try with tree supports, and it worked beautifully. The globe separated easily from the supports with a gentle twist. The print went off without a hitch.
Once printed, I drilled a small hole in the base and started experimenting with lighting. My first attempt, a 1 watt white LED, was much too bright — it looked silly and washed out most of the detail I was after. I found that a single red LED was enough light, but the color was wrong. I then tried a 10000 mcd ultrabright white LED, which created a nasty “hot spot” across from the LED. That wouldn’t do. I clearly needed a diffused white LED.
It turns out that it’s fairly simple to diffuse an LED like this. If you sand down the rounded dome shaped part of the epoxy LED case until it’s mostly flat, and the lightly scuff the outside of the case with fine sandpaper to “frost” it, you get a nice diffuse white glow instead of a spot light. Tests in a dark room showed that the light was highly satisfactory. I decided to use a 5 volt USB charger to power it, so I lopped the end off a USB cable, pulled out the power leads, and selected a current limiting resistor according to the excellent article at Evil Mad Scientist Labs.
All I needed now was a base, so I fired up OpenScad and made a hollow cone, with a sphere the diameter subtracted off. The source files and STL are up on Thingiverse, and can be easily adjusted for different size globes and wires.
It’s easiest to orient the globe when it’s lit up — it’s difficult to see surface detail unless it’s internally lit. I opted to have the power wire exit opposite the side of the moon that faces Earth, though that’s personal choice. Curious why the moon always has the same side facing us? It’s tidally locked.
The moon is secured to the base with a touch of hot glue. My young daughter immediately claimed it for her room upon completion, which I view as a success. Make one for your space!
Interested in a different solar system body? There are plenty of other planets and moons to try, available here.