Raspberry Pi Planet Finder
Outside the Science Centre in my city there is a large metal structure which could turn and point at where the planets were in the sky. I never saw it working, but I always thought it would be magical to know where these unreachable other worlds actually were in relation to my tiny self.
When I walked past this long-dead exhibit recently I thought "I bet I could make that" and so I did!
This project won 1st prize in the Instructables Space contest and was featured on Hackster.io, Hackaday and Adafruit.
This is the Planet Finder, a device which points to the planets in our Solar System so you can know where to look when you're feeling awed by space.
It uses a Raspberry Pi to look up planetary data from NASA over WiFi, then spins a 3D printed telescope to point towards its target.
Check out the link at the bottom for a detailed build guide and an explanation of the science behind it.