Astronomy A Beginners Guide to the Universe 7th edition by Chaisson – Test Bank

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Astronomy A Beginners Guide to the Universe 7th edition by Chaisson – Test Bank

Astronomy: A Beginner’s Guide to the Universe, 7e (Chaisson/McMillan)

Chapter 5   Earth and Its Moon: Our Cosmic Backyard

 

1) Our Earth is about four times larger than the Moon in diameter.

Answer:  TRUE

Diff: 1

Section Ref.:  5.1

 

2) Compared to Earth, the Moon lacks a hydrosphere, atmosphere, and a magnetosphere.

Answer:  TRUE

Diff: 2

Section Ref.:  5.1

 

3) The Earth’s hotter, inner core is liquid and its cooler, outer core is solid.

Answer:  FALSE

Diff: 2

Section Ref.:  5.1

 

4) On average, the Moon orbits Earth from a distance of about 30 Earth radii.

Answer:  FALSE

Diff: 2

Section Ref.:  5.1

 

5) Neap tides occur at first and third quarter phases of the Moon.

Answer:  TRUE

Diff: 1

Section Ref.:  5.2

 

6) The tidal pull of the Moon is an example of a differential force, as the near and far sides of the Earth do not experience the same gravitational pull of the Moon.

Answer:  TRUE

Diff: 1

Section Ref.:  5.2

 

7) The Moon keeps one side facing the Earth because it doesn’t rotate on its axis.

Answer:  FALSE

Diff: 2

Section Ref.:  5.2

 

8) The Earth and Moon always keep the same side towards each other.

Answer:  FALSE

Diff: 2

Section Ref.:  5.2

 

 

9) Spring tides occur only at new Moon, when the Moon and Sun pull together.

Answer:  FALSE

Diff: 2

Section Ref.:  5.2

10) In most places on the seacoast, there are two high and two low tides a day.

Answer:  TRUE

Diff: 2

Section Ref.:  5.2

 

11) Due to its larger mass, the Sun’s gravitational effect on Earth’s tides is greater than the Moon’s.

Answer:  FALSE

Diff: 2

Section Ref.:  5.2

 

12) Greenhouse gases in our atmosphere trap just enough heat to keep the Earth’s oceans liquid.

Answer:  TRUE

Diff: 1

Section Ref.:  5.3

 

13) Weather occurs in the troposphere.

Answer:  TRUE

Diff: 1

Section Ref.:  5.3

 

14) The continuing rise of carbon dioxide concentration in our troposphere is leading to worldwide cooling as dry ice forms at the poles.

Answer:  FALSE

Diff: 1

Section Ref.:  5.3

 

15) The ozone layer lies above the troposphere and below the mesosphere.

Answer:  TRUE

Diff: 2

Section Ref.:  5.3

 

16) The three most abundant gases in our atmosphere are nitrogen, oxygen, and argon.

Answer:  TRUE

Diff: 2

Section Ref.:  5.3

 

17) The Moon’s surface gravity is only half the Earth’s.

Answer:  FALSE

Diff: 2

Section Ref.:  5.3, 5.1

 

18) The Moon’s lower density indicates it has a smaller concentration of iron in its core, as does the absence of a lunar magnetic field.

Answer:  TRUE

Diff: 1

Section Ref.:  5.4

 

19) The Earth’s inner core is about the same temperature as the surface of the Sun.

Answer:  TRUE

Diff: 2

Section Ref.:  5.4

20) Seismic P-waves can travel through both solid and liquid materials.

Answer:  TRUE

Diff: 2

Section Ref.:  5.4

 

21) Seismic S-waves can travel through Earth’s liquid outer core.

Answer:  FALSE

Diff: 2

Section Ref.:  5.4

 

22) One source of the energy for volcanism and plate tectonics is radioactivity in the Earth’s interior.

Answer:  TRUE

Diff: 2

Section Ref.:  5.4, 5.5

 

23) A seismograph could register P but not S waves from an epicenter on the opposite side of the Earth.

Answer:  TRUE

Diff: 2

Section Ref.:  5.4

 

24) Samples of the Earth’s molten outer core come directly through the mantle, pour out of volcanoes, and can be studied in labs.

Answer:  FALSE

Diff: 2

Section Ref.:  5.4

 

25) Seismic P-waves can be detected worldwide from any strong epicenter.

Answer:  TRUE

Diff: 3

Section Ref.:  5.4

 

 

26) There is no evidence for plate tectonics on the Moon today.

Answer:  TRUE

Diff: 1

Section Ref.:  5.5

 

27) In the past, most of the landmass on Earth was concentrated in a single, large continent.

Answer:  TRUE

Diff: 1

Section Ref.:  5.5

 

28) When plates collide, they fuse together and come to rest.

Answer:  FALSE

Diff: 2

Section Ref.:  5.5

29) Early telescopic observers thought the lunar mare were seas of water; today we know they are not liquid water but molten basalt, long ago frozen out.

Answer:  TRUE

Diff: 2

Section Ref.:  5.5

 

30) Most lunar craters are volcanic in origin.

Answer:  FALSE

Diff: 2

Section Ref.:  5.6

 

31) The Moon and the crustal rocks of Earth are similar in density.

Answer:  TRUE

Diff: 2

Section Ref.:  5.6

 

32) The Van Allen belts are cloud layers in the jet streams of the stratosphere, similar to the belts that Galileo saw on Jupiter.

Answer:  FALSE

Diff: 2

Section Ref.:  5.7

 

33) The lunar mare are younger than any of the craters that sit in them.

Answer:  FALSE

Diff: 2

Section Ref.:  5.8

 

34) The lunar highlands appear brighter than the mare, because these highlands are due to meteor impact that completely avoided the mare.

Answer:  FALSE

Diff: 2

Section Ref.:  5.8

 

35) The lunar mare radioactively date back to 4.6 billion years, at the origin of the Moon, hence their dark color due to this aging.

Answer:  FALSE

Diff: 2

Section Ref.:  5.8

 

36) The crust on the near side of the Moon is on average thinner than the crust on the far side, due to our tidal pull on the Moon.

Answer:  TRUE

Diff: 2

Section Ref.:  5.8

 

37) Today most scientists favor the capture theory of the Moon’s origin, since it would explain why the Moon still orbits in the ecliptic plane, as do other planets.

Answer:  FALSE

Diff: 2

Section Ref.:  5.8

38) Which of the following layers of the Earth is unique among the terrestrial planets?

  1. A) hydrosphere
  2. B) ionosphere
  3. C) mantle
  4. D) crust
  5. E) core

Answer:  A

Diff: 1

Section Ref.:  5.1

 

39) At what phase would you expect to find extremely high and low tides?

  1. A) new moon
  2. B) first and third quarter
  3. C) full moon
  4. D) both new and full moons
  5. E) Moon phases do not impact the tides.

Answer:  D

Diff: 2

Section Ref.:  5.2

 

 

40) What is true of spring tides?

  1. A) The third quarter moon would be high overhead at dawn.
  2. B) The difference between low and high tides would be greatest.
  3. C) There would be one high and one low tide each day.
  4. D) The Moon’s phase will be first quarter.
  5. E) The difference between low and high tides would be smallest.

Answer:  B

Diff: 2

Section Ref.:  5.2

 

41) At what phase are the tides least noticeable?

  1. A) new moon
  2. B) full moon
  3. C) third quarter
  4. D) waxing crescent
  5. E) waning gibbous

Answer:  C

Diff: 2

Section Ref.:  5.2

 

42) The Moon’s near side always faces Earth due to

  1. A) the Sun’s gravity.
  2. B) Earth’s magnetic field.
  3. C) Earth’s tidal force.
  4. D) conservation of angular momentum in the solar nebula.
  5. E) the solar wind.

Answer:  C

Diff: 2

Section Ref.:  5.2

43) The smallest high tides occur when the Moon phase is

  1. A) first or third quarter.
  2. B) full.
  3. C) new.
  4. D) waxing or waning crescent.
  5. E) waxing or waning gibbous.

Answer:  A

Diff: 2

Section Ref.:  5.2

 

 

44) What is true of the Moon’s orbital and rotational periods?

  1. A) The rotational period is longer.
  2. B) The orbital period is longer.
  3. C) The rotational period varies with the Moon’s phase.
  4. D) They are equal.
  5. E) The orbital period is greatest at full moon.

Answer:  D

Diff: 3

Section Ref.:  5.2

 

45) Almost all of our atmospheric gases lie in the

  1. A) ionosphere.
  2. B) stratosphere.
  3. C) troposphere.
  4. D) ozone layer.
  5. E) mesosphere.

Answer:  C

Diff: 1

Section Ref.:  5.3

 

46) The critical part of the atmosphere for protecting life on the ground from excessive ultraviolet radiation is the

  1. A) hydrosphere.
  2. B) troposphere.
  3. C) ozone layer.
  4. D) stratosphere.
  5. E) ionosphere.

Answer:  C

Diff: 1

Section Ref.:  5.3

 

47) In what part of our atmosphere do we live?

  1. A) troposphere
  2. B) stratosphere
  3. C) mesosphere
  4. D) ionosphere
  5. E) exosphere

Answer:  A

Diff: 1

Section Ref.:  5.3

 

48) Which of these gases is least abundant in our atmosphere?

