Why Does the Moon Change?
Lesson 8 of 9
Objective: SWBAT identify the phases of the moon and determine which phase will appear at certain times of the month.
The Why Behind Teaching This
Unit 6 teaches students about Earth's Place in the Universe. Standard 5-ESS1-1: Support an argument that differences in the apparent brightness of the sun compared to other stars is due to their relative distance from Earth, is one standard covered. Standard 5-ESS1-2: Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky, is the other standard covered.
Throughout this unit, students will learn about classifying stars, patterns of stars, and the effects of rotation and revolution. We will be creating models, graphing data, tracing our shadows, and much more.
This specific lesson provides knowledge that helps students make connections in standard 5-ESS1-2. Students need to understand that stars appear at different times of the year and that the sun appears to move across the sky which changes our shadows. By developing an understanding that the moon appears to change due to its rotation and revolution around the Earth, it will help build their knowledge and understanding of these other concepts. In this lesson students are building a model to manipulate the moon to model how the appearance changes over the course of a month. Students are able to see how the position of the sun affects the phases as well.
The goal of this lesson is for students to be able to identify the phases of the moon in the correct order and determine which phase will appear based on times given.
Students will demonstrate success on this goal by using their model to correctly answer questions in the wrap up section of the lesson.
Preparing For The Lesson:
- Picture of the Earth and a Picture of the Sun to model rotation and revolution
- pictures of the moon to share with the class
- Paper plate for each student
- 8 pieces of velcro precut for each student (both sides)
- Each student will need 8 Moon Phase Outline Cards, I copied them onto cardstock to make them more durable. These will need to be precut and placed in a Ziplock bag to save time.
- Markers for coloring the Earth.
- A copy of the Moon Phase Question Cards to use on the overhead, and for each student to take home to practice with.
- A stapler to staple the Ziplock bag to each paper plate
Reviewing Rotation and Revolution
Rotation and revolution are often difficult terms for fifth graders to differentiate between. They will often time interchange the two, so reviewing these concepts frequently is important. We will be describing the revolution and rotation of the moon in today's lesson, so beginning with an activity that uses these terms in a familiar way first is the perfect way to begin today's lesson.
One student stands up holding the magnetic picture of the sun. Another student stands holding the magnetic picture of the Earth. We used these magnetic pictures in the lesson on the solar system. I ask the class how the student holding the Earth should move to model revolving. The class tells me the student should walk around the sun. The student does this. As the student is walking around the sun, I ask how long this revolution takes. They answer, 365 days.
I ask the class how the student should move to model rotating. They tell me that the student should spin the Earth in his hands while he is walking around the sun. The student begins spinning the Earth as he is walking. We have a conversation about the Earth taking 24 hours to rotate one time, and that the Earth rotates 365 times as it revolves around the sun one time.
Adding the Moon Into Our Model
There is an object that travels through space with the Earth. It revolves around the Earth once every month. Do you know what object I am describing? Students are very quick to tell me it is the moon. I show the following pictures of the moon using the pictures of the moon printout on the overhead.
The question that I pose while showing these pictures is "Why does the moon look different in the three pictures?" Students discuss the answer in their group and record their thoughts on a whiteboard. I have students record their thoughts so that they are prepared to share with the entire class at the end. This helps the ESE and ELL students feel more comfortable participating because they have had the opportunity to hear thoughts from their group, and then they are written out for them to read from.
I pull out some of the information from the whiteboards that was accurate, and focused on that. The moon is reflecting light from the sun, that is what allows us to see the moon. The moon is like a giant rock in space, it does not emit its own light. As the moon revolves around the Earth, we see different amounts of the lighted part of the moon. These are called moon phases.
Moon Phase Visual Simulation
I show the students a simulation of how the moon revolves around the Earth showing the various amounts of light we see reflected from the moon. This simulation is good because it teaches the students the names of the phases, shows how the moon revolves, and shows a picture of what the moon looks like to us from Earth.
At 3:50 in the video, a review quiz begins. I pause the video after each question is asked and allow students to discuss the answers with their group. They record their answer on a whiteboard and hold them up so I can do a quick formative assessment of what they retained from the video. There are 7 questions in the video, we go through all 7. All groups correctly identify the New Moon and Full Moon as well as the First Quarter and Last Quarter. They demonstrate an understanding of the appearance of the Gibbous and Crescent but a few groups confuse when these are waxing and waning. I reinforce this by telling them "remember, waning is not gaining. That means waning is not getting bigger, waxing is when it is getting bigger." Usually this little saying helps.
Illustrating the Moon Phases
Immediately following the quiz there is a drag and drop activity. You cannot actually drag and drop, the video does that for you. I pause after each picture is dropped and call on a student to come point out which will be next. This provided an opportunity for me to call on specific students individually.
