ESS chapter 9 concept quiz, ASTR101 Solar System Astronomy Practice Final, Astronomy 101 Final Study Guide

Strong evidence both from surface features and magnetic field data support the existence of a subsurface ocean on

Europa

Which moon is considered likely to have a deep, subsurface ocean of liquid water?

Europa

How might Triton's capture be relevant to its geological activity?

Even though Triton is much smaller than our Moon, Triton' surface shows evidence of relatively recent geological activity. This can be because of the tidal heating that occurred when the moon was captured.

Which of the following statements best describes the size of the largest asteroid, Ceres?

It is a little less than half the diameter of our Moon.

How does Jupiter's core compare to Earth?

It is about the same size but is 10 times more massive.

What happens to the energy that the ground absorbs in the form of visible sunlight?

It is returned upward in the form of infrared light.

Which statement about Io is true?

It is the most volcanically active body in our solar system.

Why does the Moon have a layer of "powdery soil" on its surface?

It is the result of countless tiny impacts by small particles striking the Moon.

Why do we think Triton is a captured moon?

It orbits Neptune in the direction opposite to Neptune's rotation. | It orbits Neptune at a high inclination to Neptune's equator.

What is Pluto's moon Charon thought to have in common with our own Moon?

It probably formed as a result of a giant impact.

On a cloudless day, what happens to most of the visible light headed toward Earth?

It reaches Earth's surface, where some is reflected and some is absorbed.

In the context of Earth's climate history, what do we mean by snowball Earth?

It refers to a very deep ice age that occurred hundreds of millions of years ago.

What is the importance of the carbon dioxide (CO2) cycle?

It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.

Why do astronomers think Miranda has such an unusual surface?

It underwent an episode of tidal heating in the past

You discover an impact crater that is 10 kilometers across. Which of the following can you conclude?

It was created by the impact of an object about 1 kilometer across.

How did molecular oxygen (O2) get into Earth's atmosphere?

It was released by life through the process of photosynthesis.

All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?

Mars lost any global magnetic field that it may once have had.

Make a prediction: If the rise in carbon dioxide concentration continues at its current pace, the concentration in the year 2050 will be about _____ parts per million.

460

How do the jovian planet interiors differ?

All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium.

Which of the following is not an expected consequence of the rising carbon dioxide concentration or global warming?

Animal deaths due to carbon dioxide poisoning.

Which of the following is not a characteristic of the seasons on Mars?

As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect.

_______ is a high-elevation region dotted by tall volcanoes.

Tharsis Bulge

Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus?

That it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space.

Based on the evidence that atmospheric carbon dioxide is a cause of planetary warming, what aspect of the graphs should most concern us?

The carbon dioxide concentration today is significantly higher than at any time in the past 800,000 years and is rapidly rising.

On a day with complete cloud cover, what happens to the visible light headed toward Earth?

The clouds reflect much of it back to space, though some still reaches the surface.

Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history?

The fact that the temperature of our planet has remained relatively steady throughout our planet's history.

Which of the following best explain what we think happened to outgassed water vapor on Venus?

Ultraviolet light split the water molecules, and the hydrogen then escaped to space.

Which jovian planet should have the most extreme seasonal changes?

Uranus

Which jovian planet should have the most extreme seasonal changes?

Uranus Its large axis tilt gives it seasons that each last about ¼ of its 84-year orbit.

Which of the following statements best describes the general pattern of composition among the four jovian planets?

Uranus and Neptune contain relatively more rock and hydrogen compounds than Jupiter and Saturn.

The long, deep canyon running along the equator is called _______

Valles Marineris

Which terrestrial world has the most atmosphere?

Venus

Which of the following statements best explains why the densities of Uranus and Neptune are higher than that of Saturn, even though Saturn is much more massive?

They have a higher proportion of hydrogen compounds and rock.

Which of the following statements best explains why the densities of Uranus and Neptune are higher than those of Jupiter and Saturn?

They have a higher proportion of hydrogen compounds and rock.

Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury?

They have thin exospheres only, with gas coming from impacts of subatomic particles and photons.

In very general terms, how do the temperature structures of the atmospheres of Venus and Mars differ from that of Earth?

They lack ultraviolet-absorbing stratospheres.

Which of the following describes a primary role of global circulation cells in a planet's atmosphere?

They transport heat from the equator toward the poles.

Suppose you find a meteorite made almost entirely of metal. According to current science, which of the following statements must be true?

Your meteorite is a fragment from the core of a large asteroid that shattered in a collision.

Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases __________.

absorb infrared light emitted by the surface

We cannot see tidal forces or tidal heating; rather, we predict that they must occur based on the orbital characteristics of the moons. What observational evidence confirms that tidal heating is important on Io?

active volcanoes on Io

Scientists have confidence in the predictions of today's best climate models because they

agree well with actual data for recent decades

Scientists have confidence in the predictions of today's best climate models because they __________.

agree well with actual data for recent decades

The belts and zones of Jupiter are

alternating bands of rising and falling air at different latitudes.

17. Which of the following best describes the geological histories of the Moon and Mercury? a) Impact cratering shaped these worlds early in their histories. Then, during the past few million years, they were reshaped by episodes of volcanism and tectonics. b) Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all. c) Impact cratering is the only major geological process that has affected their surfaces. d) All four geological processes were important in their early histories, but only impact cratering still reshapes their surfaces today.

b) Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all.

26. Why does Earth have so little carbon dioxide in its atmosphere compared to Venus? a) Earth once had a lot of carbon dioxide, but it was lost to space during the heavy bombardment early in our solar system's history. b) Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere. c) Earth's volcanoes outgassed far less carbon dioxide than those on Venus. d) Chemical reactions turned Earth's carbon dioxide into nitrogen.

b) Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.

10. All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space? a) Outgassed water molecules are split apart, and the oxygen then reacts chemically with surface rock on Mars. b) Mars lost any global magnetic field that it may once have had. c) Mars probably once had a much higher density of greenhouse gases in its atmosphere than it does today. d) The axis tilt of Mars is thought to change significantly with time.

b) Mars lost any global magnetic field that it may once have had.

The Huygens probe took numerous pictures as it descended to Titan's surface in 2005. What did the pictures show?

features or erosion, including what appeared to be dry river valleys and lakebeds

You have found that Planet Z should have active tectonics and volcanism and an atmosphere produced by volcanic outgassing. What single factor explains why the planet should have these characteristics?

has a large size for a terrestrial planet.

The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface

is absorbed by greenhouse gases, slowing the escape of this energy to space

Orbital resonance also gives Europa an elliptical orbit, so it experiences tidal heating, too. However, Europa experiences less tidal heating than Io, because Europa __________ than Io.

is farther from Jupiter

The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________.

is temporarily absorbed by greenhouse gases and then reemitted in random directions

Io experiences tidal heating primarily because __________.

its elliptical orbit causes the tidal force to vary as Io orbits Jupiter.

Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny?

its size

Which of the following is the underlying reason why Venus has so little wind erosion?

its slow rotation

What's the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead?

its small size compared to Earth

If the hypothesis tracing the extinction of the dinosaurs to an impact is correct, the dinosaurs died off largely because ________.

of global climate effects initiated by dust and smoke that entered the atmosphere after the impact

What is differential rotation?

rotation where a body rotates faster or slower at its equator than it does at its poles

The slowly increasing distance between South America and Africa is due to ______

seafloor spreading

Layered ________ exposed by erosion can be seen when looking at the Grand Canyon in the United States.

sedimentary rock

Suppose that Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be _______.

well below the freezing point of water

Why do we think that Venus has so much more atmospheric gas than Earth?

Most of the gases that have been released from volcanoes on Earth later returned to the surface.

Which of the following statements about the moons of the jovian planets is not true?

Most of the moons are large enough to be spherical in shape, but a few have the more potato-like shapes of asteroids.

Which of the following statements correctly describes the motion of the particles in Saturn's rings?

Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings.

Which statement about planetary rings is not true?

