It s a Long Way to Pluto!

Name Class Date Making Models Lab It s a Long Way to Pluto! Astronomers use astronomical units or light years to measure large distances in space. In this lab you will use astronomical units (AU) to compare distances between the planets of our solar system. One AU is the distance from Earth to the sun. The distance from Earth to the sun is approximately 150,000,000 kilometers, so one AU is 150,000,000 km. In this exercise, you will use AUs to accurately place the orbital positions of the planets in a scale model and use your model to answer questions. OBJECTIVES Convert and apply data to create a model of the solar system and relative orbital positions of the planets. Create an accurate scale representation of the solar system. MATERIALS adding machine paper tape calculator meterstick SAFETY PROCEDURE 1. Use the astronomical unit data from Table 1 as a guide to building your model of the solar system. The data show the distance of each planet in the solar system from the sun. TABLE 1: ASTRONOMICAL UNIT DATA Planet Distance from the Sun (AU) Mercury 0.39 Venus 0.72 Earth 1.0 Mars 1.52 Jupiter 5.20 Saturn 9.54 Uranus 19.19 Neptune 30.06 Pluto 39.53 Holt Earth Science 49 Planets of the Solar System

Name Class Date 2. The scale on this model will be 1 AU = 2 cm. 3. Using a 2 m strip of adding machine paper, fold the strip of paper exactly in half so it is divided into two 1 m sections. 4. Draw a solid line along the fold and label the line SUN. 5. Calculate the distance between the sun and Mercury according to the scale of your model. Show your work below. 6. Using your calculation in Step 5, draw a vertical dotted line the appropriate distance to the right of the sun on your model. Label this line Mercury. 7. Using the same method as Step 5, calculate the distance between the sun and Venus. Show your work below. 8. Using the same method as Step 6, draw a vertical dotted line for Venus on the opposite side of the sun. 9. Continue plotting planets, making sure to alternate left or right of the sun. When you are finished, you will have five planets on one side of the sun and four on the opposite side. ANALYSIS AND CONCLUSION 1. Explain Why do astronomers use the term astronomical unit when describing distances within the solar system? Holt Earth Science 50 Planets of the Solar System

Name Class Date 2. Making Inferences Would the term light-year the distance light travels in a year, or 9.5 trillion km be useful in a model of the solar system? 3. Drawing Conclusions If we were living on Mars and not Earth, what distance might an AU represent? Why? 4. Making Inferences If this model was based on a Martian astronomical unit would it also be an accurate representation of the actual distances? Explain. 5. Making Comparisons The Kuiper Belt objects are located between 30 and 100 AUs from the sun. How much more paper tape would you need to add to one side of your model to include the entire Kuiper Belt? 6. Applying Ideas The asteroid belt is located between 2.1 and 3.3 AUs from the sun. Indicate the location of the asteroid belt on your model with a series of dots. 7. Drawing Conclusions How would you describe the asteroid belt s position in relationship to Mars and Jupiter? Holt Earth Science 51 Planets of the Solar System

Name Class Date 8. Making Inferences Why do you think the asteroid belt stays within those distances? 9. Evaluating Models If everyone in your class used a different scale for astronomical units, would the models be useful? Explain why or why not. 10. Evaluating Models Place the strips of paper tape created by all groups on the floor of the classroom laid out like the spokes of a bicycle wheel with the sun in the center of the hub. What do you observe? What does this do to the value of your models? Holt Earth Science 52 Planets of the Solar System

Making Models Lab It s a Long Way to Pluto! Teacher s Notes TIME REQUIRED one 45-minute class period LAB RATINGS Teacher Prep 1 Student Set-Up 2 Concept Level 2-3 Clean Up 1 Easy 1 2 3 4 Hard Krista Hartman West Alabany High School Albany, Oregon SKILLS ACQUIRED Constructing Models Interpreting Organize and Analyzing Data Predicting THE SCIENTIFIC METHOD In this lab students will Make Observations Analyze the Results MATERIALS The adding machine paper tape is inexpensive and readily available in many office and school supply stores. TIPS AND TRICKS Laying the paper tape out in a spoke formation can be done using a push pin and a piece of corrugated cardboard as a base. It may be interesting to preserve the models in this configuration for other potential exercises. Holt Earth Science 74 Planets of the Solar System

