Astronomy Exam 2
What are greenhouse gases? A) gases that absorb visible light B) gases that absorb ultraviolet light C) gases that absorb infrared light D) gases that transmit visible light E) gases that transmit infrared light
C) gases that absorb infrared light
Volcanism is more likely on a planet that A) is closer to the Sun. B) is struck often by meteors and solar system debris. C) has high internal temperatures. D) doesn't have an atmosphere or oceans.
C) has high internal temperatures.
Ridges in the middle of the ocean are places where A) one plate slides under another, returning older crust to the mantle. B) hot mantle material rises upward, creating volcanic islands. C) hot mantle material rises upward and spreads sideways, pushing the plates apart. D) plates push together, creating ocean mountain chains. E) plates slip sideways relative to one another.
C) hot mantle material rises upward and spreads sideways, pushing the plates apart.
What is the most important factor that determines the thickness, and therefore strength, of the lithosphere? A) pressure B) composition C) internal temperature D) distance of planet from Sun
C) internal temperature
Which of the following has virtually no effect on the internal structure of a planet? A) its composition B) its size C) its magnetic field D) its mass
C) its magnetic field
There are no auroras on Venus because it A) lacks atmospheric oxygen. B) is too hot. C) lacks a strong magnetic field. D) lacks strong winds.
C) lacks a strong magnetic field.
Spacecraft have landed on all the terrestrial worlds except A) Mercury. B) Venus. C) Moon. D) Mars.
A) Mercury.
Which two geological processes appear to have been most important in shaping the present surface of Venus? A) impacts and volcanoes B) impacts and tectonics C) tectonics and erosion D) volcanoes and tectonics E) volcanoes and erosion
D) volcanoes and tectonics
A planet is most likely to have tectonic activity if it has A) low surface gravity. B) high surface gravity. C) low internal temperature. D) high internal temperature. E) a dense atmosphere.
D) high internal temperature.
Valles Marineris is a(n) A) large valley on the Moon. B) extensive plain on Mars. C) huge series of cliffs on Mercury. D) large canyon on Mars. E) large canyon on Venus.
D) large canyon on Mars.
Suppose Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be A) -16°C, which is well below freezing. B) 0°C, or about the freezing point of water. C) 10°C or about 5°C cooler than it is now. D) 15°C, or about the same as it is now. E) 20°C, or about 5°C warmer than it is now.
A) -16°C, which is well below freezing.
The greenhouse effect makes Earth warmer than it would be otherwise by about A) 30 K. B) 15 K. C) -16 K. D) There is no greenhouse effect.
A) 30 K.
If the Earth were to warm up a bit, what would happen? A) Carbonate materials would form in the oceans more rapidly, the atmospheric CO2 content would decrease, and the greenhouse effect would weaken. B) Carbonate materials would form in the oceans more rapidly, the atmospheric CO2 content would increase, and the greenhouse effect would strengthen. C) Carbonate materials would form in the oceans more rapidly, the atmospheric CO2 content would decrease, and the greenhouse effect would strengthen. D) There would be a runaway greenhouse effect, with the Earth becoming ever hotter until the oceans evaporated (as many have happened on Venus). E) The ice caps would melt and cool the Earth back to its normal temperature.
A) Carbonate materials would form in the oceans more rapidly, the atmospheric CO2 content would decrease, and the greenhouse effect would weaken.
Why is continental crust lower in density than seafloor crust? A) Continental crust is made from remelted seafloor crust and therefore only the lower-density materials rises to form it. B) Continental crust is made from volcanic rock called basalt, which is lower in density than what the seafloor crust is made from. C) Continental crust is made of rock, while seafloor crust has more metals. D) Seafloor crust is more compact due to the weight of the oceans, but it is made of the same material as the continental crust. E) Continental crust is actually denser than seafloor crust.
A) Continental crust is made from remelted seafloor crust and therefore only the lower-density materials rises to form it.
Why can we NOT depend on the natural CO2 cycle to lower carbon-dioxide levels? A) It operates too slowly. B) It only removes small amounts of CO2 from the atmosphere. C) There is no natural CO2 cycle.
A) It operates too slowly.