  1. A) hydrogen
  2. B) carbon dioxide
  3. C) argon
  4. D) nitrogen
  5. E) oxygen

Answer:  A

Diff: 2

Section Ref.:  5.3

 

49) Without the greenhouse effect operating in our atmosphere,

  1. A) we would not have to worry about any warming problems in the future.
  2. B) Earth would have an average temperature of -23 degrees Celsius.
  3. C) the ice in the polar regions would have melted long ago.
  4. D) the ozone layer would not be weakening.
  5. E) the Earth would have become much more like Venus long ago.

Answer:  B

Diff: 2

Section Ref.:  5.3

 

50) What is the average molecular speed of hydrogen (mass = 1) on Earth (temperature = 300 K)?

  1. A) 4.71 km/s
  2. B) 2.72 m/s
  3. C) 4.71 m/s
  4. D) 2.72 km/s
  5. E) None of the above

Answer:  D

Diff: 3

Section Ref.:  More Prec. 5.1

 

51) The major presence of water detected on the Moon is in

  1. A) the mare.
  2. B) the floors of deep craters in the polar regions, as ice deposits that never thaw.
  3. C) the flows of mud seen on the walls of some craters.
  4. D) the puffs of steam seen coming from some still active lunar volcanoes.
  5. E) faint clouds of ice in the thin lunar atmosphere.

Answer:  B

Diff: 2

Section Ref.:  5.3

 

 

52) After the Lunar Reconnaissance Orbiter (LRO) crashed into the moon, its sister spacecraft LCROSS detected an amount of water in the ejecta

  1. A) comparable to soggy ground on Earth.
  2. B) comparable to fertile soil on Earth.
  3. C) comparable to dried-up lake beds on Earth.
  4. D) less than is contained in desert sand on Earth.
  5. E) Actually, no water was detected at all.

Answer:  D

Diff: 2

Section Ref.:  5.3

53) The average rate of erosion on the Moon is far less than on Earth because

  1. A) the crust of the Moon is much denser than the Earth’s crust.
  2. B) the Moon is much younger than the Earth.
  3. C) the Moon lacks wind, water, and an atmosphere.
  4. D) the Moon’s magnetic field protects it from the solar wind better than ours does.
  5. E) the Moon’s mare long ago dried up, so there is no more wave erosion there.

Answer:  C

Diff: 2

Section Ref.:  5.3

 

54) We determine the structure of the Earth’s core using

  1. A) deep mine shafts.
  2. B) satellite imaging.
  3. C) radar and sonar.
  4. D) seismic wave data.
  5. E) magnetic resonance imaging.

Answer:  D

Diff: 1

Section Ref.:  5.4

 

55) The atmospheric gases primarily responsible for our greenhouse effect are

  1. A) carbon monoxide and methane.
  2. B) hydrogen and helium.
  3. C) oxygen and carbon dioxide.
  4. D) argon and water vapor.
  5. E) water vapor and carbon dioxide.

Answer:  E

Diff: 1

Section Ref.:  5.4

 

 

56) In noting that the Earth is “differentiated,” we mean that

  1. A) the density increases as you descend downward toward the core.
  2. B) the Earth is very different than any other planet we study.
  3. C) the Earth’s magnetic field varies at different locations on the globe.
  4. D) the density of oceanic basalt is less than that of granite on the mountain tops.
  5. E) the radioactive heating in the core is increasing with time.

Answer:  A

Diff: 1

Section Ref.:  5.4

 

57) Seismic waves are most useful for mapping

  1. A) the surface of Venus with Magellan.
  2. B) the surface of Mars with Global Surveyor.
  3. C) the Earth’s core and mantle.
  4. D) the density of the hydrosphere.
  5. E) the depths of the oceans.

Answer:  C

Diff: 2

Section Ref.:  5.4

58) Which statement about seismic waves is true?

  1. A) Only S waves can travel through liquid.
  2. B) P waves travel faster, and thus arrive sooner than do the S waves.
  3. C) In the shadow zones, neither type is observed.
  4. D) S waves can travel though the outer core, but P waves cannot.
  5. E) On the far side of the Earth, only the S waves on the surface can be detected.

Answer:  B

Diff: 3

Section Ref.:  5.4

 

59) Which of these is not a result of plate tectonics?

  1. A) the Grand Canyon
  2. B) the Andes
  3. C) the Mid-Atlantic Rift
  4. D) the San Andreas Fault
  5. E) the Philippine Trench

Answer:  A

Diff: 2

Section Ref.:  5.5

 

 

60) Today, an average lunar moonquake releases about as much energy as

  1. A) an atomic bomb.
  2. B) a firecracker.
  3. C) the Mount St. Helens eruption.
  4. D) a major U.S. city uses in 1 year.
  5. E) the most powerful earthquake ever recorded.

Answer:  B

Diff: 2

Section Ref.:  5.5

 

61) The far side of the Moon was first mapped

  1. A) by Galileo in 1610 with his first telescope.
  2. B) by the Apollo astronauts on the first orbit of the Moon with Apollo 8.
  3. C) by early Russian spacecraft.
  4. D) by NASA with its Lunar Orbiters in the 1960s.
  5. E) by William Herschel with his large reflectors in the early 1800s.

Answer:  C

Diff: 2

Section Ref.:  5.6

 

62) The lunar mare are found

  1. A) uniformly all over the Moon.
  2. B) mainly on the near side.
  3. C) mainly on the far side.
  4. D) only in the dark areas of the lunar poles, where water is not boiled away.
  5. E) only as layered rocks, since the original water was lost long ago.

Answer:  B

Diff: 2

Section Ref.:  5.6

63) Which of these age ranges best describes the lunar maria?

  1. A) 8.6 – 6.0 billion years
  2. B) 3.9 – 3.2 billion years
  3. C) 2.5 – 1.0 billion years
  4. D) 100 – 65 million years
  5. E) a few million years to present lava flows seen erupting

Answer:  B

Diff: 2

Section Ref.:  5.6

 

 

64) The rate of cratering in the lunar highlands shows us that

  1. A) they must be younger than the older, darker mare.
  2. B) they range from 4.6 – 4.4 billion years old, on average.
  3. C) the largest impacts are the youngest, such as Copernicus and Tycho.
  4. D) the oldest rocks are at least as old as the mare, but some craters are much younger.
  5. E) most of the asteroids must have hit the Moon, not the Earth.

Answer:  B

Diff: 2

Section Ref.:  5.6

 

65) What is true of the lunar highlands?

  1. A) They are found on the Moon’s northern hemisphere.
  2. B) They are less heavily cratered than the mare.
  3. C) They are the darker regions of the Moon seen with the naked eye.
  4. D) They are younger than the darker mare.
  5. E) They are the oldest part of the lunar surface.

Answer:  E

Diff: 3

Section Ref.:  5.6

 

66) The presence of a magnetic field is a good indication that

  1. A) the Earth’s interior is similar to Mercury’s, as both have fields.
  2. B) a huge iron meteorite lies somewhere high up in the mantle, not in the core.
  3. C) the Earth has a liquid metal outer core, spinning rapidly as it rotates.
  4. D) the Earth’s interior must be completely molten to the center.
  5. E) the Earth’s interior has had time to solidify, with a rigid bar magnet created.

Answer:  C

Diff: 1

Section Ref.:  5.7

 

67) When strong solar winds are displaced poleward by our magnetic fields, we get

  1. A) the Van Allen radiation belts.
  2. B) intense auroral displays.
  3. C) sunspots.
  4. D) hurricanes in the tropics.
  5. E) droughts and dust bowls in the American West.

Answer:  B

Diff: 1

Section Ref.:  5.7

 

68) The region in which charged particles are trapped by our magnetic fields is the

  1. A) ionosphere.
  2. B) ozone layers.
  3. C) exosphere.
  4. D) Van Allen radiation belt.
  5. E) Aurora.

Answer:  D

Diff: 2

Section Ref.:  5.7

 

69) Earth’s magnetic field

  1. A) prevents charged particles in the solar wind from reaching the surface.
  2. B) is a remnant of the solar nebula’s magnetic field.
  3. C) is weakening the Van Allen radiation belts.
  4. D) is the force behind plate tectonics.
  5. E) lines intersect the atmosphere at the equator.

Answer:  A

Diff: 2

Section Ref.:  5.7

 

70) Which statement about our core is FALSE?

  1. A) It generates a stable and permanent magnetic field much as a regular bar magnet.
  2. B) Its magnetic field generates the protective Van Allen radiation Belts.
  3. C) It must be rich in both iron and nickel.
  4. D) The seismic data indicates the outer portion is liquid, the inner part solid.
  5. E) It is almost as hot as the Sun’s glowing surface, the photosphere.

Answer:  A

Diff: 3

Section Ref.:  5.7

 

71) Which of these theories seems to best explain the Moon’s origin?

  1. A) Impact Theory
  2. B) Capture Theory
  3. C) Coformation Theory
  4. D) Fission Theory
  5. E) Fusion Theory

Answer:  A

Diff: 1

Section Ref.:  5.8

 

72) The bulk density of the Moon is ________ than that of the Earth it orbits.

Answer:  less (about 60%)

Diff: 1

Section Ref.:  5.1

 

 

73) The ________ tides occur when there is little tidal variation, near first and third quarter moons.

Answer:  neap

Diff: 1

Section Ref.:  5.2

74) The ________ tides have a large change from high to low, near new and full moons.

Answer:  spring

Diff: 1

Section Ref.:  5.2

 

75) The spring tide can occur at either ________ or ________ phases of the Moon.

Answer:  new; full

Diff: 1

Section Ref.:  5.2

 

76) The neap tide can occur at the ________ or ________ phases of the Moon.

