ast hw9 – Flashcards

1. Why are astronomers particularly interested in finding liquid water on a planet or moon? -It gives clues to the formation phase of a planet. -Liquid water is thought to be a necessary condition for the existence of life. -It points the way to possible colonization by humans. -It demonstrates the presence of tectonic activity. -It provides a source of fuel for future space missions to that planet or moon.

2. Which of the following describes planets that can best hold an atmosphere? -far from the sun; high surface gravity -far from the sun; low surface gravity -near the sun, high surface gravity -near the sun, low surface gravity

3. What is the principal origin of the atmospheres of the Terrestrial planets? -outgassing -impacts of gas-rich comets -impacts of gas-rich asteroids -the solar wind -breakdown of rocks in the crust as a result of weathering

4. The sweeping of atmospheric gas particles into space by the Sun is referred to as -a solar flare -solar wind stripping -evaporation -thermal escape

5. Smaller worlds are more prone to atmospheric loss than large worlds because they -have no plate tectonics -have weaker gravities -are more likely to be hit by asteroids -have less internal heat

6. The greenhouse effect is the -generation of heat in the outer layer of the atmosphere of the Earth due to absorption of short wavelength radiation -generation of heat in the ozone layer due to the absorption of ultraviolet radiation -release of heat by volcanism along tectonic plate boundaries -trapping of infrared radiation coming from the surface of the Earth by greenhouse gases like carbon dioxide, methane, and water

7. Why is the carbon dioxide cycle unable to easily correct for the increasing amounts of carbon dioxide introduced into our atmosphere by industrialization? -it operates far too slowly to correct for any short-term changes -pollution has stopped the carbon dioxide cycle from operating -the carbon dioxide cycle only influences carbon dioxide produced by natural sources -it operates far too quickly to correct for any short-term changes

8. Which of the following statements about the greenhouse effect is true? -A weak greenhouse effect operates on Mars. -burning of fossil fuels increases the greenhouse effect on Earth because of the release of carbon dioxide. -Without a naturally occurring greenhouse effect, the earth would be too cold to have liquid oceans. -One result of an increased greenhouse effect on Earth may be an increased number of severe storms. -All of the above are true.

9. What is the leading hypothesis for Venus's lack of water? -Venus formed closer to the Sun and accreted very little water. -Its water is locked away in the crust. -Its water molecules were broken apart, and hydrogen was lost to space.

10. The Earth's stratosphere is important for life on Earth because -it diminishes the level of greenhouse gasses in the atmosphere -its ozone layer prevents damaging ultraviolet radiation from reaching the Earth's surface -it makes possible the existence of liquid water on the planet -it shields the Earth from the solar wind

11. Most of the carbon dioxide of the Earth -has dissolved in the oceans and is locked up in sedimentary carbonate rocks like limestone -is present in the atmosphere -has escaped into space -has been destroyed in the atmosphere by solar radiation

12. The ancient water erosion features on the surface of Mars suggest that the planet must have had a much -warmer, thinner atmosphere in the past -cooler, thicker atmosphere in the past -cooler, thinner atmosphere in the past -warmer, thicker atmosphere in the past

13. The oxygen in Earth's atmosphere was originally released by -outgassing from volcanoes -plants -cyanobacteria.

14. Which terrestrial world has the most atmosphere? -Venus -Earth -Mars

15. The greenhouse effect occurs in the

16. What kind of light warms the stratosphere? -infrared -visible -ultraviolet

17. What kind of light warms the troposphere? -infrared -visible -ultraviolet

18. Which of the following is a strong greenhouse gas? -nitrogen -water vapor -oxygen

19. What kind of gas is most affected by thermal escape from an atmosphere? -greenhouse gases -light gases -heavy gases -all gases equally

20. About what fraction of Earth's atmosphere is carbon dioxide? -90% -1% -less than 0.1%