Including Students Model Earth, Moon, Sun System

Transcription

1 Including Students Model Earth, Moon, Sun System by Elysa Corin and Todd Boyette ncorporating models into classroom activities is especially useful in the study of astronomy, as the cosmic actors under investigation are remote and not easily observed from multiple perspectives. Focusing student attention on a model of a space system makes the abstract and unfamiliar more tangible and accessible for exploration. The activity described below asks students to become a component of a kinesthetic model and adopt the perspective of an object within the system under investigation. 30

2 This activity was influenced by the Sky Time lesson (Morrow and Zawaski 2004) and initially adapted to assist teachers with little to no astronomy content knowledge teach Earth, Moon, and Sun (EMS) system concepts in their classrooms (Corin et al. 2010). The version presented here is further streamlined, influenced by our experience teaching this lesson to students and educators in a variety of contexts, and adjusted to help middle school students reach performance expectation MS-ESS1-1 of the Next Generation Science Standards (NGSS) (MS-ESS1-1: Develop and use a model of the Earth-sun-moon system to describe the cyclic patterns of lunar phases, eclipses of the sun and moon, and seasons; NGSS Lead States 2013). The activity is divided into several smaller parts that may each be taught in single class periods on consecutive days or spread throughout an astronomy unit. In each section students manipulate the kinesthetic model to explore key concepts of the EMS system, including rotation, revolution, Moon phases, and seasons. The activity was intentionally organized into these subsections to provide teachers with several exercises to add to their repertoire that cover components of performance expectation MS-ESS1-1. In addition to being structured to highlight the astronomy content presented in NGSS disciplinary core idea ESS1: Earth s Place in the Universe (NGSS Lead States 2013), this activity is designed to guide middle school educators in the integration of relevant crosscutting concepts and science and engineering practices into their instruction. Throughout this activity, students are asked to reason with, consider, and critique their model, which are recommended practices of the NGSS discussed in the crosscutting concept Systems and System Models and science and engineering practice Developing and Using Models (NGSS Lead States 2013). Student observations of the model s behavior will uncover patterns in motion and time of the Earth, Moon, and Sun system (crosscutting concept Patterns), and students will use those patterns to predict cause-and-effect relationships of EMS system phenomena (crosscutting concept Cause and Effect) (NGSS Lead States 2013). Students will also have the opportunity to engage in several science and engineering practices as they ask clarifying questions that arise from their use of the model (science and engineering practice Asking Questions) and as they construct explanations of EMS system phenomena using evidence from the model (science and engineering practice Constructing Explanations) (NGSS Lead States 2013). Once students are fluent in the model, and armed with their new understanding of the EMS system, they may continue to use the model to make predic- FIGURE 1 Materials and setup Materials All parts of the activity (per class) Dark trash bags to tape over classroom windows 1 Earth globe 1 lamp (with lightbulb, without lamp shade) Desk or chair on which to place the lamp Parts 1 and 2: Earth s rotation and Earth s revolution (per class) 1 star cut from yellow paper Tape Part 3: Moon phases (per student) 1 3 foam sphere 1 craft stick Part 4: Seasons (per class) 1 star cut from yellow paper Tape 1 sheet of paper labeled Summer Solstice June 1 sheet of paper labeled Autumnal Equinox September 1 sheet of paper labeled Winter Solstice December 1 sheet of paper labeled Vernal Equinox March Setup Parts 1, 2 and 4 Tape the yellow star in the corner of the classroom farthest from the lamp and circle of students. Tape the star where the wall meets the ceiling. This star will represent the North Star, Polaris. Part 3 Prepare the class set of Moon balls by placing a craft stick in each foam sphere. Smooth foam spheres are recommended, though you may also use Styrofoam spheres. You should have a Moon ball for every student. Part 4 Nail two thin nails into the Earth globe so they stick out about 2.5 cm (1 in.) above the surface of the globe. Place one in the Northern Hemisphere and the other in the Southern Hemisphere, both on the same line of longitude. (It is recommended to place one of the nails in your town.) Summer

