<% Dim chemin_langue showdate="2002/12/31" chemin_langue = "../../../../../fr/jeunes_educateurs/educateurs/ressources/dossiers/dossiers.asp" %> Phases of the Moon Lesson


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Lesson Overview
Background Information
Developing the Lesson

Module 3 - Lesson 4

Phases of the Moon

Module 3: The Earth and the Moon



This activity will require approximately 2 class periods (~50 minutes each)

  • 1 class to introduce the topic, demonstrate the processes with flashlight and globe and to introduce the applet (activity 1 & 2)
  • 1 class to have students work with the applet describing the reasons for the phases (activity 3), and closure activity (activity 4)



Pan-Canadian Curriculum Objectives:

describe and explain the apparent motion of celestial bodies

describe the composition and characteristics of the components of the solar system

describe the effects of solar phenomena on Earth


Lesson Overview:

By engaging students in a variety of activities targeting different learning styles (kinesthetic, visual, and technological), students will become familiar with the phases of the moon, and will be able to explain the reasons for the lunar phases depending on the orientation of the sun, moon, and Earth.

The lesson plan is divided into four separate activities:

  1. Activity 1: demonstrate the phases (students participate)
  2. Activity 2: introduce the applet to later be used by students
  3. Activity 3: in the computer lab, students work with the phases of the moon applet in groups of two
  4. Activity 4: closure activity: teacher uses the applet in a lecture-style delivery format, stopping the animation at key moments and eliciting feedback from the students as to an explanation for the observed phase


Materials and Resources:

  1. Phases of the Moon applet
  2. Charting the Moon worksheet
  3. Phases of the Moon worksheet
  4. Globe
  5. Model of the moon (a simple ball will do)
  6. Bright flashlight
  7. Phases class demonstration diagram
  8. Moon Phase Calendar generator:



    • lunar phase
    • synodic month
    • lunar cycle
    • crescent
    • gibbous
    • blue moon


Background Information:

Phases of the Moon

Animated Phases of the Moon

By observing the Moon over a period of several weeks, one will notice that the Moon rises and sets at different times each night, and that there is a regular progression through lunar phases. In a synodic month, the Moon progresses through one lunar cycle and will vary between being a completely dark new moon and a fully illuminated full moon . The lunar phases are caused because the orbit of the Moon around the Earth will vary the Moon’s position in relation to the Sun. Half of the Moon is always lit by the Sun, but the portion that we see will change depending on where the Moon is in its orbit. The synodic month “begins” at new moon. Because the Moon is in the same part of the sky as the Sun, the illuminated half of the Moon is not facing us and is not visible. During new moon, the Moon rises and sets at the same time as the Sun, and is therefore in the sky during the day. There is then a progression through the growing crescent phase until we see the right half illuminated; this is known as a first quarter moon. After the first quarter phase, there is another progression, this time through the waxing gibbous phases. The Moon becomes full about 15 days after new moon. During a full moon, the Moon is opposite the Sun and is fully lit. The Moon rises at sunset and sets at sunrise when it is full, so the Moon is always visible in the night sky while full. The Moon then begins to wane through another gibbous phase until it reaches its next phase called last or third quarter moon, and again proceeds through another crescent phase, ultimately returning to the new moon almost 30 days later. The saying “Once in a blue moon” is a referral to when two full moons occur in the same calendar month.


Developing the Lesson:

Anticipator Set

Ask students what current phase the moon is in.


Begin with focus questions:

  1. Have you ever noticed that the moon looks different from night to night?
  2. Have you ever noticed that some nights, there doesn't appear to be a moon at all?
  3. Have you ever seen a beautiful full moon rising from the eastern horizon?
  4. What makes a full moon look so big?
  5. Have you ever seen the man in the moon?

Explain the nature of the activities that will be used to help students become better acquainted with the phases of the moon:

  • Activity 1: students participate in a visual demonstration of the moon's phases with globe and flashlight
  • Activity 2: teacher uses computer with projection system to display the "Phases of the Moon" applet. Teacher explains how the applet works and what students will do with the applet in Activity 3
  • Activity 3: teacher demonstrates the applet and distributes the "Phases of the Moon" worksheet to the students. The students are given approximately 40 minutes to complete the worksheet using the applet.
  • Activity 4: simply mention to the students that there will be a final activity that will help to reinforce what they have learned about the phases of the moon (Activity 4 should follow approximately 2 days after the completion of Activities 1, 2 and 3.

Hands-on Activities

Class 1 - in classroom with computer and LDC Projector

Activity 1: Phases class demonstration diagram

  1. arrange students into a large circle (students will need a piece of paper and a black marker)
  2. place one student at the center to hold the ball (explain to students that they will be using the ball as a model for the moon)
  3. place the bright flashlight at one corner of the room
  4. darken the classroom and turn on the flashlight
  5. instruct students to observe the globe and to draw on their paper the shape of the shadow they see
  6. once all students have completed their drawings, have the students share their drawings with the class beginning with student closest to the flashlight (proceed clockwise around the circle until all students have shared their drawings)
  7. initiate a short discussion as to why the shadows appear as they do and the progression of the shadows around the circle
  8. have students write the phase on their diagrams (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent, new moon)

Activity 2: Phases of the Moon applet

  1. with the classroom back in order, the teacher begins demonstrating the applet
  2. identify the key elements (moon, Earth, and sun)
  3. play the applet animation straight through at least two times
  4. have the students focus first on the phases shown on the bottom right
  5. then have the students focus on the progression of the moon around the Earth.
  6. run the animation a few more times, stopping at key stages (new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent, new moon)
  7. as class is dismissed, distribute Charting the Moon worksheet and instruct students to monitor the phase of the moon over the next month


Class 2 - In computer lab

Activity 3:

  1. provide students with a brief review of the applet's functionality
  2. distribute the Phases of the Moon worksheet
  3. explain that students will be required to complete the worksheet by the end of the current class time

Activity 4:

  1. repeat steps as per Activity 2


Check for Understanding

Throughout the activities, the teacher should circulate through the class, assisting students having difficulties.

Independant Practice

Students should be encouraged to review the Phases of the Moon worksheet for homework in preparation for a short quiz to follow.



As a closure to the activities, the teacher uses the applet in a lecture-style delivery format, stopping the animation at key moments and eliciting feedback from the students as to an explanation for the observed phase.



After completing this lesson, students should be presented with the Observing and Sketching the Moon lesson.



Evaluate both student participation as well as the completion of the Phases of the Moon worksheet and the Charting the Moon worksheet . Student participation can be evaluated during activities 1, 2 and 3, even when the students are working with the applet. Students could also be presented with a short quiz in which they would have to correctly identify and explain the phases of the moon.


Teacher Reflections: