1. Astronomy The Phases of the Moon Name:
As the Moon orbits Earth, it is sometimes between Earth and the Sun, sometimes on the opposite side of
Earth as the Sun, and sometimes in between. Because of this, it exhibits phases, or altering states of
illumination. In this activity, you will use a light source as the Sun, a volleyball as the Moon, and you as
Earth. As you rotate, with the “Moon” held out in front of you, the phases will become apparent.
Procedure:
1. Hold the volleyball (“Moon”) out in front of you and between you (“Earth”) and the light source
(the “Sun”). Rotate counterclockwise one-half revolution and note how the illumination of the Moon
changes. When you complete the half-rotation, the Moon should be illuminated completely. Now reset
and repeat. Answer the following question: As you rotate from having the Moon between Earth and
Sun through a half-rotation (to having the Moon on the opposite side of Earth as the Sun), does the
Moon become illuminated from its right side to its left side, or from its left side to its right side?
2. Orient you and the ball so that the Moon is completely illuminated. Rotate counterclockwise one-
half revolution and note how the illumination of the Moon changes. When you complete the half-
rotation, the Moon should be dark, from your perspective. Now reset and repeat. Answer the
following question: As you rotate from having the Moon on the opposite side of between Earth as
the Sun through a half-rotation (to having the Moon between Earth and the Sun), does the Moon
become darkened from its right side to its left side, or from its left side to its right side?
3. Reset the system so that the Moon is between Earth and Sun (a “New Moon”). As you rotate
through a half-rotation, the Moon becomes completely illuminated (a “Full Moon”). As it becomes
illuminated from New to Full, we say the Moon is waxing. As you rotate from Full Moon to New
Moon, we say the Moon is waning. When the Moon is less than halfway illuminated, we refer to it
as a crescent. When the Moon is more than halfway illuminated, we refer to it as gibbous.
4. Fill in the Table below. Color in the circles where the Moon is dark. Leave it white where it is
illuminated.
New Moon
Waxing Crescent
First Quarter
Waxing Gibbous
Full Moon
Waning Gibbous
Third Quarter
Waning Crescent

2. 5. In the boxes below, shade in the circle with the appearance of the Moon from Earth. Then, label each
box with the term describing the appearance ( example: waxing gibbous ).
sun
sun