3 FIGURE 2 Establishing the model A Students pointing to the north pole of their model tions and develop explanations about more complex EMS system phenomena including, but not limited to, seasonal constellations, eclipses, and setting/ rising times of Moon phases. Students may also adjust the model to respond to its limitations, allowing them to study additional space systems. Specifically, students may add additional planets to the model to learn about opposition and inferior/superior conjunction, to learn how the positions of planets in the solar system determine when and where planets will be visible in the Earth s sky, and to explore the role of gravity in influencing planetary motions, etc. The strength of this model is its versatility and flexibility, as it may be adjusted to teach a variety of astronomy concepts. This is a model to come B Students pointing to the city located on their nose in the model back to many times during an astronomy unit; the activities described below should not be taught in a single day. Setup For all of the activities, prepare an empty space large enough for your class to stand in a circle with outstretched arms. Cover large windows with dark trash bags to make the classroom dark. Situate a lamp so that when placed in the middle of the circle, its lightbulb is approximately at students eye level; you may need to place the lamp on a chair or desk. See Figure 1 for a complete materials list and setup instructions specific to each separate part of the activity. FIGURE 3 The view from the city on their nose A sketch illustrating how the objects students see in their field of vision translate to what the city on their nose sees in their sky Objects in student s field of vision What people living in the city on their nose see above them in the sky. 32

4 Make sure you closely read the section you plan to teach and try out the directions prior to teaching the activity. This will help you foresee problems and know where to adjust the instructions for your specific teaching environment. Before you begin, provide students with guidelines for moving around the classroom. In these activities, they will pretend to be Earth; they should move smoothly and slowly whenever you ask them to move. Students should also pay attention to their surroundings and avoid entering the personal space of their classmates. Part 1: Earth s rotation Begin the activity by engaging students in a pre-lesson discussion about the Earth, Sun, and solar system. By asking questions and probing their ideas, you will make students thinking visible to both you and students and identify any misconceptions present. To begin, ask students to name objects located in our solar system and to describe the motion of these objects. Students should understand that the Sun is moving relative to other stars in the Milky Way galaxy, but we may think of the Sun as a stationary object in our solar system. All solar system objects are gravitationally bound to the Sun and travel with it through the galaxy. Inside the solar system, the planets, including the Earth, move in two main ways: They rotate (spin) as they revolve (orbit) around the Sun. This part of the activity is perhaps the most crucial, as you will introduce students to the model they will use, adjust, and build on during the subsequent sections of the activity. Plan to spend sufficient time guiding students as they build their understanding of this model, and provide plenty of opportunities for students to question the model and for you to check their understanding. Have students stand in a circle and tell them they are going to model one way the Earth moves in space: rotation. In this model, they will pretend their head is the Earth (Figure 2A). Ask, Where on your head is the North Pole? (On the top.) Where is the South Pole? (Underneath their chin.) Where is the equator? (A circle that runs around their FIGURE 4 head, equidistant from the North and South poles.) Explain they re going to pretend there is a city of people living on their nose, between their eyes (Figure 2B). When the imaginary people living on their nose look up into the sky, they will see everything that students are able to see in their field of vision (Figure 3). Ask, What part of your field of vision corresponds to the horizon for the people living on your nose? (The periphery of their vision.) What part of your field of vision corresponds to the zenith, the highest part of the sky, for the people living on your nose? (The center of their field of vision, the area directly in front of their eyes.) Turn off the classroom lights. Tell students it is very dark in their cities. Ask, Is it daytime or nighttime? (Nighttime.) What object do we need in the sky for our cities to experience the daytime? (The Sun.) Turn on the Sun lamp and place it in the center of the circle. All students should face the lamp (Figure 4). Remind students that just as they wouldn t want to stare at the real Sun, they should not look directly at the Sun lamp, nor should they touch it. As students are facing the Sun, ask them what time it is in the city on their nose. (Noon; the Sun is high in the sky.) Ask students to make it midnight in their cities. (They should stand with their backs to the Sun lamp.) Ask students to return to noon and then to model one day passing on their Earth. As they rotate, direct students to look straight ahead. Their heads should remain fixed relative to their shoulders. Ask students how many hours Ready to begin Place the lamp inside the circle of students. All classroom windows should be covered so the only light comes from the lamp once the overhead lights are turned off. Summer

5 FIGURE 5 Modeling Earth s rotation Noon, or 12 p.m.; students/earths should face the Sun. Sunset, or 6 p.m.; students/earths should be looking straight ahead and see the Sun out of the corner of their right eye. Midnight, or 12 a.m.; students/earths should have their back to the Sun. Sunrise, or 6 a.m.; students/earths should be looking straight ahead and see the Sun out of the corner of their left eye. pass as the Earth rotates one time. (Twenty-four hours.) Once students have completed their rotation, ask if they turned to the right or the left. Ask, Does the real Earth turn to its right or its left? If students are unsure, let them use the globe to figure out the answer to your question. Students should place the globe in the circle and slowly rotate it to the Earth s right and the Earth s left, observing the direction that the terminator, the boundary separating the daytime and nighttime sides of the Earth, moves across the surface of the planet in both situations. If students need more guidance, ask them if the Sun rises in the east or the west. (East.) Direct them to look at the East and West Coasts of the United States as they spin the Earth. On which coast should they first observe sunrise? (East Coast.) Alternatively, students can think about this in terms of time zones: The East Coast is in a later time zone than the West Coast and will experience sunrise before the West Coast. By manipulating the globe, students should arrive at the conclusion that the Earth spins counterclockwise when viewed from above the North Pole; this means the Earth spins to its left. Students sometimes have trouble connecting the direction they observe the Earth globe spinning to the direction they should rotate their bodies in the kinesthetic model. When spinning the globe to its left, a student across the circle will observe the globe spinning to the right. This is similar to reporting that a person facing you raises the hand on the right side of her body when she is actually raising her left hand. When students model the rotation of the Earth they will turn to their left, yet it will appear to an outside observer they are turning to the right. Have students model one day on Earth, rotating to their left. Once students have returned to noon, direct them to turn (still to their left!) until they can just barely see the Sun lamp out of the corner of their right eye. Remind students to continue to look straight ahead as they rotate, turning their bodies but keeping their necks from turning. Ask, What time of day is it in the city on your nose? (Sunset, approximately 6 p.m.) Does the Sun set in the east or the west? (West.) Is the Sun lamp setting in your right periphery or your left periphery? (Right.) Tell students, In this model, the right side of your face is the western horizon of the Earth. From the sunset position, direct students to move through midnight and model sunrise. (Approximately 6 a.m.) Students should see the Sun lamp in their left periphery; the Sun is rising in the east. Figure 5 illustrates how students should stand to model noon, sunset, midnight, and sunrise. To conclude the activity and reinforce how students should position their heads relative to the Sun 34

6 to model different times of day, play a few rounds of Sun-Earth Simon Says with the times noon, sunset (6 p.m.), midnight, and sunrise (6 a.m.). To challenge students, encourage them to always spin to their left like the real Earth and add the times 3 a.m., 9 a.m., 3 p.m., and 9 p.m. to the game. Make sure to give students plenty of time to work out the correct orientation. Model limitations Now that students are familiar with the model, take a moment to discuss its strengths and weaknesses. What is the model good at explaining? What does the model not illustrate well? What are the limitations of this model? The first limitation students usually identify is that the model is not to scale. In this case, students are modeling the Earth so it is as large as their head, as this helps visualize the motions and relative positions of objects in the Earth-Moon-Sun system. If they were to accurately scale this model to the size of their Earthhead, the Sun would be about the size of a six-story building, and students/earths would need to stand a little more than a mile from the Sun. Discuss with students why it is not useful to accurately model scale for the purposes of this activity. Another limitation students often mention is that the real Earth is tilted as it rotates. How can students adjust the model to incorporate tilt? Direct students attention to the North Star you taped to the wall/ceiling during setup (see Figure 1 for full setup instructions). Position the globe s axis so the North Pole is pointed toward Polaris; demonstrate the Earth spinning on its axis while tilted. (The Earth s rotational axis is tilted 23.5 from a line perpendicular to the orbital plane/ floor of the classroom.) The Earth is tilted in such a way that the North Pole (the top of students head) always points to Polaris. Have students bend their body at the waist so the top of their head points to the North Star and rotate while maintaining this position. Part 2: Earth s revolution Ask students about the second way planets move in space, in addition to rotating. As a class, form a consensus of what students know about the orbital motion of the Earth. (The Earth revolves around the Sun. The path the Earth takes around the Sun is called its orbit. The shape of the Earth s orbit is an ellipse but is very nearly circular. It takes the Earth one year, or days, to complete one trip around the Sun. Earth maintains an average distance of 150 million km [93 million mi.] from the Sun as it travels FIGURE 6 A student using the globe to model Earth revolving around the Sun Summer

7 in its orbit.) Ask students how many trips around the Sun they have taken in their lifetimes. Direct students to form a circle around the Sun lamp. Ask for a student volunteer to use the globe and model one revolution for the rest of the class (Figure 6). Once the volunteer has completed a revolution, ask the class if the volunteer correctly modeled one year on Earth. Ask, What should the volunteer have done differently? Would anyone else like to try? (The student should hold the globe and walk around the Sun once. Looking down on the North Pole, the Earth orbits counterclockwise around the Sun; the student s left shoulder should point toward the center of the circle as the student orbits. While revolving, the student should rotate the globe to its left as the North Pole of the Earth points toward the North Star. The real Earth would spin times during one orbit.) Once students have observed and critiqued how Earth revolves, ask them to model one week on the Earth while pretending their head is the Earth. They should rotate and revolve, moving in the correct direction. Remind students that they should move slowly, just like the Earth, and not crash into their neighbors. To make this more challenging, have students model the Earth s tilt as they rotate. Part 3: Moon phases Uncovering preconceptions Engage students in a pre-lesson discussion about the Moon. You may ask questions such as the following: How does the Moon move in space? Why are we able to see the Moon in the sky (as it is made of rock and does not create its own light)? Why do we sometimes observe the Moon in the daytime and sometimes in the nighttime? Review the shapes/phases of the Moon students have seen in the real sky. Ask why the Moon appears to change shape and what causes those changes. Ask students, How long does it take the Moon to move through all of its phases? Listen and take note of students preconceptions so you may modify your instruction to directly address student ideas about the phases of the Moon during the activity. The model introduced in Part 3 helps students refine their ideas about Moon phases. (The video A Private Universe from the Harvard-Smithsonian Center for Astrophysics [see Resource] provides a good introduction to common student misconceptions about the causes of the phases of the Moon and the seasons. You may wish to review the 20-minute video before teaching these activities.) FIGURE 7 Correctly using Moon balls Ask students to elevate the Moon ball slightly above their head to prevent them from creating eclipses, blocking the Sun lamp with the Moon ball during a new Moon, or moving the full Moon through the shadow cast by students heads. (Modeling these events is useful during a discussion of eclipses but can be confusing during a discussion of Moon phases.) A student is creating a solar eclipse if when the student is facing the Sun lamp you see a round shadow cast on the student s face. Students often intentionally use the Moon balls to block the light from the Sun lamp; try to discourage this during the discussion of Moon phases. A student correctly using the Moon ball. A student incorrectly using the Moon ball; notice the shadow on her face. 36

