Moons and Rings Review Choose the best response. Write the letter of that choice in the space provided. 1. Dark areas on the moon that are smooth and reflect little light are called a. rilles. b. maria. c. rays. d. breccia. 2. Most of the information astronomers have gathered about the interior of the moon has come from a. telescopes. b. satellites. c. spectrographs. d. seismographs. 3. Soon after the moon formed, it was covered with a. water. b. anorthosites. c. frozen hydrogen. d. molten rock. 4. In the most recent stage in the development of the moon, a. the densest material sank to the core. b. the crust began to break. c. the earth s gravity captured the moon. d. the number of meteoroids hitting the moon decreased. 5. The moon is closest to the earth at a. new moon. b. full moon. c. perigee. d. apogee. 6. During each orbit around the earth, the moon spins on its axis a. 1 time. b. about 27 times. c. about 29 times. d. 365 times. 7. In a lunar eclipse, the moon a. casts a shadow on the earth. b. is in the earth s shadow. c. is between the earth and the sun. d. blocks part of the sun from view. 8. When the size of the visible portion of the moon is decreasing, the moon is a. full. b. annular. c. waxing. d. waning. 9. In the crescent phases, the entire moon shines dimly because of a. light produced by the earth. b. sunlight reflected off the earth. c. hydrogen fusion in the core of the moon. d. energy produced by the rotation of the moon. Study Guide 117
Choose the best response. Write the letter of that choice in the space provided. 10. The two moons of Mars are a. Io and Europa. b. Titan and Charon. c. Phobos and Deimos. d. Triton and Nereid. 11. Compared with the other moons of Jupiter, the four Galilean moons are a. larger. b. farther from Jupiter. c. denser. d. younger. 12. The rings of Saturn are probably composed of a. regolith. b. small pieces of black rock. c. several hundred small moons. d. billions of pieces of ice and rock. Critical Thinking 1. How would the craters on the moon be different today if the moon had developed an atmosphere that had wind and contained water? 2. If meteoroids had stopped hitting the moon before the outer surface of the moon cooled, why would the maria not have developed? 118 Study Guide
3. Suppose that the moon spun twice on its axis during each orbit around the earth. How would study of the moon from the earth be easier? 4. Venus does not cause a solar eclipse even though it passes between the earth and the sun. Instead, it appears as a black dot moving across the face of sun. Explain why this happens. 5. Would a satellite orbiting the earth go through phases like those of the moon? Explain your answer. Study Guide 119
Application 1. Your friend who just got a new telescope wants to look at Venus during its fullest phase. Explain why that is impossible. 2. Imagine a planet that orbits the sun in 100 days and has one moon. The moon goes through a complete set of phases in 20 days. On this planet, how many months would one year have? 3. Using any of the new terms listed on page 634 of your textbook, construct a concept map starting with the term Time. See how many terms you can include. 120 Study Guide
Pages 627 629: Class Activity (Extension) To extend students cultural awareness, have them find out about other calendars used today for example, the Chinese, Jewish, and Islamic calendars. Page 633: Discussion (Extension) To extend students knowledge of the moons of Uranus, tell them about the strangest of those moons, Miranda. Miranda is the innermost of the planet s five large moons and shows evidence of intense thermal activity. The surface of the moon has deep grooves arranged in concentric rings and intersecting lines with areas covered with ropelike marks. Although Miranda is only 485 kilometers in diameter, it has cliffs rising from the long faults on its surface that are ten times higher than those of the earth s Grand Canyon. Small-Scale Investigation Eclipses (p. 625) Science Process Skills: constructing models, observing, predicting outcomes Answers to Analysis and Conclusions 1. the earth; the moon; the sun 2. As viewed from the earth, the model produced a lunar eclipse. As viewed from the moon, the model produced a solar eclipse. 3. As viewed from the earth, the model produced a solar eclipse. As viewed from the moon, the model produced an eclipse of the earth. 4. In this model, there would be both a lunar and a solar eclipse each month. The eclipses would occur with this frequency because the model shows the earth and the moon orbiting in exactly the same plane around the sun. Actually, there is an angle of about 5 between the two orbits. As a result, the planets are usually above or below the shadow of the other, and an eclipse does not occur. Review Answers to Review 1. b 4.d 7. b 10. c 2. d 5. c 8. d 11. a 3. d 6. a 9. b 12. d Answers to Critical Thinking 1. Erosion would make the craters less evident. 2. The crust would not have been broken, allowing molten rock to flow onto the surface. 3. The entire moon would be visible from the earth at various times. 4. Venus is too far away from the earth for its shadow to reach the earth. 5. Yes, because the part of the satellite reflecting sunlight and facing the earth would change. Answers to Application 1. At its fullest phase, Venus would be behind the sun and hidden by its brightness. 2. five months 3. Student concept maps should connect new terms with appropriate linking words, indicating their understanding of the concepts within the chapter. In-Depth Investigation Galilean Moons of Jupiter (pp. 636 637) Approximate time: 2 class periods Objectives: to verify that the orbital motions of Jupiter s moons obey Kepler s third law Skills: measuring, recording, applying theoretical models, predicting Prelab Discussion Before students begin this investigation, it is very important that they understand Kepler s third law. Have students identify the variables and the constant in the equation. Review the use of exponents in recording very large numbers. Point out that Jupiter s four largest moons are called the Galilean Moons because they were discovered by Galileo Galilei, and their motions were used by him in support of a heliocentric solar system. Teaching Strategies 1. Students can do this investigation without a partner. However, if you do choose to have the students work in groups of two, try to pair a student proficient in math with one who is not as adept. 2. Have students practice reading the chart on page 636. Give them different dates and an approximate time of day, and have them identify the positions of the four moons at that time. T144