Emergency Fake Moon
A friend was having birthday party late yesterday, to coincide with viewing the total lunar eclipse. That evening I realized there was quite a lot of cloud cover, and it was cold outside. I decided to build a moon simulator so that we could keep an eye on the eclipse regardless of the weather.
The enclosure was whipped up in about 20 minutes, using white poster board and clear packing tape. I found a good moon photo online, printed it out and glued it over a cutout in the box. Grabbed a bunch of parts from the spares box: an Arduino UNO, a ShiftBrite Shield, a ShiftBar, a ChronoDot, and a Satellite Module 001. Soldered the ChronoDot in place, taped everything inside the box, and started developing code. All told, about an hour and a half for the whole project due to a couple false starts.
The simulator doesn't show a moving shadow, but it does begin dimming the moon brightness through penumbra. During umbra, the moon dims further and takes on a orange-red hue into totality. The photo shows up a lot redder than in person, it's a bit more orange. The process is reversed out of eclipse. Each phase was synchronized using the ChronoDot, according to NASA eclipse data. I don't have the code to post here yet, but will do so in a couple days.
It was a success, and let us keep an eye on the eclipse. Fortunately there were occasional breaks in the cloud cover, so we were able to walk outside and view the real eclipse once in a while.
Submitted by Garrett on Tue, 12/21/2010 - 18:09.