Name Class Date Making Models Lab It s a Long Way to Pluto! Astronomers use astronomical units or light years to measure large distances in space. In this lab you will use astronomical units (AU) to compare distances between the planets of our solar system. One AU is the distance from Earth to the sun. The distance from Earth to the sun is approximately 150,000,000 kilometers, so one AU is 150,000,000 km. In this exercise, you will use AUs to accurately place the orbital positions of the planets in a scale model and use your model to answer questions. OBJECTIVES Convert and apply data to create a model of the solar system and relative orbital positions of the planets. Create an accurate scale representation of the solar system. MATERIALS adding machine paper tape calculator meterstick SAFETY PROCEDURE 1. Use the astronomical unit data from Table 1 as a guide to building your model of the solar system. The data show the distance of each planet in the solar system from the sun. TABLE 1: ASTRONOMICAL UNIT DATA Planet Distance from the Sun (AU) Mercury 0.39 Venus 0.72 Earth 1.0 Mars 1.52 Jupiter 5.20 Saturn 9.54 Uranus 19.19 Neptune 30.06 Pluto 39.53 Holt Earth Science 49 75 Planets of the Solar System

Name Class Date 2. The scale on this model will be 1 AU = 2 cm. 3. Using a 2 m strip of adding machine paper, fold the strip of paper exactly in half so it is divided into two 1 m sections. 4. Draw a solid line along the fold and label the line SUN. 5. Calculate the distance between the sun and Mercury according to the scale of your model. Show your work below. 6. Using your calculation in Step 5, draw a vertical dotted line the appropriate distance to the right of the sun on your model. Label this line Mercury. 7. Using the same method as Step 5, calculate the distance between the sun and Venus. Show your work below. 8. Using the same method as Step 6, draw a vertical dotted line for Venus on the opposite side of the sun. 9. Continue plotting planets, making sure to alternate left or right of the sun. When you are finished, you will have five planets on one side of the sun and four on the opposite side. ANALYSIS AND CONCLUSION 1. Explain Why do astronomers use the term astronomical unit when describing distances within the solar system? Answers may vary. Sample answer: The distances between the planets are extremely small when compared to the vastness of space. It is much easier to have a grasp of the relationships without using numbers. Holt Earth Science 50 76 Planets of the Solar System

Name Class Date 2. Making Inferences Would the term light-year the distance light travels in a year, or 9.5 trillion km be useful in a model of the solar system? Answers may vary. Sample answer: In this case we would be dealing with light minutes. For example, it takes light from the sun about 8 minutes and 20 seconds to reach Earth. The concept would not have any relevance for this exercise. 3. Drawing Conclusions If we were living on Mars and not Earth, what distance might an AU represent? Why? Answers may vary. Sample answer: An astronomical unit woud be the distance from Mars to the sun. If we were Martians the rules would be different! 4. Making Inferences If this model was based on a Martian astronomical unit would it also be an accurate representation of the actual distances? Explain. Answers may vary. Sample answer: Yes. The relative orbital position of a planet doesn t change so proportionately the models would be accurate. 5. Making Comparisons The Kuiper Belt objects are located between 30 and 100 AUs from the sun. How much more paper tape would you need to add to one side of your model to include the entire Kuiper Belt? One meter. 6. Applying Ideas The asteroid belt is located between 2.1 and 3.3 AUs from the sun. Indicate the location of the asteroid belt on your model with a series of dots. 7. Drawing Conclusions How would you describe the asteroid belt s position in relationship to Mars and Jupiter? Answers may vary. Sample answer: The belt is about midway between Mars and Jupiter. Holt Earth Science 51 77 Planets of the Solar System

Name Class Date 8. Making Inferences Why do you think the asteroid belt stays within those distances? Answers may vary. Sample answer: The belt is held in place by the combined effects of the gravities of Mars, Jupiter, and the sun. 9. Evaluating Models If everyone in your class used a different scale for astronomical units, would the models be useful? Explain why or why not. Answers may vary. Sample answer: Location of the planets orbits do not change, so if the model is accurate all scales would be useful. 10. Evaluating Models Place the strips of paper tape created by all groups on the floor of the classroom laid out like the spokes of a bicycle wheel with the sun in the center of the hub. What do you observe? What does this do to the value of your models? Answers may vary. Sample answer: The value of the model increases since I will see the entire orbits of at least the outer planets to scale. Holt Earth Science 52 78 Planets of the Solar System