How did the lunar maria form? A) Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins. B) The early bombardment created heat that melted the lunar surface in the regions of the maria. C) Volatiles escaping from the Moon's interior heated and eroded the surface in the regions of the maria. D) The giant impact that created the Moon left smooth areas that we call the maria. E) The maria are the result of gradual erosion by micrometeorites striking the Moon.
A) Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins.
Which of these upcoming observations will help test the idea that Mars' atmosphere thinned due to interactions with the solar wind? A) The upcoming MAVEN orbiter will measure present-day gas loss from Mars' atmosphere. B) The Curiosity rover will measure the carbon content of rocks on Mars' surface. C) Astronomers will use spectrographs on the Keck telescope to measure the density of Mars' atmosphere. D) Geologists will measure the carbon content of Martian rocks that were transported to Earth by asteroid impacts.
A) The upcoming MAVEN orbiter will measure present-day gas loss from Mars' atmosphere.
Why would the weather become more severe as the greenhouse effect increased? A) Warming would increase the evaporation of the oceans, leading to more water in the atmosphere and more frequent and severe storms. B) Warming of the planet would lead to terrible droughts and reduce the amount of water on the Earth. C) Warming would dry out the atmosphere and the crust, leading to devastation of the Earth through more meteor bombardment and volcanism. D) The depleted ozone layer would let in more particles from the solar wind. E) all of the above
A) Warming would increase the evaporation of the oceans, leading to more water in the atmosphere and more frequent and severe storms.
How fast do tectonic plates move on Earth? A) a few centimeters per year B) a few centimeters per century C) a few kilometers per century D) quite fast, but only during earthquakes E) about 1 mile per hour
A) a few centimeters per year
What drives the motion of the continental plates on Earth? A) convection cells in the mantle B) rotation of the liquid core C) lava flows in trenches along the sea floor D) Earth's magnetic field E) tidal forces
A) convection cells in the mantle
Deep trenches in the ocean mark places where A) one plate slides under another, returning older crust to the mantle. B) plates pull apart, leaving great rifts in the crust. C) hot mantle material rises upward and spreads sideways, pushing the plates apart. D) plates push together, creating ocean mountain chains E) plates slip sideways relative to one another.
A) one plate slides under another, returning older crust to the mantle.
From where did the oxygen in the Earth's atmosphere originate? A) photosynthesis from plant life and single-celled organisms B) chemical reactions between gas in the upper atmosphere and the solar wind C) outgassing from volcanoes D) atmospheric bombardment E) oxidation of the surface rocks
A) photosynthesis from plant life and single-celled organisms
Which of the following describes impact cratering? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface
How deep is an impact crater compared to its width? A) 1-10% B) 10-20% C) 30-40% D) 50-100% E) 100-200%
B) 10-20%
The CO2 concentration in the atmosphere has increased by about ________ since 1750. A) 10 parts-per-million B) 100 parts-per-million C) 1000 parts-per-million D) None. It has decreased.
B) 100 parts-per-million
The CO2 concentration of the atmosphere has increased by about ________ since 1750. A) 2.5% B) 25% C) 250% D) None. It has decreased.
B) 25%
In the greenhouse effect, what is the direct cause of extra heating of the Earth's surface? A) Additional carbon dioxide makes the atmosphere more transparent to infrared light, allowing the sun to more directly heat the surface. B) Additional carbon dioxide makes the atmosphere more opaque to infrared light, trapping part of the blackbody radiation that would normally escape into space. C) Additional carbon dioxide makes the atmosphere denser, and thus heat passes through it more slowly.
B) Additional carbon dioxide makes the atmosphere more opaque to infrared light, trapping part of the blackbody radiation that would normally escape into space.
Why does the burning of fossil fuels increase the greenhouse effect on Earth? A) Burning fuels warms the planet. B) Burning releases carbon dioxide into the atmosphere. C) Burning depletes the amount of ozone, thereby warming the planet. D) Burning produces infrared light, which is then trapped by existing greenhouse gases. E) All of the above are true.
B) Burning releases carbon dioxide into the atmosphere.
