Have you ever looked in the night sky and wondered why the Moon seems to change shapes in the sky? The Moon reflects light from the Sun as it orbits, or moves in a circular path, around the Earth. Half of the moon is always lit up by light, but on Earth we don’t always see this half. Instead, we see the shadow and light change shape as it moves towards the Sun, and then away from the Sun. We call these changes in shadow shapes phases of the Moon.

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Materials:

- Small Round Object

- Flashlight or Lamp

- Yourself!

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Procedure:

1. This activity will be using models to represent different parts:

- Small Round Object: The Moon

- Flashlight or Lamp: The Sun

- Your Head: The Earth

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2. Place your light (the Sun) so it is a little higher than your head (the Earth). If you are using a flashlight, have someone hold it for you.

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3. Turn off all the lights in the room except your Sun, and make sure there is no extra light coming in through the windows.

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4. Hold your small round object (the Moon) out at arm’s length facing the Sun. Your hand should be under the Moon, not on the sides. Now look at your Moon, what are the shadows like? It should be completely covered in shadow. This phase is called New Moon.

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5. Now turn 1/4 to the left. The right side of your Moon should be light, and the left side should be shadowed. This phase is called First Quarter.

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6. Turn another 1/4 to the left (facing away from the Sun). Your Moon should be lit up all the way. If it is not, you may need to move your Sun a little higher. This phase is called Full Moon.

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7. Turn one more 1/4 to the left. The right side of your Moon should be in shadow and the left side should be in the light. This phase is called Third Quarter.

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What happened? You just did four moon phases, but there are actually four more!  Can you find them? Try finding the Waning Gibbous, Waning Crescent, Waxing Crescent, and Waxing Gibbous. Here’s a few hints on how to find them.

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1. The first hint is they’re between the phases you just did. So instead of turning 1/4 , now turn 1/8.

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2. Secondly, you can find them using their names. Waning means the light is getting smaller, while waxing means the light is going to get bigger. A gibbous means it’s more than half-light, while a crescent means you only have a tiny bit of light.

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Check out the image below to see if you named them right!

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Explore more! Now what if you were the Sun instead?  What if you had someone else be the Earth, and you watched the Moon turn around the Earth?  What happens to the shadows?  Do they change?  Or do you always see half the Moon lit up?

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