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.

Lunar eclipse simulator

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.

Lunar eclipse simulator

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.

Lunar eclipse simulator

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.

Nicely done! Three

Nicely done! Three comments/questions:

The main benefit of the ChronoDot is to be able to "set and forget" time, correct? In other words, the benefit of high-precision time is not that applicable to this application, correct? Meaning, the micro's crystal would normally keep track of time well enough, I think..

As you mentioned, it does not really eclipse the moon, but that raises the issue of reproducing the same angles and directions of the occlusion (and how to do it all in a small-ish box). Still, it would be awesome to -simulate- an eclipse. :)

Third, another idea would be to be able to "set your location" in longitude and latitude, and see the eclipse occur from that angle (including/extending second paragraph idea, above). THAT would make an awesome kit!

(While I'm motivated to make exactly this type of project from scratch, I'm really just getting started with the Uno, and solving problems like how to cast different shape shadows inside that box would be a big problem for me at this stage. But now I have an extended idea for an eventual project! :-D )

Interesting--a personal

Interesting--a personal planetarium.

You should send your

You should send your accomplishments to your alma mater (not me, you know I'm always on here.) Your work is much more exciting than anything I read in the Echoes. The Olympics stuff you did is especially cool, plus your whole entrepreneurial business milieu. The issue I got today is all about "innovation." I know you're busy innovating, but you should drop them a line at . They will probably bug you for donations ad infinitum but they should have thought of that before making us take out all those loans.



Seems like some Chinese

Okay, so where is the

Okay, so where is the emergency fake sun with the transit of Venus? ;p