Of the four gases CO2, H2O, N2, and O2, which are greenhouse gases? A) only CO2 B) CO2 and H2O C) CO2 and N2 D) all except O2 E) all four
B) CO2 and H2O
Which of the terrestrial worlds has the strongest magnetic field? A) Mars B) Earth C) the Moon D) Venus E) Mercury
B) Earth
Which of the following best describes convection? A) It is the process by which rocks sink in water. B) It is the process in which warm material expands and rises while cool material contracts and falls. C) It is the process in which warm material gets even warmer and cool material gets even cooler. D) It is the process in which a liquid separates according to density, such as oil and water separating in a jar. E) It is the process in which bubbles of gas move upward through a liquid.
B) It is the process in which warm material expands and rises while cool material contracts and falls.
Which of the following most likely explains why Venus does NOT have a strong magnetic field? A) It does not have a metallic core. B) Its rotation is too slow. C) It is too close to the Sun. D) It is too large. E) It has too thick an atmosphere.
B) Its rotation is too slow.
Why is Mars red? A) It is made primarily of red clay. B) Its surface rocks were rusted by oxygen. C) Its atmosphere scatters blue light more effectively than red light. D) Its surface is made of ices that absorb blue light. E) Its surface is made of ices that absorb red light.
B) Its surface rocks were rusted by oxygen.
Why do we think Mercury has so many tremendous cliffs? A) They were probably carved in Mercury's early history by running water. B) They were probably formed by tectonic stresses when the entire planet shrank as its core cooled. C) They probably formed when a series of large impacts hit Mercury one after the other. D) They are almost certainly volcanic in origin, carved by flowing lava. E) They represent one of the greatest mysteries in the solar system, as no one has suggested a reasonable hypothesis for their formation.
B) They were probably formed by tectonic stresses when the entire planet shrank as its core cooled.
Which of the following worlds has the most substantial atmosphere? A) Mercury B) Venus C) the Moon D) Mars E) Earth
B) Venus
The three principal sources of internal heat of terrestrial planets are A) conduction, differentiation, and accretion. B) accretion, differentiation, and radioactivity. C) accretion, differentiation, and eruption. D) convection, differentiation, and eruption. E) conduction, convection, and eruption.
B) accretion, differentiation, and radioactivity.
Which of these is the dominant mechanism for the removal of carbon dioxide from the atmosphere? A) subduction B) dissolving carbon dioxide in seawater C) photosynthesis in plants D) formation of carbonate-rich rocks at the seafloor
B) dissolving carbon dioxide in seawater
Where is most of the water on Mars? A) in its clouds B) in its polar caps and subsurface ground ice C) frozen on the peaks of its tall volcanoes D) in deep underground deposits E) distributed evenly throughout its atmosphere
B) in its polar caps and subsurface ground ice
Sunsets are red because A) the Sun emits more red light when it's setting. B) sunlight must pass through more atmosphere, and this scatters even more light at bluer wavelengths, transmitting mostly red light. C) sunlight must pass through more atmosphere, and this scatters more light at red wavelengths than bluer wavelengths. D) the cooler atmosphere in the evening absorbs more blue light. E) none of the above
B) sunlight must pass through more atmosphere, and this scatters even more light at bluer wavelengths, transmitting mostly red light.
Which of the following describes volcanism? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
B) the eruption of molten rock from a planet's interior to its surface
The relatively few craters that we see within the lunar maria A) were formed by impacts that occurred before those that formed most of the craters in the lunar highlands. B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands. C) were created by the same large impactor that led to the formation of the maria. D) are volcanic in origin, rather than from impacts. E) are sinkholes that formed when sections of the maria collapsed.
B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands.
How large is an impact crater compared to the size of the impactor? A) the same size B) 10-20 percent larger C) 10 times larger D) 100 times larger E) 1,000 times larger
C) 10 times larger
Given the current emission rate of carbon dioxide, how much will the Earth's average temperature increase over the next century? A) 0°C B) 0-3°C C) 3-5°C D) 5-7°C E) 7-10°C
C) 3-5°C
Why does Earth have the strongest magnetic field among the terrestrial worlds? A) It is the only one that has a metallic core. B) It rotates much faster than any other terrestrial world. C) It is the only one that has both a partially molten metallic core and reasonably rapid rotation. D) It is by far the largest terrestrial world. E) It is the most volcanically active world.
