Lesson 4: The Lunar Cycle – Phases of the Moon [Teacher Pages]
Purpose:
The purpose of this lesson is to engage students with the phases of the moon within the
context of the lunar cycle. Students will collect data as they observe the phases of the moon in
the order of appearance. As students observe the moon, the students can identify the fraction
of the visible at specific times of the year by using the following site created by the United
States Navy:
http://aa.usno.navy.mil/data/docs/MoonFraction.php
Learning Objectives:
By the completion of this lesson, students will be able to:
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Create a graph illustrating the fraction of the moon’s face visible from the Earth using
the following Naval website:
http://aa.usno.navy.mil/data/docs/MoonFraction.php
Complete a data chart of moon phases gathered over one lunar cycle, beginning and
ending with a new moon.
Materials:
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Pictures of the moon
Access to a computer – go online to investigate the fraction of the moon visible at a
specific date: [http://aa.usno.navy.mil/data/docs/MoonFraction.php]
Access to a computer – observe the lunar cycle for the current month of the current
year at this site.
Lunar cycle data sheet to record daily observations
Potential Misconceptions and Accurate Explanations:
It is important to remember that students come into the classroom with misconceptions about
the phases of the moon. These misconceptions are difficult to dispel and may interfere with
student learning and understanding the actual reasons for lunar phases.
Several misconceptions and accurate explanations are shown below:
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Misconception: The phases of the moon are actually caused by the shadow of the Earth
on the Moon.
o Explanation: The appearance of the moon in the sky is determined by the
amount of the sunlit portion of the moon that is visible from the Earth at any
one time during the lunar cycle.
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Misconception: Different regions of the world see different phases of the moon on the
same day or at the same time.
o Explanation: Everyone on earth sees the same phase of the moon at the same
point in time.
Misconception: The moon orbits the Earth in a single day.
o Explanation: the Moon does orbit the Earth, however, the Moon will complete
one orbit of the Earth in approximately 27.3 days.
Misconception: The Moon generates its own light.
o Explanation: The Moon is not a star and therefore, does not generate its own
light. Instead, the Moon reflects light from the sun. Remember, that the planets
are visible from the Earth for the very same reason. The planets also reflect the
Sun’s light. During the lunar cycle, portions of the sunlit Moon are visible from
the Earth during the lunar cycle.
Misconception: The Moon does not rotate as it orbits the Earth.
o Explanation: The Moon does rotate and one complete rotation takes about 27.3
days. The time it takes the Moon to complete a single rotation is the same time
required for the Moon to make one revolution around the Earth. Because the
timing for the Moon’s rotation on its axis and one full revolution around the
Earth is the same, we only see one side of the moon.
Misconception: There is a dark side of the Moon because the same side of the Moon is
consistently in darkness.
o Explanation: There is no side of the Moon that is consistently in darkness,
because we only see one side of the moon from the Earth, we could call the side
of the moon that we do not see the ‘far side’ of the Moon rather than the dark
side of the Moon.
Misconception: There is no gravity on the moon.
o Explanation: There is gravity on the moon, however, because the Moon has less
mass than the Earth, the gravitational pull on the Moon is approximately 1/6 of
that on Earth.
Misconception: The Moon is only visible at night.
o Explanation: The Moon is also visible during the day because it is reflecting light
from the sun.
Observing Lunar Phases:
It is impossible for students to observe the phases of the moon from space. However, this
website provides a Lunar Phase Simulator which allows students to gain a better understanding
of the portion of the moon we are able to see from the Earth. Stude3nts can see the Earth
rotating as the Moon orbits. The can see the sunlit portion of the moon and in the upper right
hand corner of the website, they are able to see an image of the Moon as it appears from the
Earth. The name of the lunar phase appears below the changing image of the Moon. This would
also be an excellent site to share with your students. This animation allows you to regulate the
speed of the Earth and Moon during the lunar cycle, place a pink landmark on the moon, show
time in terms of sunrise, noon, sunset, and midnight, as well as the angle of the Moon’s orbit
around the Earth.
http://astro.unl.edu/classaction/animations/lunarcycles/lunarapplet.html
Figure 1: This figure is an image of the Lunar Cycle Simulator. This animation can be found at the
following URL: http://astro.unl.edu/classaction/animations/lunarcycles/lunarapplet.html
Lesson Format:
Engage:
Begin the lesson by engaging students with the Phases of the Moon Keeley Probe. This probe is
designed to reveal student thinking about the moon and the phases of the moon that we see
from the earth.
When students have completed the probe, collect their work and discuss their ideas about the
phases of the Moon. Do not reveal the correct response at this time, instead use the discussion
as a means of revealing student thinking.
Explore:
Activity 1: The Lunar Cycle: This activity engages students with the creation of a model to
explain the changing image of the Moon during a complete lunar cycle.
