Product Idea |

Earth and Moon Orrery

A fully working Earth and Moon orrery, with a handle that can be rotated causing the Moon to magically orbit around the Earth. See it in action in my video below.

I've created a basic Earth and Moon orrery before (see my other contest entries!) but I wanted to go a step further this time and include more astronomical details. My new orrery features the following:

Orbital period - 27:1 in my model, which closely represents the 27.3 days it takes for the Moon to actually orbit the Earth.

Orbit direction - the Moon orbits the Earth with Prograde motion in my model (moving in the same direction as the Earth rotates), just like the real thing.

Earth's tilt - it's 22.5 degrees in my model, not far off the real tilt of the Earth at 23.4 degrees.

Angle of The Moon's orbital plane - The Moon orbits Earth on an angled plane of about 5 degrees, I tried to represent this as closely as possible in my model.

Relative size - the Moon's relative size compared to the Earth closely represents the real scale of approximately 1:4.

Earth details - I tried to represent all the continents on my brick-built scaled down Earth.

I wanted to hide away most of the gearing that makes the orrery function, so I housed it all in a vintage style octagonal box and decorated the panels with the phases of the moon. The angled yellow support girder (part 77107) is part of the mechanism that makes the moon orbit on an angled plane, and proved difficult to hide, but in the end I think it looks quite good exposed and the yellow colour works nicely as a subtle nod to the sun.

I hope you agree, this would make a great display model as well as a fun educational toy. Please vote if you would like to see it made into a real LEGO set! Thanks for looking :-)

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