Question 1 Which of the following correctly lists the terrestrial worlds in order from the thickest atmosphere to the thinnest atmosphere? (Note: Mercury and the Moon are considered together in this question.) a. Venus, Earth, Mars, Moon/Mercury b. Venus, Mars, Moon/Mercury, Earth c. Mars, Venus, Earth, Moon/Mercury d. Earth, Venus, Mars, Moon/Mercury Question 2 Which planet(s) have an atmosphere that consists mostly of carbon dioxide? a. Venus, Earth, and Mars b. Venus and Mars c. Venus only d. Mars only Question 3 Which of the following is the most basic definition of a greenhouse gas? a. a gas that keeps warm air from rising, and therefore warms the surface b. a gas that absorbs infrared light c. a gas that reflects a lot of sunlight d. a gas that makes a planet much hotter than it would be otherwise, even in small amounts Question 4 Suppose that Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be _______. a. about the same as it is now b. slightly cooler, but still above freezing c. slightly warmer, but still well below the boiling point of water d. well below the freezing point of water Question 5 Why is the sky blue (on Earth)? a. because deep space is blue in color b. because molecules scatter red light more effectively than blue light. c. because molecules scatter blue light more effectively than red light d. No one knows—this is one of the great mysteries of science. e. because the Sun emits mostly blue light Question 6 Which of the following general statements about light and Earth's atmosphere is NOT true? a. Visible light from the Sun is absorbed in the exosphere. b. Ultraviolet from the Sun is absorbed in the stratosphere. c. Infrared light emitted by Earth itself is absorbed in the troposphere. d. X rays from the Sun are absorbed in the thermosphere. Question 7 Which terrestrial world has the most atmosphere? a. Earth b. Venus c. Mars Question 8 What kind of light warms the stratosphere? a. infrared b. visible c. ultraviolet Question 9 Which of the following is a strong greenhouse gas? a. nitrogen b. water vapor c. oxygen Question 10 What important change in the Sun over the past four billion years is thought to be very important to understanding the climates of Venus, Earth, and Mars? a. a gradual dimming with time b. a gradual brightening with time c. a gradual weakening of the solar wind with time d. a gradual reduction in the amount of ultraviolet and X-ray radiation coming from the Sun Question 11 What is the leading hypothesis for Venus’s lack of water? a. Venus formed closer to the Sun and accreted very little water. b. Its water is locked away in the crust. c. Its water molecules were broken apart, and hydrogen was lost to space. Question 12 Which planet experiences the greatest change between its actual day temperature and actual night temperature? a. Earth b. Venus c. Mars d. Mercury Question 13 X rays from the Sun's corona a. are absorbed in Earth's thermosphere. b. cause meteor showers. c. break apart ozone in the stratosphere. d. generally reach Earth's surface and fry us. e. are absorbed in Earth's troposphere. Question 14 What is the troposphere? a. the part of the atmosphere that absorbs X rays b. the highest layer in the atmosphere c. the part of the atmosphere that absorbs optical light d. the part of the atmosphere that absorbs ultraviolet e. the lowest layer in the atmosphere Question 15 Why does Mars have more extreme seasons than Earth? a. because it is farther from the Sun b. because it has a larger axis tilt c. because it has more carbon dioxide in its atmosphere d. because it has a more eccentric orbit in addition to its tilt e. all of the above Question 16 Winter and summer differ in length on Mars because of its elliptical orbit. True False Question 17 What causes the release of oxygen into Earth’s atmosphere? a. evaporation/sublimation b. photosynthesis c. outgassing Question 18 Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury? a. They have thin tropospheres only, with gas coming from evaporation and sublimation. b. They have thin exospheres only, with gas coming from impacts of subatomic particles and photons. c. They have very thin atmospheres produced by outgassing but still have the layers of a troposphere, thermosphere, and exosphere. d. They have only small amounts of gas, all of which is left over from outgassing long ago. Question 19 Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history? a. the fact that Earth's climate can be affected by changes in its axis tilt b. the fact that Earth apparently got a lot of atmospheric gas from outgassing by volcanoes c. the fact that the temperature of our planet has remained relatively steady throughout our planet's history d. the fact that Earth had enough water to form oceans Question 20 Which of the following is NOT an expected consequence of global warming? a. warming up of the entire Earth by the same amount b. an increase in the severity of winter blizzards c. melting of polar ice and glaciers d. an increase in the number and intensity of hurricanes