47658/Moon's Motions

Modeling the Moon’s Motions 47658

KIT CONTENTS

ITEM QUANTITY/VOLUME DESCRIPTION 1 10 Sun models (yellow balls) 2 10 Earth models (blue and black balls) 3 10 Moon models (white and black balls) 4 10 Moon reference markers (white ball with black dot) 5 10 Zip-lip plastic storage bags 6 30 Screw caps 7 1 set of 3 Transparencies 8 1 pad of 100 “Orbit of the Moon” sheets (legal sized) 9 1 Instructions (this booklet) Teacher’s Guide — pages 1 -18 Student Guide and Worksheets (reproducible — pages S1 - S12)

Additional materials needed (not included in kit): Flashlights (optional) Masking tape Pencils Overhead projector (for transparencies) Washable marking pen, to fill in answers on transparencies

TOPICS/OBJECTIVES

¥ To model the motion of the Moon. ¥ To observe the effects of the Moon’s motions on Earth-bound observations. ¥ To discriminate between rotation and revolution. ¥ To understand the difference between a lunar month and a sidereal month. INTRODUCTION

This kit uses a combination of teacher-directed lessons and student activities to help students understand the motions of the moon and how to interpret them. Primarily, students will learn about the phases of the moon, as well as the difference between a lunar (synodic) month and a sidereal month.

Teaching tools provided in this kit include:

¥ transparencies for the teacher to use as part of his/her classroom lessons; students are provided with blank hard copies of the transparencies, to fill in and take notes on during the lecture/discussion.

¥ small models of the Sun, Earth, and Moon, which students manipulate as part of their activities.

¥ worksheets with analysis questions, to be completed by students at the end of each activity. These are designed to test students’ understanding of the concepts modeled during each activity.

Generally, you should plan on spending one 40-minute class period for each activity. This will allow time for the activity and any related discussion or analysis. If desired, the questions at the end of each activity can be completed as homework.

This kit contains enough materials for 10 groups of students. For the student activities, groups of 2-3 are recommended.

p.1 SK04561-00 PRIOR TO CLASS

1. Read through this Teacher’s Guide and the Student Guide to familiarize yourself with the activities.

2. Make photocopies of the Student Guide and Worksheets (pages S1-S12 of this booklet; one per student or lab group) for distribution.

3. Prepare introductory lesson(s) for students. This kit includes three instructional transparencies, as well as a glossary and short introductory notes for the teacher to use as a guide. You may want to supplement this information to more thoroughly cover terminology, historical background, overall concepts, etc. Additional lesson suggestions are listed below, under the “General Suggestions For Use” heading.

4. Organize and assemble materials for each student group. Each group will need:

¥ 1 yellow ball (or flashlight), to represent the Sun ¥ 1 blue and black ball, to represent the Earth ¥ 1 white ball with black dot, to represent the Moon in Student Activity #1 ¥ 1 black and white ball, to represent the Moon in Student Activity #2 ¥ 3 screw caps, to hold balls in place ¥ 1 zip-lip plastic bag, to store materials ¥ 1 copy of the Student Guide (you may want to make additional copies of the Questions for each activity, if you prefer that students complete these individually) ¥ 1 “Orbit of the Moon” sheet (from the legal sized pad) GENERAL SUGGESTIONS FOR USE

¥ Advise students that the diagrams they receive and the notes that they take during the lesson(s) are the only resources that they will be allowed to use during the lab investigations. This encourages students to pay attention, take notes, and work with each other to successfully complete each lab task.

¥ As part of your introductory lesson(s), you may want to present historical information that is pertinent to the activities in this kit. Suggested lessons include information on geocentric versus heliocentric models of the solar system and how various cultures interpreted the phases of the Moon, etc. This provides an opportunity to address the science history component of the National Science Education Standards.

¥ This kit includes three transparencies. Use the transparencies in a lecture/discussion format to introduce students to the concepts of lunar (synodic) months vs. sidereal months and the motions of the Moon and Earth. Transparency #1 can be used to illustrate occultation and the difference between a sidereal month and a lunar month. Transparency # 2 can be used to illustrate the changing times of moonrise as a result of sidereal motion. Transparency #3 can be used to illustrate the phases of the Moon, as well as the phases of Earth as viewed from the Moon. A key for each transparency is provided in the Teacher’s Guide. Students have blackline copies of each transparency in their Student Guide. As you go through your lectures, have students take notes and fill in the blanks on their blackline copies.

¥ In the student activities, a medium sized blue and black ball is used to represent the Earth; a large yellow ball is used to represent the Sun; and there are two models used to represent the Moon: a small white ball with a black dot marked on it, to help illustrate the rotation of the Moon as it revolves around the Earth (Activity 1), and a small black and white ball, to illustrate phases of the Moon (Activity 2). For your more concrete operational students, you may wish to replace the yellow Sun model with a flashlight. This helps some students better understand that the Moon’s light is reflected sunlight, and that the apparent size and shape of the Moon as viewed from Earth are a function of the Sun, Earth, and Moon’s positions relative to each other.

p.2 SK04561-00 SUGGESTED LESSON OUTLINE

1. Initial Lesson on Occultation, and the Difference Between a Lunar and Sidereal Month Present a lesson on occultation and the difference between a lunar and sidereal month, using the notes on page 5, Transparency #1, and/or any other materials you desire. The key for Transparency #1 is on page 6. The student blackline copy of this transparency is on page S2. Using the key as your guide, fill in the blanks on the transparency as you teach your lesson, and have students fill in the blanks and take notes on their blackline copies.

