Astro 1010 Planetary Astronomy Sample Questions for Exam 4 Chapter 8 1. Which of the following processes is not important in shaping the surface of terrestrial planets? a) Impact cratering b) Tectonism c) Volcanism d) Condensation 2. Impact cratering a) is important on all solid bodies in the solar system. b) has never been a significant factor in shaping the Earth s surface. c) was important in shaping Earth s surface long ago but isn t any more. d) is the dominant process in shaping Earth s current surface. 3. If a planetary body is found with large numbers of craters it a) has a cold, solid or near solid interior with little or no geologic activity. b) has a hot, molten interior with lots of geologic activity. c) may have a cold or hot interior, we cannot tell from the cratering of the surface. 4. The cratering rate on terrestrial planets has a) remained constant since the bodies formed 4.5 billion years ago. b) has steadily increased since the bodies formed 4.5 billion years ago. c) rapidly decreased in the first two billion years after formation and then slowly decreased since then. d) slowly decreased in the first two billion years after formation and then rapidly decreased since then. 5. By counting the density of impact craters on a surface it is possible to determine a) the absolute age of the surface. b) the relative age of the surface. c) the chemical composition of the surface. d) the temperature of the surface. 6. The dominant mechanism for heat flow in the Earths interior is a) convection. b) conduction. c) radiation.
7. In the Giant Impact model for the formation of the moon a) a Mars sized protoplanet struck the proto-earth in a glancing collision and much of the vaporized mantle material eventually condensed to form the moon while the two cores merged into the new Earth. b) a Venus sized protoplanet collided head-on with the proto-earth and two new objects, the Earth and the Moon, condensed out of the debris from the collision. c) the earth and the moon both formed in separate orbits and the Earth captured the moon after a near-miss between the two. d) a protoplanet slightly smaller than the moon struck the proto-earth, gouged out some mantle material from the Earth (the Pacific ocean basin) and bounced off only to be captured again by the Earth. 8. Earth s magnetic field is a) very weak and has not changed since the earth was formed. b) very strong and reverses polarity every few centuries. c) of moderate strength and is due to currents in the liquid outer core. d) is perfectly aligned with the rotation axis of the earth. 9. The magnetosphere of Venus is a) very strong and created by currents in the molten outer core. b) extremely weak and created by ionization of the upper atmosphere by solar radiation and the solar wind. c) the highest layer in the planets atmosphere. d) the innermost layer of the interior of the planet. 10. We learn about the interior structure of the Earth by a) Drilling deep wells all the way down into the core of the planet. b) Building manned drilling ships that bore down into the deep interior of the planet. c) Observing seismic waves at multiple locations around the planet and how they travel through layers of different characteristics. d) Traveling through the interior in deep caves that go down to the core 11. The theory of plate tectonics holds that a) the crust is broken into plates which slide over the mantle, colliding and rubbing against each other. b) the crust is an unbroken solid that never changes. c) every few billion years the crust melts and reforms into new continents. d) the crust used to move and change but it doesn t any more. 12. Which of the following does not occur at the boundary between crustal plates? a) Earthquakes. b) Volcanoes. c) Subduction. d) Impact craters.
13. Tectonics on Venus a) ended billions of years ago. b) is very similar to plate tectonics on Earth. c) is probably active in some way but how is not well understood. d) is very similar to the one-plate tectonics of Mars. 14. Tectonics on Mars a) ended billions of years ago. b) is similar to plate tectonics on Earth. c) is very similar to the one-plate tectonics on Venus. d) was very active one-plate tectonics but has decreased to very low levels now. 15. Gradation processes on the Moon and Mercury are a) extremely slow and due mainly to bombardment by the solar wind and meteorites. b) extremely strong and due mainly to erosion by flowing water and strong winds. c) completely non-existent. 16. The most important current mechanism for gradation on Mars and Venus a) is erosion by flowing water. b) is erosion by wind. c) is erosion by bombardment from meteorites and the solar wind. d) None of the above, there is no current gradation on Mars and Venus. Short Answer Questions 1. Describe the four processes which are important in shaping the surface of a terrestrial planet. Give examples of each process. 2. Briefly describe the current theory of how the Moon formed. How did the evidence found in the Apollo moon rocks convince scientists that this is how the Earth got its moon? 3. Briefly describe the theory of plate tectonics. How has it influenced the shape of the continents, what is the driving force behind it, what are some of the activities associated with it? 4. Briefly describe the source of Earth s magnetic field, its interaction with the solar wind and its long term variation. 5. Briefly describe some of the surface features found on Venus. What kinds of rock do we suspect are found on the surface? What kind of tectonics might exist on the planet? 6. Describe the general topography of Mars and some of the largest features found on the surface of Mars. Discuss the tectonics that lead to the creation of the major surface features.