Saturn's rings formed along with its moons 4.6 billion years ago.

Which planet may have helium rain in its interior, and what does this rain do?

Saturn, where it generates heat as it falls downward.

Which planet may have helium rain in its interior, and what does this rain do?

Saturn, where it generates heat as it falls downward. Models suggest that this helium rain may explain Saturn's internal heating.

Australia is composed of relatively old and thick ______

continental crust

Which of the following best describes the internal layering of Jupiter, from the center outward?

core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer

Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings?

countless icy particles, ranging in size from dust grains to large boulders

46. All of the following have occurred over long periods of time on Earth. Which one is not thought to have played a major role in long-term changes in Earth's climate? a) Changes in the Earth's axis tilt. b) Changes in the Earth's overall reflectivity. c) Changes in the atmospheric concentration of greenhouse gases. d) A gradual rise in the atmospheric content of oxygen.

d) A gradual rise in the atmospheric content of oxygen.

18. Why didn't a planet form where the asteroid belt is now located? a) The temperature in this portion of the solar nebula was just right to prevent rock from sticking together. b) There was too much rocky material to form a terrestrial planet, but not enough gaseous material to form a jovian planet. c) There was not enough material in this part of the solar nebula to form a planet. d) Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

d) Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

50. How do scientists determine the age of the solar system? a) Radiometric dating of Moon rocks. b) Theoretical calculations tell us how long it has taken the planets to evolve to their present forms c) Radiometric dating of the oldest Earth rocks. d) Radiometric dating of meteorites

d) Radiometric dating of meteorites

The earthquakes that occur in Southern California generally occur above a _________

fault

Which of the following does not provide evidence that Mars once had abundant liquid water on its surface?

the presence of canali, discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell.

What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?

the presence of many long, tall cliffs

In the context of planetary geology, what do we mean by outgassing?

the release by volcanism of gases that had been trapped in a planetary interior

In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers?

the rings of Saturn

Earth's temperature remains fairly steady, which means that Earth must return the same amount of energy to space that it receives from the Sun. In what forms does Earth return most of this energy to space?

visible light reflected by the surface, reflected by clouds, and infrared light emitted by the surface and atmosphere

Which of the following is a strong greenhouse gas?

water vapor

The major processes that heat the interiors of the terrestrial worlds are:

(1) Heat deposited as the planets were built from planetesimals; (2) heat deposited as the planets underwent differentiation; (3) heat released by radioactive decay.

The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their distance from the Sun, from closest to farthest. (Not to scale.)

(CLOSEST) Earth, Jupiter, Saturn, Uranus, Neptune (FARTHEST)

Shown below are the four terrestrial planets of our solar system. Assume that all the planets started out equally hot inside. Rank the planets based on their expected cooling rates, from fastest cooling to slowest cooling.

(FASTEST COOLING) Mercury, Mars, Venus, Earth (SLOWEST COOLING)

The following images show the four terrestrial planets in our solar system. Rank the planets from left to right based on the amount by which the greenhouse effect increases their surface temperatures, compared to what their temperatures would be without the greenhouse effect, from largest to smallest increase.

(LARGEST INCREASE) Venus, Earth, Mars, Mercury (SMALLEST INCREASE)

Shown following are three terrestrial planets of our solar system. Rank the planets based on the amount of time the surface of the planet has had a moderate to high level of volcanic/tectonic activity, from longest to shortest.

(LONGEST TIME) Earth, Mars, Mercury (SHORTEST TIME)

The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their mass, from lowest to highest. (Not to scale.)

(LOWEST) Earth, Uranus, Neptune, Saturn, Jupiter (HIGHEST)

The following images show Earth and the four jovian planets of our solar system. Rank these planets from left to right based on their size (average equatorial radius), from smallest to largest. (Not to scale.)

(SMALLEST) Earth, Neptune, Uranus, Saturn, Jupiter (LARGEST)

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system. All Four Jovian Planets

- Approximately 10 Earth-mass core - Orbited by rings of ice and rock - Magnetic field stronger than Earth's - Strong atmospheric winds and storms

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system. Uranus and Neptune Only

- Blue color because of methane - Composed mostly of hydrogen compounds

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system. Jupiter and Saturn Only

- Composed mostly of hydrogen and helium - Interior is mostly liquid or metalilic

All the following statements are true. Which two represent the two facts that lead us to expect Earth to be warming up as a result of human activity? Be sure to choose two of the statements below.

- Greenhouse gases make Earth warmer than it would be otherwise. - Human activity is increasing the concentration of carbon dioxide and other greenhouse gases in the atmosphere.

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects. Asteroids

- typically orbit the Sun at approximately 3 AU - compositions similar to that of the terrestrial planets

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects. Comets

- form a coma when near the Sun - most are located either in Kuiper belt or Oort cloud - visible in the sky as a fuzzy patch of light that rises and sets with the stars

Listed following are some distinguishing characteristics of comets, meteors, and asteroids. Match these to the appropriate category of objects. Meteors

- visible in the sky as a bright streak of light for only a few seconds - dust particles entering Earth's atmosphere at high speed

Although the data show only a correlation between the carbon dioxide concentration and the global average temperature, scientists have other reasons to think that a rise in the carbon dioxide concentration actually causes a rise in the global average temperature. All of the following statements are true. Which statements lend support to the idea that carbon dioxide is a cause of planetary warming? Check all that apply.

-Models of the greenhouse effect successfully predict the temperatures of Venus and Mars from their atmospheric carbon dioxide amounts. -We understand the physical mechanism of the greenhouse effect, through which carbon dioxide can increase a planet's temperature. -Models of Earth's climate that include recent increases in the carbon dioxide concentration match observed temperature increases better than those that do not include it.

Start on the home screen of the interactive figure, with "Elevation is off." Then turn elevation on, and compare what you see. You may wish to switch back and forth between elevation on and off a few times. Then select the statements below that are true. Note: Features such as impact craters that are actually round in shape are distorted into oval shapes at mid- to high-latitudes by map projection effects. Select all that apply.

-Most of the northern hemisphere has much lower elevation than the southern hemisphere. -There is a long, deep canyon that stretches along a region close to Mars's equator. -Several large volcanoes are found near or somewhat north of Mars's equator. -There is a large, roundish region of low-elevation in the southern hemisphere.

Go to the screen "Key Evidence of Water," and and select the feature called "Recurring Slope Lineae." Study this feature at each of the four zoom levels offered, and be sure to view the animation called "recurring slope linaea (gif)" that you will see at the third zoom level. Which of the following statements are true?

-The recurring slope lineae look like narrow dark streaks. -The recurring slope lineae are found among impact craters. -The recurring slope lineae appear to grow in spring and summer.

Based on Planet Z's size, orbital distance, and rotation rate, which of the following properties is it likely to have? Check all that apply.

-an atmosphere produced by outgassing -active tectonics -active volcanoes

Earth's temperature remains fairly steady, which means that Earth must return nearly the same amount of energy to space that it receives from the Sun. In what forms does Earth return most of this energy to space? Check all that apply.

-infrared light emitted by the surface and atmosphere -visible light reflected by clouds -visible light reflected by the surface

1. Most of the charged particles from the Sun are deflected around Earth by the 2. Earth's absorbs most of the ultraviolet light arriving here from the Sun. 3. Most of the X-rays coming from the Sun are absorbed in the 4. Gas particles in Earth's atmosphere most easily escape from the 5. The densest layer of the atmospheres of Venus, Earth, and Mars is the

1. magnetosphere 2. stratosphere 3. thermosphere 4. exosphere 5. troposphere

What are the basic requirements for a terrestrial world to have a global magnetic field?

A core layer of molten, convecting material and sufficiently rapid rotation.

All of the following have occurred over long periods of time on Earth. Which one is not thought to have played a major role in long-term changes in Earth's climate?

A gradual rise in the atmospheric content of oxygen.

In the context of plate tectonics, what is a subduction zone?

A place where a seafloor plate is sliding under a continental plate.

Which of the following best describes how the greenhouse effect works?