2. Classroom demonstration — Modeling the Moon’s Motions

In this teacher directed activity, two students, representing the Earth and Moon, respec- tively, model the motions of each of these bodies relative to the Sun (represented by a third student). The students properly position themselves with respect to one another and then rotate and revolve, as appropriate. The rest of the students in the class observe this activity and use it as the basis for Student Activity #1, described below. Step-by-step instructions for this activity/demonstration are on pages 7-8.

3. Student Activity #1 — Modeling the Moon’s Motions

In this activity, students basically repeat the demonstration described above. This time, however, they manipulate the models of the Sun, Earth, and Moon that are provided in this kit. By using the models to demonstrate one complete revolution in the Moon’s orbit, students illustrate one complete sidereal month. Teacher instructions for this activity are on page 8; student instructions are on page S3. The key to the Student Worksheet for this activity is on pages 9-10 of the Teacher’s Guide.

4. Lesson on The Changing Times of Moonrise as a Result of Sidereal Motion

Present a lesson on the changing times of moonrise, using the notes on page 11, Transparency #2, and/or any other materials you desire. The key for Transparency #2 is on page 12. The student blackline copy of this transparency is on page S6. Using the key as your guide, fill in the blanks on this transparency as you teach your lesson, and have students fill in the blanks and take notes on their blackline copies.

5. Lesson on the Phases of the Moon

Present a lesson on the phases of the Moon and the related terminology, using the notes on page 13, Transparency #3, and/or any other materials you desire. The key for the phases of the Moon is on page 13. The student blackline copy of the phases of the Moon is on page S7. Using the key as your guide, have students fill in information for the phases of the Moon. After you have presented your lesson on the phases of the Moon, use Transparency #3 as you present a lesson on viewing the Moon’s orbit from various perspectives. The key for Transparency #3 is on page 14. NOTE: Students should not fill in their blackline copies of this transparency during the lesson; they will fill this in as part of the Student Activity #2 (described below).

6. Student Activity #2 — The Phases of the Moon and the Earth

In this activity, students place Sun, Earth, and Moon models in the proper positions on the “Orbit of the Moon” worksheet, and then manipulate the models. By observing the models from various points along the orbit of the Earth, students are able to observe the various phases of the Moon in one complete lunar or synodic month. Students also observe the models from other points of reference in space.

p.3 SK04561-00 GLOSSARY

The following terms are among those used in the lessons/activities discussed in this kit. By the end of all of the activities, students should have a good understanding of these terms. A blank copy of this glossary is provided on page S1 of the Student Guide. You may want to have students fill this in during your lessons/discussions, or you may have students complete this as a quiz or post-lab activity. apparent motion — the continuous change of position of a celestial body with respect to a second body. celestial body — a natural or man-made object found on the celestial sphere. Examples of celestial bodies include planets, stars, asteroids, and man-made satellites. celestial sphere — the imaginary sky dome encircling the Earth, on which all celestial bodies appear to be affixed. Only a portion of the celestial sphere can be seen from any position on Earth at a given time. day — the length of time it takes for a planet to make one complete rotation on its axis. For the planet Earth, a day is 24 hours long. For the planet Jupiter, a day is nearly 10 Earth hours long. For the planet Venus, a day is approximately 5832.5 Earth hours long. geocentric model — Earth-centered model of the universe. heliocentric model — Sun-centered model of the solar system. lunar or synodic month — the time required for the Moon to pass through its complete series of phases from new moon to new moon; this takes 29.5 days. occultation — the hiding of a distant star or celestial body when the Moon passes between Earth and the distant star or celestial body. revolution — the motion of an object around a closed orbit, following a circular or elliptical path. rotation — the circular motion of an object turning on its own axis. satellite — a small solid body moving in an orbit around a larger body. The moon is a natural satellite of the Earth. sidereal month — the time required for the Moon to complete a 360° revolution around the Earth; this takes 27.3 days. year — the time required for a planet to complete a 360° revolution around the Sun. For the planet Earth, this takes 365.25 days. For other planets, a revolution around the Sun can take from 88 Earth days (for Mercury) to more than 90,000 Earth days (for Pluto).

p.4 SK04561-00 NOTES FOR TRANSPARENCY #1: THE DIFFERENCE BETWEEN A SIDEREAL MONTH AND A LUNAR MONTH

As you explain the information shown on this transparency, fill in the answers on the transparency, using the key on page 6 as a guide. (Answers are written in italics.) Have students fill in the same information on their blackline copies of this art as you discuss it during your lesson.

A sidereal month is the time it takes for the Moon to make one complete revolution around the Earth and return to the same position among the stars. In other words, a sidereal month is the time it takes for the Moon to occult (pass in front of) a particular star for the second time. It takes 27.3 days for the Moon to make a complete 360° revolution, meaning that the Moon revolves about 13° (13.19° to be exact) every 24 hours. Occultation is illustrated in Diagrams 1A and 1B of Transparency #1. (See Key on page 6).

Stress that there is a difference between a sidereal month and a lunar month. Most students think of a month as the time from new moon to new moon — or what is known as a lunar or synodic month. It takes 29.5 days for the Moon to pass through a complete series of phases, from new moon to new moon. The difference between a sidereal month (27.3 days) and a lunar month (29.5 days) is illustrated in Diagram 2 of Transparency #1.

One trick to help students remember the differences between the terms “sidereal” and “synodic” is to think of these word associations:

•“synodic” is synonymous with a month of phases (new moon to new moon); this is depen- dent on the position of the Moon in relation to the Sun as seen from the Earth.

