# How the Sun and Moon Can Appear to be the Same Size

The diameter of the Sun is over 400 times the diameter of the Moon. So how can they appear to be the same size? Try this experiment! You need three people for this activity.

### Materials Needed:

• 1 dodge ball or beach ball

• 1 softball or tennis ball

• tape measure or meter stick

1.Have one person hold out the large ball, which will represent the Sun. Hold it out away from your body so that your hands are on the top and bottom of the ball.

2.Have another person hold up the small ball (representing the Moon) directly in front of the "Sun". Stand about 6 feet away and hold the ball out in the same way the person is holding the "Sun".

3. The third person should stand in front of the person holding the "Moon", looking toward the person holding the "Sun". This person will represent what someone on Earth would see. Have the Sun and Moon adjust themselves so that they appear to be in a straight line, with the Moon between the Earth and Sun.

4.The person holding the Sun should begin moving away from the person holding the Moon (again keeping the Earth, Moon, and Sun in a straight line) until the Sun and the Moon appear to be the same size to the person representing the Earth.

Measure and record the diameters of the Sun and Moon.

Measure and record the distances from the Earth to the Moon and the Sun when they appear to be the same size.

• Why do you think they look the same size to the Earth observer?

• What happens when you look at the values of distance/diameter for the Moon and Sun?

• Given what you know about the relative sizes of the Sun and Moon, what can you conclude about their relative distances from Earth?

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StarChild Authors: The StarChild Team
StarChild Graphics & Music: Acknowledgments
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