A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.

In the context of a planetary atmosphere, what is a bar?

A unit of pressure roughly equal to the atmospheric pressure at sea level on Earth.

Which of the following best describes the internal layering of Jupiter, from the center outward? A) Core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer B) Core of rock and metal; mantle of lower density rock; upper layer of gaseous hydrogen; cloud layer C) Liquid core of hydrogen compounds; liquid hydrogen layer; metallic hydrogen layer; gaseous hydrogen layer; cloud layer D) Solid rock core; layer of solid metallic hydrogen; layer of pure liquid hydrogen; cloud layer

A) Core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer

Which of the following best explains why Jupiter's density is higher than Saturn's? A) Jupiter is more massive than Saturn. B) Jupiter is closer to the Sun than Saturn. C) Jupiter has a higher proportion of hydrogen compounds and rock than Saturn. D) Jupiter has a stronger magnetic field than Saturn.

A) Jupiter is more massive than Saturn.

Which of the following statements best explains why the densities of Uranus and Neptune are higher than those of Jupiter and Saturn? A) They have a higher proportion of hydrogen compounds and rock. B) They have higher masses. C) Their interiors are more compressed due to stronger gravity. D) They are at greater distances from the Sun. E) They have stronger magnetic fields.

A) They have a higher proportion of hydrogen compounds and rock.

We cannot see tidal forces or tidal heating; rather, we predict that they must occur based on the orbital characteristics of the moons. What observational evidence confirms that tidal heating is important on Io?

Active volcanoes on Io

Which of the following is not a piece of evidence supporting the idea that Europa may have a subsurface ocean?

Astronomers have detected small lakes of liquid water on Europa's surface.

Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings? A) Nothing—up close, the rings would be so completely invisible that you'd have no way to know they are there. They can be seen only from a distance. B) Countless icy particles, ranging in size from dust grains to large boulders C) A solid, shiny surface, looking much like a piece of a DVD but a lot bigger D) Dozens of large "moonlets" made of metal and rock, each a few kilometers across

B) Countless icy particles, ranging in size from dust grains to large boulders

From Part A, Io's elliptical orbit is necessary to its tidal heating. This elliptical orbit, in turn, is a result of the orbital resonance among Io, Europa, and Ganymede. This orbital resonance causes Io to have a more elliptical orbit than it would otherwise, because __________. A) All three moons orbit with the same period, staying aligned at all times B) Lo periodically passes Europa and Ganymede in the same orbital position C) Europa and Ganymede are unusually large moons D) Europa and Ganymede always pull on Io from the same direction as Jupiter pulls on Io

B) Lo periodically passes Europa and Ganymede in the same orbital position

How do typical wind speeds in Jupiter's atmosphere compare to typical wind speeds on Earth? A) They are slightly faster than average winds on Earth. B) They are much faster than hurricane winds on Earth. C) They are about the same as average winds on Earth. D) They are slightly slower than average winds on Earth.

B) They are much faster than hurricane winds on Earth.

We now know of many Jupiter-size planets around other stars. Suppose that future observations show that one of these planets has two orbiting moons. What additional information, if any, would we need to decide whether these moons experience tidal heating? A) We need to know whether the planet also has a third moon. B) We need to know their orbital periods. C) We need to know whether either moon is volcanically active. D) No other information is needed: With two moons, there is sure to be tidal heating. E) No other information is needed: With two moons, there is no chance of any tidal heating.

B) We need to know their orbital periods.

Why is the Coriolis effect so weak on Venus?

Because Venus rotates so slowly.

Why is the sky blue (on Earth)?

Because molecules scatter blue light more effectively than red light.

Why is thermal escape of atmospheric gas much easier from the Moon than from Earth?

Because the Moon's gravity is so much weaker than Earth's.

We cannot see tidal forces or tidal heating; rather, we predict that they must occur based on the orbital characteristics of the moons. What observational evidence confirms that tidal heating is important on Io? A) Lo's unusual, egg-like shape B) The orbital resonance between Io, Europa, and Ganymede C) Active volcanoes on Io D) Lo's surprisingly elliptical orbit

C) Active volcanoes on Io

Saturn's rings... A) Have looked basically the same since they formed along with Saturn. B) Were created long ago when tidal forces tore apart a large moon. C) Are continually supplied by impacts with small moons.

C) Are continually supplied by impacts with small moons.

Based on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have a significantly different composition and higher density than Jupiter and Saturn? A) The lower masses of Uranus and Neptune allowed more of their hydrogen and helium gas to escape into space. B) The lower temperatures at the locations of Uranus and Neptune allowed more material to condense into solid form into solid form. C) Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune. D) Jupiter and Saturn formed closer to the Sun, where there was more hydrogen and helium gas and less hydrogen compounds and rock.

C) Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune.

Which lists the jovian planets in order of increasing distance from the Sun? A) Jupiter, Saturn, Uranus, Pluto B) Saturn, Jupiter, Uranus, Neptune C) Jupiter, Saturn, Uranus, Neptune

C) Jupiter, Saturn, Uranus, Neptune

Lo experiences tidal heating primarily because __________. A) Lo has an unusually elongated shape that makes it look more like an egg than a sphere B) Lo is made of relatively soft materials that deform quite easily C) Lo's elliptical orbit causes the tidal force on Io to vary as it orbits Jupiter D) Lo is located very close to Jupiter

C) Lo's elliptical orbit causes the tidal force on Io to vary as it orbits Jupiter

Which of the following is a general characteristic of the four jovian planets in our solar system? A) They have very little hydrogen, helium, and hydrogen compounds. B) They have solid surfaces. C) They are lower in average density than are the terrestrial planets. D) They are less massive than any of the terrestrial planets.

C) They are lower in average density than are the terrestrial planets.

is the most distant of Jupiter's four Galilean moons.

Callisto

Which of the following gases is not a significant ingredient of the jovian planet atmospheres?

Carbon Dioxide

In general, which things below are affected by a magnetic field?

Charged particles or magnetized materials (such as iron).

Why is Mars red?

Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface.

Which statement is not thought to be true of all comets in our solar system?

Comets always have tails.

Why is Earth's continental crust lower in density than seafloor crust?

Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.

Suppose Earth were to cool down a little. How would the carbon dioxide cycle tend to restore temperatures to normal?

Cooler temperatures lead to slower formation of carbonate minerals in the ocean, so carbon dioxide released by volcanism builds up in the atmosphere and strengthens the greenhouse effect.

Which of the following best describes the internal layering of Jupiter, from the center outward?

Core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer

From center to surface, which of the following correctly lists the interior layers of a terrestrial world?

Core, mantle, crust.

The orbital resonance also gives Europa an elliptical orbit, so it also experiences tidal heating. However, Europa experiences less tidal heating than Io, because Europa __________ than Io. A) Contains much more ice B) Is more perfectly spherical in shape C) Is much smaller D) Is farther from Jupiter

D) Is farther from Jupiter

Which of the following statements best describes the general pattern of composition among the four jovian planets? A) Jupiter is made mostly of hydrogen, Saturn is made mostly of helium, Uranus is made mostly of hydrogen compounds, and Neptune is made mostly of rock. B) Jupiter is made mostly of hydrogen and helium, while the other three jovian planets are made mostly of hydrogen compounds. C) All four planets have essentially the same composition. D) Jupiter and Saturn have compositions that are fairly different from the compositions of Uranus and Neptune.

D) Jupiter and Saturn have compositions that are fairly different from the compositions of Uranus and Neptune.

Look at the densities of the jovian planets given in Figure 1. Which of the following statements best describes the pattern of jovian planet densities? A) The more massive the planet, the higher the density. B) Jupiter is the densest, and the densities of the other planets decrease in order of distance from the Sun. C) Jupiter is the densest, and the densities of the other planets increase in order of distance from the Sun. D) There is no clear trend in the densities. E) The more massive the planet, the lower the density.

D) There is no clear trend in the densities.

Which of the following best describes the geological histories of the Moon and Mercury?

Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all.

Why does Earth have so little carbon dioxide in its atmosphere compared to Venus?

Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.

When we see a meteor shower, it means that ________.

Earth is crossing the orbit of a comet

When we see a meteor shower, it means that _________.

Earth is crossing the orbit of a comet

Which of the following is not a piece of evidence supporting the idea that an impact caused the mass extinction that occurred 65 million years ago?

Fossilized dinosaur bones contain fragments of rock from the impact.

The largest moon in the solar system is

Ganymede

Why didn't a planet form where the asteroid belt is now located?

Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

In Part A, you found that Earth emits only infrared light. This infrared light can be absorbed by greenhouse gases, such as carbon dioxide and water vapor, in the atmosphere. In fact, all the terrestrial planets emit infrared light from their surfaces. The following images show the four terrestrial planets in our solar system. Rank these planets from left to right based on the total amount of infrared-absorbing greenhouse gases in their atmospheres, from greatest to least.

Greatest to least Venus, Earth, Mars, Mercury

The following images represent four types (wavelength bands) of light. Rank these from left to right based on the amount of each that is emitted (as thermal radiation) by Earth's surface, from greatest to least. If you think that two (or more) types should be ranked as equal, drag one on top of the other(s) to show this equality.

Greatest: infared (Xray, visible, UV) equal

Which of the following places is the result of volcanoes erupting over a hot spot in the mantle?

Hawaii

Which internal heat source still generates heat within the terrestrial worlds today?

Heat from radioactive decay.

The large, roundish, low-elevation region in the southern hemisphere is called _______

Hellas Basin

Observations indicate that the Moon has water ice in craters near the poles. Where do scientists suspect this water came from?

Ice brought by comet impacts long ago.

How is it possible that the Moon might have some water ice today?

Ice brought by comet impacts may be frozen in craters near the Moon's poles.

What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size?

Ice has a lower melting point than rock.

Each of the following statements is best associated with one of the four major geological processes. Drag each statement into the correct bin for its associated process. Drag the appropriate items to their respective bins.

Impact Cratering: -Mostly occurred during heavy bombardment. -Affected all solid worlds similarly. Volcanism: -Created the smooth lunar maria. -Erased virtually all craters on Io. -Responsible for the existence of Earth's atmosphere and oceans. Tectonics: -On Earth, involves motion of plates. -Includes surface compression that builds mountains. Erosion: -Includes features sculpted by wind.

All the following statements are true. Which one is most important in explaining the tremendous tidal heating that occurs on Io?

Io orbits Jupiter on an elliptical orbit as a result of orbital resonances with other satellites.

All the following statements are true. Which one is most important in explaining the tremendous tidal heating that occurs on Io?

Io orbits Jupiter on an elliptical orbit, due to orbital resonances with other satellites.

All the following statements are true. Which one is most important in explaining the tremendous tidal heating that occurs on Io?

Io orbits Jupiter on an elliptical orbit, due to orbital resonances with other satellites. On an elliptical orbit, tides vary and flex Io's shape.

As you learned in Part A, Io's elliptical orbit is necessary to its tidal heating. This elliptical orbit, in turn, is a result of the orbital resonance among Io, Europa, and Ganymede. This orbital resonance causes Io to have a more elliptical orbit than it would otherwise, because __________.

Io periodically passes Europa and Ganymede in the same orbital position.

Io experiences tidal heating primarily because __________.

Io's elliptical orbit causes the tidal force on Io to vary as it orbits Jupiter.

As you saw in Part A, Io's elliptical orbit is necessary to its tidal heating. This elliptical orbit, in turn, is a result of the orbital resonance among Io, Europa, and Ganymede. This orbital resonance causes Io to have a more elliptical orbit than it would otherwise, because __________.

Io, Europa and Ganymede periodically return to the same orbital positions, creating the same gravitational tugs

Listed following are some of the distinguishing characteristics of the four Galilean moons of Jupiter. Match each characteristic to the appropriate moon.

Io: -volcanoes currently erupting -hot, glowing lava visible in some photos -source of ionized gas in the donut-shaped charged particle belt around Jupiter Europa: -double-ridged surface features strongly suggest a subsurface ocean below -ice covered surface with few impact craters Ganymede: -largest moon in the solar system -heavily cratered terrain adjacent to fairly smooth terrain Callisto: -most distant from Jupiter of these four moons -entire surface appears heavily cratered and ancient

Suppose we discover a new comet on an orbit that brings it closer to the Sun than Mercury every 125 years. What can we conclude?

It has been on its current orbit for only a very short time compared to the age of our solar system.

Suppose there were no solar wind. How would the appearance of a comet in our inner solar system be different?

It would have only one tail instead of two.

What would happen to Jupiter if we could somehow double its mass?

Its density would increase but its diameter would barely change.

What would happen to Jupiter if we could somehow double its mass?

Its density would increase but its diameter would barely change. You can understand why by thinking about the pillow stack analogy described in Section 11.1 of The Cosmic Perspective.

What would happen to Jupiter if we could somehow double its mass?

Its density would increase, but its diameter would barely change.

Which of the following most likely explains why Venus does not have a global magnetic field like Earth?

Its rotation is too slow.

What is the leading hypothesis for Venus's lack of water?

Its water molecules were broken apart, and hydrogen was lost to space.

Which of the following best explains why many jovian moons have been more geologically active than the Moon or Mercury?

Jovian moons are made mostly of ice that can melt or deform at lower temperatures than can the rock and metal that make up the Moon and Mercury.

Based on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have a significantly different composition and higher density than Jupiter and Saturn?

Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune.

Based on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have a significantly different composition than Jupiter and Saturn?

Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune.

Which of the following statements best describes the general pattern of composition among the four jovian planets?

Jupiter and Saturn have compositions that are fairly different from the compositions of Uranus and Neptune.

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system.

Jupiter and Saturn only: -interior is mostly liquid or metallic hydrogen -composed mostly of hydrogen and helium Uranus and Neptune only: -blue color because of methane -composed mostly hydrogen compounds all four jovian planets: -approximately 10 Earth-mass core -orbited by rings of ice and rock -magnetic field stronger than Earth's -strong atmospheric winds and storms no jovian planets: -solid surface under a thick atmosphere

Which of the following most likely explains why Jupiter's interior releases so much heat?

Jupiter is contracting gradually.

Which of the following most likely explains why Jupiter's interior releases so much heat?

Jupiter is contracting very gradually. This contraction would be too small for us to measure with current technology, but would be sufficient to convert enough gravitational potential energy into thermal energy to explain our observations.

Which of the following best explains why Jupiter's density is higher than Saturn's?

Jupiter is more massive than Saturn

Which of the following best explains why Jupiter's density is higher than Saturn's?

Jupiter is more massive than Saturn.

Why is Saturn almost as big as Jupiter, despite its smaller mass?

Jupiter's greater mass compresses it more, thus increasing its density.

How does the strength of Jupiter's magnetic field compare to that of Earth's magnetic field?

Jupiter's magnetic field is about 20,000 times as strong as Earth's.

In which list are the jovian planets in order of increasing distance from the Sun?

Jupiter, Saturn, Uranus, Neptune

Recent evidence suggests that Mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic field like that of Earth?

Mars's interior has cooled so much that its molten core layer no longer undergoes convection.

What atmospheric constituent is responsible for the blue color of Uranus and Neptune?

Methane

Why do Uranus and Neptune have blue methane clouds but Jupiter and Saturn do not?

Methane does not condense into ice in the warmer atmospheric temperatures of Jupiter and Saturn.

When were the heat-trapping effects of gases that cause the greenhouse effect first measured by scientists?

More than 150 years ago.

Suppose that large jovian planets had never formed in our solar system. Which of the following would most likely be true?

Neither the asteroid belt nor Oort cloud would exist.

Does Venus have auroras around its poles, like Earth? Why or why not?

No, because it lacks a global magnetic field.

Does Venus have auroras around its poles, like the Earth? Why or why not?

No, because it lacks a global magnetic field.