•“sidereal” refers to the how long it really takes the moon to make a complete 360° revolution, using occultation of one distant star as a guide.

p.5 SK04561-00 KEY: TRANSPARENCY #1 — THE DIFFERENCE BETWEEN A SIDEREAL MONTH AND A LUNAR MONTH

Diagram 1A:

Occultation: the hiding of a star or celestial body Earth's orbit when the Moon passes between the around the Sun Earth and the star or celestial body

sidereal Month = position of the Moon on the first evening, resulting in 27.3 Days occultation of a distant star Distant Star M occulted E M position of the Moon on the next evening: 13° difference

Diagram 1B: Earth's orbit After one revolution of the Moon around the Sun

Same Distant Star M E same star occulted for the second time, after Moon has revolved 360°; this occurs 27.3 days after the star was first occulted (as shown in Diagram 1A)

Diagram 2: Lunar or Synodic New moon to new moon Earth's orbit around the Sun Month: lunar Month =

29.5 Days Moon out of position on the next day

new moon phase E Sun

— at this point,

new moon the Moon has completed a lunar month which = 29.5 days + 2.2 days

27.3 days: at this point, the Moon has revolved 360û in its orbit and has completed a sidereal month

p.6 SK04561-00 CLASSROOM DEMONSTRATION — MODELING THE MOON’S MOTIONS

General Notes:

¥ Arrange student desks into a circle, leaving a large open space in the middle of the classroom.

Procedure:

1. Select three student volunteers to represent the Moon, Earth, and Sun.

2. Arrange these three students in the open area so that they are in appropriate positions for their assigned roles. As shown on the “Orbit of the Moon” worksheet (found on the legal sized pad provided with this kit), the Earth should be in the center of the circle. The Moon will rotate as it revolves around the Earth. The Sun is positioned beyond the Moon. Allow enough room for all three students to rotate and revolve.

3. Instruct the Moon to face Earth. Tell the Moon to slowly revolve or walk around Earth in a counter-clockwise motion, so that the Moon (student) is always facing Earth. In order to face the Earth at all times, the Moon must rotate or turn slightly at each position.

4. Some students may have difficulty discriminating between revolution and rotation. Remind students that rotation refers to a body turning on its own axis, while revolution refers to a body moving in an orbit around another body. Ask students if they think the Moon is rotating and/or revolving during this demonstration.

5. Explain that even though the Moon does not appear to rotate (turn on its own axis) from the Earth’s point of view, it is indeed rotating as it revolves around the Earth. You can show students that the Moon is rotating at the same time that it is revolving, as follows: Make an X out of masking tape on the floor at some point on the Moon’s orbital path. Label this X position 1 (see Figure 1, below). Make a second X on the Moon’s orbital path, at a position 180° from position 1. Label this X as position 2. Have the Moon start at position 1 and make one complete revolution around the Earth, while also rotating (as described in Step 3, above), so that the Moon is always facing the Earth.

After the Moon has completed the revolution, have the Moon move from position 1 to position 2 without rotating — in other words, the Moon should always face the same wall as it is revolving. At position 2, the back of the Moon will be facing the Earth. Ask students if this is how the Moon looked as it revolved around the Earth the first time (as described in Step 3). Now, have the Moon slowly rotate without revolving, until it is facing the Earth again. This shows that in order for the same side of the Moon to always be facing the Earth, the Moon must be rotating even as it revolves.

wall Moon position 2

Earth

Moon position 1

Figure 1 p.7 SK04561-00 6. Direct the Moon (student) to revolve around the Earth again. Have the Sun call out to the class the side of the Moon that is observable to him/her during the Moon’s orbit (for instance, the face of the person representing the Moon, or the side of that person, or the back of that person, etc.). Explain that although the Earth observes the same side of the Moon (that is the “Moon’s” face) throughout the Moon’s revolution, the Sun eventually views all sides of the person representing the Moon throughout the course of the Moon’s revolution because the Moon is rotating.

STUDENT ACTIVITY #1 — MODELING THE MOON’S MOTIONS

Introduction:

In this activity, students repeat the demonstration described above; this time, however, they will use the models of the Sun, Earth, and Moon provided in this kit. By manipulating the models to demonstrate one complete revolution in the Moon’s orbit, students illustrate one complete sidereal month.

Procedural Notes:

Step-by-step instructions are listed in the Student Guide (page S3). In the first part of this activity, students simply set up and manipulate the models. Once they are familiar with this process, they repeat the procedure and interpret/analyze these motions by answering questions on the worksheet for this activity (pages S4-S5).

During this activity you should do the following:

1. Show students how to place the models in the caps provided to prevent the models from rolling off the table.

2. Assist students who have difficulty setting up the models.

3. If necessary, help students complete the worksheet questions for this activity.

¥ If students have difficulty with question #5, help them set up the following ratio:

360 degrees /27.5 days = X degrees / 1 day

¥ If students have difficulty with question #6, remind them that there are 24 hours in a day; help students set up the following ratio:

13.19 degrees/24 hours = X degrees / 1 hour

p.8 SK04561-00 Name: ______KEY — ACTIVITY #1 WORKSHEET: MODELING THE MOON’S MOTIONS ______Date: ______Move the moon counterclockwise completely around the Earth (positions 1-8). Class/Period: ______1. This motion of the Moon around the Earth is called (rotation/revolution)

______.revolution

2. The time that it takes for the Moon to make one complete revolution around the Earth is known as a (sidereal/lunar) ______sidereal month.

3. How many Earth days does it take for the Moon to make one complete revolution around the Earth?

27.3 days

4. How many degrees does the Moon move during one complete revolution around the Earth? ______360°

5. Using your answers from questions 3 and 4, determine how many degrees the Moon moves each Earth day. ______.~ 13° (Show your work for this answer. Round your answer to the nearest degree.)