C) It is the only one that has both a partially molten metallic core and reasonably rapid rotation.
Mars' atmosphere is mostly carbon-dioxide. Why does it NOT experience a runaway greenhouse effect like Venus? A) It is protected by its magnetic field. B) It does not have enough additional water to magnify the warming. C) Its atmosphere is too thin.
C) Its atmosphere is too thin.
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 a more eccentric orbit D) because it has more carbon dioxide in its atmosphere E) all of the above
C) because it has a more eccentric orbit
The terrestrial planet cores contain mostly metal because A) the entire planets are made mostly of metal. B) metals condensed first in the solar nebula and the rocks then accreted around them. C) metals sank to the center during a time when the interiors were molten throughout. D) radioactivity created metals in the core from the decay of uranium. E) convection carried the metals to the core
C) metals sank to the center during a time when the interiors were molten throughout.
The footprints left on the moon by the Apollo astronauts will likely last for A) no time; they were quickly erased by micrometeorites. B) a few decades. C) millions of years. D) the remaining existence of the Moon.
C) millions of years.
Which of the following is NOT a product of outgassing? A) water B) nitrogen C) oxygen D) carbon dioxide
C) oxygen
What process has shaped Earth's surface more than any other? A) impact cratering B) volcanism C) plate tectonics D) wind erosion E) acid rain
C) plate tectonics
What type of stresses broke Earth's lithosphere into plates? A) impacts of asteroids and planetesimals B) internal temperature changes that caused the crust to expand and stretch C) the circulation of convection cells in the mantle, which dragged against the lithosphere D) cooling and contracting of the planet's interior, which caused the mantle and lithosphere to be compressed E) volcanism, which produced heavy volcanoes that bent and cracked the lithosphere
C) the circulation of convection cells in the mantle, which dragged against the lithosphere
Which of the following describes tectonics? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
C) the disruption of a planet's surface by internal stresses
The lithosphere of a planet is the layer that consists of A) material above the crust. B) material between the crust and the mantle. C) the rigid rocky material of crust and uppermost portion of the mantle. D) the softer rocky material of the mantle. E) the lava that comes out of volcanoes.
C) the rigid rocky material of crust and uppermost portion of the mantle.
Which of the following show evidence of ancient river beds? A) the Moon B) Mercury C) Venus D) Mars E) all of the above
D) Mars
Rank the five terrestrial worlds in order of size from smallest to largest. A) Mercury, Venus, Earth, Moon, Mars B) Mercury, Moon, Venus, Earth, Mars C) Moon, Mercury, Venus, Earth, Mars D) Moon, Mercury, Mars, Venus, Earth E) Mercury, Moon, Mars, Earth, Venus
D) Moon, Mercury, Mars, Venus, Earth
Which internal energy source produces heat by converting gravitational potential energy into thermal energy? A) accretion B) differentiation C) radioactivity D) both A and B E) all of the above
D) both A and B (accretion and differentiation)
What are the conditions necessary for a terrestrial planet to have a strong magnetic field? A) a molten metallic core only B) fast rotation only C) a rocky mantle only D) both a molten metallic core and reasonably fast rotation E) both a metal core and a rocky mantle
D) both a molten metallic core and reasonably fast rotation
How have we been able to construct detailed maps of surface features on Venus? A) by studying Venus from Earth with powerful telescopes B) by studying Venus with powerful telescopes on spacecraft that were sent to orbit Venus C) by making computer models of geological processes on Venus D) by using radar from spacecraft that were sent to orbit Venus E) by landing spacecraft on the surface for close-up study
D) by using radar from spacecraft that were sent to orbit Venus
Earth's atmosphere contains only small amounts of carbon dioxide because A) the Earth's volcanoes did not outgas as much carbon dioxide as those on Venus and Mars. B) most of the carbon dioxide was lost during the age of bombardment. C) chemical reactions with other gases destroyed the carbon dioxide and replaced it with the nitrogen that is in the atmosphere now. D) carbon dioxide dissolves in water, and most of it is not contained in the oceans and carbonate rocks. E) Earth doesn't have as strong a greenhouse effect as is present on Venus.
D) carbon dioxide dissolves in water, and most of it is not contained in the oceans and carbonate rocks.