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You will need the following materials:
o Styrofoam balls [one per student]
o Pencil
o Light source [a bare bulb works nicely-placed in the center of the room
Protocol:
o Place the light source in the center of the classroom
 During the activity be sure to turn off the lights in the classroom so the
bare bulb is the only source of light in the room
o Provide a Styrofoam ball and pencil per student
 Instruct students to push the pencil into the ball so that the ball can be
held in place with the pencil\
o Explain to the students that in this model:
 The lamp represents the Sun
 The ball represents the Moon
 The ball [representing the Moon] should be held slightly higher than the
student’s head
 Your head represents the Earth
o Explain the meaning of a ‘counter clockwise’ direction
o Instruct the students to slowly turn in a counter clockwise direction until the
Styrofoam ball is between the lamp [represents the Sun] and your head
[represents the Earth]
 This is a New Moon, the opposite side of the Moon is lit by the Sun and
from the Earth the Moon is not visible because the dark side of the Moon
is facing the Earth.
o Continue to turn your body in a counter clockwise direction, instruct the
students to stop once the Moon has completed ¼ of a revolution around the
Earth
 Ask the students to describe what they see. At this point, a small portion
of the Moon should be visible because students are now able to see a
portion of the half of the Moon lit by the Sun
o Instruct the students to continue to turn in a counter clockwise direction until
the Moon has completed ½ of a revolution around the Earth.
 What does the Moon look like now?
 At this point, they will notice that more of the lit half of the Moon is
visible from the Earth. Remind the students that at any one time only ½
of the Moon is lit by the Sun but the portion of the Moon we are able to
see from the Earth changes during the lunar cycle.
 Ask for predictions, how will the Moon look if ¾ of the revolution around
the Earth is complete?
o Instruct the students to continue to turn in a counter clockwise direction until
the Moon has completed ¾ of a revolution around the Earth.
 Note that students are able to see even more of the lit portion of the
Moon. Ask students to predict how the appearance of the moon will
change as they continue to complete one revolution of the Moon around
the Earth.
o Ask the students to work in groups of two to continue to work on the lunar cycle.
Challenge the students to explain the lunar cycle and the changes observed in
the representation of the Moon in this model.
o Ask students to share their ideas with the class.
Activity 2: The Moon Journal: This activity engages students with real-time observations of the
Moon during the lunar cycle. The students will use the Moon journal provided to make and
record daily observations of the Moon. Arrange student observations of the Moon
Assign students into small groups and discuss the following questions, ask each group to share
their ideas with the class prior to making their observations. Arrange the Moon journal
observations to begin with a New Moon. Encourage students to draw from their experiences
with the Styrofoam Moon model created earlier. The activity will take place in the background
as students continue to explore the phases of the Moon during classroom activities.
Discussion Questions:
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Will the Moon the same shape each time you look for it in the sky?
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Does the Moon orbit the Earth? If so, how long do you think it takes for the Moon to
make one complete orbit around the Earth?
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Do you think that you will see the Moon in the same place in the sky each night?
Do you think that you will see the Moon in the sky during the day?
What do you think the Moon will look like on the first day of your journal?
Do you think the Moon makes its own light, like the Sun?
Activity 3: Oreo Cookie Moon Cycle Model: This activity engages the students with a very basic
model of the lunar cycle which relies upon Oreo cookies to represent the Moon.
 You will need the following materials:
o 1 packet per student team
o 8 Oreo cookies per team
 Protocol:
o Students begin the packet by matching:
 The phases of the moon with photographs of the Moon phases
o A teacher page showing the accurate position of each of the images and the
appropriate name is included in the packet but should not be shared with the
students.
o Review key terms of the Lunar Cycle with the students:
o Ask students to cut and paste the images of the lunar cycle in the correct
positions using the diagram and photos provided
o Challenge the students to create their own model of the lunar cycle using Oreo
cookies. A direction sheet is provided, you can discuss the directions with your
students or provide the sheet.
Explain:
 With of the activities provided, engage students with an explanation for their
observations.
o It is important that the explanations are provided by the students rather than
the teacher.
o Ask students to reference images in the PowerPoint or the model of the lunar
phases they created in their explanation.
Evaluation:
 Formative evaluations include:
o Student responses to the probes
o Models or representations developed by the students
o Presentations provided by student teams explaining the lunar cycle.
Extension:
 Extension activities could include:
o The Moon Journal
o Documenting the phases of the moon each day with
https://stardate.org/nightsky/moon
Name:
Moon Journal
Sunday
Month:
Monday
Starting Date:
Tuesday
Wednesday
Ending Date:
Thursday
Friday
Saturday
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Teacher Resources
http://tycho.usno.navy.mil/vphase.html
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Your students will be able to view the phase of the moon for any date and time within
the following time frame: 1800 through 2199. This images of the lunar cycle were
created by R. Schmidt from ray-traced images of the moon.
http://nssdc.gsfc.nasa.gov/planetary/factsheet/
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Use the planetary fact sheet to obtain interesting information about the solar system
and about Earth’s moon.
http://www.csun.edu/~vceed002/geoscience/astronomy/graphics/gif_jpg/lunar_map1.jpg
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If you are your students are curious about the moon, this lunar map will be helpful in
understanding the shape and surface of the moon. This is a great way to stimulate
discussion about the many creators on the moon.