360° / 27.3 days = 13.19°/day

6. Using your answer from question #5 above, determine how many degrees the Moon moves in 1 hour. ______.~ .5 ° (Show your work for this answer.)

13° / 24 hours = .54° hour

Repeat the entire activity, moving the Moon around the Earth. Make sure that the dot on the Moon always faces the Earth as it revolves around the Earth.

7. Does an Earth-bound observer ever see the back side of the Moon (that is, the side with no dot) at any point during the Moon’s rotation? ______No.

8. To an Earth-bound observer, does the Moon appear to rotate? _____.No. Does the Moon actually rotate? ______.Yes.

9. To an Earth-bound observer, in which direction does the Moon appear to move through the celestial sphere (east to west /west to east)? ______east to west

Repeat the entire activity again, moving the Moon around the Earth. Make sure that the dot always faces the Earth as it revolves around the Earth.

10. Did the dot on the Moon always face the Sun? ______No.

11. Would an observer on the Sun ever see the back of the Moon (that is, the side with no dot on it) at any point during the Moon’s rotation? ______Yes

12. To an observer on the surface of the Sun, does the Moon appear to rotate? ______Yes

13. From this activity you should be able to see that the Moon rotates on its axis as it revolves around Earth. To an Earth-bound observer, however, the Moon does not appear to rotate as it revolves around the Earth. For this to occur, the Moon must rotate (faster than/slower than/at exactly the same speed as) ______at exactly the same speed as it revolves.

p.9 SK04561-00 14. In other words, the Moon’s rate of rotation is equal to its revolution. Therefore, how many Earth days does it take for the Moon to complete one rotation? ______27.3 days

15. A day is defined as the amount of time it takes for a body to complete one rotation. A year is defined as the time it takes a body to complete one revolution. A day on the Moon is (shorter than/longer than/ exactly as long as) ______exactly as long as one Moon year. (HINT: Remember — the Moon’s rate of rotation is equal to its revolution.)

p.10 SK04561-00 NOTES FOR TRANSPARENCY #2: THE CHANGING TIMES OF MOONRISE AS A RESULT OF SIDEREAL MOTION

As you explain the information shown on this transparency, fill in the answers on the transparency, using the key on page 12 as a guide. (Answers are written in italics. Diagrams to be filled in are shown in gray shading.) Have students fill in the same information on their blackline copies of this art as you discuss it during your lesson.

Transparency #2 illustrates why an observer on Earth sees the Moon rise and set by a difference of 52 minutes each day. Diagram 1 sets up the situation, choosing an arbitrary 9:00 PM time for moonrise. (You may choose any other appropriate time for moonrise; you may want to consult a website or almanac to show the moonrise time for the day of your lecture on this topic. Write the time you choose on the line for time on each of the diagrams.) On the first night of lunar observation (shown on the right side of the diagram), the observer on Earth sees the Moon rise at 9:00 PM. On the second or next night of lunar observation (shown on the left side of the diagram) the observer, standing at the same place on Earth, would not see the Moon rise at 9:00 PM. Why does this occur?

The answer to this question is illustrated in Diagram 2. By this point, students should understand that the Moon revolves about 13° each day (360°/ 27.3 days). It takes about 52 minutes for the Earth to rotate 13°. The math for this is as follows:

24 hours x 60 minutes = 1440 minutes per one complete rotation (360°), or Earth day.

360° 13° = 1440 min X

× ° 1440 min 13 = 52 min 360°

In Diagram 2, everything is exactly the same on Night One of Lunar Observation as in Diagram 1: the observer on Earth sees the Moon rise at 9:00 PM. On Night Two, the observer is still in the same spot, but the Moon has rotated 13° from its position on the previous day, so that it is out of the observer’s horizon. The observer will not be on the same horizon as the Moon until the Earth rotates 13°. This will take 52 minutes, so that the observer on Earth will not see the Moon rise until 9:52 PM. Show this by drawing in the position of the observer at 9:52 PM., as well as the observer’s horizon. These are shown in gray on the key.

p.11 SK04561-00 KEY: TRANSPARENCY #2 — THE CHANGING TIMES OF MOONRISE AS A RESULT OF SIDEREAL MOTION

Diagram 1 START HERE Night two of lunar observation Night one of lunar observation

Time: 9:00 PM Time: 9:00 PM

No Moon! Why? M

moonrise E E

Earth's observer orbital North pole observer's path celestial Earth's sphere rotation observer's horizon

Diagram 2 Night two of lunar observation Night one of lunar observation

Moon out of position by 13û: Earth must rotate observer Time: 9:52 PM 9:00 PM for 52 additional minutes to Time: "catch up with the Moon"*

M M

E E

observer after 24 hours (9:00 PM)

* Moon takes 27.3 days to revolve 360û 360û = about 13û of Moon's orbital motion per day 27.3 days

The Earth takes 52 minutes to rotate 13û, so the times of moonrise and moonset occur 52 minutes later each successive day over the course of a sidereal month. That is why it is sometimes possible to see the Moon during daylight hours.

p.12 SK04561-00 NOTES FOR TRANSPARENCY #3: LESSON ON THE PHASES OF THE MOON

As you explain the information shown on this transparency, fill in the answers on the transparency, using the key on page 14 as a guide. (Answers are written in italics. Diagrams to be filled are shown in black shading.) NOTE: Students should not fill in their blackline copy of Trans- parency #3 during the lesson; they will fill these diagrams in later, as an exercise in Student Activity #2. Begin this lesson by explaining the phases of the Moon to students. Students have a copy of Figure 4 (below) in their Student Guide. The diagrams are filled in; however, the definitions and explanations are not. The students will need to fill in these explanations. During the lesson you may want to use a model to show the phases of the Moon; you may have a large Sun/Earth/Moon model in your classroom, or you can use the models provided in this kit (see the instructions for Student Activity #2, on page 15).

full Moon new Moon

Note: gibbous* crescent* quarter** These phases are not in the correct sequence.