Answer:  first; third quarter

Diff: 1

Section Ref.:  5.2

 

77) The Moon’s spin-orbit resonance shows it is ________ with the Earth.

Answer:  tidally locked

Diff: 1

Section Ref.:  5.2

 

78) The Sun reinforces the Moon’s tidal pull during ________ tides.

Answer:  spring

Diff: 1

Section Ref.:  5.2

 

79) The tidal pull of the Sun largely cancels that of the Moon at the ________ phases.

Answer:  quarter

Diff: 1

Section Ref.:  5.2

 

80) Plate ________ is the process by which convection within the mantle reforms the crust above it.

Answer:  tectonics

Diff: 1

Section Ref.:  5.5

 

81) The ________ has the largest gravitational pull on Earth.

Answer:  Sun

Diff: 1

Section Ref.:  5.2

 

82) The difference in the Moon’s gravitational force on the near and far sides of the Earth produces a ________.

Answer:  tidal bulge

Diff: 2

Section Ref.:  5.2

 

83) The greenhouse effect always results in a ________ surface temperature.

Answer:  higher or hotter

Diff: 1

Section Ref.:  5.3

84) The ozone layer blocks much of the Sun’s ________ radiation.

Answer:  ultraviolet

Diff: 1

Section Ref.:  5.3

 

85) The most abundant gas in the Earth’s atmosphere is ________.

Answer:  nitrogen

Diff: 1

Section Ref.:  5.3

 

86) The oxygen in our atmosphere is produced by ________.

Answer:  life processes

Diff: 1

Section Ref.:  5.3

 

87) The ________ in our atmosphere is the result of photosynthesis by plants.

Answer:  oxygen

Diff: 1

Section Ref.:  5.3

 

88) ________ radiation is trapped close to our surface by the greenhouse effect.

Answer:  Infrared (or heat)

Diff: 1

Section Ref.:  5.3

 

89) The Moon lacks an atmosphere because its surface gravity is only ________ the Earth’s.

Answer:  one-sixth

Diff: 2

Section Ref.:  5.3

 

90) The water that has been detected on the Moon lies at its ________.

Answer:  poles

Diff: 2

Section Ref.:  5.3

 

 

91) Weather always occurs in the lowest layer of the atmosphere, the ________.

Answer:  troposphere

Diff: 2

Section Ref.:  5.3

 

92) Our molten core is believed to consist primarily of the element ________.

Answer:  iron

Diff: 1

Section Ref.:  5.4

 

93) To map the Earth’s interior, we rely on ________ waves created by earthquakes.

Answer:  seismic

Diff: 1

Section Ref.:  5.4

94) The most important greenhouse effect gas in our atmosphere is ________.

Answer:  carbon dioxide

Diff: 1

Section Ref.:  5.4

 

95) Because the interior of the Earth is ________, the crust is much less dense than the core.

Answer:  differentiated (or molten)

Diff: 2

Section Ref.:  5.4

 

96) The ________ seismic waves can pass through both solid and liquid portions of the Earth’s interior, and be detected on the other side of the globe.

Answer:  P

Diff: 2

Section Ref.:  5.4

 

97) For differentiation to have occurred, the Earth’s interior must have been ________.

Answer:  molten

Diff: 2

Section Ref.:  5.4

 

98) ________ waves cannot travel through the Earth’s liquid outer core.

Answer:  S

Diff: 2

Section Ref.:  5.4

 

99) A hot, molten body of different materials will become ________.

Answer:  differentiated

Diff: 2

Section Ref.:  5.4

 

 

100) ________ is responsible for heating the Earth’s interior today.

Answer:  Radioactive decay

Diff: 2

Section Ref.:  5.4

 

101) The oldest rocks found on the Earth’s surface date back about ________ billion years.

Answer:  four

Diff: 1

Section Ref.:  5.8

 

102) The ________ in the oceans arise where two advancing plates meet and one is pushed beneath the other, a process called subduction.

Answer:  trenches

Diff: 2

Section Ref.:  5.5

 

103) Dominating the lunar ________, craters are the result of asteroid and comet impacts.

Answer:  highlands

Diff: 1

Section Ref.:  5.6

104) The dominant dark features on the near side of the Moon are the ________.

Answer:  mare

Diff: 1

Section Ref.:  5.6

 

105) The age dating of the solar system is done by radioactive dating of ________.

Answer:  meteorites

Diff: 1

Section Ref.:  5.6

 

106) The mare are really seas of long since hardened ________, a dark volcanic rock that also makes up the ocean basins of Earth.

Answer:  basalt

Diff: 2

Section Ref.:  5.6

 

107) When strong solar wind storms are diverted poleward by our magnetic fields, we often observe ________ in the ionosphere.

Answer:  aurorae

Diff: 1

Section Ref.:  5.7

 

108) The ________ are two layers of charged particles trapped by our magnetic fields.

Answer:  Van Allen radiation belts

Diff: 1

Section Ref.:  5.7

 

109) In order for the dynamo effect to generate a magnetic field, Earth’s outer core must be rapidly spinning, molten, and made of ________.

Answer:  conducting materials

Diff: 3

Section Ref.:  5.7

 

110) The coformation hypothesis for the origin of the Moon is difficult to reconcile with the dissimilar ________ and ________ of the Earth and Moon.

Answer:  density; composition.

Diff: 1

Section Ref.:  5.8

 

111) The ________ hypothesis is now the most popular to explain the Moon’s origin.

Answer:  impact

Diff: 1

Section Ref.:  5.8

 

112) In general, the ________ lunar craters sit atop the mare.

Answer:  youngest

Diff: 2

Section Ref.:  5.8

113) The Moon’s composition is similar to Earth’s ________.

Answer:  mantle.

Diff: 3

Section Ref.:  5.8

 

114) List the six main regions of the Earth, in order, starting from the center.

Answer:  core, mantle, crust, hydrosphere, atmosphere, magnetosphere

Diff: 3

Section Ref.:  5.1

 

115) When do spring tides occur? How much tidal variation is noted?

Answer:  When Earth, Moon, and Sun are aligned, at new and full phases. The difference between high and low tides is large.

Diff: 2

Section Ref.:  5.2

 

116) When and why do neap tides occur? How much tidal variation is noted?

Answer:  At first and third quarter phase, the Sun cancels out the Moon’s tidal pull to some degree, and the tidal variation is small.

Diff: 2

Section Ref.:  5.2

 

 

117) What is meant by tidal locking?

Answer:  The gravitational force of the Earth on the Moon has slowed the Moon’s rotation so that it rotates (spins) once during every orbit. One side always faces the Earth.

Diff: 3

Section Ref.:  5.2

 

118) What are the short- and long-term effects of the Moon’s tides on our rotation?

Answer:  The Moon slows down our rotation slightly, with precession being the long-term effect of this tidal distortion.

Diff: 3

Section Ref.:  5.2

 

119) Why does the Moon lack an atmosphere?

Answer:  Its atmosphere escaped into space due to the low surface gravity of the Moon.

Diff: 2

Section Ref.:  5.3

 

120) Name the layers of the Earth’s atmosphere, going up from the surface.

Answer:  troposphere, stratosphere, mesosphere, ionosphere

Diff: 3

Section Ref.:  5.3

 

121) Why does the Earth’s atmosphere contain much more nitrogen than hydrogen?

Answer:  Heavier nitrogen can be retained by our gravity, whereas lighter hydrogen leaks away into space, because its average molecular speed at the Earth’s temperature exceeds the Earth’s escape velocity.

Diff: 3

Section Ref.:  More Prec. 5.1

122) What does it mean when we say the Earth’s interior is differentiated?

Answer:  In a molten state, the denser materials sank to our core, and the lighter material rose to form our crust.

Diff: 1

Section Ref.:  5.4

 

123) What were the two primary courses of heating that let the Earth differentiate?

Answer:  Impacts of interplanetary debris and radioactive decay.

Diff: 2

Section Ref.:  5.4

 

124) Which side of the Moon has the thicker crust? Why?

Answer:  The far side, because our tides pulled the molten core toward us, making the Earth-side crust thinner.

Diff: 2

Section Ref.:  5.4

 

 

125) Where is the newest material in the Earth’s crust found?

Answer:  At the mid-ocean ridges, where plate tectonics constantly extrudes new lava.

Diff: 2

Section Ref.:  5.5

 

126) Note at least three surface features that are driven by plate tectonics.

Answer:  Rift valleys, trenches, mountain ranges, volcanic chains, faults, midocean ridges

Diff: 1

Section Ref.:  5.5

 

127) What surface region of the Moon is oldest? How do we know this?

Answer:  The highlands are older than the maria, as evidenced both by the higher degree of cratering and the actual radioactive dating of Apollo samples.

Diff: 1

Section Ref.:  5.6

 

128) List the two major regions of the near side of the Moon, as seen with the naked eye.

Answer:  The darker maria and the brighter highlands

Diff: 1

Section Ref.:  5.6

 

129) What is the primary source of erosion on the Moon today?

Answer:  Meteorite and micrometeorite bombardment of the surface slowly reduces and alters the features, creating a thick layer of dust.

Diff: 3

Section Ref.:  5.6

 

130) Name two consequences of the Earth’s magnetic field detected from space.

Answer:  The Van Allen radiation belts lie around our equator, and the tail of charged particles much like a comet’s tail extending past the Moon.

Diff: 3

Section Ref.:  5.7

131) Name two observable consequences of the Earth’s tidal pull on the Moon.

