Paul Floyd's Astronomy & Space Website: Make your own 3D Southern Cross model

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Make your own 3D Southern Cross model

Ask Australians what constellation they know in the night sky and they will most likely say the Southern Cross. I thought I would challenge myself to create a model of the Southern Cross which can be quickly made and which shows the 3D nature of the night sky. By this I am referring to the fact that different stars are located at different distances away from our Solar System.

The below photograph shows the completed model which has been painted black to highlight the viewing hole. Looking through this hole with one eye shows how the stars line up in the familiar pattern known as the Southern Cross. Unlike the real thing (!) you can then look from above and discover that the stars are located at dramatically different distances. The distances have been scaled correctly with 1 mm equal to 1.28 light years.

Material required:

5 small polystyrene balls
5 skewers
Cardboard box (which reams of paper come in)
Scissors
Glue stick
Blue tack
3D Southern Cross back board master
3D Southern Cross base master

Instructions:

Refer to the above image of the completed model when reading the below instructions.

Print out both masters.
Glue the base to the bottom of the box
Cut an eye hole in the box side opposite the backboard end (see image).
Cut of the excess pieces of paper off the back board master and glue to the inside of the box.
Carefully impale the polystyrene balls on the skewers (one per stick). These become the stars.
One by one, position the sticks at the end of the lines. You will notice that there are circles at the end of each line placed there as a guide. Use the Blue tack to hold the sticks vertically.
You will now need to look through the hole and individually adjust the position of the 'star' balls. This is done by sliding the ball up or down the star until it is in front of the star that the ball represents.

Your model is now complete. You will now be able to see how the stars line up to resemble the real Southern Cross when looking through the eye hole. Looking down on your model will reveal that the stars are nowhere each other in space.