Teacher resources and professional development across the curriculum

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Looking at Learning ... Again


Tune in to the Moon

The Moon Journal – Activities

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Workshop 2
Measuring the Moon's Diameter

When making your Moon observations, take a ruler with you. Hold the ruler at arm's length from your body and measure the diameter of the Moon in centimeters. Record your finding and try it again the following night. Does the diameter of the Moon change every night? Can the diameter of the Moon really be measured in centimeters with a ruler?

For more accuracy, you can measure the Moon's diameter using a Cross Staff. Here's how.

Building a Cross Staff

Materials: Cross Staff template
Paste or glue
Meter stick


  1. Adhere the Cross Staff template to a piece of cardstock and cut along the solid lines. Be sure to cut out the notch at the top of the template and the rectangular slot in the center.
  2. Push a meter stick through the rectangular slot and make sure that the card can move freely up and down the length of the meter stick.

Using a Cross Staff

  1. On a night when the Moon is at or near full, hold the meter stick with the zero end touching your cheek and the meter stick pointing towards the Moon.
  2. Slide the card along the meter stick until the Moon just fills the notch. (It may be helpful to close one eye while looking at the Moon through the notch.)
  3. Note the distance along the meter stick between the card and the end closest to your eye.
  4. You can now calculate the diameter of the Moon using the following ratio:
width of notch   diameter of Moon

distance from card to eye   distance to Moon

Use the distance 400,000 km as the distance from the Earth to the Moon. (The accepted value is 384,401 km.)


Often the Moon looks "bigger" when it is near the horizon. How could you use a Cross Staff to check whether or not this is a true phenomenon?

A Cross Staff can be used to determine the dimensions of other objects once their distance from the observer is known.

Adapted from:

Hall, J. (1994). Calculating the Moon's diameter. In N.B. Ball, H.P. Coyle, & I.I. Shapiro (Eds.) A teacher resource to enhance astronomy education: Project SPICA. Kendall/Hunt Publishing Co.: Dubuque, Iowa.

Wong, O.K. (1987, October). How wide is the Moon? The Science Teacher.

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Workshop 3
Measuring the Elevation of the Moon

One piece of information helpful in describing the Moon's position is its height in angles (angular height) above the horizon. The horizon is the line along which the sky and land -- or sea -- appear to meet. You can determine the Moon's height above the horizon if you know the angle between the line from your eyes to the Moon and the line from your eyes to a point on the horizon directly below the Moon.

Measuring with Fists

You can estimate the Moon's angular height by simply using your hands. Stretch one arm out straight and make a fist with the hand on your outstretched arm. From the horizon to the highest point in the sky is one quarter of a circle or 90 degrees. If you measure with fists, putting one fist on top of the other, nine fists will about equal this angle -- one (adult) fist is roughly the same as 10 degrees.

To measure the angular height of the Moon at any given time, stretch one arm out straight and make a fist with the hand on your outstretched arm. Close one eye and adjust your sight so the outstretched fist is aligned with the horizon. Make a fist with your other hand and stack it on top of the first. Continue stacking your fists, one on top of the other, until the Moon appears to be covered by one of the fists. The number of fists you stacked indicates the angular height of the Moon. For example, if you counted six fists, the angular height of the Moon above the horizon would be approximately 60 degrees.

Measuring with a Clinometer

A clinometer is a tool that can help you to measure the angular height of the Moon more accurately than with your fists.

Materials:Protractor template, Cardstock, Paste or glue, Drinking straw, Clear tape, Scissors, 30 cm fishing line or kite string, Metal washer or weight with hole, Tack or pin

Building a Clinometer

  1. Adhere the protractor template to a piece of cardstock and cut along the dotted lines.
  2. Center the straw lengthwise along the edge of the template directly above the straight side of the protractor. Secure it in this position with tape.
  3. At the point where the protractor's center line (0 degrees) meets with the line that runs parallel to the straw, use a tack or pin to make a hole.
  4. Thread one end of the fishing line or kite string through the hole so that approximately 2 cm extends out the back side of the protractor. Secure this portion of string to the back side of the protractor.
  5. Tie the metal washer to the opposite end of the fishing line or kite string. The string and washer should swing freely along the front side of the protractor.

Using a Clinometer

  1. Position the Clinometer straw-side up so the straw is parallel to the ground and the string hangs parallel to the 0 degree marking on the protractor.
  2. Look through the straw and adjust the position of the Clinometer until you sight the horizon directly below the Moon (while keeping the straw parallel to the ground).
  3. While looking through the straw, tip the entire Clinometer upward until you can sight the Moon through the straw.
  4. As you move the Clinometer, the string moves along the protractor. By noting the position of the string along the protractor, you can determine how many degrees you are tipping the Clinometer to sight the Moon. This measurement is the angular height of the Moon.