Answer:  The Moon is tidally locked by our tides, with the same heavier side always pointed toward us; the tides also caused the dark mare to flow out on our side chiefly.

Diff: 2

Section Ref.:  5.8

 

132) Of the six layers of Earth, which is unique among the planets? Why?

Answer:  The hydrosphere, since liquid water is found on the surface in abundance here only.

Diff: 2

Section Ref.:  5.1

 

 

133) Why does the Moon play a larger role in tides than the Sun?

Answer:  The Sun is much more massive, and has a greater gravitational pull, but the Moon is much closer, and differentially pulls more on the side of Earth it faces.

Diff: 2

Section Ref.:  5.2

 

134) Contrast spring and neap tides.

Answer:  At spring tides, the Sun and Moon act in concert, making for large tidal variation. At neap tides, the Sun lies 90 degrees from the Moon at quarter phases, and largely cancels out the tidal pull of the Moon.

Diff: 2

Section Ref.:  5.2

 

135) Contrast S and P waves in terms of speed and transmission through the interior.

Answer:  P waves travel faster, and can move through the molten outer core, while slower S waves are not able to pass through a fluid such as the core.

Diff: 2

Section Ref.:  5.4

 

136) Why are plate tectonics not as important a factor on the Moon as they are on Earth?

Answer:  The Moon no longer has a molten core, and as it chilled faster than did the larger Earth, the Moon has a thicker crust. The Earth’s thin crust is constantly being broken by the conveyor belt of magma pushing upward through our mantle.

Diff: 3

Section Ref.:  5.4, 5.5

 

137) How do earthquakes allow us to model the structure of Earth’s core?

Answer:  Examining the different seismic waves we find P and S waves are not recorded by all over the planet. There is a blind spot for S waves on the side of Earth opposite the earthquake, and there is a shadow zone part way around the surface from the earthquake. Since we know S waves cannot travel through liquid and P waves can, we conclude the Earth’s core is liquid. Since P waves bend when they enter the liquid core, but some travel straight through, it implies there is a solid center to the liquid outer core.

Diff: 3

Section Ref.:  5.4

138) Name the three principal divisions of the structure of the Earth’s interior and the chemical composition of each.

Answer:  The core is made of molten iron and nickel, the mantle of silicates, and the crust of still less dense silicates.

Diff: 3

Section Ref.:  5.4

 

 

139) According to the reanalysis of the Apollo seismic data in 2011, what is the structure of the lunar interior?

Answer:  The central core is about 330 km in radius. The innermost 240 km is solid; the rest, as well as the innermost 150 km of the surrounding inner mantle, is liquid. The rest of the inner mantle, 250 km worth, is semi-solid; the outer mantle is about 900 km thick and is solid. The solid crust varies in thickness from 60 to 150 km.

Diff: 2

Section Ref.:  5.5

 

140) Which two continents are the most obvious pieces in the continental jigsaw puzzle of plate tectonics? Why?

Answer:  South America and Africa were split by the mid-Atlantic rift, and have spread apart in the last 70 million years.

Diff: 2

Section Ref.:  5.5

 

141) Where is the most obvious example of a mountain chain built by continental collision in plate tectonics? Which plates are involved in this head-on collision?

Answer:  The Himalaya Mountains are the result of the uplifting as the Indian subcontinent has rammed into Asia in the last 30 million years.

Diff: 2

Section Ref.:  5.5

 

142) Which plates are causing the formation of the Andes mountains in western South America? Describe their motions.

Answer:  The Nazca plate and South American Plate are moving toward each other, causing the Andes mountains.

Diff: 3

Section Ref.:  5.5

 

143) Why are Moon rocks older than Earth rocks, if the impact theory has the Moon being made by another body striking the newly formed Earth?

Answer:  The Earth’s surface is constantly being reformed by plate tectonics and atmospheric erosion processes, while the Moon is no longer geologically active.

Diff: 3

Section Ref.:  5.5

 

144) Why is the Moon heavily cratered but Earth is not?

Answer:  The Moon lacks an atmosphere which means it has no weather. It also lacks a molten interior which means it has no plate tectonics. On the Moon the major form of erosion is meteorite bombardment, which is a very slow process. On Earth, wind and rain cause weathering (rapid erosion) of crater features. Plate tectonics is constantly changing the surface of the Earth, creating new crust and recycling old.

Diff: 3

Section Ref.:  5.5, 5.6

 

145) What features are conspicuously absent from the far side of the Moon? Why?

Answer:  The mare are found chiefly on the side facing Earth, since our tides have pulled the formerly molten lunar core closer to us, making the crust thinner on our side.

Diff: 2

Section Ref.:  5.6

 

146) Explain how crater counts allow us to estimate the ages of surfaces throughout the solar system.

Answer:  Craters are the rule…everybody was a target in the early days of accretion. The longer the surface has sat without internal deformation, the more impacts have cratered the surface. If craters are absent, it is because other processes, such as lava flows or erosion, have replaced the older cratering.

Diff: 2

Section Ref.:  5.6

 

147) What is the primary source of erosion on the Moon? Why does change there take so long?

Answer:  A constant fall of meteoroids from space pelts the moon, pulverizing the surface with tiny craters. But really big impacts are rare, and these microscopic changes take a long time to show up as seen from Earth. Our erosive agents like wind, water, and ice can make much more dramatic changes in short periods of time, such as floods, sandstorms, glaciers, etc.

Diff: 3

Section Ref.:  5.6

 

148) Relate our magnetic field to the aurorae.

Answer:  The magnetic field’s Van Allen radiation belts deflect the charged particles away from our equator toward the poles, where the charged particles spiral down the magnetic field lines and hit the ionosphere to create the colorful ionized patterns.

Diff: 2

Section Ref.:  5.7

 

149) Why is the impact theory now preferred as an explanation for the Moon’s origin?

Answer:  The capture theory is unlikely for a body as big as the Moon, while the coformation theory would have the Moon orbit our equator as it condensed. The impacting body would be of different composition than the Earth, and the heat of impact would drive off the lighter materials, as noted for the Moon’s crust. The body would also have been moving in the ecliptic plane before impact, and the Moon still orbits close to the ecliptic even now.

Diff: 3

Section Ref.:  5.8

 

Astronomy: A Beginner’s Guide to the Universe, 7e (Chaisson/McMillan)

Chapter 7   The Jovian Planets: Giants of the Solar System

 

1) A gravitational assist, or slingshot, can be used to either speed up or slow down a spacecraft.

Answer:  TRUE

Diff: 1

Section Ref.:  7.1

 

2) All nine planets in the solar system have been visited by spacecraft.

Answer:  FALSE

Diff: 1

Section Ref.:  7.1

 

3) William Herschel was the discoverer of Uranus.

Answer:  TRUE

Diff: 1

Section Ref.:  7.2

 

4) Galileo’s early telescopes revealed the four large moons of Jupiter, the rings of Saturn, and its large moon Titan.

Answer:  FALSE

Diff: 2

Section Ref.:  7.1

 

5) While Voyagers were probes that flew past in a few days, Galileo and Cassini are orbiters, designed to study Jupiter and Saturn over prolonged periods of time.

Answer:  TRUE

Diff: 2

Section Ref.:  7.1

 

6) Most of our detailed knowledge of the jovian planets comes from the Hubble Space Telescope.

Answer:  FALSE

Diff: 2

Section Ref.:  7.1

 

7) The Galileo probe was deliberately steered into Jupiter’s atmosphere, ending its mission.

Answer:  TRUE

Diff: 2

Section Ref.:  7.1

 

8) When Cassini entered orbit around Saturn, it caused the planet’s orbit to change.

Answer:  TRUE

Diff: 3

Section Ref.:  7.1, More Prec. 7.1

 

 

9) Like the discovery of Uranus, the finding of Neptune was accidental.

Answer:  FALSE

Diff: 1

Section Ref.:  7.2

10) Changes in the predicted motion of Uranus led to the search for an eighth planet.

Answer:  TRUE

Diff: 2

Section Ref.:  7.2

 

11) Saturn is less dense than water.

Answer:  TRUE

Diff: 1

Section Ref.:  7.3

 

12) All four jovian planets are made primarily of hydrogen and oxygen.

Answer:  FALSE

Diff: 1

Section Ref.:  7.3

 

13) Differential rotation is when a planet’s equatorial and polar regions rotate at different rates.

Answer:  TRUE

Diff: 1

Section Ref.:  7.3

 

14) All four jovian planets spin faster than any of the terrestrials.

Answer:  TRUE

Diff: 2

Section Ref.:  7.3

 

15) The equators of all four jovian planets rotate more rapidly than the polar regions.

Answer:  FALSE

Diff: 2

Section Ref.:  7.3

 

16) Jupiter’s axial tilt is similar to that of Mercury, while Saturn’s is more like ours.

Answer:  TRUE

Diff: 2

Section Ref.:  7.3

 

17) The rotation of the magnetic fields of the jovian planets is believed to also give us the rotation rate of the planet’s core.

Answer:  TRUE

Diff: 2

Section Ref.:  7.3

 

 

18) There is a clear relationship between the interior and atmospheric rotation rates of the jovian planets.

Answer:  FALSE

Diff: 2

Section Ref.:  7.3

 

19) The axial tilts of Uranus and Neptune are similar.

Answer:  FALSE

Diff: 2

Section Ref.:  7.3

20) Jupiter’s Great Red Spot is similar to a hurricane on Earth except for its size.

Answer:  TRUE

Diff: 1

Section Ref.:  7.4

 

21) Jupiter’s atmosphere looks uniform and calm, with no visible detail.