*For gibbous and crescent moons — Explain/demonstrate the difference between waxing and waning. Waxing = as the lit portion of the Moon increases or grows larger, the Moon is said to wax. Waning = as the lit portion of the Moon decreases or grows smaller, the Moon is said to wane.

**For quarter moons — Explain/demonstrate to students how to tell whether the Moon is in the first or third quarter. First quarter = Left side of the moon is dark (in the Northern Hemisphere) Third quarter = Right side of the moon is dark (in the Northern Hemisphere)

Figure 4 Once students are clear on the terminology of the Moon’s phases, go a step further and explain the concept of geocentricity. (They will need to understand this in order to correctly complete Activity #2.) We view the phases of the Moon from our position as observers on Earth — in other words, from a geocentric point of view. However, there are other ways to view the Moon, and where it is viewed from will affect the viewer’s interpretation of its phases. These are shown on the key to Transparency #3. They will also be demonstrated in Activity #2. Transparency #3 shows the phases of both the Moon and the Earth as viewed from various places in space. The numbers on the transparency refer to the positions of the Moon as shown on the Orbit of the Moon worksheet (the legal sized pad in this kit). As you explain this information, fill in the circles and the answers on the transparency, using the key on page 14 as a guide.

Diagram #1 shows that, from space, as the Moon rotates, the same side of the Moon is always facing the Earth. This was explained in Student Activity #1. Diagram #2 shows how the Moon looks to an observer on Earth. These are the phases of the Moon that most of us are familiar with, obviously, because we are viewing the Moon as observers on the Earth. Diagram #3 presents a scenario that most of us are not familiar with — a sort of “lunar-centric view.” These are the phases of the Earth, or what we would see if we were standing on the rotating Moon, looking at the Earth at various times. p.13 SK04561-00 KEY: TRANSPARENCY #3/STUDENT ACTIVITY #2 WORKSHEET — THE PHASES OF THE MOON AND THE EARTH

Diagram 1 The Moon in Orbit As Viewed From Above

6. 4.

Night

Earth

7. Day 3.

8. 2.

The Sun's Rays

Diagram 2 The Moon Viewed From the Earth

waxing first waxing waning third waning 1. new 2. crescent 3. quarter 4. gibbous 5. full 6. gibbous 7. quarter 8. crescent

Diagram 3 The Earth Viewed From the Moon

third first 1. full 3. quarter 5. new 7. quarter p.14 SK04561-00 STUDENT ACTIVITY #2 — THE PHASES OF THE MOON AND THE EARTH

General Notes:

Step-by-step instructions for this activity are listed in the Student Guide (pages S8-S12). During this activity you should do the following:

1. Have students set up the Sun, Earth, and Moon models on the “Orbit of the Moon” sheet so that the Moon is at Position 1, between the Sun and the Earth. At the beginning of this exploration, the black side of the Moon should face the Earth and the white side of the Moon should face the Sun; the blue side of the Earth should also be facing the Sun.

2. Point out to students that as they move the Moon along its path, they should take extra care not to turn or rotate the Moon. The white side of the Moon should always be facing the Sun, as shown in Figure 4.

3. In order to see the phases correctly when using the models eye as an observer from Earth, tell students to imagine they are on the Earth model, looking directly at the Moon model. As t of the Mo Orbi on such, they will need to move out of their chairs and crouch 5 down to observe the Moon model at eye-level from the eye Earth’s perspective each time the Moon is placed in a new 6 4 position, as shown in Figure 3. They will also need to move around the circle, to a point directly opposite the Moon Earth model, as shown in Figure 4. For instance, when the Moon is at Position 1 on the “Orbit of the Moon” sheet, students will Earth 7 W E 3 need to look the Moon from Position 5; when the Moon is at eye d n ire tio Position 2, students will need to look at it from Position 6; ction of rota and so on.

8 2

Earth eye 1 Moon

Sun

Figure 3 sun

4. Remind students to use proper terminology (i.e., waxing, Figure 4 waning, first quarter, third quarter, etc.) in their answers and diagrams.

5. Monitor your students as they proceed through this activity. It is especially important that they start out correctly, as each subsequent step builds on the previous one. A wrong answer early on will probably result in wrong answers throughout the activity.

p.15 SK04561-00 Name: ______KEY — ACTIVITY #2 WORKSHEET: THE PHASES OF THE MOON AND THE EARTH ______Date: ______Position 1 Class/Period: ______1. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the ______Moon model appears at Position 1, when viewed from above. 2. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the Moon model appears at Position 1, when viewed from the perspective of a person on Earth. On the line below the circle at Position 1, write the name of the phase of the Moon in this position.

3. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the Earth model appears at Position 1, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 1, write the name of the phase of the Earth in this position. 4. What is the phase of the Moon in Position 1? ______New moon. 5. How many days will pass before this phase will be repeated? ______29.5 days.

6. The time period in question 5, above, is the length of a ______lunar or synodic month. Position 2 7. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 2, so it shows how the Moon model appears at Position 2, when viewed from above. 8. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 2, so it shows how the Moon model appears at Position 2, when viewed from the perspective of a person on Earth. On the line below the circle at Position 2, write the name of the phase of the Moon in this position.

9. The term used to describe the Moon as the lit portion increases is ______waxing . The term used to describe the Moon as the lit portion decreases is ______.waning

10. At Position 2, which side of the Moon is lit — the left or the right? ______The right.

11. What is the phase of the Moon in Position 2? ______Waxing crescent. Position 3 12. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 3, so it shows how the Moon model appears at Position 3, when viewed from above.

13. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 3, so it shows how the Moon model appears at Position 3, when viewed from the perspective of a person on Earth. On the line below the circle at Position 3, write the name of the phase of the Moon in this position. 14. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 3, so it shows how the Earth model appears at Position 3, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 3, write the name of the phase of the Earth in this position. 15. At Position 3, the Moon has now completed ______25 percent of its orbit around the Earth.

16. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 3? (HINT: How many days make up 25 percent of the a lunar cycle?)

______Approximately 7 days (29.5 × .25 = 7.375). 17. What is the phase of the Moon in Position 3? ______First quarter. p.16 SK04561-00 Position 4 18. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 4, so it shows how the Moon model appears at Position 4, when viewed from above. 19. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 4, so it shows how the Moon model appears at Position 4, when viewed from the perspective of a person on Earth. On the line below the circle at Position 4, write the name of the phase of the Moon in this position. 20. What is the phase of the Moon in Position 4? Be sure to note whether the Moon is waxing or waning.

______Waxing gibbous. Position 5

21. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 5, so it shows how the Moon model appears at Position 5, when viewed from above.

22. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 5, so it shows how the Moon model appears at Position 5, when viewed from the perspective of a person on Earth. On the line below the circle at Position 5, write the name of the phase of the Moon in this position.

23. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 5, so it shows how the Earth model appears at Position 5, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 5, write the name of the phase of the Earth in this position.

24. The Moon has now completed ______50 percent of its orbit around the Earth.

25. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 5? ______14.75 days (29.5 × .5 = 14.75)

26. What is the phase of the Moon in Position 5? ______Full moon. Position 6 27. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 6, so it shows how the Moon model appears at Position 6, when viewed from above. 28. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 6, so it shows how the Moon model appears at Position 6, when viewed from the perspective of a person on Earth. On the line below the circle at Position 6, write the name of the phase of the Moon in this position. 29. As the Moon moves from Position 5 to Position 6, does the lit portion appear to increase or decrease? ______Decrease.

30. What is the term used to describe your answer to question 29? ______Waning.

31. What is the phase of the Moon in Position 6? ______Waning gibbous.

(continued on next page)

p.17 SK04561-00 Position 7 32. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 7, so it shows how the Moon model appears at Position 7, when viewed from above.

33. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 7, so it shows how the Moon model appears at Position 7, when viewed from the perspective of a person on Earth. On the line below the circle at Position 7, write the name of the phase of the Moon in this position.

34. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 7, so it shows how the Earth model appears at Position 7, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 7, write the name of the phase of the Earth in this position.

35. The Moon has now completed ______75 percent of its orbit around the Earth.

36. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 7? ______Approximately 22 days (29.5 × .75 = 22.125).

37. What is the phase of the Moon in Position 7? ______Third quarter. Position 8 38. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 8, so it shows how the Moon model appears at Position 8, when viewed from above.

39. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 8, so it shows how the Moon model appears at Position 8, when viewed from the perspective of a person on Earth. On the line below the circle at Position 8, write the name of the phase of the Moon in this position.

40. What is the phase of the Moon in Position 8? ______Waning crescent. Position 1 (at completion of orbit) New moon. 41. What is the phase of the Moon when it has returned to Position 1? ______42. From new moon back to new moon means that the Moon has completed one ______lunar or synodic month. 43. Explain why the Moon appears to go through a cycle of phases.

The waxing and waning phases of the Moon are the result of the changing position of the Moon as it orbits the Earth. The amount of sunlight reflected off the surface of the Moon as seen from Earth changes as the position of the Moon changes. KEY — STUDENT ACTIVITY #2 WORKSHEET

See the key to Transparency #3, on page 14.

® Mark Hall ® Earth Science Teacher Mehlville Senior High School St. Louis, MO Tonawanda, NY/San Luis Obispo, CA 1-800-828-7777 © 2001, SKBL Printed in U.S.A. SK04561-00 St. Catharines, Ontario, Canada 1-800-387-9393 p.18 SK04561-00 Modeling the Moon’s Motions — Student Guide

OVERVIEW

The lessons and activities in this kit are designed to help you understand the motions of the moon and how to interpret them. Primarily, you will learn about the phases of the moon, as well as the difference between a lunar (synodic) month and a sidereal month.

The diagrams that you receive and the notes that you take during the lesson(s) are the only resources that you will be allowed to use during the lab investigations. You will need to pay attention, take good notes, and work with each other to successfully complete each lab task. GLOSSARY

The following terms are among those used in the lessons/activities discussed in this kit. By the end of all of the activities, you should have a good understanding of these terms. apparent motion — celestial body — celestial sphere — day — geocentric model — heliocentric model — lunar or synodic month — occultation — revolution — rotation — satellite — sidereal month — year —

p.S1 SK04561-00 STUDENT NOTES #1 — THE DIFFERENCE BETWEEN A SIDEREAL MONTH AND A LUNAR MONTH

As your teacher explains the diagrams below, fill in the blank spaces. The completed diagrams and explanations will serve as your notes

Diagram 1A:

Occultation: Earth's orbit around the Sun

Month = Days

Distant Star E

Diagram 1B: Earth's orbit After one revolution of the Moon around the Sun

Same Distant Star E

Diagram 2: Lunar or Synodic Earth's orbit around the Sun Month: Month = Days

E Sun

p.S2 SK04561-00 ACTIVITY #1 — MODELING THE MOON’S MOTIONS

Objectives:

¥ To investigate the rotation and revolution of the Moon

¥ To investigate the apparent and actual motions of the Moon

Materials Needed:

“Orbit of the Moon” sheet Sun model (yellow ball) Earth model (blue and black ball) Moon model (white ball with black dot) 3 caps Your notes on rotation and revolution

General Procedure:

1. Place each model (Sun, Earth, and Moon) in a cap. This will keep the models from rolling around while you work with them.