8 FIGURE 8 An illustration of how students should orient their bodies relative to the Sun lamp to create each phase, as well as what their view of the Moon ball will be in each of these positions. A. New Moon E. Full Moon B. Waxing crescent Moon F. Waning gibbous Moon C. First quarter Moon G. Third quater Moon D. Waxing gibbous Moon H. Waning crescent Moon Summer

9 The activity Direct students to stand in a circle around the Sun lamp and give each one a Moon ball (see Figure 1 for directions on how to create Moon balls). Students should hold the Moon ball with the craft stick in their fist, similar to how they would hold a lollipop. As they did in Parts 1 and 2, students will pretend their head is the Earth and that there is a city on their nose. Explain that the Moon ball represents the Moon in this model. Direct students to hold the Moon at arm s length and elevate it slightly above their head. (See Figure 7 for tips on the correct use of the Moon balls.) Ask students while keeping the Moon ball positioned in front of their bodies to make the Moon ball orbit around the Earth in the counterclockwise direction (counterclockwise if an observer looked down on the Earth from above the North Pole). This can be achieved if students turn to their left and move the Moon with them as they turn. Following these directions will model the phases as people in the Northern Hemisphere observe them. Direct students to locate the terminator, the line that separates the illuminated and shadowed halves of the Moon. Ask students to observe how the line moves across the face of the Moon as it orbits. Students should also note which half of the Moon faces the Sun (and is lit by the Sun) as the Moon orbits the Earth. Ask, How much of the lit portion of the Moon is visible from the city on your nose? Does this change as the Moon revolves around the Earth? Students should see that the Sun illuminates half of the Moon at all times. (Exception: during a lunar eclipse.) However, the entire lit side of the Moon does not always face the Earth/the city on their nose. Ask all students to face the center of the circle. With their Moon ball held slightly elevated in front of them, direct students to move the Moon in a counterclockwise direction around the Earth (to their left) until the entire lit side of the Moon is facing them. (They should all have their back to the Sun.) Ask which phase students are observing. (Full Moon.) Have students model one orbit of the Moon, turning toward their left and watching the phases of the Moon cycle from full to full. Ask students to describe how their Moon appeared to change shape throughout the month. Introduce the words waxing and waning and ask students to show you a waxing Moon (between new and full) and a waning moon (between full and new). Ask students to form a new Moon (they face the lamp); a first quarter Moon (their right side toward the center of the circle); a full Moon (their back to the lamp); a third quarter moon (their left side toward the center of the circle); and a new Moon once again. Next ask students to model all eight phases, including the four intermediate phases: FIGURE 9 A view of sunrise and sunset during Northern Hemisphere summer and Southern Hemisphere winter At left: Sunrise. Notice the nail in the Northern Hemisphere is experiencing daytime a few hours after sunrise. The nail in the Southern Hemisphere is still in shadow; people living in this location would be experiencing the twilight just before sunrise. At right: Sunset. The nail in the Southern Hemisphere is experiencing nighttime, just after sunset. The nail in the Northern Hemisphere is still experiencing daytime. The Sun won t set for another few hours at this location. 38

10 waxing crescent, waxing gibbous, waning gibbous, and waning crescent. Call students attention to the relative positions of the Earth, Moon, and Sun necessary for each of the eight phases. See Figure 8 for an illustration of how students should orient their body relative to the Sun lamp to create specific phases, as well as what their view of the Moon ball will be in each of these positions. To conclude the activity, play a round of Moonphase Simon Says with your students by calling out the eight Moon phases for them to model (new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent). Challenge students to always move the Moon counterclockwise around the Earth (to their left), just like the real Moon. Model limitations Ask students to think about the Moon model. What did the model help them understand? Did the model make some ideas more confusing? What does the model explain well, and what are its limitations? As students share their thoughts, they may point out that this model successfully demonstrates the orbital motion of the Moon and does not accurately demonstrate the rotational motion of Earth. They should understand that the Moon completes a full phase cycle in 29.5 days, or about a month. In this model, students do not rotate their Earth-head every 24 hours during the Moon-phase cycle. This Moon-phase model clarifies student ideas about Moon phases and the orbital motion of the Moon while simplifying other aspects of the Earth-Moon system. Part 4: Seasons Addressing misconceptions Before starting this activity, ask students to write down their ideas about the cause of seasons on planet Earth. Students should explain their ideas with words and draw pictures to illustrate. Review student responses (the video A Private Universe [see Resource] also discusses common student misconceptions about the seasons and might be helpful to review), and address common misconceptions about the seasons. Based on the results of your formative assessment you may choose to address more than the common misconception explained here. Ask students, During what month is Earth closest to the Sun? (January.) Does this information support/not support your ideas about seasons? Discuss how seasons are not caused FIGURE 10 The positions in the Earth s orbit that correspond to the dates of the solstices and equinoxes As students move the globe through Earth s orbit, make sure the North Pole of the Earth is always pointing toward Polaris. Summer