Answer:  FALSE

Diff: 1

Section Ref.:  7.4

 

22) The zonal flows giving rise to the belts and zones are similar to the jet streams in our own stratosphere.

Answer:  TRUE

Diff: 1

Section Ref.:  7.4

 

23) Although water and ammonia can produce Jupiter’s white clouds, the complex coloration we observe in Jupiter’s atmosphere requires more complex chemistry.

Answer:  TRUE

Diff: 2

Section Ref.:  7.4

 

24) The Galileo probe into Jupiter’s atmosphere found more water than expected.

Answer:  FALSE

Diff: 2

Section Ref.:  7.4

 

25) Helium is more abundant on Saturn than on Jupiter.

Answer:  FALSE

Diff: 2

Section Ref.:  7.5

 

 

26) Although it is almost the same size as Jupiter, Saturn’s gravity is about 2.5 times less, because of Saturn’s lower mass and density.

Answer:  TRUE

Diff: 2

Section Ref.:  7.3, 7.5

 

27) There is less ammonia in the atmospheres of Uranus and Neptune than in Jupiter or Saturn.

Answer:  TRUE

Diff: 2

Section Ref.:  7.5

 

28) Neptune has a larger fraction of methane in its atmosphere than Uranus.

Answer:  TRUE

Diff: 2

Section Ref.:  7.5

 

29) The less internal heat a jovian planet emits, the more it stirs up its clouds.

Answer:  FALSE

Diff: 2

Section Ref.:  7.5

30) The Great Dark Spot of Neptune is probably just as long-lived as the more famed Great Red Spot of Jupiter; both lie at about the same latitudes, and are about the same size, relative to their planet.

Answer:  FALSE

Diff: 2

Section Ref.:  7.5

 

31) Methane absorbs red light readily, so we would expect a planet with a mostly methane atmosphere to appear blue.

Answer:  TRUE

Diff: 3

Section Ref.:  7.5

 

32) All four jovian planets are oblate, with larger polar than equatorial diameters.

Answer:  FALSE

Diff: 1

Section Ref.:  7.6

 

33) We have observed a comet strike Jupiter.

Answer:  TRUE

Diff: 1

Section Ref.:  7.6

 

 

34) Most of Jupiter’s volume is probably in the form of liquid metallic helium.

Answer:  FALSE

Diff: 2

Section Ref.:  7.6

 

35) In keeping with its Greek god, Neptune probably contains a lot of water, in a slushy mantle ocean.

Answer:  TRUE

Diff: 2

Section Ref.:  7.6

 

36) Jupiter’s magnetic field is much stronger than Earth’s, and has a magnetic tail that extends beyond the orbit of Saturn.

Answer:  TRUE

Diff: 2

Section Ref.:  7.6

 

37) Aurorae like ours have been seen above the poles of Jupiter and Uranus.

Answer:  FALSE

Diff: 2

Section Ref.:  7.6

 

38) All four Jovian magnetic fields are good examples of the dynamo theory, with the magnetic fields aligned well with the planets’ rapid rotations.

Answer:  FALSE

Diff: 2

Section Ref.:  7.6

39) Jupiter puts back into space twice the energy it gets from the Sun.

Answer:  TRUE

Diff: 2

Section Ref.:  7.6

 

40) Uranus’ rotation axis is tipped over 98 degrees, so its magnetosphere is tipped over the same amount.

Answer:  FALSE

Diff: 2

Section Ref.:  7.6

 

 

41) Our most detailed knowledge of Uranus and Neptune comes from

  1. A) spacecraft exploration.
  2. B) the Hubble Space telescope.
  3. C) ground-based visual telescopes.
  4. D) ground-based radio telescopes.
  5. E) manned missions.

Answer:  A

Diff: 1

Section Ref.:  7.1

 

42) The spacecraft Cassini went into orbit around

  1. A) Jupiter.
  2. B) Saturn.
  3. C) Uranus.
  4. D) Neptune.
  5. E) Pluto.

Answer:  B

Diff: 1

Section Ref.:  7.1

 

43) The Galileo mission put a spacecraft into orbit around Jupiter. Which statement is true?

  1. A) The spacecraft crashed into the moon Europa.
  2. B) The spacecraft used a gravity assist from both Venus and Earth.
  3. C) A saltwater ocean was discovered on Jupiter.
  4. D) Intense magnetic fields were discovered in the asteroid belt.
  5. E) A probe was released which soft landed on Io.

Answer:  B

Diff: 2

Section Ref.:  7.1

 

44) Which three played a role in the finding of Neptune?

  1. A) Herschel, Hubble, and Einstein
  2. B) Newton, Einstein, and Tombaugh
  3. C) Adams, Leverrier, and Galle
  4. D) Bode, Herschel, and Fraunhofer
  5. E) Shapley, Hubble, and Whipple

Answer:  C

Diff: 2

Section Ref.:  7.2

 

45) Small deviations in a planet’s orbital motion

  1. A) show we don’t fully understand gravitational forces yet.
  2. B) indicate the presence of an extensive atmosphere.
  3. C) indicate the presence of a powerful magnetic field.
  4. D) imply the nearby presence of a massive body.
  5. E) show the planet’s orbit isn’t stable.

Answer:  D

Diff: 2

Section Ref.:  7.2

 

46) Adams and Leverrier both predicted the position of Neptune, based on its effects on

  1. A) the Sun.
  2. B) Jupiter.
  3. C) Saturn.
  4. D) Uranus.
  5. E) Pluto.

Answer:  D

Diff: 2

Section Ref.:  7.2

 

47) Uranus was discovered

  1. A) by Galileo.
  2. B) thousands of years ago.
  3. C) with a radio telescope.
  4. D) after examining perturbations in Neptune’s orbit.
  5. E) less than 250 years ago.

Answer:  E

Diff: 2

Section Ref.:  7.2

 

48) At which planet can the pole remain in darkness for 42 years, then have 42 years of constant daylight?

  1. A) Jupiter
  2. B) Saturn
  3. C) Uranus
  4. D) Neptune
  5. E) Pluto

Answer:  C

Diff: 1

Section Ref.:  7.3

 

 

49) In terms of axial tilt, which of the jovian planets shows us the largest inclination?

  1. A) Jupiter
  2. B) Saturn
  3. C) Uranus
  4. D) Neptune
  5. E) Pluto

Answer:  C

Diff: 1

Section Ref.:  7.3

50) If you could find a bathtub big enough for Saturn, the planet would

  1. A) precipitate more helium.
  2. B) float.
  3. C) explode due to its liquid metallic hydrogen.
  4. D) catch fire, as liquid sodium reacts with water.
  5. E) sink due to its metallic interior.

Answer:  B

Diff: 1

Section Ref.:  7.3

 

51) The planet whose pole was facing the Sun when Voyager 2 approached in 1986 was

  1. A) Jupiter.
  2. B) Saturn.
  3. C) Uranus.
  4. D) Neptune.
  5. E) Mars.

Answer:  C

Diff: 1

Section Ref.:  7.3

 

52) Jupiter and the other jovian planets are noticeably oblate because

  1. A) they all have strong magnetic fields that deform their shape.
  2. B) their powerful gravity acts stronger on the closer poles than the distant equator.
  3. C) they are fluid bodies that are spinning rapidly.
  4. D) they are tidally distorted by the pulls for their satellite systems.
  5. E) All of the above are correct.

Answer:  C

Diff: 2

Section Ref.:  7.3

 

 

53) Cometary impacts with Jupiter

  1. A) are impossible to observe from Earth.
  2. B) have been observed from Earth at least twice.
  3. C) are extremely rare.
  4. D) are spectacular but do not teach us much.
  5. E) would not be catastrophic if they happened on Earth.

Answer:  B

Diff: 2

Section Ref.:  Discovery 7.2

 

54) Which of these is true about the seasons of Uranus?

  1. A) With a tilt of 29 degrees, they are not that different from our solstices and equinoxes.
  2. B) Its strange tilt produces extreme seasonal variations, especially at the poles.
  3. C) At the Uranian equator, the Sun would pass overhead every sixteen hours.
  4. D) At the Uranian pole the Sun sets every 16 hours during the summer and winter.
  5. E) There are no seasons at the poles.

Answer:  B

Diff: 2

Section Ref.:  7.3

55) The reason the jovian planets lost very little of their original atmosphere is due to their

  1. A) rapid rotation.
  2. B) strong magnetic fields.
  3. C) ring systems.
  4. D) large mass.
  5. E) many moons.

Answer:  D

Diff: 2

Section Ref.:  7.3

 

56) Compared to Saturn, Jupiter is about

  1. A) half as massive and denser.
  2. B) three times more massive and denser.
  3. C) 100 times more massive.
  4. D) twice the diameter, but less dense.
  5. E) half as dense, but the same mass since it is larger.

Answer:  B

Diff: 2

Section Ref.:  7.3

 

 

57) Studying the magnetospheres of the jovian planets has allowed us to measure their

  1. A) interior rotation rates.
  2. B) orbital periods.
  3. C) orbital radius.
  4. D) gravity.
  5. E) ring system diameters.

Answer:  A

Diff: 2

Section Ref.:  7.3

 

58) Essentially, the Great Red Spot is

  1. A) Neptune’s largest atmospheric feature.
  2. B) a large cyclonic storm (hurricane).
  3. C) always located within 10 degrees of Jupiter’s north pole.
  4. D) composed primarily of iron oxide.
  5. E) traveling north and south across Jupiter’s face.

