During a solar eclipse, when the moon is positioned between the sun and the earth, the air temperature beneath the moon's shadow drops a few degrees. Building a model of a solar eclipse may not change the temperature on the model Earth, but it will illustrate how a solar eclipse occurs. The same model can also be used to demonstrate a lunar eclipse, when the Earth is positioned between the sun and the moon. In this activity, a scale model of the Earth-moon system is built using simple materials.
Attach a 10-centimeter hard foam ball with glue to the end of a three-meter-long board to represent the Earth.
Insert one end of a stiff wire into a 2.5-centimetre hard foam ball.
Attach the small ball by the wire to the other end of the board to represent the moon. Adjust the wire so the centres of the two balls line up.
Go outside on a sunny day to demonstrate the lunar eclipse.
Hold the board with the Earth closer to the sun than the moon.
Adjust the position of the board until the shadow of the earth completely covers the moon to create the lunar eclipse.
Go outside on a sunny day to demonstrate the solar eclipse.
Hold the board with the moon closer to the sun than the Earth.
Adjust the position of the board until the shadow of the moon falls across the Earth to create the solar eclipse.
Observe how the shadow of the moon does not completely cover the Earth. This is the way it happens during a real solar eclipse.
Do not look directly at the sun.