I pause the video at 4:46 so that the visual is on the overhead for the students. I provide each student with a paper plate and ask them to draw and color a picture of the Earth in the center. While they are doing this, I pass out a sandwich sizes Ziplock bag with 8 Moon Phase Outline Cards in it along with 8 pieces of velcro (both sides of the velcro).
After students have finished drawing and coloring the Earth, they take out the moon outline cards and lay them out in a row. I tell them that we will be starting with the New Moon and ask how the circle should be shaded to illustrate a new moon. The students tell me it should be all black, because none of the lit side is visible from Earth. Students completely shade in the circle and write new moon on the back on the square. Our discussion continues like this:
Since we can't see any of the moon when it is a New Moon, over the next few days are we going to see more of less of it? More
Students shade in all but a crescent shape on the right and label the back of the square waxing crescent.
Next, we will see a little more, please shade the circle in to show me what the moon will like next. I circulate to make sure that all students have shaded half of the moon, leaving the right side lit up. Very good, the right side should be lit up. This is called the First Quarter. Student write the name of the moon on the back of the square.
Please shade the next circle to illustrate the next moon and label the correct name on the back. I circulate to make sure all students are only shading a tiny bit on the left so that about 3/4 of the moon is lit up on the right. I also check to make sure they are writing waxing gibbous on the back.
I have students continue the rest on their own. I began with very specific directions, by telling them what the first moon phase was, and having one student identify how to shade it for the whole group. I slowly turn over the responsibility of having to shade the moons and label the moons to an independent activity. By doing this I am helping to ensure that all students see the pattern that the moon gradually appears larger until it is full, then gradually appears smaller until we can't see it at all. This gradual release helps the ESE and ELL students be successful on the independent portion of the activity.
Building the Practice Model
As students finish shading in all their moon cards, I tell them to place the fluffy side of the velcro strips around the outer edge of the plate as the boxes in the video appear (the video is still paused at 4:46 so they can see the empty boxes on the screen). Then place the rough side of the velcro on the the back of the moon phase cards. As students do this, I circulate to ensure that mistakes are not being made. As you can see in the video of group creating their moon models, the student places one side of the velcro on the plate and then does the matching moon phase right after. She puts them in order as she goes for extra practice.
Once all students have velcro on their plates, we begin to build our model. I tell them that the first time we are going to build it as if the sun is on the left hand side of the plate. I tell them that no matter where the sun is in a diagram, the moon phase that appears between the sun and Earth is always the New Moon. I ask why this is the case. A student tells me it is because the lit side of the moon is facing away from Earth so we can't see it. All students place the New Moon on the plate on the square on the left. I point out that the moon revolves counter clockwise as we saw in the video so the next moon phase should be place to the lower right of the New Moon. I ask the class if the moon is going to get bigger or smaller, they tell me bigger which is waxing. I tell them the saying that helps me remember this "waning is not gaining" which means that waning is not gaining in size it is getting smaller so waxing is getting bigger. Waxing is on the right, waning is on the left. They find the moon phase that has a crescent on the right and place it next. I tell them to continue with their group, helping to build their model.
When all groups have a completed model, I play the rest of the video which shows them the correct order. They check their model to make sure they did not make any errors.
I ask the students to remove the moon phase cards. I tell them this time the sun is on the right. This time they have to build their model independently. I circulate as they put their moon phase cards on in the correct order. I stop to spend more time with students who are struggling. When all students are done, I take one student's model that is correct and place it on the overhead for others to use to check theirs.
Timing of the Lunar Cycle
We always see the same side of the moon. Does this mean the moon is rotating or not rotating as it revolves around the Earth? Some students say it is rotating, others say it is not. I take the full moon model card from the model on the overhead. I hold it up facing the Earth and move it with rotating it. This shows that the side of the moon facing the Earth would be pointing away from the Earth on the other side. I then demonstrate the revolution of the moon again, but this time rotate it slowly as it revolves showing that the side facing the Earth as a Full Moon is still facing the Earth as a New Moon.
I tell them that it takes about a month (a little over 27 days) for the moon to rotate one time, and the same amount of time for it to revolve around the Earth one time. So it takes about a month for the moon to go from a full moon back to a full moon. If there are 8 phases of the moon, and it takes about 27 days for the moon to go through all of these phases, how many days would each phase last? A couple of students do the math in their head and tell me about 3 days which is correct.
If it takes about a month to go from a full moon to another full moon, how long would it take to go from a full moon to a new moon? About 12 days.
Using the Model to Answer Practice Questions
I place Moon Phase Question Cards on the overhead and allow students to use their model to help them answer the questions. They work with their group to determine the correct answer and record the answer on their whiteboard. I am noting any areas of weakness so that I know what to review further during future lessons.
I provide students with a set of these questions to put in their Ziplock bag and take with them to practice. They remove their moon phase cards from the model and place those in their Ziplock bag as well. We staple the bag to their paper plate model and they take them with them.