The impact of a 100 meter asteroid could kill many people if it struck a major city. Suppose the probability of such an impact in any single year is 1 in 1,000, and suppose we know (somehow) that it has been 1200 years since the last impact. What would that tell us?

Nothing, we would still presume that the chance of such an impact during the next year is 1 in 1000.

The tallest mountain on Mars is called ___________

Olympus Mons

Which of the following objects are probably not located in the same general region of the solar system in which they originally formed?

Oort cloud comets

The fact that Europa orbits Jupiter twice for every one orbit of Ganymede is an example of a(n)

Orbital Resonance

According to our theory of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn?

Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula.

According to our theory of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn?

Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula. Based on this idea, larger planets might have formed if the solar nebula had taken longer to clear.

Why won't Pluto collide with Neptune?

Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits.

________ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.

Seafloor crust

How does seafloor crust differ from continental crust?

Seafloor crust is thinner, younger, and higher in density.

Why are there fewer large impact craters on the Earth's seafloor than on the continents?

Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts.

The following figures show four positions (1-4) of a comet during its orbit of the Sun. Also shown is the orbit of the Earth around the Sun. Rank the positions of the comet from left to right based on the size of its tail, from shortest to longest. (Not to scale; tails not shown.)

Shortest to Longest - Top right - Lower right - Left of Earth's orbit - Exactly on Earth's orbit

The choices below describe four hypothetical planets. Which one would you expect to have the most features of erosion? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)

Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours.

The choices below describe four hypothetical planets. Which one's surface would you expect to be most crowded with impact craters? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)

Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

The choices below describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.)

Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months.

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system. No Jovian Planets

Solid surface under a thick atmosphere

The following images show the four terrestrial planets in our solar system. Rank the planets from left to right based on the strength of the greenhouse effect occurring at their surfaces, from strongest to weakest.

Strongest to weakest: Venus, Earth, Mars, Mercury

Which of the following is a real piece of evidence pointing to recent geological activity on Pluto?

Surface regions that suggest glacial movement of frozen ices of nitrogen and methane.

All the following statements are true. Which one explains why convection can occur in the troposphere but not in the stratosphere?

Temperature declines with altitude in the troposphere but increases with altitude in the stratosphere.

Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?

Temperatures on Jupiter and Saturn are too high for methane to condense.

Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?

Temperatures on Jupiter and Saturn are too high for methane to condense. But methane can condense on Uranus and Neptune because they are farther from the Sun and hence colder.

What makes us think that Mars must once have had an atmosphere that was warmer and had higher surface pressure?

The atmosphere is too cold and thin for liquid water today, yet we see evidence of flowing water in the past.

Which of the following is not an expected consequence of global warming?

The entire Earth will warm up by the same amount.

Why is Jupiter denser than Saturn?

The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn

When you see the bright flash of a meteor, what are you actually seeing?

The glow from a pea-sized particle and the surrounding air as the particle burns up in our atmosphere

Which of the following is not an example of tectonics?

The gradual disappearance of a crater rim as a result of wind and rain.

Many scientists suspect that Venus has a stronger and thicker lithosphere than Earth. If this is true, which of the following could explain it?

The high surface temperature that has "baked out" all the liquid water from Venus's crust and mantle.

Which of the following best explains why we see horizontal "stripes" in photographs of Jupiter and Saturn?

The light stripes are regions of high clouds, and the dark stripes are regions where we can see down to deeper, darker clouds.

Which of the following best why we see horizontal "stripes" in photographs of Jupiter and Saturn?

The light stripes are regions of high clouds, and the dark stripes are regions where we can see down to deeper, darker clouds.

Which of the following best explains why we see horizontal "stripes" in photographs of Jupiter and Saturn?

The light stripes are regions of high clouds, and the dark stripes are regions where we can see down to deeper, darker clouds. And the reason these stripes stretch all the way around these planets is the strong Coriolis force that comes from the planets' rapid rotation.

Which of the following is not generally true of all the terrestrial world lithospheres?

The lithosphere is broken into a set of large plates that float upon the softer rock below.

Most of the Moon's surface is densely covered with craters, but we find relatively few craters within the lunar maria. What can we conclude?

The maria formed after the heavy bombardment ended.

According to current understanding, which of the following is required in order for a planet to have rings?

The planet must have many small moons that orbit relatively close to the planet in its equatorial plane.

Which of the following statements about ozone (in Earth's stratosphere) is not true:

The presence of ozone was crucial to the origin of life some 4 billion years ago.

Why is the radiation so intense in the region that traces Io's orbit around Jupiter (the Io torus)?

The region is full of gases that become ionized after they are released from volcanoes on Io.

Why is the radiation so intense in the region that traces Io's orbit around Jupiter (the Io torus)?

The region is full of gases that become ionized after they are released from volcanoes on Io. Io's low gravity allows these gases to escape.

Go to the screen "Mars Mission Landing Sites," and and select Opportunity landing site (2004). Explore all five zoom levels offered, making sure to read the captions at the tops of the screens. Based on the information provided, why was the landing site,called Meridiani Planum, chosen for the Opportunity mission?

The region was already known to have minerals likely to have formed in liquid water.

Which statement about Saturn's rings is not true?

The rings must look much the same today as they did shortly after Saturn formed.

Which statement about Saturn's rings is not true?

The rings must look much the same today as they did shortly after Saturn formed. Ring particles cannot last long compared to the age of the solar system, so the rings much change their appearance with time.

In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers?

The rings of Saturn

Which of the following general statements about Earth's atmosphere is not true?

The sea level temperature depends primarily on the total amount of gas in our atmosphere.

Suppose that Earth's ice caps melted, but everything else about the Earth's surface and atmosphere stayed the same. What would happen to Earth's average surface temperature?

The surface temperature would increase.

Why does Jupiter have three distinct layers of clouds?

The three layers represent clouds made of gases that condense at different temperatures.

Why does Jupiter have three distinct layers of clouds?

The three layers represent clouds made of gases that condense at different temperatures. The three cloud layers are ammonia, ammonium hydrosulfide, and water. Each of these gases condenses at a different temperature and hence at a different altitude in Jupiter's atmosphere.

Why does atmospheric pressure decrease as you go higher in altitude on Earth?

The weight of the atmosphere above you decreases with altitude.

Why do jovian planets bulge around the equator, that is, have a "squashed" appearance?

Their rapid rotation flings the mass near the equator outward.

Notice that the peaks and troughs on the temperature graph occur at the about the same times as peaks and troughs on the carbon dioxide graph. What can we infer from this fact alone?

There is a correlation between the carbon dioxide concentration and the global average temperature.

Look at the average densities of the jovian planets given in Figure 1. Can you identify a trend in jovian planet densities with mass or distance from the Sun?

There is no clear trend in the densities with mass or distance.

Look at the densities of the jovian planets given in Figure 1. Which of the following statements best describes the pattern of jovian planet densities?

There is no clear trend in the densities.

Jupiter and the other jovian planets are sometimes called "gas giants." In what sense is this term misleading?

They actually contain relatively little material in a gaseous state.

Jupiter and the other jovian planets are sometimes called "gas giants." In what sense is this term misleading?

They actually contain relatively little material in a gaseous state. Much more of their mass is liquid, metallic, or in strange high-pressure states that we don't naturally find on Earth.

Which of the following statements comparing the jovian interiors is not thought to be true?

They all have the same exact set of internal layers, though these layers differ in size.

Which of the following is not a general characteristic of the four jovian planets in our solar system?

They are higher in average density than are the terrestrial planets.

How do typical wind speeds in Jupiter's atmosphere compare to typical wind speeds on Earth?

They are much faster than hurricane winds on Earth

How do typical wind speeds in Jupiter's atmosphere compare to typical wind speeds on Earth?

They are much faster than hurricane winds on Earth.

According to scientists, the naturally occurring greenhouse effect makes Earth about 31∘C warmer than it would be if there were no greenhouse gases in our atmosphere. How do scientists "know" what Earth's temperature would be without greenhouse gases?

