Materials Needed:

• 1 dodge ball or beach ball
• 1 softball or tennis ball

You need three people for this activity.

1. Have one person hold up the large ball (Sun).
2. Have another person hold up the small ball (Moon) directly in front of the sun – about 6 feet away.
3. Have another person stand in front of the person holding the “Moon.” This person will represent an earth observer.
4. The Earth observer and the person holding the Sun should begin moving away from the person holding the Moon until the Sun and the Moon appear to be the same size.

Record the positions of the Moon and the Sun when they appear to be the same size.