This beautiful project by Instructable's user meethumalu just won the site's Maker Family Contest and for great reason. It's beauty sparks curiosity in both electronics and astronomy making it a great education tool for those wanting to expose their kids to STEM activities.
Check out a time-lapse video of the project being made here.
Meethumalu says, "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!
'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]
Black paper for creating the night sky