2. Find the “Orbit of the Moon” sheet and lay it down on a flat surface. Place the Sun model on the spot on the sheet labeled “Sun”. Place the Earth model and cap on the dot labeled “Earth.” Make sure you place the Earth model so that the blue side, representing daylight, faces the Sun. Place the Moon model and cap on top of position 1 on the sheet. Make sure you place the Moon model so that black dot faces the Earth.

3. Move the Moon from position 1 to position 2, making sure that the black dot continues to face the Earth. To do this, you will need to slightly turn or rotate the Moon model.

4. Move the Moon model from position 2 to position 3, making sure that the black dot continues to face the Earth. Again, you will need to slightly turn or rotate the Moon model.

5. Continue moving the Moon model from one position to the next along its orbital path around the Earth, until the Moon has completed its orbit around the Earth. Throughout this exploration, make sure that the black dot on the Moon ALWAYS faces the Earth.

6. Follow the directions on the Activity #1 Worksheet (pages S4-S5) and answer the worksheet questions.

p.S3 SK04561-00 Name: ______ACTIVITY #1 WORKSHEET— MODELING THE MOON’S MOTIONS ______Date: ______Move the moon counterclockwise completely around the Earth (positions 1-8). Class/Period: ______1. This motion of the Moon around the Earth is called (rotation/revolution)

______.

2. The time that it takes for the Moon to make one complete revolution around the Earth is known as a (sidereal/lunar) ______month.

3. How many Earth days does it take for the Moon to make one complete revolution around the Earth?

______

4. How many degrees does the Moon move during one complete revolution around the Earth? ______

5. Using your answers from questions 3 and 4, determine how many degrees the Moon moves each Earth day. ______. (Show your work for this answer. Round your answer to the nearest degree.)

6. Using your answer from question #5 above, determine how many degrees the Moon moves in 1 hour. ______. (Show your work for this answer.)

Repeat the entire activity, moving the Moon around the Earth. Make sure that the dot on the Moon always faces the Earth as it revolves around the Earth.

7. Does an Earth-bound observer ever see the back side of the Moon (that is, the side with no dot) at any point during the Moon’s rotation? ______

8. To an Earth-bound observer, does the Moon appear to rotate? _____. Does the Moon actually rotate? ______.

9. To an Earth-bound observer, in which direction does the Moon appear to move through the celestial sphere (east to west /west to east)? ______

Repeat the entire activity again, moving the Moon around the Earth. Make sure that the dot always faces the Earth as it revolves around the Earth.

10. Did the dot on the Moon always face the Sun? ______

11. Would an observer on the Sun ever see the back of the Moon (that is, the side with no dot on it) at any point during the Moon’s rotation? ______

12. To an observer on the surface of the Sun, does the Moon appear to rotate? ______

p.S4 SK04561-00 14. In other words, the Moon’s rate of rotation is equal to its revolution. Therefore, how many Earth days does it take for the Moon to complete one rotation? ______

15. A day is defined as the amount of time it takes for a body to complete one rotation. A year is defined as the time it takes a body to complete one revolution. A day on the Moon is (shorter than/longer than/ exactly as long as) ______one Moon year. (HINT: Remember — the Moon’s rate of rotation is equal to its revolution.)

p.S5 SK04561-00 STUDENT NOTES #2 — THE CHANGING TIMES OF MOONRISE AS A RESULT OF SIDEREAL MOTION As your teacher explains the diagrams below, fill in the blank spaces. The completed diagrams and explanations will serve as your notes.

Diagram 1 START HERE Night two of lunar observation Night one of lunar observation

Time: Time:

No Moon! Why?

E E

Diagram 2 Night two of lunar observation Night one of lunar observation

Time: Time:

E E

p.S6 SK04561-00 STUDENT NOTES — THE PHASES OF THE MOON

As your teacher explains the phases of the Moon, fill in the spaces in the diagram, below. This diagram will serve as your notes.

Note: These phases are not in the correct sequence.

Waxing:

Waning:

How to tell whether the Moon is in the first or third quarter: First quarter =

Third quarter =

p.S7 SK04561-00 STUDENT ACTIVITY #2 — THE PHASES OF THE MOON AND THE EARTH Objective: ¥ To observe the phases of the Moon, and to observe the Moon and Earth from various perspectives. Materials Needed:

“Orbit of the Moon” sheet Sun model (yellow ball) Earth model (blue and black ball) Moon model (black and white ball) 3 caps Your notes on the phases of the Moon Procedure: 1. Place each model (Sun, Earth, and Moon) in a cap. This will keep the models from rolling around while you work with them.

2. Find the “Orbit of the Moon” sheet. Place the Sun model on the spot on the sheet labeled “Sun”. Place the Earth model on the dot labeled “Earth.” Make sure you place the Earth model so that the blue side, representing daylight, faces the Sun. Place the Moon model on top of position 1 on the sheet. Make sure you place the Moon model so that black side faces the Earth.

