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Investigate Phases of the Moon: Science Activity for Middle School Students

When I admire the wonders of a sunset or the beauty of the moon, my soul expands in the worship of the creator.
Mahatma Gandhi

Lunar Phases

Because the moon revolves around the Earth, it seems to change shape from one day to the next. The changing shapes of the moon in the sky over the course of a month are known as the lunar phases. These moon phases depend upon the position of the moon relative to the Sun and the Earth. As the moon completes its orbit around the Earth, light from the Sun reflects off of it at different angles. The lighted portion of the moon always points the way to the Sun. Lunar phases begin with a new moon and 29½ days later end with a full moon. Eight lunar phases in all comprise a complete cycle. Complete the following activity with your own children or school class and allow them to discover how lunar phases occur.

Did You Know?

If you are viewing the moon from the equator, a crescent moon is shaped like a smile!

A lunar month is approximately 29½ days!

Objectives For Investigating Phases Of The Moon

  1. Be able to identify the main phases of the lunar cycle.
  2. Follow instructions carefully in an investigation.
  3. Make careful observations during a science activity.
  4. Understand why we are able to see the moon despite it not being a light source in itself.
  5. Understand why the moon appears to change shape.

Did You Also Know?

The moon moves by about 12° each day towards the east.

A Blue Moon is the second full moon occurring in a calendar month. They occur about every three years and the last Blue Moon occurred August 2012.

Materials Required To Investigate Moon Phases

  • a light source (lamp or flashlight)
  • styrofoam ball painted black or a dark-colored play ball
  • black paint (if using styrofoam ball)
  • pencil or knitting needle (for the handle)
  • darkened room
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Method For Investigating Phases Of The Moon

  1. Put an X on one side of the ball (this represents the face of the moon you would see from earth).
  2. In a dark room, HOLD the ball at arm's length above your head.
  3. Have a friend shine a flashlight directly at the moon or have a spot upon which the flashlight can be anchored so that it is shining on your moon. A flashlight with a large beam would give better results.
  4. Slowly TURN yourself counterclockwise on the spot. ENSURE the X is always facing you and that the light stays in the same spot.
  5. RECORD and have a friend TAKE or DRAW pictures of what happens to the lighted portion of the ball at various positions during one trip around your spot. Stop at 45°, 90°, 135°, 180°, 225°, 270°, 315° and 360° angles to the light Using the diagram to the right as a guide, create a circle on the floor and mark out the angles using clock measurements. The flashlight (Sun) faces noon. .

Observation Table For Phases Of Moon Activity

Angle to LightPosition of X Relative to Lighted Surface

















Diagram Of Your Results Investigating Moon Phases

  • Organize your photos or drawings into a series of events labelling each lunar phase.
  • Pixlr is free photo editing software which has a collage feature perfect to showcase your photos if you chose to photograph your results.

Discussion Of The Phases Of The Moon

Answer the following questions.

  1. Is the lighted portion of the moon facing towards the sun or away from it?
  2. When the moon is full, where is it in relation to the sun (light source) and earth (your spot on the floor)?
  3. Once the moon is full and you continue moving in the same direction around, what do you notice about the lighted portion?
  4. Why can we see the moon?
  5. Why does the moon appear to change shape?


Teresa Coppens (author) from Ontario, Canada on February 17, 2013:

Thanks so much Theresa. I have a grade 9 class to whom I will be teaching space later in the semester. I am hoping to make use of this hub with them. Its been a while since I've had my own class to experiment with, he, he, he!

Theresa Ast from Atlanta, Georgia on February 17, 2013:

Great Hub and great activiites for students. Which you had been my teacher of so many years ago. :) Sharing.

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