Name ______________________________ Class ___________________ Date __________________ Skills Worksheet Directed Reading B (Lesson 21-3) Section: The Outer Planets Circle the letter of the best answer for each question. 1. What is one way that gas giants differ from the terrestrial planets? a. They are much smaller. b. They are rocky and icy. c. They are made mostly of gases. d. They have hard surfaces. 2. Which outer planet is farthest from the sun? a. Neptune b. Jupiter c. Saturn d. Uranus JUPITER: A GIANT AMONG GIANTS 3. Which is the largest planet in our solar system? a. Jupiter b. Earth c. Saturn d. Neptune 4. Which gases is Jupiter made of? a. mainly oxygen and nitrogen b. mainly organic compounds c. mainly hydrogen and helium d. mainly water and carbon dioxide Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 29 A Family of Planets Name ______________________________ Class ___________________ Date __________________ Directed Reading B continued Circle the letter of the best answer for each question. 5. What is unusual about Jupiter’s energy supply? a. It gets energy from the sun. b. It gives off more energy than it takes in. c. It gets energy from its moons. d. It gets energy from a neutron star. 6. What is Jupiter’s Great Red Spot? a. thick clouds b. colorful compounds c. metallic hydrogen d. a huge storm system NASA Missions to Jupiter 7. What new information did Voyager bring back about Jupiter? a. details about its weather b. facts about its temperature c. images of its system d. facts about its makeup SATURN: STILL FORMING 8. Where does Saturn’s “extra energy” seem to come from? a. nuclear reactions b. helium sinking to the core c. volcanic activity d. powerful storm systems Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 30 A Family of Planets Name ______________________________ Class ___________________ Date __________________ Directed Reading B continued Circle the letter of the best answer for each question. The Rings of Saturn 9. What are Saturn’s rings made of? a. rocks and dust b. iron and metals c. different sized bits of ice d. organic compounds NASA’s Exploration of Saturn 10. Which spacecraft was sent in 1997 to study Saturn and its moons? a. Cassini b. Galileo c. Pioneer d. Voyager URANUS: A SMALL GIANT 11. How does the chemical makeup of Uranus differ from that of other gas giants? a. Uranus is made of lighter elements. b. Uranus is made of heavier materials. c. Uranus is mainly hydrogen and helium. d. Uranus is mainly organic compounds. 12. Who discovered the planet Uranus? a. Isaac Newton b. Galileo Galilei c. William Herschel d. Voyager Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 31 A Family of Planets Name ______________________________ Class ___________________ Date __________________ Directed Reading B continued A Tilted Planet Circle the letter of the best answer for each question. 13. What is unusual about Uranus’s axis? a. The planet is tipped on its side. b. The axis is tipped at an angle of 45°. c. The axis is tipped at an angle of 65°. d. The planet’s poles are reversed. 14. What do scientists think may have caused Uranus’s tilt? a. Uranus escaped Jupiter’s gravity. b. Uranus’s moons had a cosmic tug of war. c. Uranus was pulled by Saturn’s gravity. d. Uranus was struck by a large object. NEPTUNE: THE BLUE WORLD 15. Why did early astronomers believe there was another planet beyond Uranus? a. Uranus’s orbit is not regular. b. Uranus does not have gravity. c. Neptune’s orbit is not regular. d. Neptune does not have gravity. 16. What is released from inside Neptune that helps make belts of clouds? a. water b. nuclear fission c. nitrogen gas d. thermal energy Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 32 A Family of Planets Name ______________________________ Class ___________________ Date __________________ Directed Reading B continued Circle the letter of the best answer for each question. 17. Where did the images of Neptune’s very narrow rings come from? a. Cassini b. Sojourner c. Voyager 1 d. Voyager 2 PLUTO: A DWARF PLANET A Small World 18. Based on its density, what materials does Pluto seem to be made of? a. hydrogen and helium b. mainly organics and ice c. hydrogen and water d. rock and ice 19. What is unusual about Pluto’s moon? a. Its orbit is not regular. b. It is more than half the size of Pluto. c. It is about the same size as Pluto. d. It is denser than Pluto. 20. Pluto is covered by frozen a. water. b. helium. c. nitrogen. d. methane. Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 33 A Family of Planets Name ______________________________ Class ___________________ Date __________________ Directed Reading B continued Other Dwarf Planets Circle the letter of the best answer for each question. 21. Since 2006, how has Pluto been classified? a. as a planet b. as a gas giant. c. as a moon d. as a dwarf planet 22. Which of the following is not classified as a dwarf planet? a. Eris b. Charon c. Ceres d. Pluto Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor. Holt Science and Technology 34 A Family of Planets .