3. Keep the following rules in mind throughout this exploration: ¥ The white side of the Moon should always face the Sun. In order to achieve this, you must not turn or rotate the Moon. ¥ For a portion of this activity, you will be asked to observe the Moon from the perspective of an observer on Earth. As such, you will need to move out of your chair and crouch down to observe the Moon model at eye-level from the Earth’s perspective, as shown in Figure 1. You will also need to move around the circle, to a point directly opposite the Moon model, as shown in Figure 2. For instance, when the Moon is at Position 1, you should observe it at eye-level from Position 5.; when the Moon is at Position 2, you should observe it from Position 6, and so on. ¥ When identifying each phase of the Moon, be sure to note whether the Moon is waxing or waning, gibbous or crescent, full or new, or first or third quarter, as appropriate.

Earth eye Moon eye

t of the Mo Orbi on Sun eye 5

6 4 Figure 1 Earth 4. On Worksheet page S9, answer the questions for Position 1.

Earth 5. Without rotating the model, move the Moon counterclockwise 7 W E 3

eye

from position 1 to position 2 along the Moon’s orbital path, as d n ire tio shown in Figure 2. Answer the worksheet questions for ction of rota Position 2. 8 2 6. Without rotating the model, move the Moon counterclockwise to the next position along the Moon’s orbital path, as shown in 1 Figure 2. Answer the worksheet questions for the next position. 7. Repeat step 6 for all of the remaining positions on the “Orbit of the Moon” sheet, until you have completed the entire orbit and are back at Position 1. Be sure to answer all the questions for each position and fill in the diagrams on the sun worksheet (page S12). Figure 2 p.S8 SK04561-00 Name: ______ACTIVITY #2 WORKSHEET: THE PHASES OF THE MOON AND THE EARTH ______Date: ______Position 1 Class/Period: ______1. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the ______Moon model appears at Position 1, when viewed from above. 2. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the Moon model appears at Position 1, when viewed from the perspective of a person on Earth. On the line below the circle at Position 1, write the name of the phase of the Moon in this position. 3. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 1, so it shows how the Earth model appears at Position 1, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 1, write the name of the phase of the Earth in this position.

4. What is the phase of the Moon in Position 1? ______

5. How many days will pass before this phase will be repeated? ______

6. The time period in question 5, above, is the length of a ______month.

Position 2

7. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 2, so it shows how the Moon model appears at Position 2, when viewed from above.

8. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 2, so it shows how the Moon model appears at Position 2, when viewed from the perspective of a person on Earth. On the line below the circle at Position 2, write the name of the phase of the Moon in this position.

9. The term used to describe the Moon as the lit portion increases is ______. The term used to describe the Moon as the lit portion decreases is ______.

10. At Position 2, which side of the Moon is lit — the left or the right? ______

11. What is the phase of the Moon in Position 2? ______Position 3 12. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 3, so it shows how the Moon model appears at Position 3, when viewed from above.

14. Locate Diagram 3 (“The Earth as viewed from the Moon”) on page S12. Use a pencil to fill in the circle at Position 3, so it shows how the Earth model appears at Position 3, when viewed from the perspective of a person on the Moon. On the line below the circle at Position 3, write the name of the phase of the Earth in this position.

15. At Position 3, the Moon has now completed ______percent of its orbit around the Earth.

16. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 3? (HINT: How many days make up 25 percent of the a lunar cycle?) ______17. What is the phase of the Moon in Position 3? ______p.S9 SK04561-00 Position 4 18. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 4, so it shows how the Moon model appears at Position 4, when viewed from above. 19. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 4, so it shows how the Moon model appears at Position 4, when viewed from the perspective of a person on Earth. On the line below the circle at Position 4, write the name of the phase of the Moon in this position. 20. What is the phase of the Moon in Position 4? Be sure to note whether the Moon is waxing or waning.

______Position 5

24. The Moon has now completed ______percent of its orbit around the Earth.

25. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 5? ______

26. What is the phase of the Moon in Position 5? ______Position 6 27. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 6, so it shows how the Moon model appears at Position 6, when viewed from above. 28. Locate Diagram 2 (“The Moon as viewed from Earth”) on page S12. Use a pencil to fill in the circle at Position 6, so it shows how the Moon model appears at Position 6, when viewed from the perspective of a person on Earth. On the line below the circle at Position 6, write the name of the phase of the Moon in this position. 29. As the Moon moves from Position 5 to Position 6, does the lit portion appear to increase or decrease? ______

30. What is the term used to describe your answer to question 29? ______

31. What is the phase of the Moon in Position 6? ______

(continued on next page)

p.S10 SK04561-00 Position 7 32. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 7, so it shows how the Moon model appears at Position 7, when viewed from above.

35. The Moon has now completed ______percent of its orbit around the Earth.

36. In an actual lunar or synodic month, approximately how long does it take for the Moon to travel from position 1 to position 7? ______

37. What is the phase of the Moon in Position 7? ______Position 8 38. Locate Diagram 1 (“The Moon in orbit as viewed from above”) on page S12. Use a pencil to fill in the circle at Position 8, so it shows how the Moon model appears at Position 8, when viewed from above.

40. What is the phase of the Moon in Position 8? ______Position 1 (at completion of orbit)

41. What is the phase of the Moon when it has returned to Position 1? ______42. From new moon back to new moon means that the Moon has completed one ______month. 43. Explain why the Moon appears to go through a cycle of phases.

p.S11 SK04561-00 ACTIVITY #2 WORKSHEET: THE PHASES OF THE MOON AND THE EARTH (continued)

Instructions for filling out this worksheet are on pages S9-S11.

Diagram 1 The Moon in Orbit As Viewed From Above

6. 4.

Night

Earth

7. Day 3.

8. 2.

The Sun's Rays

Diagram 2 The Moon Viewed From the Earth

1. 2. 3. 4. 5. 6. 7. 8.

Diagram 3 The Earth Viewed From the Moon

1. 3. 5. 7. p.S12 SK04561-00