They calculate this temperature from Earth's reflectivity and distance from the Sun.

is responsible for the tremendous volcanic activity on Io.

Tidal Heating

Which moon has a thick atmosphere made mostly of nitrogen?

Titan

Which of the following best describes why scientists seek to identify even very small asteroids that could potentially hit Earth?

To try to prevent an impact that might destroy a town or city.

Which large jovian moon is thought to have been captured into its present orbit?

Triton

Why do astronomers believe that Triton is a captured moon?

Triton orbits Neptune in a direction opposite that of Neptune's rotation.

Why do astronomers believe that Triton is a captured moon?

Triton orbits Neptune in a direction opposite that of Neptune's rotation. This "backward" orbit is a tell-tale sign of a captured moon.

If Earth had as much carbon dioxide in its atmosphere as Venus, our planet would be too hot for liquid water to exist on the surface.

True

Which planet(s) have an atmosphere that consists mostly of carbon dioxide?

Venus and Mars

All of the following statements are true. Which one provides strong observational support for the claim that greenhouse gases make a planet warmer than it would be otherwise?

Venus has a higher average temperature than Mercury.

All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450 C hotter than the surface of Earth?

Venus has a much stronger greenhouse effect than Earth.

All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450°C hotter than the surface of Earth?

Venus has a much stronger greenhouse effect than Earth.

All the following statements about Venus are true. Which one offers evidence of a global repaving about a billion years ago?

Venus has relatively few impact craters and these craters are distributed fairly evenly over the entire planet.

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.)

Venus, Earth, Mars, Moon/Mercury

Which of the following general statements about light and Earth's atmosphere is not true?

Visible light from the Sun is absorbed in the exosphere.

Which of the following is an example of convection?

Warm air expanding and rising while cooler air contracts and fall.

Which of the following is not caused by the Coriolis effect on Earth?

Water going down a drain swirls in opposite directions in the northern and southern hemispheres.

What is the Great Red Spot?

a long-lived, high-pressure storm on Jupiter

We now know of many Jupiter-size planets around other stars. Suppose that future observations show that one of these planets has two orbiting moons. What additional information, if any, would we need to decide whether these moons experience tidal heating?

We need to know their orbital periods

We now know of many Jupiter-size planets around other stars. Suppose that future observations show that one of these planets has two orbiting moons. What additional information, if any, would we need to decide whether these moons experience tidal heating?

We need to know their orbital periods.

Based solely on an understanding of the greenhouse effect (as displayed in the figure), which one of the following statements is true?

We should expect an increase in the greenhouse gas concentration to lead to global warming.

Although the data show only a correlation between the carbon dioxide concentration and the global average temperature, scientists have other reasons to think that a rise in the carbon dioxide concentration actually causes a rise in the global average temperature. All of the following statements are true. Which statements lend support to the idea that carbon dioxide is a cause of planetary warming?

We understand the physical mechanism of the greenhouse effect, through which carbon dioxide can increase a planet's temperature. Models of the greenhouse effect successfully predict the temperatures of Venus and Mars from their atmospheric carbon dioxide amounts. Models of Earth's climate that include recent increases in the carbon dioxide concentration match observed temperature increases better than those that do not include it.

What is the difference between weather and climate?

Weather refers to short-term changes in wind, rain, and temperature, while climate refers to the long-term average of weather.

What do we mean when we say that the terrestrial worlds underwent differentiation?

When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces.

On average, how fast do the plates move on the Earth?

a few centimeters per year

Which of the following is the most basic definition of a greenhouse gas?

a gas that absorbs infrared light

Based on its surface features, the most important event on Venus in the past billion years or so was _______.

a global "repaving" that erased essentially all the surface features that had existed earlier.

Suppose we use a baseball to represent Earth. On this scale, the other terrestrial worlds (Mercury, Venus, the Moon, and Mars) would range in size approximately from that of ______.

a golf ball to a baseball

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 gradual brightening with time

In Part A, you found that Planet Z should not have polar ice caps or liquid water. What single change to Planet Z's characteristics would allow it to have these things?

a greater distance from its star

What do we mean by a runaway greenhouse effect?

a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere

Olympus Mons is ______.

a huge shield volcano on Mars

The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that ________.

a large baked potato takes longer to cool than a small baked potato

According to current evidence, Pluto is best explained as ________.

a large member of the Kuiper belt

A terrestrial world's lithosphere is ________.

a layer of relatively strong, rigid rock, encompassing the crust and part of the mantle

What is a magnetosphere?

a region of space around a planet in which the planet's magnetic field can trap charged particles

On the graphs shown, you can identify an ice age by looking for

a trough (bottom of a dip) on the temperature graph

On the graphs shown, you can identify an ice age by looking for __________.

a trough (bottom of a dip) on the temperature graph

19. Why is Earth's continental crust lower in density than seafloor crust? a) Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones. b) Continental crust comes from Earth's inner core while seafloor crust comes from the outer core. c) Continental crust comes from volcanoes while seafloor crust comes from geysers. d) Continental crust is made from a low-density volcanic rock called basalt.

a) Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.

32. What would happen to Earth if we somehow moved our planet to the orbit of Venus? a) Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus. b) Temperatures would rise only slightly, but enough to melt the polar caps. c) The fact that we have oceans would moderate the temperature change due to moving our planet, so temperature would hardly change at all. d) Being so much closer to the Sun would almost immediately cause the surface of Earth to melt, and all our cities would then be destroyed by the hot lava.

a) Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.

14. When is the soonest we are likely to have images and spectra of Earthlike planets around other stars? a) In a decade or two, through space missions now in the early planning stages. b) Any day now, thanks to new, large, ground-based telescopes. c) In just a few years, through the Kepler mission. d) We already have images and spectra of Earthlike planets around other stars.

a) In a decade or two, through space missions now in the early planning stages.

21. Suppose we discover a new comet on an orbit that brings it closer to the Sun than Mercury every 125 years. What can we conclude? a) It has been on its current orbit for only a very short time compared to the age of our solar system. b) It came from the Oort cloud. c) It has a coma and tail during most of each orbit. d) It came from the Kuiper belt.

a) It has been on its current orbit for only a very short time compared to the age of our solar system.

11. What would happen to Jupiter if we could somehow double its mass? a) Its density would increase but its diameter would barely change. b) Its density would stay about the same and its volume would double. c) It would become a star, with nuclear fusion in its core. d) Its density would decrease and its diameter would double.

a) Its density would increase but its diameter would barely change.

31. Does Venus have auroras around its poles, like the Earth? Why or why not? a) No, because it lacks a global magnetic field. b) Yes, because strong winds generate light near its poles. c) Yes, because it is bombarded by charged particles from the Sun. d) No, because its atmosphere is too thick.

a) No, because it lacks a global magnetic field.

13. According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth? a) Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more. b) Oxygen released by life was removed from the atmosphere by dissolving in the ocean until the oceans could dissolve no more. c) Early life did not release oxygen, and oxygen releasing organisms didn't evolve for a billion years after the earliest life. d) Early forms of animal life consumed the oxygen released by plants during the first billion years of life on Earth.

a) Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more.

9. Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus? a) That it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space. b) That the greenhouse effect on Venus must have been much weaker in the distant past. c) That volcanoes on Venus did not outgas as much water as volcanoes on Earth. d) That it once had a much stronger magnetic field than it does today.

a) That it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space.

