Step by step

Step 1

Trim the barbecue skewer to 19cm, then paint it black with paint or permanent marker. This will be the support for the larger ball – Earth in the model. It will need to be sturdy as it will also have to support the additional arm for the Moon.

Step 2

Push the pointed end of the skewer into the larger ball then paint it to look like Earth using water-based paint. This is excellent opportunity for a geography lesson, but it is up to you how accurately you want to paint the features!

Step 3

To form the arm for the Moon, tightly wind one end of the wire six times around something slightly larger than the skewer. Slide it onto the skewer and make sure it rotates freely. Place a small elastic band 4cm below the Earth ball to hold the arm in place.

Step 4

Gently angle the remaining wire upwards; then put a bend 1cm from the other end of the wire so it is pointing straight up, and push the smaller Moon ball onto it. Make sure the Moon is in line with Earth with a 5cm gap between them.

Step 5

Make a hole about the same size as the diameter of the skewer in the centre of the box lid and push the skewer into it. Next, put a blob of Blu Tack inside the box to help to keep the skewer in place. We painted the box black for a nice finish.

Step 6

Place a lamp 25cm from the model; move the Moon in front of Earth (right) to see the lunar umbral and penumbral shadow, simulating a solar eclipse. Move it behind Earth (left) to see Earth’s umbral and penumbral shadow cast on the Moon, a lunar eclipse.