Modelling the Earth and Moon allows an appreciation for the angles involved in creating the phases of the Moon. The Moon is illuminated on one side by the Sun, while the side of the Moon facing away from the Sun is dark. As the Moon orbits the Earth, different angles between the Earth, Sun, and Moon bring different portions of the illuminated and dark side into view. A view of the dark side of the Moon is called a new moon while a view of the illuminated side of the Moon is called a full moon. When the Moon is progressing from new to full it is said to be waxing and from full to new it is waning.
Paint the large polystyrene foam ball blue to represent the Earth. Paint the small polystyrene foam ball grey to represent the Moon.
Bend the end of a piece of floral wire into a small hook shape. The hook should be approximately 1.3 cm (0.5 inches) in length.
Slide the floral wire through the polystyrene foam ball representing Earth to the hooked end of the wire. Secure the ball to the floral wire by piercing the ball with the hook.
Bend the end of another piece of floral wire into a small hook shape. Again, the hook should be approximately 1.3 cm (0.5 inches) in length.
Slide the floral wire through the polystyrene foam ball representing the Moon to the end of the hooked wire. Secure the ball to the floral wire by piercing the ball with the hook.
Twist the floral wire protruding from the top of the Moon around the floral wire protruding from the top of the Earth. The floral wire between the Earth and the Moon should be long enough for the Moon to hang over the side of the Earth but not so long that it hangs below the Earth. The floral wire twist should remain loose enough for the Moon to spin around the Earth.
Hang the model near a light source such as a lamp. The side of the Earth illuminated represents the day side. As the Moon is moved around the Earth, the side facing the light will remain lit. Viewed from the model of Earth, different amounts of the light side and dark side of the Moon will be visible showing the phases of the Moon.