28. In general, which type of planet would you expect to cause the largest Doppler shift in the spectrum of its star? a) a massive planet that is close to its star b) a massive planet that is far from its star c) a low-mass planet that is close to its star d) a low-mass planet that is far from its star

a) a massive planet that is close to its star

33. Suppose a planet is discovered by the Doppler technique and is then discovered to have transits. In that case, we can determine all the following about the planet except ______________. a) its rotation period b) its orbital period c) its physical size (radius) d) its precise mass e) its density

a) its rotation period

49. What's the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead? a) its small size compared to Earth b) its slow rotation compared to the Earth c) its closer distance than Earth to the Sun d) its large size compared to the Earth e) its rapid rotation compared to the Earth f) its farther distance than Earth to the Sun

a) its small size compared to Earth

3. What are the two geological features that appear to set Earth apart from all the other terrestrial worlds? a) plate tectonics and widespread erosion b) mantle convection and a thick atmosphere c) shield volcanoes and plate tectonics d) significant volcanism and tectonics

a) plate tectonics and widespread erosion

36. In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers? a) the rings of Saturn b) the atmosphere of Jupiter c) the asteroid belt d) the Oort cloud

a) the rings of Saturn

Suppose we represent Earth with a basketball. On this scale, most of the air in Earth's atmosphere would fit in a layer that is _________.

about the thickness of a sheet of paper

Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases

absorb infrared light emitted by the surface

43. Based on everything you have learned about the formation of our solar system, which of the following statements is probably not true? a) Other solar systems will also have planets in the two basic categories of terrestrial and jovian. b) Only a tiny percentage of stars are surrounded by spinning disks of gas during their formation. c) Other planetary systems will have far more numerous asteroids and comets than actual planets. d) Planets always tend to orbit their star in the same direction and approximately the same plane.

b) Only a tiny percentage of stars are surrounded by spinning disks of gas during their formation.

7. What is the primary reason that astronomers suspect that some jovian moons were captured into their current orbits? a) Astronomers have observed moons being captured. b) Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to their planet's equator. c) Some moons are surprisingly large in size. d) Some moons have a composition that differs from the composition of the planets

b) Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to their planet's equator.

22. How can we best observe the Sun's chromosphere and corona? a) The chromosphere is best observed with infrared telescopes and the corona is best observed with ultraviolet telescopes. b) The chromosphere is best observed with ultraviolet telescopes and the corona is best observed with X-ray telescopes. c) The chromosphere and corona are both best studied with radio telescopes. d) The chromosphere and corona are both best studied with visible light.

b) The chromosphere is best observed with ultraviolet telescopes and the corona is best observed with X-ray telescopes.

8. Why is the radiation so intense in the region that traces Io's orbit around Jupiter (the Io torus)? a) Io's gravity allows this region to capture huge numbers of charged particles from the solar wind. b) The region is full of gases that become ionized after they are released from volcanoes on Io. c) An orbital resonance between Io, Europa, and Ganymede makes the radiation intense. d) Jupiter's strong magnetic field makes the radiation intense everywhere, and the region around Io is no different than any other region.

b) The region is full of gases that become ionized after they are released from volcanoes on Io.

6. Suppose that Earth's ice caps melted, but everything else about the Earth's surface and atmosphere stayed the same. What would happen to Earth's average surface temperature? a) The surface temperature would decrease. b) The surface temperature would increase. c) The temperature would not be affected at all. d) The surface temperature would change radically, until it was equal to the melting temperature of ice.

b) The surface temperature would increase.

40. What is the primary basis upon which we divide the ingredients of the solar nebula into four categories (hydrogen/helium; hydrogen compound; rock; metal)? a) The locations of various materials in the solar nebula. b) The temperatures at which various materials will condense from gaseous form to solid form. c) The atomic mass numbers of various materials. d) The amounts of energy required to ionize various materials.

b) The temperatures at which various materials will condense from gaseous form to solid form.

44. Why do sunspots appear dark in pictures of the Sun? a) They are holes in the solar surface through which we can see through to deeper, darker layers of the Sun. b) They actually are fairly bright, but appear dark against the even brighter background of the surrounding photosphere. c) They are extremely hot and emit all their radiation as X rays rather than visible light. d) They are too cold to emit any visible light.

b) They actually are fairly bright, but appear dark against the even brighter background of the surrounding photosphere.

30. Why do astronomers believe that Triton is a captured moon? a) Triton appears to be made mostly of ice. b) Triton orbits Neptune in a direction opposite that of Neptune's rotation. c) Triton is too large to have been formed in the "miniature solar nebula" thought to have surrounded Neptune in its very early history. d) Triton is very small and potato-shaped, which is common of captured moons.

b) Triton orbits Neptune in a direction opposite that of Neptune's rotation.

47. Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by _____. a) the fact that our politicians spout a lot of hot air b) human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere c) the human release of chemicals called CFCs into the stratosphere d) the increase in forest fires during recent years

b) human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere

15. Which of the following is not expected for a "hot Jupiter" that orbits 0.05 AU from its star a) cloudtop temperatures over 1000 K b) intense volcanism c) density similar to or lower than Jupiter's d) clouds made of rock dust

b) intense volcanism

42. Which two factors are most important to the existence of plate tectonics on Earth? a) the existence of life and oxygen in the atmosphere b) mantle convection and a thin lithosphere c) Earth's liquid outer core and solid inner core d) oxygen in the atmosphere and mantle convection

b) mantle convection and a thin lithosphere

23. Gaps in the asteroid belt (often called Kirkwood gaps) are caused by ______. a) tidal forces from Jupiter b) orbital resonances with Jupiter c) tidal forces from the Sun d) the competing gravitational tugs of Mars and Jupiter

b) orbital resonances with Jupiter

The asteroid belt is located ________.

between the orbits of Mars and Jupiter

How do astronomers think Jupiter generates its internal heat?

by contracting, changing gravitational potential energy into thermal energy

How do astronomers think Saturn generates its internal heat?

by raining dense helium droplets from higher to lower altitudes, resembling the process of differentiation

45. How can we determine the reflectivity of an asteroid? a) By taking a photograph of it. b) By measuring its mass and radius. c) By comparing its brightness in visible light to its brightness in infrared light. d) By where it is located in the asteroid belt.

c) By comparing its brightness in visible light to its brightness in infrared light.

41. Which of the following is not a piece of evidence supporting the idea that an impact caused the mass extinction that occurred 65 million years ago? a) Grains of quartz formed under high pressure are found in a layer of clay that dates to 65 million years ago. b) Unusually large abundances of iridium and other rare metals are found in a layer of clay that dates to 65 million years ago. c) Fossilized dinosaur bones contain fragments of rock from the impact. d) A large impact crater along the coast of Mexico dates to 65 million years ago.

c) Fossilized dinosaur bones contain fragments of rock from the impact.

20. What is Pluto's moon Charon thought to have in common with our own Moon? a) It has the same basic composition. b) It has the same approximate mass. c) It probably formed as a result of a giant impact. d) It has the same average density.

c) It probably formed as a result of a giant impact.

39. Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together? a) Fusion can proceed only by the proton-proton chain, and therefore requires that protons come close enough together to be linked up into a chain. b) Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. c) Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold. d) Nuclei are attracted to each other by the electromagnetic force, but this force is only strong enough to make nuclei stick when they are very close together.

c) Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold.

4. Why won't Pluto collide with Neptune? a) Pluto is always much farther from the Sun than Neptune. b) Actually, a collision of the two is inevitable within the next billion years. c) Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits, which ensures they never come close together. d) Pluto's orbit never comes anywhere close to Neptune's orbit.

c) Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits, which ensures they never come close together.

5. The choices below describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) a) Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours. b) Size: same as Mars. Distance from Sun: same as Earth. Rotation rate: once every 18 hours. c) Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months. d) Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

c) Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months.

29. If the Sun's core suddenly shrank a little bit, what would happen in the Sun? a) The density of the core would decrease, causing the core to cool off and expand. b) The core would heat up, causing it to radiate so much energy that it would shrink even more. c) The core would heat up, fusion rates would increase, the core would re-expand. d) The core would cool off and continue to shrink as its density increased.

c) The core would heat up, fusion rates would increase, the core would re-expand.

48. According to our present theory of solar system formation, how did Earth end up with enough water to make oceans? a) The water was mixed in the other materials in the planetesimals that accreted at our distance from the Sun. b) The water was formed by chemical reactions among the minerals in the Earth's core. c) The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars. d) Earth formed in the relatively narrow region of the solar nebular in which liquid water was plentiful.

c) The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars.