Chapter 9 1. The primary atmosphere of the terrestrial planets was a) mostly hydrogen and helium. b) mostly CO2 and nitrogen. c) mostly nitrogen and oxygen. d) mostly argon and neon. 2. The secondary atmospheres of the terrestrial planets is or was a) mostly hydrogen and helium. b) mostly CO2 and nitrogen. c) mostly nitrogen and oxygen. d) mostly argon and neon. 3. The atmosphere of Venus is a) 78% nitrogen, 20% oxygen and traces of others. b) 96% carbon dioxide, <4% nitrogen and traces of others. c) almost entirely sulfuric acid. d) 80% hydrogen, 19% helium and traces of others. e) None of the above, Venus doesn t have an atmosphere. 4. The Martian atmosphere is a) 95% CO2, 3% N2 with traces of water, argon, O2 and CO. b) very thin with the surface pressure being only 0.007 atmospheres. c) similar in composition to the atmosphere of Venus but much thinner. d) fairly active with high winds and thin clouds but no rain. e) All of the above. 5. The clouds of Venus are a) at very low altitudes, from the surface up to a few kilometers. b) over 100 km thick. c) cover most (but not all) of the planet. d) mostly droplets and crystals of sulfuric acid. 6. The layers of Earth s atmosphere from the ground up are a) the stratosphere, the mesosphere, the thermosphere and the troposphere. b) the mesosphere, the thermosphere, the troposphere and the stratosphere. c) the stratosphere, the troposphere, the thermosphere and the mesosphere. d) the troposphere, the stratosphere, the mesosphere and the thermosphere. 7. The level of carbon dioxide in the Earth s atmosphere is a) decreasing due an increase in the amount of life on the planet. b) staying the same. c) increasing because of the burning of fossil fuels by man. d) so small and insignificant that no one needs to worry about it.
8. The greenhouse effect heats the atmosphere because a) more sunlight gets reflected away. b) infrared radiation gets trapped by the atmosphere. c) more sunlight gets in. d) clouds cannot form because of the greenhouse effect. e) None of the above. 9. Which of the following is not influencing the evolution of the earth s atmosphere? a) life. b) meteorite impacts. c) volcanism. d) Man. e) All of the above influence Earth s atmosphere. 10. Almost all of the weather that occurs on Earth is in the a) troposphere. b) thermosphere. c) stratosphere. d) magnetosphere. e) None of the above, the Earth has no weather. 11. The Earth s magnetic field is a) very weak and has not changed since the earth was formed. b) very strong and reverses polarity every few centuries. c) of moderate strength and is due to currents in the liquid outer core. d) is perfectly aligned with the rotation axis of the earth. 12. On the surface of Venus a) the temperature is over 800 F. b) the air pressure is almost 90 atmospheres. c) the winds are relatively calm. d) it never rains. e) All of the above. 13. The high temperature on the surface of Venus is probably due to a) the cloud cover blocking the outgoing heat from escaping. b) an internal energy source, possibly nuclear reactions in the planets core. c) the large amount of fire and brimstone on the surface. d) the high concentration of CO2 in the atmosphere trapping the heat in a greenhouse effect. 14. Scientist think that most of Mars water a) is locked in the polar icecaps and permafrost below the surface. b) is found in the thick clouds which completely cover the planet. c) fills the numerous lakes and rivers found on the planet. d) is in the large ocean that now covers the northern hemisphere.
Short Answer Questions 1. Describe the greenhouse effect, its cause and possible consequences on Earth, Venus and Mars. 2. Use words and a diagram to describe Earth s atmosphere from the ground to space. Include information about how the temperature, density and composition changes with altitude. 3. Describe the origin and evolution of Earth s atmosphere. How has its elemental composition changed over time and what has caused the changes. 4. Briefly describe the surface conditions on Venus (temperature, pressure, winds, weather, etc.) 5. Briefly describe the atmosphere of Venus from the above the top of the clouds all the way down to the surface. Include a discussion of how the greenhouse effect has created the surface conditions found on Venus. 6. Describe the atmosphere of Mars. How does it change with the seasons? What kinds of storms, if any, are there on Mars? What are some of the causes of the weather on Mars?