Step by step

Step 1

Paint the barbecue skewers black so they can’t be seen when the lights are turned out. Then poke them into the polystyrene balls, using a bit of PVA glue to secure them firmly in place. The balls represent the stars.

Step 2

Using the full-sized print out of the Plough, hold the paper a suitable distance above the box and measure the height of each star to represent the vertical extent of the star positions. This gives us the familiar ‘shape’ of the Plough we see in the sky.

Step 3

Cut the sticks to the correct length using the height measurements from Step 2. Label each stick as you go otherwise it would be easy to mix them up and get the wrong positions for the stars. You don’t want to accidently distort the Plough’s shape.

Step 4

Also using the full-sized print out of the stars, measure the positions of the stars from left to right. The photo shows how the measurements were taken and marked on the print out. Exact measurements are in a downloadable table (see page 5).

Step 5

Draw a rectangle, 35x25cm, on the box’s top. Calculate the distances of each star, allowing 1cm for 2 lightyears. Assume the front of the rectangle begins at 75 lightyears and ends at 125 lightyears. Mark where each skewer will go and make a hole.

Step 6

Paint the box black and label each hole so it is easy to put the model together. Poke the skewers into the holes, using a blob of Blu Tack under each hole to secure them. To keep things in scale, make sure the model is viewed from 37.5cm away.