To measure the height of an object that makes a right angle with the land, such as a tree or a building, sight the top of the object through your clinometer and walk towards the object until the clinometer measures 45 degrees. By mentally tracking from your observation point to the base of the object to the top of the object and back to your observation point, you will make an isosceles triangle. Given that two sides of an isosceles triangle are equal, you can determine that the distance from the observation point to the object itself will be equal to the height of the object.

Adapted from:

Coyle, H.P., Gregory, B., Luzader, W.M., Sadler, P.M., & Shapiro, I.I. (1993). Project STAR: The universe in your hands. Kendall/Hunt Publishing Co.: Dubuque, Iowa.

Education Development Center, Inc. (1968). Where is the moon? Webster Division, McGraw-Hill Book Co.: New York.

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Workshop 4
Sun, Earth, and Moon Angles

One way to chart the Moon's behavior is to chart its position with respect to the Sun and the Earth. Specifically, you can measure the angle between the Moon and the Sun, with the Earth as the vertex of the angle.

At a time when both the Moon and the Sun are visible measure the angle between the Moon and the Sun from your observing location. Each time you measure and record the angle, also observe and record the shape (phase) of the Moon, and notice whether the lit or unlit portion of the Moon is nearest the Sun.

CAUTION: Never look directly at the Sun.

Estimating Angles with Fists

Just as you can use fists to measure the elevation of the Moon, you can do the same to measure the angle between the Sun and the Moon. Make a fist with each of your hands and hold them out in front of you at arm's length. Count how many fists make up the distance between the Moon and the Sun.

Measuring Angles with a Protractor

Materials: Clinometer


  1. Position your clinometer with the protractor numbers face-up.
  2. Point one end of the straw to the Moon.
  3. Slide the string along the top of the protractor until it is aligned with the direction of the Sun.
  4. Use the numbers along the side of the protractor to calculate the angle between the Sun and the Moon.


  1. Is the lit or unlit part of the Moon facing the direction of the Sun?
  2. Which direction are the "horns" of a crescent facing with respect to the Sun? Does this change as the angle between the Moon and the Sun changes?
  3. Do you notice a pattern between the Moon-Sun angle and the phases of the Moon?

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Workshop 5
Modeling the Phases of the Moon

To do this activity effectively, the room must be as dark as possible. Darken the room by closing the blinds and covering all window and door cracks with black paper or cloth and tape.

Materials: Lamp, Extension cord, Clear light bulb (75 watts or more), 3-inch Styrofoam ball, Craft stick


  1. Make a "handle" for your Styrofoam ball by carefully pushing a craft stick into the ball. Hold the handle so the Moon ball is positioned upright.
  2. You will be part of a model that portrays the phases of the Moon. In the model, your head will represent the Earth, the Styrofoam ball will represent the Moon, and the lamp will represent the Sun.
  3. Place the lamp in the center of the room and turn it on. Turn off the room lights and then stand approximately two arm-lengths away from the lamp.
  4. Hold the Moon ball directly in front of the lamp and at arm's length from your body, pointing upwards approximately 45 degrees. Notice that as you hold the Moon ball in front of your body and turn around, sometimes part of the ball is lit, and sometimes the whole hemisphere facing you is lit.
  5. Keep turning until you can see a thin crescent lit up on the Moon ball.
  6. Continue moving in the same direction until the Moon ball looks like a half-lit circle.
  7. Continue moving in the same direction until the ball looks completely lit.


  1. Is the brightest side of the Moon facing towards or away from the Sun?
  2. For the Moon to appear "fuller," how does it have to change its position relative to the Sun?
  3. When the Moon is full, is it on the side of the Earth that's closest to the Sun, or the side that's farthest away from the Sun?
  4. Are the phases of the Moon the same in the northern and southern hemispheres?


On a sunny day when the Moon is visible, go outside with your Styrofoam Moon ball. Stand facing the Moon, holding out your Moon ball at arm's length "covering" the Moon in the sky. The Sun will shine on the ball and illuminate it exactly as it illuminates the Moon.

Adapted from:

Foster, G.W. (1996). Look to the Moon. Science and children. 34(3), 30-33.

Braile, S. (1994). Moon phase modeling. In N.B. Ball, H.P. Coyle, & I.I. Shapiro (eds.), Project SPICA. Kendall/Hunt Publishing Co: Dubuque, Iowa.

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Workshop 6
Observing the Features of the Moon

Sketching Features of the Moon

Materials: Pencil, Paper, or sketch pad, Binoculars (optical), Moon Map


Before using the Moon Map to identify features on the Moon, sketch the features you observe. When the Moon is not full, you should notice that the Moon is divided by a line -- the terminator line -- that separates the Moon's sunlit side from its shadowed side. The features on the Moon's surface stand out best near the terminator line. These features are even more apparent when using high-powered binoculars. Use your Moon Map to help identify interesting features on the Moon.

To observe a feature on the Moon over time, use your Moon Map to identify a feature close to the "curved" edge of the lit portion of the Moon. Examine this feature over a week or two. Is the feature always visible? Does the feature change its relative position? Does the feature seem to "move" across the Moon or stay in the same place?