The core, mantle, and crust of a planet are defined by differences in their A) geological activity. B) temperature. C) strength. D) density.
D) density.
The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that A) erosion destroyed the smaller craters that formed on the basin. B) Mercury's atmosphere prevented smaller objects from hitting the surface. C) only very large impactors hit Mercury's surface in the past. D) the Caloris Basin formed toward the end of the solar system's period of heavy bombardment. E) the Caloris Basin was formed by a volcano.
D) the Caloris Basin formed toward the end of the solar system's period of heavy bombardment.
Which of the following can act like a long-term "thermostat" for the Earth's average temperature? A) radioactive elements trapped in the Earth's mantle B) heat stored in the Earth's magnetosphere C) heat stored in the Earth's liquid core D) the carbon dioxide cycle
D) the carbon dioxide cycle
What are fossil fuels? A) any fuel that releases CO2 into the atmosphere upon burning B) any fuel that is extracted from the interior of the Earth C) mineral-rich deposits from ancient seabeds D) the carbon-rich remains of plants that died millions of years ago E) carbonate-rich deposits from ancient seabeds
D) the carbon-rich remains of plants that died millions of years ago
Which of the following describes erosion? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
In what ways is Earth different from the other terrestrial planets? A) Its lithosphere is broken into plates that move around. B) It has oxygen in its atmosphere. C) Most of its surface is covered with liquid water. D) Life can be found almost everywhere. E) All of the above are true.
E) All of the above are true.
Which of the following statements about the greenhouse effect is TRUE? A) Without the naturally occurring greenhouse effect, Earth would be too cold to have liquid oceans. B) A weak greenhouse effect operates on Mars. C) The burning of fossil fuels increases the greenhouse effect on Earth because of the release of carbon dioxide. D) One result of an increased greenhouse effect on Earth may be an increased number of severe storms. E) All of the above are true.
E) All of the above are true.
Which of the following worlds have the thinnest lithospheres? A) Earth and the Moon B) Venus and the Moon C) Mercury and Venus D) Earth and Mars E) Earth and Venus
E) Earth and Venus
How is the atmosphere of a planet affected by the rotation rate? A) The rotation rate determines how much atmosphere a planet has. B) The rotation rate determines how long the planet is able to retain its atmosphere. C) Faster rotation rates raise surface temperatures and thus determine how much material is gaseous versus icy or liquid. D) Faster rotation rates raise the atmospheric temperature. E) Faster rotation rates produce stronger winds.
E) Faster rotation rates produce stronger winds.
Which of the following planets has the least substantial atmosphere? A) Venus B) Earth C) Mars D) Neptune E) Mercury
E) Mercury
Under what circumstances can differentiation occur in a planet? A) The planet must have a rocky surface. B) The planet must be made of both metal and rock. C) The planet must have an atmosphere. D) The planet must be geologically active, that is, have volcanoes, planetquakes, and erosion from weather. E) The planet must have a molten interior.
E) The planet must have a molten interior.
What kind of surface features may result from tectonics? A) mountains B) valleys C) volcanos D) cliffs E) all of the above
E) all of the above
Which of the following does NOT have a major effect in shaping planetary surfaces? A) impact cratering B) volcanism C) tectonics D) erosion E) magnetism
E) magnetism
Which of the following gases absorbs ultraviolet light best? A) carbon dioxide B) nitrogen C) oxygen D) hydrogen E) ozone
E) ozone
When we see a region of a planet that is not as heavily cratered as other regions, we conclude that A) there is little volcanic activity to create craters. B) the planet is rotating very slowly and only one side was hit by impactors. C) the planet formed after the age of bombardment and missed out on getting hit by leftover planetesimals. D) the surface in the region is older than the surface in more heavily cratered regions. E) the surface in the region is younger than the surface in more heavily cratered regions.
E) the surface in the region is younger than the surface in more heavily cratered regions.
What are the circumstances under which convection can occur in a substance? A) when the substance is subjected to a strong magnetic field B) when dense material is being added to the substance C) when the substance is strongly shaken or disturbed by a strong wind D) when the substance is strongly cooled from underneath E) when the substance is strongly heated from underneath
E) when the substance is strongly heated from underneath
