Ever looked in a sky full of stars and wondered what you were looking at? Where's the north star? Where's the Great Bear? Well, here's presenting - 'Starry Night' a great educational tool for Kids (and maybe adults) to learn about astronomy and electronic circuits [open and closed circuits] at the same time!
This project was inspired by Leah Buechley and Jie Qi's Computational Sketchbook at MIT. 'Starry Night' has one big huge circuit which has all the stars [blue LEDs] connected in parallel in this circuit. Once the moon's out [acts like a switch], all the stars shine thus activating the big circuit. By pressing on the names of different constellations, you see green lights between stars that help you identify the shape of the constellation. Each of the four constellations has a separate circuit with green LEDs to show the edges of the constellations.
To build this, you will need:
- Lots of Copper Tape
- 3V coin cells 
- LEDs [about 60 LEDs were used in this project]
- Copper Foil [since its conductive both sides, it was used to activate switches]
- Long fingernails [optional but HIGHLY RECOMMENDED - to help smooth the bumps while making a circuit or even to fold the copper tape while making sure its still conducting electricity]
- Soldering Iron
This instructable was made as part of the CS graduate course "Tangible Interactive Computing" at the University of Maryland, College Park taught by Professor Jon Froehlich. The course focused on exploring the materiality of interactive computing and, in the words of MIT Professor Hiroshii Ishii, sought to "seamlessly couple the dual worlds of bits and atoms." Please see http://cmsc838f-s14.wikispaces.com/ for more details.
This was done in collaboration with Hitesh Maidasani.
Step 1: Sketching the circuit
It is important to first sketch out the entire sky (circuit) - where all the stars (Blue LEDs) go, where each of the constellation (Blue LEDs with Green edges) goes. Once you have figured that out, draw this circuit on a piece of cardboard.
All the Blue LEDs will be connected in parallel on the main circuit.
Step 2: Taping the Copper Wire
It is very important to understand how to make circuits using Copper Wire. A good place to learn about the basics is this place. This website teaches about folding, making curves, adding LEDs and using coin cells for paper circuits. I learnt from this website and it was easy to make the big sky circuits then.
All the blue LEDs will be connected in parallel on the circuit. One copper wire will be the positive end and the other one will be the negative one.
I recommend making the two wires (positive and negative) run parallely all along the circuit and then soldering the LEDs. Once you make the entire circuit, it should look like whats shown in the figure.
Quick Tip: Keep testing the LEDs at every few turns and folds you make with the copper wire as shown in the figure
Step 3: Start making Constellation Circuits
Each of the constellations have a separate circuit. In this project, I shared the positive side of the copper wire from the main big circuit with all other smaller constellation circuits. Only the negative side of the constellation circuit is separate which has the green LEDs that act as edges to connect the stars thus highlighting the constellation. This separate circuit shares the positive side with the main big circuit. Once pressed on the name of the constellation [activating the switch], the green LEDs highlight showing the path of that constellation.
In order to make this circuit, you will have to perform several hacks like jumping positives and negatives over each other by not removing the sticky side of the copper tape, folding the copper tape in several different ways to maintain its conductivity, soldering at corners in case we had to stick two pieces of copper tape.
Also, at every point keep testing with LEDs to make sure both the circuits are working fine.
Step 4: Soldering the LEDs and connecting batteries
I recommend soldering the LEDs on the circuits to make the connections strong. The circuit should look like as shown in the figure. You also need to figure out a place to connect the batteries in the circuit. I chose to connect the batteries on the side and made them switches so that only when you press them, does the circuit activate.
Connecting the batteries at the right spot can be a challenge because the positive terminal is shared with 4 different circuits. So to make sure that all the blue stars are shining even when any or all of the constellation circuits are activated, we had to connect the batteries at the right spot. Soldering the LEDs, green as well as blue on the right sides and making sure it doesn't touch any other copper tape in between was important to make sure we don't activate other circuits by shorting any of them.