May be you have seen home planetarium but the one showing galaxy like are rare ( I haven't seen one yet myself). So I decided to make this super easy-dirt cheap galaxy planetarium. Head on and you will be having your own in less than 5 minutes.
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Step 1: Materials Required

 You will need:
1 Plastic Glass
Aluminium Foil
1 thin needle ( you can use anything which is pointed and has more thickness than the needle)
1 medium thickness nail
1 flashlight (mine was Blue LED based. I don't know whether ordinary bulb flashlight will work or not since for "Diffraction" and "Interference" to take place(on which my planetarium is based) you need a monochromatic light .Simply just use a LED flashlight.
Sticking Tape(optional)

Step 3: How to use

 Place the flashlight below the glass as shown on the picture. If the flashlight is larger than the cup's circumference then you have to cover the extra leaking light with electrician's tape. Now switch on the flashlight, switch off the room lights and project the image on a wall and enjoy your galactic ride.

Try with different pattern of holes and every time a new galaxy will be born.

How it works:
It works on diffraction mainly which is distortion due to very small slits and holes which is due to the wave nature of light. Also the rough and reflective edges of aluminium foil also helps in reflecting and distorting the light creating a galaxy like pattern.

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joknrok3 years ago
Could be really cool if you print out a nice detailed diagram of constellations, then overlay the foil and use it as a template to make an accurate night sky.
Great results with this idea manish15.
RENUKA.NAVI4 years ago
its nice from india akash
manish15 (author)  RENUKA.NAVI4 years ago
To help with unwanted light caused by relfections inside the foil coated cup, you could paint the inside of the foil black with spray paint, might help clean up any non-stars on the ceiling.
manish15 (author)  mattthegamer4634 years ago
yes very helpful when you want to create precise constellations.Thanks.
lemonie4 years ago
Did you put any design or reproduction in this, or is the pattern creative / random?

manish15 (author)  lemonie4 years ago
 Its totally random, you don't know what you will get! However you may try some pattern of your own by experimenting.