Answer:  B

Diff: 1

Section Ref.:  7.4

 

59) Alternating zones of rising and sinking gas in Jupiter’s atmosphere

  1. A) create light and dark bands.
  2. B) cause Jupiter’s magnetic field to ripple.
  3. C) produced the ring system discovered by Voyager.
  4. D) generate magnetic fields.
  5. E) circle the planet from pole to pole.

Answer:  A

Diff: 3

Section Ref.:  7.4

60) The only probe into the atmospheres of any jovian planet was launched by

  1. A) Voyager 2 into Titan’s atmosphere.
  2. B) Pathfinder into Mars’ atmosphere.
  3. C) Cassini into Saturn’s clouds.
  4. D) Galileo into Jupiter’s equatorial zone.
  5. E) Huygens into Saturn’s equatorial belt.

Answer:  D

Diff: 3

Section Ref.:  7.4

 

 

61) The two outer jovian planets appear bluish in color because

  1. A) methane gas in their atmospheres absorbs red light well.
  2. B) ammonia absorbs blue light well.
  3. C) hydrogen and helium are both blue in large concentrations.
  4. D) dust motes in their atmospheres scatter blue well, just as in our own blue sky.
  5. E) from their distance, the Sun would appear hotter and bluer than from Earth.

Answer:  A

Diff: 1

Section Ref.:  7.5

 

62) Which common gas is less abundant in the top of Saturn’s atmosphere, compared to what we observe at Jupiter?

  1. A) hydrogen
  2. B) helium
  3. C) nitrogen
  4. D) methane
  5. E) argon

Answer:  B

Diff: 2

Section Ref.:  7.5

 

63) Why does Saturn radiate even more excess heat than Jupiter?

  1. A) Only Saturn is still radiating heat left over from its formation.
  2. B) Saturn’s thick clouds give it a stronger greenhouse effect.
  3. C) Helium rain falling inward generates heat as it descends.
  4. D) Saturn’s atmosphere contains much methane, which is very flammable.
  5. E) Saturn is more massive than Jupiter, so its gravitational compression is stronger.

Answer:  C

Diff: 2

Section Ref.:  7.6

 

64) Which planet had the Great Dark Spot in 1989, but had lost it by 1995?

  1. A) Jupiter
  2. B) Saturn
  3. C) Uranus
  4. D) Neptune
  5. E) Mars

Answer:  D

Diff: 2

Section Ref.:  7.5

 

65) Of the jovian planets, which generates the least internal heat?

  1. A) Jupiter
  2. B) Saturn
  3. C) Uranus
  4. D) Neptune
  5. E) Pluto

Answer:  C

Diff: 2

Section Ref.:  7.6

 

66) The magnetic field tilts of which two bodies are the most unusual?

  1. A) Mercury and Earth
  2. B) Jupiter and Saturn
  3. C) Uranus and Neptune
  4. D) Saturn and Pluto
  5. E) Mars and Saturn

Answer:  C

Diff: 2

Section Ref.:  7.6

 

67) What is the source of Jupiter’s intense radio waves and magnetism?

  1. A) charged particles trapped in Jupiter’s solid iron core similar to Earth
  2. B) liquid metallic hydrogen swirling in the rapidly spinning mantle
  3. C) the ionized sulfur ejected into a torus around Jupiter by Io
  4. D) the auroral displays in the polar regions, just like with Earth
  5. E) a liquid iron and nickel outer core, just like Earth’s magnetic field

Answer:  B

Diff: 2

Section Ref.:  7.6

 

68) Jupiter gives back into space twice the energy it gets from the distant Sun. Where is this energy coming from, for the most part?

  1. A) the impact energy of comets like SL-9
  2. B) helium rain descending into its mantle and core
  3. C) the slow escape of gravitational energy left from its formation
  4. D) the radioactive decay of U-238 in its iron-rich core, just as with the Earth
  5. E) the combined tidal stress of all four large Galilean moons

Answer:  C

Diff: 2

Section Ref.:  7.6

 

 

69) What is true of Jupiter’s magnetosphere?

  1. A) Although its surface field is greater, since the planet is larger the total field is actually weaker than Earth’s.
  2. B) It does not trap protons and electrons, as Earth’s Van Allen belts do.
  3. C) It has a tail that extends at least to Saturn’s orbit.
  4. D) It is most extensive on the sunward side of the planet.
  5. E) It is only slightly stronger than Saturn’s.

Answer:  C

Diff: 2

Section Ref.:  7.6

70) What is thought to lie at the center of Jupiter?

  1. A) a hot sea of liquid metallic hydrogen
  2. B) a solid core of crystalline helium
  3. C) a massive core of rocky materials with some iron mixed in
  4. D) gaseous hydrogen and helium, for Jupiter is not differentiated like Earth
  5. E) a fusion core like the Sun’s, with hydrogen being turned into helium

Answer:  C

Diff: 2

Section Ref.:  7.6

 

71) Which two jovian planets have magnetic field tilts that are not along their rotation poles?

  1. A) Jupiter and Saturn
  2. B) Jupiter and Uranus
  3. C) Saturn and Neptune
  4. D) Uranus and Neptune
  5. E) All jovian planets have magnetic fields close to their rotational axes.

Answer:  D

Diff: 2

Section Ref.:  7.6

 

72) In brightness, Jupiter is second only to the planet ________ most of the time.

Answer:  Venus

Diff: 1

Section Ref.:  7.1

 

73) In the telescope, ________ shows the most turbulent atmosphere, with changes easily seen even with amateur telescopes.

Answer:  Jupiter

Diff: 1

Section Ref.:  7.1

 

74) The most famous and long lasting storm in the solar system is ________.

Answer:  (Jupiter’s) Great Red Spot

Diff: 1

Section Ref.:  7.1

 

75) Jupiter is largest and brightest in our skies when seen at ________.

Answer:  opposition

Diff: 2

Section Ref.:  7.1

 

76) A “gravitational slingshot” enables a spacecraft to ________.

Answer:  speed up, or slow down, or change direction.

Diff: 2

Section Ref.:  7.1

 

77) Adams and Leverrier predicted the position of ________, which Galle confirmed.

Answer:  Neptune

Diff: 1

Section Ref.:  7.2

78) William Herschel discovered the green disk of ________ as the first telescopic planet.

Answer:  Uranus

Diff: 1

Section Ref.:  7.2

 

79) While Saturn is almost as large as Jupiter, its mass is only about ________ of Jupiter’s.

Answer:  one-third

Diff: 1

Section Ref.:  7.3

 

80) The oblateness of the jovian planets’ disks is caused by their ________.

Answer:  rapid rotations

Diff: 1

Section Ref.:  7.3

 

81) Compared to the terrestrial planets, the jovian planets have ________ average densities.

Answer:  low.

Diff: 1

Section Ref.:  7.3

 

82) Of the planets, ________ is the least dense, and could float on water.

Answer:  Saturn

Diff: 1

Section Ref.:  7.3

 

83) The oblateness of the jovian planets’ disks refers to their ________ equatorial diameters, compared to the polar diameters.

Answer:  larger

Diff: 1

Section Ref.:  7.3

 

 

84) Like Jupiter’s, Saturn’s rotation is fast and differential, with the ________ rotating fastest.

Answer:  equator

Diff: 1

Section Ref.:  7.3

 

85) Unlike Jupiter and Saturn, at Uranus and Neptune the ________ rotates the slowest.

Answer:  equator

Diff: 2

Section Ref.:  7.3

 

86) In general, wind direction ________ between adjacent bands in Jupiter’s atmosphere.

Answer:  alternates

Diff: 2

Section Ref.:  7.4

 

87) Jupiter’s bright zones are cloud streams made of ________ ice crystals.

Answer:  ammonia

Diff: 1

Section Ref.:  7.4

88) Jupiter’s darker ________ are complex in color and origin, with complex organic molecules including carbon, sulfur, and nitrogen.

Answer:  belts

Diff: 1

Section Ref.:  7.4

 

89) The Great ________ Spot of Neptune was striking in 1989, but gone by 1995.

Answer:  Dark

Diff: 1

Section Ref.:  7.5

 

90) Uranus and ________ are very similar in size, mass, and color.

Answer:  Neptune

Diff: 1

Section Ref.:  7.5

 

91) The most abundant molecule in Saturn’s atmosphere is ________.

Answer:  hydrogen.

Diff: 1

Section Ref.:  7.5

 

92) ________ looked very bland in Voyager 2 photos in 1986, but as equinox approached in the 1990s, its disk showed belts, zones, and storms.

Answer:  Uranus

Diff: 1

Section Ref.:  7.5

 

93) The white zones of Jupiter and Saturn are made of ________ ice, apparently dissolved in the deep oceans of Uranus and Neptune.

Answer:  ammonia

Diff: 1

Section Ref.:  7.5

 

94) Because it has a higher percentage of ________, Neptune appears even bluer than Uranus.

Answer:  methane

Diff: 1

Section Ref.:  7.5

 

95) Methane gas absorbs the color ________, accounting for the colors of Uranus and Neptune.

Answer:  red

Diff: 2

Section Ref.:  7.5

 

96) Compared to Jupiter, the element ________ is notably less common in Saturn’s atmosphere, perhaps condensing to fall toward the core as rain.

Answer:  helium

Diff: 2

Section Ref.:  7.5

97) Compared to Jupiter, Saturn’s east-west zonal (band) flow is ________.

Answer:  more stable or faster.

