Inquiry 2.1 (Investigating Lunar Phases) Purpose: What causes you to see the moon going through eight different moon phases?

Transcription

1 Inquiry 2.1 (Investigating Lunar Phases) Purpose: What causes you to see the moon going through eight different moon phases? Background Information: What is an orbital plane? Does the moon make or reflect light? What is illumination? What are moon phases? Hypothesis: IF you see the illuminated side of the moon from different, THEN you will see the eight moon phases because. Procedures: A. Look at the picture to the right of the materials you will have for this inquiry. How can you use the Sun-Earth-Moon (SEM) Board and a flashlight to investigate how much of the Moon is illuminated (lit up) by the Sun at any one time as the Moon revolves around the Earth? Discuss your ideas with your group and explain to me your group s idea. B. Bring the SEM board to your table. C. Put the smaller white sphere onto rod #1 through the predrilled hole representing the Moon in its orbit around Earth. D. Look at the image to the right. What do you notice about the Moon s orbital plane (RED CIRCLE) compared to the Earth / Sun? #1) Discuss this with your group and write down your answer. E. Now compare the picture above to your SEM Board. #2a) What do the different rods on the board represent? #2b) Why are the rods different heights? #2c) Why does a rod go through the globe at an angle? Write down your answers and show me them to receive the 2.1worksheet. F. Shine the flashlight directly on the sphere on rod #1. Keep the flashlight steady and parallel with the moon. Look at the sphere from all directions as if you are looking down at the Moon from space above. #3a) How much of the sphere reflects light at any one time? Discuss and record your observations with your group. Color circle #1 on the worksheet 2.1 to show how much of the Moon is dark and how much of it reflects light. Make sure that the worksheet is facing the same direction as your SEM Board is facing. G. Now move the sphere to rod #2. Shine the flashlight directly on your white sphere as you did with rod #1 (As the picture to the right shows, the flashlight should ALWAYS be on the side that is labeled SUN because the Sun does

2 not move). Discuss your observations with your group. Record what you see in circle #2 on worksheet 2.1. H. Repeat Step G with the other rods (#3 #8). Record your observations on worksheet 2.1 after each time. Analyzing the Data Answer the following questions in your spiral after discussing them with your group. Put part of the question into each answer. #4a) As seen from outer space, how much of the moon is always illuminated (lit up) by the Sun? #4b) Given the results from this inquiry, why do you think the Moon appears to change its shape (moon phases) when viewed from Earth? (This is your best guess!) I. Cut along the perimeter of the circle by cutting through each of the moons. J. Glue your circle into your spiral and copy the data table below. K. Complete the first column for the amount of the illuminated (lit) side of the Moon that you can see (from Earth) using your cutout 2.1 circle. Choose only ONE of the following answers: All or more than half or exactly half or less than half or none. You will complete the Moon Phase column later after inquiry Part II. (NOT NOW) Moon Position Amount Seen of the Illuminated Side of the Moon Moon Phase 1 Don t fill in this column now! 2 You 3 Will 4 Complete 5 This 6 AFTER 7 Part 8 II #5) What pattern do you see when moving from rod position 1 to 5? #6) What pattern do you see is taking place from rod positions 5 to 8? #7) What pattern do you see in the data table from position 1 all the way around to position 8? Show me your work when your entire group has completed the Analyzing the Data questions and then I will hand you the Part II worksheet.

3 Part II - Modeling Lunar Phases A. Remove the Earth from the blue axis peg on the SEM board. B. Put the Moon back at position #1 on the SEM board. Shine the flashlight at the Moon again like you did for inquiry 2.1, holding the flashlight on the side labeled Sun. C. With one group member holding the flashlight, the other group members should look at the moon from the opposite side of the SEM board (looking from behind position #5 at the moon). Make sure your head is level with the moon (you will have to bend down to do this). D. Observe how much of the Moon is lit up by the flashlight (Sun) from this position. Using the outside circle on worksheet 2.2 (beginning with position #1) draw how much of the Moon is illuminated (lit up). Make sure the worksheet s Sunlight side is the same side as your flashlight / SEM board. E. Move the Moon to position #2 on the SEM board and shine the flashlight on the Moon. Make sure you keep the flashlight on the side labeled Sun and is pointing straight at the moon. F. With a different member holding the flashlight, the other members should take turns looking at the moon from the opposite side of the SEM board (looking from behind position #6 at the moon this time). Make sure you are viewing the moon at eye level. G. Observe how much of the Moon is lit up by the flashlight (Sun) at this angle. Shade in the outside circle on worksheet 2.2 for position #2 showing how much of the Moon is illuminated (lit up). H. Continue this procedure for the remaining positions. Remember to always look from the opposite side of the SEM board and have the worksheet the same way the SEM board is positioned. I. Put the Earth back on the center peg when finished and return the SEM board. Show me your completed worksheet 2.2 to get a large Styrofoam Moon from me. J. Open and read How Moon Phases Work from my website.

4 Part III - Modeling the Moon Phases A. Have one partner place the black-and-white sphere on the end of a pencil representing the Moon. Make sure to discuss the questions and answers for each step. B. Face the Sun on the overhead. Hold the Moon out in front of you so that the white half of the Moon is facing the Sun (as shown in the picture). How much of the white part of the moon can you see? C. Orbit the Moon around you. STOP when your back is facing the Sun. The white part of the Moon will always face the Sun (your head represents the Earth). Was the white part of the moon appearing to grow larger or smaller as you turned? D. Now continue to turn around while looking at the moon until you are facing the Sun again. Did the white part of the moon appear to be getting larger or smaller? E. Compare your observations of this moon phase to the answers that you drew on worksheet #2. Make sure that the Sun on your worksheet is facing the same direction as the Sun on the screen. F. Switch roles with your partner and repeat Steps 2 4. Make sure to discuss the questions and answers for each step as you did before. Analyzing Data: Directions: After discussing the following questions with your group, answer the following questions in your spiral. Make sure to put part of the question into your answer. 1. As seen from Earth, what causes the Moon to change its apparent shape throughout the month? 2. Approximately how long does it take for the Moon to go through all of its phases (from New Moon back to a New Moon)? 3. Explain why (or why not) the moon is only visible during the night? Hint: Think about what you saw when you were facing the Sun that represented daytime in Illinois. 4. Explain why everyone in the world does not see the same Moon phases on any given day? 5. Explain why the sun does not always illuminate the near and far sides of the Moon? Now go back to your data table and label each moon phase and answer this question: 6. What patterns do you see of the illuminated side of the moon (use your data table)? 7. What is the independent variable for this inquiry? 8. What is the dependent variable for this inquiry? ** Show me your group s answers to the Analyzing the Data questions.

5 Conclusion: 1. Restate your entire hypothesis. 2. Explain why your hypothesis was correct or incorrect using information from the lab. 3. What was the independent variable for your hypothesis? 4. What was the dependent variable for your hypothesis? 5. How much of the moon is always illuminated by the Sun? 6. What are the two main reasons why we see different moon phases? 7. Explain why people on Earth do not see the moon illuminated during a New Moon phase. 8. Describe the patterns that the moon phases go through starting with a New Moon and all the way back to another New Moon. Use the correct moon phases and describe how much of the moon that you see for each. (Don t just list the different moon phases).