11 by the Earth s changing distance from the Sun over the course of a year. The Earth s orbit is elliptical but very nearly circular. The farthest distance from the Sun that the Earth reaches (aphelion) and the closest distance (perihelion) are, relatively speaking, not much larger/ smaller than the Earth s average distance from the Sun. Ask students, When it is summer in the United States, what season is it in Argentina? (Winter.) If the changing Earth-Sun distance is responsible for the seasons, the Northern Hemisphere and Southern Hemisphere would experience the same seasons at the same time. After these common misconceptions about seasons are addressed, many students will recognize that their old theories are not sufficient to fully explain seasons. The following activity will help students revise their thinking and their ideas about the cause of the seasons. The activity As students form a circle around the Sun lamp, have a student model one year with the globe as in Part 2: Earth s Revolution, making sure the North Pole of the Earth is pointed toward Polaris. Students should notice the Northern Hemisphere points toward the Sun, away from the Sun, and neither toward nor away from the Sun at different points in Earth s orbit. Have students identify the two positions in the Earth s orbit where the Northern Hemisphere points toward and away from the Sun. Ask students, In which of these two positions will the Northern Hemisphere experience a longer day? How can we answer this question using our model? Students will use the globe to demonstrate why Northern and Southern Hemisphere locations experience different amounts of daylight hours at various times throughout the year. Call students attention to the two nails in the surface of the globe (see Figure 1 for setup instructions), one in the Northern Hemisphere and the second in the Southern Hemisphere. Place the globe in the position where the Northern Hemisphere is pointed toward the Sun. (The North Pole of the Earth should still be pointing toward Polaris.) Slowly rotate the Earth to its left. Have students standing on this side of the circle alert you when the nails in the Northern Hemisphere and Southern Hemisphere experience sunrise and when they experience sunset. Students will observe that the northern nail will experience sunrise before, and sunset after, the southern nail. This means that a person living in the Northern Hemisphere location will experience more daylight hours than a person living in the Southern Hemisphere location. As the Sun spends more time above the horizon, it will travel higher in the sky. See Figure 9 for a view of sunrise and sunset during Northern Hemisphere summer/southern Hemisphere winter. Travel six months in the Earth s orbit to the position where the Southern Hemisphere is pointed toward the Sun. (The North Pole of the Earth should still be pointing toward Polaris.) Repeat the experiment. Students standing on this side of the circle will observe the opposite situation: The southern nail will experience sunrise before, and sunset after, the northern nail. As such, the southern nail will experience more daylight hours than the northern nail. Students should understand that when a hemisphere points toward the Sun, the Sun is above the horizon for more hours and reaches a higher position above the horizon during the day. Ask students to decide in which of these two orbital positions a person living in the Northern Hemisphere will experience summer and winter. Next have students place sheets of paper (see materials list in Figure 1) on the floor to label the positions in the Earth s orbit that correspond to the dates of the two solstices and two equinoxes (Figure 10). The summer-solstice paper should be placed on the floor where the Northern Hemisphere is pointed directly toward the Sun lamp, receiving the most direct light. The winter-solstice paper should be placed on the floor where the Northern Hemisphere is pointed away from the Sun, receiving less direct light. The two equinoxes fall between the solstices. Ask a student to move the globe to either of the equinoxes and then ask, Which hemisphere is pointed toward or away from the Sun in this location? (The Earth leans neither toward nor away from the Sun at the equinoxes; the Northern and Southern Hemispheres receive equal amounts of sunlight.) As before, slowly rotate the Earth to its left. Have students alert you when the northern and southern nails experience sunrise and sunset. Students should observe that at the equinox, days are similar in length in the two hemispheres. (The word equinox comes from the Latin words for equal and night.) To conclude the activity, ask students to again write down what causes seasons on planet Earth. Student claims should be supported with clear reasons and relevant evidence, as described in the Common Core State Standards, ELA literacy standards for middle school writing (NGAC and CCSSO 2010). Encourage students to use evidence from the modeling activity to develop their argument; they should explain their idea with words and draw pictures to illustrate. Have students compare their answers to the ideas they had before the activity. 40

