Moons, Rings, and Relationships

Transcription

1 Names Moons, Rings, and Relationships Materials Rubber ball Paper, markers, pencils Procedure Part I: What Do We Know about Objects in Orbit? 1. In your group, discuss, predict, and draw what they think will happen to a ball after it rolls off the edge of a table first when it s rolling slowly, then when it s rolling quickly. Record your answers below. 2. To test your prediction, your assignment is to develop an experiment that tests your prediction. You will be using a rubber ball for your experiment. Attach a copy of your experiment to this paper. Make sure you explain why your ball follows the path it does.. Look a Figure 1. Imagine an enlarged mountain on Earth with a baseball player on top who hits a pitched ball from space. The mountain is very high and that most of the atmosphere is below the top of the mountain. What happens when the baseball player hits the ball? Why does ball follow the path it does? Why doesn t the hit baseball fly off into space? What would happen if the player hits the baseball harder? Record your answers.

2 4. Look at Figure 2. Predict what would happen if a cannonball were to be blown out of the cannon with more and more force? Record your answer. 5. What keeps Earth s Moon in orbit? Record your answer. Part IIa: Making Connections to Saturn the Nature of the Rings 1. What orbits Saturn? What do you know about the orbits of these objects? Record your answers. 2. Look at Figure (an illustration a close-up view of Saturn s rings, a ring particle, and a house). Develop explanations about the illustration. How do you think the individual particles of Saturn s rings move? Record your answers.

3 Part IIb: Making Connections to Saturn Orbital Speed 1. How is the speed the rings and moons move around Saturn different? Does it depend on the mass of the orbiting object? Does it depend on the distance of the orbiting body (moon or ring particle) from the Saturn? Record your answers. 2. You will test your ideas (hypotheses) about orbital speed will be tested by graphing the orbital speeds of some of Saturn s moons and also ring particles at the inner and outer edges of the A ring. Using Figures 4 & 6, complete the graph comparing orbital speed vs. distance from center of Saturn.. Once complete, explain how orbital speed changes as you go farther from the center of Saturn? Part III: Assessment Each person in your group will complete the assignment worksheet. You may discuss them with other group members. Staple the papers to this worksheet.

4 Names Moons, Rings, and Relationships 1. Write a description of the forces that keep the planets and asteroids of our Solar System in orbit about the Sun. 2. Write down your predictions how the orbital speed of the planets in our Solar System changes with distance from the center of the Sun.. Interpret the graph (Orbital Speed vs. Distance from Sun) and write a summary of your discoveries about orbital speed. (How does orbital speed depend on distance from the center of Saturn? For a given distance from the center of Saturn, does the orbital speed depend on mass or size? ) 4. Compare your group s conclusions with your initial predictions, writing down how your ideas changed.

5 Baseball Player Hitting a Baseball Pitched from Space L E S S O N Figure 1 75

6 Cannon Shooting a Cannonball L E S S O N Figure 2 77

7 L E S S O N Wm. K. Hartmann Figure 79 Saturn Educator Guide Cassini Program website EG JPL

8 Moon and A Ring Data for Students L E S S O N Figure 4 Use this information to complete your plot of Orbital Speed vs. Distance from Center of Saturn. Distance from Center Speed of Moon Moon or Ring Special Features or Behavior of Saturn (10 km) in Orbit (km/sec) A Ring Forms outer edge of Cassini Division Inner Edge Pan Orbits in Encke Gap, sweeping it clean A Ring Guarded in its outer edge by the moon Atlas Outer Edge Atlas May keep the outer edge of the A ring well defined Pandora Shepherd moon; helps keep the F ring narrow Epimetheus Irregular; may have been joined with Janus Mimas Has giant crater called Herschel; looks like Death Star moon Enceladus Icy, shiny; may have ice geysers that feed E ring Tethys Has large trench called Ithaca Chasma; large crater called Odysseus Telesto Same orbit as Tethys (60º behind); less massive than Tethys Dione Cratered leading face; wispy features on trailing hemisphere Rhea Largest icy satellite; densely cratered

9 L E S S O N Orbital Speed vs. Distance from Center of Saturn for Students to Complete Figure 5 18 Orbital Speed vs. Distance from Center of Saturn DISTANCE FROM CENTER OF SATURN (10 km) ORBITAL VELOCITY (km/sec) 8

10 L E S S O N Figure 6 Moon and A Ring Data for the Teacher (shading shows items for students to plot) Use this information to complete your plot of Orbital Speed vs. Distance from Center of Saturn. Distance from Center Speed of Moon Moon or Ring Special Features or Behavior of Saturn (10 km ) in Orbit (km/sec) A Ring Forms outer edge of Cassini Division Inner Edge Pan Orbits in Encke Gap, sweeping it clean A Ring Guarded in its outer edge by the moon Atlas Outer Edge Atlas May keep the outer edge of the A ring well defined Prometheus Shepherd moon; helps keep the F ring narrow Pandora Shepherd moon; helps keep the F ring narrow Epimetheus Irregular; may have been joined with Janus Janus Irregular; trades orbits with Epimetheus Mimas Has giant crater called Herschel; looks like Death Star moon Enceladus Icy, shiny; may have ice geysers that feed E ring Tethys Has large trench called Ithaca Chasma; large crater called Odysseus Telesto Same orbit as Tethys (60º behind); less massive than Tethys Calypso Same orbit as Tethys (60º ahead); less massive than Tethys Dione Cratered leading face; wispy features on trailing hemisphere Helene Same orbit as Dione (60º ahead); less massive than Dione Rhea Largest icy satellite; densely cratered

11 L E S S O N Figure 7 Orbital Speed vs. Distance from Center of Saturn Completed Plot for Teacher Orbital Speed vs. Distance from Center of Saturn A RING INNER EDGE 18 DISTANCE FROM CENTER OF SATURN (10 km) A RING OUTER EDGE PANDORA PAN ATLAS EPIMETHEUS AND JANUS MIMAS ENCELADUS TETHYS, TELESTO, AND CALYPSO DIONE AND HELENE RHEA ORBITAL VELOCITY (km/sec) 87

12 Solar System Data for Students L E S S O N Figure 8 Use this chart to plot Orbital Speed vs. Distance from Sun. Object Distance from Orbital Speed Mass Diameter Sun ( 10 6 km) (km/sec) ( kg) (km) Venus ,104 Earth ,756 Mars ,794 Asteroid Ceres Unknown 1,000 Jupiter , ,984 89

13 L E S S O N Figure 9 Orbital Speed vs. Distance from Sun for Students to Complete 40 Orbital Speed vs. Distance from Sun DISTANCE FROM THE SUN (10 6 km) ORBITAL VELOCITY (km/sec) 91

14 Orbital Speed vs. Distance from Sun Completed Plot for Teacher L E S S O N Figure 10 Orbital Speed vs. Distance from Sun VENUS EARTH MARS 40 DISTANCE FROM THE SUN (10 6 km) CERES JUPITER ORBITAL VELOCITY (km/sec) 9