Phases of the Moon
Topic: Half of the moon is always bright, the half facing the sun. However, the amount we can see of the bright half of the moon changes as the moon orbits earth. This results in the phases of the moon we observe on earth.
Rationale: The moon is part of everyone’s daily lives. It is an object that is the source of a variety of different arts, and often admired by many people during the night. The students have seen the moon change shape, but the majority of them are not sure how to explain this occurrence. By participating in minds on activities and listening to an ancient myth, the students will take an active role in their understanding of why the moon changes shape.
Prior Knowledge: The students have seen the various phases of the moon when they look in the sky every night. They realize that the moon can be seen both during the day and at night. The children know that the earth rotates and revolves, and can apply these concepts when we discuss the rotation of the moon in relationship to the phases of the moon.
Curriculum Content Standards:
5.11.1: Observe and identify objects and their apparent motion in the day and night sky
Relate the motions of the earth-sun-moon system to units of time (days, months,
Students will be able to describe why the moon has phases.
Students will be able to describe the relationship between the phases of the moon and its revolution.
Students will be able to name the phases of the moon in the order in which they occur, and describe what happens in each phase.
Hook: I will ask the students to recall the myths “Father Moon” and “Bahloo” and ask them, “what were these myths written to explain?” Then, the class will read the short Inuit myth about the phases of the moon. I will explain that the Inuits were ancient people who lived near Greenland. The myth tells the story of their moon god, Annigan. Annigan chased his sister, Malina, the sun goddess, across the sky every month. During the chase, Annigan forgets to eat. “What do you think happens to Annigan if he doesn’t eat?” Annigan gets thinner because he doesn’t eat. Then, he leaves for three days to eat. He returns full to chase his sister all over again.
Narrative: I will ask, “Did you notice any similarities between Annigan and the moon?” If the students need help, she will ask them to recall that Annigan forgot to eat. “What happened to him because he did not eat? What happened when he ate for the three days he was gone?” We will discuss that Annigan changed shapes from being a thin sliver of a person to a full person. “What have you observed about the moon from the nights that you have looked at it?” Miss Aronis will point out that Annigan and the moon both change shapes, and in fact, Annigan was the moon in the above myth.
“On Monday, you said that the myths we read described that the moon appears in many different ways. Does anyone know what we call the many views of the moon?” I will introduce the word “phases” to the students. She will explain that the phases are different shapes the moon seems to have when it is viewed from the earth. “Does the moon actually change shape?” Explain that the phases we see are caused by reflected sunlight. The side of the moon facing the sun is always lighted. The side of the moon turned away from the sun is always dark. “We can see this by doing an activity, however in order to do this activity, you have to understand a few things. Who know the difference between “rotate” and “revolve?” Demonstrate by having a child rotate (spin in place) while another child revolves, or walks around, that person.
Do an activity, where the sun is held in the front of a circle of students, and eight students stand in an ellipsis and hold the letters A-H. One child will be earth, and stand in the middle of the circle, while another child will be the moon, and move from letter to letter, holding a foam moon so that the white side is always facing the sun. “Earth, what did you just do in that activity? (rotated) Moon, what did you just do in that activity? (rotated and revolved) Moon, what did you have to do to the moon in your hand to keep the white side of the moon towards the sun? (spin or rotate it)” Explain as the moon revolves around the earth, it slowly rotates. “How many times did the moon rotate when it was revolving around the earth?” (one time) Explain that it takes the moon as long to make one rotation as it takes it to make one revolution. This means that the same side of the moon always faces the earth, which is why we can see the phases of the moon. Ask students if they understand
“How long does it take the earth to make one rotation?” (24 hours) Explain that it take the moon one month to revolve and rotate once around the earth. “How many days is that?” Then, repeat the activity and have the students look for the phases. “At what point did you observe the most of the white half of the moon? (when earth was between the sun and the moon) What shape was it? (circle) At what point did you observe the least of the white half of the moon? (when the moon was between the earth and the sun) What color did you see? (black)So why do you think the moon seems to change shape?” (from earth, we see different amounts of the sunlit side)
Next, I will use an overhead transparency of the phases of the moon to explain the order in which the phases occur. The students will have the same sheet in front of them so that they can take notes on what happens during the different phases. Each phase will lead to different questions such as, “Do you think you could see the new moon at night when the sun is not shining? In which phase does the new moon occur? What does waxing mean? (Students will know from previous discussion). Can we see the new moon? If waxing means getting bigger, what do you think waning means?
After we have discussed what happens during each phase of the moon, students will be able to open their books called Probing the Moon, and look at actual photographs of each phase. This will help the students to picture each phase, and recognize that they have seen most of these phases in the night sky, instead of trying to imagine what it might look like from a drawing.
For homework, the students will have to observe the moon that night, write their observations out, and say which phase they think the moon is in. We will discuss this at the beginning of the next lesson. I will conclude by saying, “Tomorrow we will look at the moon phases on the Internet.”
See the pictures!
Moon Phase Sequence Puzzle
Back to Moon Unit