How do your observations help you to learn something about the revolution time of the Moon as compared with the rotation time of the Moon?

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Workshop 7
Moon Phase Guide

If you know the directions in which the Moon rises and sets, a Moon Phase Guide is a useful tool for determining the time at which the Moon rises and sets.

Building a Moon Phase Guide

Materials: Moon Phase Guide template, Corrugated cardboard (15 cm x 15 cm), Pushpin or thumbtack, Almanac, newspaper, or calendar, Scissors, Glue or paste


  1. Cut out both pieces of the Moon Phase Guide.
  2. Glue or paste the larger piece to the center of the cardboard.
  3. Orient the smaller piece on top of the larger such that the center points are aligned.
  4. At the center point, push a pushpin or thumbtack through both template pieces and the cardboard.

Using a Moon Phase Guide

  1. Determine the current Moon Phase (consult an almanac, newspaper or calendar).
  2. Position the Moon Phase Guide so that the text is face-up and parallel to the ground.
  3. Holding the half-circle in place, rotate the cardboard until the current Moon phase is directly under the Moon Rise portion of the half-circle.
  4. Note the time the arrow on the half-circle is pointing to. This is about the time the current Moon phase rises.
  5. Next, rotate the cardboard until the phase of the current Moon phase is directly under the Moon Set portion of the half-circle.
  6. Note the time the arrow on the half-circle is pointing to. This is about the time the current Moon phase sets.


  1. The Moon Phase Guide indicates that the Moon is visible for 12 hours each day. Is this accurate?
  2. Why is there a predictable pattern to the changing appearance of the Moon?
  3. How does the Moon Phase Guide work? What assumptions does it make about the Sun-Moon-Earth relationships in its design? What assumptions does it make about the directions of Moon rise and set.

Adapted from:

Becker, K. (1994). Moon phase dial. In N.B. Ball, H.P. Coyle, I.I. Shapiro (Eds.) Project SPICA.Kendall/Hunt Publishing Co:Dubuque, Iowa.

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Workshop 8
Moon Legends

Our scientific understanding of the Moon and its behavior has not always been what we currently accept to be true. Throughout history and across cultures, civilizations have developed what we know of today as legends and folklore as explanations of Moon observations and its behavior. Legends were the first scientific explanations. People would observe a phenomenon and then describe it with a story. People eventually began comparing different legends of similar phenomenon to find out which were most helpful in explaining what they saw. The following are stories developed by early cultures to describe possible reasons for the behavior of the Moon:

According to Central Mexican (non-Mayan) cultures, the Moon and the Sun were created at the same time when the two gods, Tecuciztecatl and Nanahuatzin threw themselves into the Fires of Creation and turned into two Suns. But the gods who organized this also threw a rabbit into the face of Tecuciztecatl, dimming his brightness, making him the Moon.

The Mayans believe the Moon Goddess to be a feisty woman. It is said that she once quarreled with her husband, the Sun, who became so angry that he poked out one of her eyes. That is why the Moon Goddess is dimmer than her spouse the Sun.

The Cherokee tribe of California tells the story of Father Sun and Mother Moon who lived inside Rock House. Their light did not shine from the sky, so the world was full of darkness. Coyote thought it would be a fun trick to dump some fleas on Father Sun and Mother Moon. Coyote got Gopher to help dig a hole through the soil into Rock House, and Rabbit to help shake a bag of fleas down the opening. The fleas soon covered Father Sun and Mother Moon. When they could no longer stand the fleas, Mother Moon flew out of the house, followed by Father Sun, and they began to race around the Earth trying to get rid of the fleas. That is why, to this day, the Sun follows the Moon across the sky.

The Snoqualmie tribe in Washington tells the story of a time when the sky was completely dark and there were two brothers, One Who Walks All Over the Sky, and Walking About Early. One Who Walks was sad to see the sky always dark so he made a mask out of wood and lit it on fire. Each day he walks across the sky wearing his fiery mask. At night he sleeps below the horizon and when he snores sparks fly from his mask and make stars. The other brother became jealous. He smeared fat and charcoal on his face, and makes his own path across the sky.

The Zunipu tribe of New Mexico and Arizona tells a story of a time when it was always dark, and always summer. Coyote and Eagle were hunting and they came across a tribe that had the Sun and the Moon in a box. After the people of the tribe had gone to sleep, the two animals stole the box. At first Eagle carried the box, but soon Coyote convinced Eagle to let him carry it. Coyote, being curious, opened the box and the Sun and the Moon escaped and flew up into the sky. This gave light to the land, but it also took away heat, which is why we now have winter.


  1. What kinds of Moon behavior do the legends try to explain?
  2. What descriptive features of the Moon or Moonlight, visible to the naked eye, are explained by the legends?
  3. How are these legends related to the culture of the people who developed them and maintained them over the centuries?
  4. Find out something about the people who developed the legends and relate these ideas to the reasons for the importance of each legend.

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