37. The region of our solar system between Mercury and Mars has very few asteroids, while the region between Mars and Jupiter has many asteroids. Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars? a) Gravity was too weak to allow asteroids to form in this part of the solar system. b) All the asteroids that formed between Mercury and Mars later migrated to the asteroid belt between Mars and Jupiter. c) There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed. d) It was too hot for asteroids to form in this part of the solar system.

c) There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed.

25. Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny? a) its distance from the Sun b) whether or not it has liquid water c) its size d) its composition

c) its size

1. The astrometric technique looks for planets with careful measurements of a star's _________. a) velocity towards or away from us b) brightness c) position in the sky d) all of the above

c) position in the sky

35. When you see the bright flash of a meteor, what are you actually seeing? a) emission of visible light from a particle that has not yet entered Earth's atmosphere b) a star that has suddenly shot across the sky c) the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere d) the flash that occurs when a speeding rock from space hits the ground

c) the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere

Which of the following gases is not a significant ingredient of the jovian planet atmospheres?

carbon dioxide

Which of the following gases is not a significant ingredient of the jovian planet atmospheres?

carbon dioxide Carbon dioxide is important in the terrestrial planet atmospheres, but not in the jovian planet atmospheres.

In which direction do hurricanes in the Southern Hemisphere rotate?

clockwise

Jupiter's colors come in part from its three layers of clouds. Which of the following is not the primary constituent of one of Jupiter's cloud layers?

clouds of sulfuric acid

34. The choices below describe four hypothetical planets. Which one's surface would you expect to be most crowded with impact craters? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) a) Size: twice as big as Earth. Distance from Sun: same as Mercury. Rotation rate: once every 6 months. b) Size: same as Venus. Distance from Sun: same as Mars. Rotation rate: once every 25 hours. c) Size: same as Mars. Distance from Sun: same as Earth. Rotation rate: once every 18 hours. d) Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

d) Size: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.

24. Which of the following correctly compares the Sun's energy generation process to the energy generation process in human-built nuclear power plants? a) The Sun generates energy through fission while nuclear power plants generate energy through fusion. b) Both processes involve nuclear fusion, but the Sun fuses hydrogen while nuclear power plants fuse uranium. c) The Sun generates energy through nuclear reactions while nuclear power plants generate energy through chemical reactions. d) The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting) of large nuclei.

d) The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting) of large nuclei.

38. How does the Sun's mass compare to Earth's mass? a) The Sun's mass is about 300 times the mass of the Earth. b) Both have approximately the same mass. c) The Sun's mass is about 30 times the mass of the Earth. d) The Sun's mass is about 300,000 times the mass of the Earth.

d) The Sun's mass is about 300,000 times the mass of the Earth.

2. Most of the Moon's surface is densely covered with craters, but we find relatively few craters within the lunar maria. What can we conclude? a) The regions of the maria were hit by fewer impacts than the densely cratered regions. b) The maria formed within the past 1 billion years. c) Erosion affects the maria more than it affects other regions of the Moon. d) The maria formed after the heavy bombardment ended.

d) The maria formed after the heavy bombardment ended.

16. The Sun's surface seethes and churns with a bubbling pattern. Why? a) The Sun's surface is boiling. b) The churning gas is being stirred up by the strong solar wind. c) The churning is an illusion created by varying radiation, as the gas on the Sun's surface is actually quite still. d) We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface.

d) We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface.

12. Which of the following gases is not a significant ingredient of the jovian planet atmospheres? a) water b) hydrogen c) helium d) carbon dioxide

d) carbon dioxide

27. The discovery of Eris __________. a) was surprising, due to its "backwards" orbit around the Sun b) was not surprising, because the existence of a massive "Planet X" had been predicted nearly a century ago c) was surprising, since we thought we knew about all large objects in the solar system d) was not surprising, because other Kuiper belt objects approaching the size of Pluto had already been discovered

d) was not surprising, because other Kuiper belt objects approaching the size of Pluto had already been discovered

Gas particles in Earth's atmosphere most easily escape from the __________

exosphere

Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a _______

hot spot

Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by _____.

human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere

The outer layers of most jovian moons are made primarily of

ices

The processes responsible for virtually all surface geology are _________.

impact cratering, volcanisms, tectonics, and erosion

Scientists can estimate the age of a planetary surface by counting __________.

impact craters

Planetary rings are

known to exist for all of the jovian planets. nearer to their planet than any of the planet's large moons. orbiting in the equatorial plane of their planet. composed of a large number of individual particles that orbit their planet in accord with Kepler's third law.

Which of the following is most unlikely to be found on Titan?

lakes of liquid water in the warmer equatorial regions

Saturn's rings look bright because __________.

light from the Sun reflects off the material in the rings

What kind of gas is most affected by thermal escape?

light gases

The jovian moon with the most geologically active surface is

lo

Where is most of the CO2 that has outgassed from Earth's volcanoes?

locked up in rocks

Saturn's rings are composed of __________.

lots of individual particles of ice and rock

Most of the charged particles from the Sun are deflected around Earth by the _______

magnetosphere

Which two factors are most important to the existence of plate tectonics on Earth?

mantle convection and a thin lithosphere

Which of the following best describes the lunar maria?

relatively smooth, flat plains on the Moon

The cores of the terrestrial worlds are made mostly of metal because ______.

metals sunk to the centers a long time ago when the interiors were molten throughout

What atmospheric constituent is responsible for the blue color of Uranus and Neptune?

methane

If we could put all the asteroids together, their total mass would be ________.

much less than the mass of any terrestrial planet

If we could put all the asteroids together, their total mass would be _________.

much less than the mass of any terrestrial planet

Suppose we had a device that allowed us to see Earth's interior. If we looked at a typical region of the mantle, what would we see happening?

not much - on human time scales, the mantle looks like solid rock

Gaps in the asteroid belt (often called Kirkwood gaps) are caused by ______.

orbital resonances with Jupiter

Which of the following is not a greenhouse gas?

oxygen (O2)

What causes the release of oxygen into Earth's atmosphere?

photosynthesis

Which two factors are critical to the existence of the carbon dioxide (CO2) cycle on Earth?

plate tectonics and liquid water oceans

What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?

plate tectonics and widespread erosion

Earth's ______ absorbs most of the ultraviolet light arriving here from the Sun.

stratosphere

The extremely deep ocean Marianas Trench is a result of _______

subduction

Which region of Earth has warmed the most in recent decades?

the Arctic

Overall, Jupiter's composition is most like that of ________.

the Sun

Overall, Jupiter's composition is most like that of _________.

the Sun

Which characteristic of Earth explains why we have an ultraviolet-absorbing stratosphere?

the existence of photosynthetic life

When you see the bright flash of a meteor, what are you actually seeing?

the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere

Most of the X-rays coming from the Sun are absorbed in the _______

thermosphere

The densest layer of the atmospheres of Venus, Earth, and Mars is the _______

troposphere

The greenhouse effect occurs in the

troposphere

Which of the following correctly lists the layers of Earth's atmosphere from the ground upward?

troposphere, stratosphere, thermosphere, exosphere

What kind of light warms the stratosphere?

ultraviolet

Which jovian planet should have the most extreme seasonal changes?

uranus

The average temperature over the past 1000 years has been about 15∘C. From the graphs, you can conclude that Earth's average temperature during the past 800,000 years has

varied between about 7∘C and 19∘C

The average temperature over the past 1000 years has been about 15∘C. From the graphs, you can conclude that Earth's average temperature during the past 800,000 years has __________.

varied between about 7∘C and 19∘C

The energy that warms Earth's surface comes primarily in the form of

visible light from the Sun

The energy that warms Earth's surface comes primarily in the form of __________.

visible light from the Sun

Earth's temperature remains fairly steady, which means that Earth must return nearly the same amount of energy to space that it receives from the Sun. In what form(s) does Earth return most of this energy to space?

visible light reflected by the surface infrared light emitted by the surface and atmosphere visible light reflected by clouds