Diff: 2

Section Ref.:  7.5

 

98) While the mantles of Jupiter and Saturn are made of liquid metallic hydrogen, the mantles of Uranus and Neptune are chiefly ________.

Answer:  water (and ice)

Diff: 1

Section Ref.:  7.6

 

99) Jupiter radiates twice as much energy as it receives from solar light; the source of this “excess” energy is ________.

Answer:  gravitational contraction

Diff: 1

Section Ref.:  7.6

 

100) While ________ rotation axis is only tilted 29 degrees, its magnetic fields are just as strange as its twin’s.

Answer:  Neptune’s

Diff: 1

Section Ref.:  7.6

 

 

101) Their magnetic fields should originate in the planets’ ________, but those of Uranus and Neptune don’t even come close.

Answer:  cores

Diff: 1

Section Ref.:  7.6

 

102) Jupiter’s magnetic field is produced in its rapidly spinning mantle of ________.

Answer:  liquid metallic hydrogen

Diff: 2

Section Ref.:  7.6

 

103) How are Jupiter and Saturn similar?

Answer:  Both are about the same size, with oblate disks due to rapid rotation, striped with white zones and brownish belts.

Diff: 1

Section Ref.:  7.1

 

104) Name two space probes to the jovian planets and their destinations.

Answer:  Voyager I to Jupiter and Saturn, Voyager 2 to all four jovians, Galileo to Jupiter, Cassini to Saturn.

Diff: 1

Section Ref.:  7.1

 

105) Contrast the destinations of the probes dispatched by the Galileo and Cassini missions.

Answer:  Galileo‘s probe fell into the atmosphere of Jupiter, soon to be destroyed by heat and pressure. Cassini‘s probe, built by the ESA, was sent into the atmosphere of Saturn’s moon, Titan.

Diff: 1

Section Ref.:  7.1

106) Describe how the motion of Uranus led to the discovery of Neptune.

Answer:  Uranus at first was moving faster than predicted, then after 1822 mysteriously slowed down, as it had passed Neptune and was now pulled back by Neptune’s gravity. Adams and Leverrier used this perturbation to predict the position of Neptune, which Galle used to telescopically locate its blue disk.

Diff: 3

Section Ref.:  7.2

 

107) Contrast the rotation rates of the jovian planets with the terrestrial planets.

Answer:  All four jovian planets have a much faster rotation rate than any of the Terrestrial planets.

Diff: 1

Section Ref.:  7.3

 

 

108) Contrast the differential rotations of the four jovian planets. Explain.

Answer:  At Jupiter and Saturn, the equators rotate the fastest, but at Uranus and Neptune, the higher latitudes rotate faster than the equator. We do not yet understand this.

Diff: 3

Section Ref.:  7.3

 

109) Uranus and Neptune are often called twin worlds. How do their axial tilts differ?

Answer:  At 98 degrees, Uranus is flopped over on its side, and can have its pole pointing directly at the Sun, as it did when Voyager 2 passed it in 1986. Neptune’s tilt is a more normal 29 degrees.

Diff: 3

Section Ref.:  7.3

 

110) What element is notably deficient in Saturn’s atmosphere, and why?

Answer:  Helium seems to be condensing and raining downward toward Saturn’s mantle.

Diff: 2

Section Ref.:  7.5

 

111) What common gas assumes an uncommon state in the mantles of Jupiter and Saturn? Why?

Answer:  Hydrogen. On Earth hydrogen is a gas because of the pressure and temperature in our atmosphere. On Jupiter and Saturn, it can be liquid and have the properties of a metal because of the much higher temperatures and pressures.

Diff: 2

Section Ref.:  7.6

 

112) In what ways are the magnetic fields of Uranus and Neptune unusual?

Answer:  Unlike the magnetic fields of Earth, Jupiter, and Saturn, the fields of Uranus and Neptune are not aligned with the rotational axis of their planet. Additionally, both fields are offset from their planet’s center by a significant amount.

Diff: 3

Section Ref.:  7.6

 

113) Why do Uranus and Neptune appear bluish?

Answer:  Methane absorbs red light, and is common in their atmospheres.

Diff: 3

Section Ref.:  7.6

114) Compare and contrast the Galileo and Cassini missions.

Answer:  Both are orbiters of jovian planets, but the probe for Galileo fell into Jupiter’s atmosphere, while the Huygens probe from Cassini was sent to Saturn’s large moon Titan. Both used a gravitational slingshot via Earth and Venus to reach their destinations, resulting in reduced fuel consumption and possibly a longer than expected useful life. Cassini was able to collect data on Jupiter as it flew past.

Diff: 2

Section Ref.:  7.1

 

 

115) Why was Voyager 2 an extremely efficient and productive probe?

Answer:  Using gravitational assists, Voyager 2 was able to visit all four jovian planets, making many discoveries along the way. In effect, one spacecraft performed the equivalent of four missions.

Diff: 2

Section Ref.:  7.1

 

116) Compare the differential rotation rates of the four jovian planets.

Answer:  Jupiter and Saturn rotate rapidly, in about ten hours, with their equators spinning fastest. Both Uranus and Neptune spin slower (but still faster than Earth), and their equators spin slower than their higher latitudes.

Diff: 2

Section Ref.:  7.3

 

117) Discuss the seasons of Uranus.

Answer:  Flopped over with a 98 degree tilt, Uranus’ pole was pointing toward the Sun at solstice in 1986 when Voyager 2 flew past. With one hemisphere in constant daylight, the atmosphere was very bland. But by equinox in 2008, the whole planet was receiving eight hours of day and night, and the heating patterns were producing more normal jovian belts and zones. At each pole, you would get 42 years of constant Sun, then 42 years of darkness.

Diff: 2

Section Ref.:  7.3

 

118) How might the odd tilt of Uranus have been produced?

Answer:  As with the making of our Moon and Earth’s axial tilt, a large impact is possibly the factor that flipped Uranus over on its side.

Diff: 2

Section Ref.:  7.3

 

119) Contrast the compositions of Jupiter’s belts and zones.

Answer:  The zones are high, cold regions of ammonia ice crystals, white in color. But the lower, warmer belts are brownish from complex chemistry involving hydrogen sulfide, ammonia, and other chemicals.

Diff: 2

Section Ref.:  7.4

120) Discuss the roles that ammonia, hydrogen sulfide, and methane play in the appearances of the jovian planets.

Answer:  White ammonia ice makes up the zones of Jupiter and Saturn, and combines with hydrogen sulfide and other chemicals to make up the brownish belts. But it is not as common at Uranus and Neptune, perhaps instead dissolved in their water mantles. At Uranus and Neptune, methane is the chief coloring agent, absorbing red light strongly, and reflecting the blue light back into space.

Diff: 2

Section Ref.:  7.5

 

 

121) Name two ways the magnetic fields of Uranus and Neptune defy the normal behavior of planetary magnetic fields.

Answer:  Their fields are tilted very far off the rotation axes of both planets; most other planets have fields within 10 degrees of their poles. Neither field goes directly through the core of its planet, while all other fields seem to originate in the cores of their planets.

Diff: 2

Section Ref.:  7.6

 

122) Contrast the Great Red and Great Dark Spots.

Answer:  Both storms are oval, and lie at mid-southern latitudes. But Jupiter’s Great Red Spot has been continuously observed since we had telescopes that could spot it, while the Great Dark Spot was prominent for Voyager 2 in 1989, but had vanished from the disk of Neptune by 1995.

Diff: 3

Section Ref.:  7.6

 

123) Describe the interaction between Jupiter and Comet Shoemaker-Levy 9.

Answer:  When the comet passed close to Jupiter in 1992, gravitational tidal forces tore the nucleus apart, leaving it in fragments. On its approach in 1994, it struck the planet. Vibrations in the interior and atmospheric effects lasted for days. Huge fireballs were observed from Earth. Debris from the comet spread completely around the planet, taking years to settle out.

Diff: 3

Section Ref.:  7.6, Disc. 7.1

 

 

Astronomy: A Beginner’s Guide to the Universe, 7e (Chaisson/McMillan)

Chapter 17   Cosmology: The Big Bang and the Fate of the Universe

 

1) An infinite universe is a basic assumption of the cosmological principle.

Answer:  FALSE

Diff: 1

Section Ref.:  17.1

 

2) The cosmological principle is the ultimate extension of the Copernican principle to the entire universe, in that there is no center at all.

Answer:  TRUE

Diff: 1

Section Ref.:  17.1

 

3) Olbers’s paradox seeks the explanation for why the night sky is dark.

Answer:  TRUE

Diff: 1

Section Ref.:  17.2

 

4) Galaxies are moving away from us and into the vast, empty space of the outer universe beyond the Big Bang.

Answer:  FALSE

Diff: 1

Section Ref.:  17.2

 

5) The cosmological redshift is a direct measure of the expansion of the universe, thus independent of direction.

Answer:  TRUE

Diff: 1

Section Ref.:  17.2

 

6) Hubble’s law implies that, at some time in the past, all the matter in the universe was at one place.

Answer:  TRUE

Diff: 1

Section Ref.:  17.2

 

7) The cosmological redshift is not really a velocity at all, but a measure of the expansion of space-time.

Answer:  TRUE

Diff: 2

Section Ref.:  17.2

 

8) The Big Bang was an expansion of matter into empty space.

Answer:  FALSE

Diff: 2

Section Ref.:  17.2

9) Olbers’s paradox is solved in part by the fact that the universe is neither infinitely large nor infinitely old.