12 This model demonstrating the cause of the seasons also illustrates the changing distribution of sunlight on the Earth s surface during different times of year. This model could be used to provide an introduction to performance expectation MS-ESS2-6 (Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates; NGSS Lead States 2013). The next step Once students understand how to use the model, they should continue to use this kinesthetic tool to help them reason about the EMS system. When asked at a later date about the relative positions of the Earth, Moon, and Sun necessary to create a specific Moon phase, we have seen students imagining themselves standing in front of the Sun lamp and moving their outstretched fist around their head to determine the correct position of the Moon. With guidance from their teacher, students may amend the model to help them reason about solar system concepts beyond rotation, revolution, Moon phases, and seasons. Many observable phenomena may be explained with this kinesthetic model with only minor adjustments. Some of our favorite extensions can be found at though we expect there are more applications. This model is powerful because it gives students the necessary tools to reason about the EMS system, and students always have the object of the model, their body, with them ready to be used. The end goal is for students to so thoroughly understand the dynamics of the model presented in this activity that they are able to visualize the abstract system without relying on the tangible objects of the model. This kinesthetic activity offers an important bridge that assists students in reaching that destination. n Acknowledgments We would like to thank our astronomy education colleagues Richard McColman, Amy Sayle, and Mickey Jo Sorrell for their constant advice, support, and guidance. References Corin, E., P. Dornette, C. Harden, and A. Vogel Showcasing the solar system: Grade 4 6 activities to investigate the size, composition, and motion of objects in the solar system. Chapel Hill, NC: Morehead Planetarium and Science Center, University of North Carolina. Morrow, C., and M. Zawaski Kinesthetic astronomy: Sky time. kinesthetic_astronomy/download.html. National Governors Association Center for Best Practices and Council of Chief State School Officers (NGAC and CCSSO) Common core state standards. Washington, DC: NGAC and CCSSO. NGSS Lead States Next Generation Science Standards: For states, by states. Washington, DC: National Academies Press. next-generation-science-standards. Resource A private universe html Connecting to the Next Generation Science Standards (NGSS Lead States 2013) Standard MS-ESS1: Earth s Place in the Universe Performance expectation MS-ESS1-1: Develop and use a model of the Earth- Sun-Moon system to describe the cyclic patterns of lunar phases, eclipses of the Sun and Moon, and seasons. Science and engineering practices Developing and using models Constructing explanations and designing solutions Asking questions and defining problems Disciplinary core idea ESS1: Earth s place in the universe Crosscutting concepts Systems and system models Patterns Cause and effect Elysa Corin (encorin@ncsu.edu) is a graduate student in the Department of STEM Education at North Carolina State University in Raleigh, North Carolina. Todd Boyette (tboy@ .unc. edu) is the director of the Morehead Planetarium and Science Center and a clinical assistant professor of education at the University of North Carolina in Chapel Hill, North Carolina. Summer

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