Answer:  TRUE

Diff: 2

Section Ref.:  17.2

 

10) The darkness of the night is due in part to the cosmological redshift, with the energy of the most distant objects diluted in the universal expansion.

Answer:  TRUE

Diff: 2

Section Ref.:  17.2

 

11) If the value of H has not changed since the Big Bang, then H = 70 km/s/Mpc will give a Hubble Time of about 14 billion years.

Answer:  TRUE

Diff: 3

Section Ref.:  17.2

 

12) If the value of H is doubled, it would also double the age of the universe.

Answer:  FALSE

Diff: 2

Section Ref.:  17.2

 

13) In the Big Bang model, two possible fates exist: expansion forever, or cosmic collapse.

Answer:  TRUE

Diff: 1

Section Ref.:  17.3

 

14) The critically bound universe, with omega = 1, is saddle shaped.

Answer:  FALSE

Diff: 2

Section Ref.:  17.3

 

15) A gravitationally bound universe, with omega greater than 1.0, will expand forever.

Answer:  FALSE

Diff: 2

Section Ref.:  17.3

 

16) The density of the universe is large enough that gravity alone will eventually halt its expansion.

Answer:  FALSE

Diff: 2

Section Ref.:  17.3

 

 

17) In a closed universe, if you could send out a powerful enough light, it would eventually return from behind you.

Answer:  TRUE

Diff: 2

Section Ref.:  17.3

18) Euclidean geometry is useful for most common problems, but the geometry of space requires general relativity as well.

Answer:  TRUE

Diff: 1

Section Ref.:  17.4

 

19) The universe has been expanding at the same rate since its formation.

Answer:  FALSE

Diff: 1

Section Ref.:  17.4

 

20) The latest observations of distant Type I supernovae suggest the universe is slowing down more than we had expected.

Answer:  FALSE

Diff: 2

Section Ref.:  17.4

 

21) Einstein originally added a cosmological constant to his equations to prevent a presumably static universe from either contracting or expanding. Modern cosmologists have reintroduced it to their equations, where as the source of dark energy it causes the universe to expand ever faster.

Answer:  TRUE

Diff: 2

Section Ref.:  17.4

 

22) Like dark matter, dark energy will also retard the expansion of the universe.

Answer:  FALSE

Diff: 2

Section Ref.:  17.4

 

23) The fate or future of the universe depends only on the total number of galaxies and quasars.

Answer:  FALSE

Diff: 2

Section Ref.:  17.4

 

24) Perhaps as much as 95% of the matter in superclusters is dark matter.

Answer:  TRUE

Diff: 2

Section Ref.:  17.4

 

 

25) From the best current data, we infer the universe will expand forever.

Answer:  TRUE

Diff: 2

Section Ref.:  17.4

 

26) The cosmic microwave background is the total of all the radio emissions from all the galaxies and quasars in the universe.

Answer:  FALSE

Diff: 2

Section Ref.:  17.5

27) The radiation era lasted for only the first few billion years of the Big Bang.

Answer:  FALSE

Diff: 2

Section Ref.:  17.5

 

28) The background hiss that Bell Labs detected was the best observational evidence for the Big Bang.

Answer:  TRUE

Diff: 2

Section Ref.:  17.5

 

29) Of normal matter, about 25% of it by mass is still primordial helium even today.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

30) The carbon in your DNA was fused in the first few minutes of the Big Bang.

Answer:  FALSE

Diff: 2

Section Ref.:  17.6

 

31) The 3 K background radiation is just the redshifted gamma wavelength radiation of the decoupling.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

32) During the epoch of decoupling, nuclei and electrons combined to form atoms.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

33) Decoupling refers to the separation of matter and antimatter during inflation.

Answer:  FALSE

Diff: 2

Section Ref.:  17.6

 

34) The majority of dark matter is normal protons and neutrons.

Answer:  FALSE

Diff: 2

Section Ref.:  17.6

 

35) At decoupling, the electrons and protons were made from neutron decay.

Answer:  FALSE

Diff: 2

Section Ref.:  17.6

 

36) Primordial nucleosynthesis implies the Big Bang makes all elements up to iron.

Answer:  FALSE

Diff: 2

Section Ref.:  17.6

37) The Big Bang has time in primordial nucleosynthesis to make only H and He in abundance.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

38) In the Big Bang, about 75% of the normal matter by mass was hydrogen atoms, and the other 25% almost entirely helium.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

39) At decoupling, the protons and electrons formed transparent hydrogen atoms, allowing the radiation to escape and become the present microwave background.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

40) Almost all the helium in the universe was formed between 2-15 minutes after the Big Bang.

Answer:  TRUE

Diff: 2

Section Ref.:  17.6

 

41) Deuterium abundance suggests that normal matter makes up only 3-4% of the critical density.

Answer:  TRUE

Diff: 3

Section Ref.:  17.6

 

 

42) If the inflation theory is correct, the geometry of the universe is flat and Euclidean.

Answer:  TRUE

Diff: 2

Section Ref.:  17.7

 

43) The horizon problem relates to the isotropy of the microwave background radiation.

Answer:  TRUE

Diff: 2

Section Ref.:  17.7

 

44) Cosmic inflation continues today in the cosmological red shifts and dark energy.

Answer:  FALSE

Diff: 2

Section Ref.:  17.7

 

45) There is a superforce that separates into the electromagnetic, weak, and strong nuclear forces below a critical temperature.

Answer:  TRUE

Diff: 2

Section Ref.:  17.7

 

46) In the GUT, electromagnetism and the strong nuclear force are the last to appear.

Answer:  FALSE

Diff: 3

Section Ref.:  17.7

47) The COBE data allow us to test the isotropy of the universe.

Answer:  TRUE

Diff: 2

Section Ref.:  17.8

 

48) The COBE satellite was designed to image the microwave cosmological background radiation and thus study the earliest stages of the universe.

Answer:  TRUE

Diff: 2

Section Ref.:  17.8

 

49) It appears that the universe is composed of nearly three times as much dark energy as normal and dark matter combined.

Answer:  TRUE

Diff: 2

Section Ref.:  17.8

 

 

50) In the cosmological principle, we can easily test cosmic homogeneity with the red shift surveys, but isotropy cannot be so tested.

Answer:  FALSE

Diff: 2

Section Ref.:  17.8

 

51) COBE found the cosmic microwave background to be absolutely uniform everywhere.

Answer:  FALSE

Diff: 2

Section Ref.:  17.8

 

52) Homogeneity and isotropy, taken as assumptions regarding the structure and evolution of the universe, are known as

  1. A) Olbers’s paradox.
  2. B) Hubble’s law.
  3. C) Wien’s law.
  4. D) the cosmological principle.
  5. E) the Grand Unified Theory.

Answer:  D

Diff: 1

Section Ref.:  17.1

 

53) The concept that the direction of observation does not matter overall is

  1. A) relativity.
  2. B) homogeneity.
  3. C) universality.
  4. D) isotropy.
  5. E) geometry.

Answer:  D

Diff: 1

Section Ref.:  17.1

54) The concept that on the grandest of scales, the universe is similar in appearance everywhere is

  1. A) special relativity.
  2. B) general relativity.
  3. C) homogeneity.
  4. D) isotropy.
  5. E) universality.

Answer:  C

Diff: 1

Section Ref.:  17.1

 

 

55) Because almost all galaxies show redshifted spectra, we know that

  1. A) our understanding of redshift is wrong.
  2. B) we must be at the center of the universe.
  3. C) the universe is expanding.
  4. D) the sky must be dark at night.
  5. E) the universe is closed.

Answer:  C

Diff: 1

Section Ref.:  17.2

 

56) If Euclid is right, then Ωo is

  1. A) zero.
  2. B) 0.3.
  3. C) 1.0.
  4. D) 2.0.
  5. E) infinite.

Answer:  C

Diff: 1

Section Ref.:  17.4

 

57) The darkness of the night sky in an infinite universe is addressed in

  1. A) General Relativity.
  2. B) Special Relativity.
  3. C) Steady State Physics.
  4. D) Olbers’s paradox.
  5. E) the Cosmological principle.

Answer:  D

Diff: 1

Section Ref.:  17.2

 

58) The redshift of the galaxies is correctly interpreted as

  1. A) a Doppler shift due to the random motions of galaxies in space.
  2. B) an aging of light as gravity weakens with time.
  3. C) space itself is expanding with time, so the photons are stretched while they travel through space.
  4. D) placing our Galaxy near the center of the Local Group.
  5. E) the differences in temperatures and star formation in old and young galaxies.

Answer:  C

Diff: 2

Section Ref.:  17.2

 

59) What does Hubble’s law imply about the history of the universe?

  1. A) The universe must be infinitely old and huge.
  2. B) The universe had a beginning and has expanded since, giving it a finite age.
  3. C) The Milky Way lies exactly at the center of this expansion.
  4. D) The redshifts will lengthen with time due to dark energy.
  5. E) The redshifts will turn to blueshifts as universe contraction follows the expansion.

Answer:  B

Diff: 2

Section Ref.:  17.2

 

60) If the accepted value of H were to double,

  1. A) the age of the universe would be twice as old as we originally believed.
  2. B) the age of the universe would be half what we believed.
  3. C) the Copernican principle would not be valid beyond our solar system.
  4. D) the ages of the oldest globular clusters would be invalid.
  5. E) the critical density would be halved.

Answer:  B

Diff: 3

Section Ref.:  17.2

 

61) In which of the following models will the universe stop expanding?

  1. A) open universe
  2. B) closed universe
  3. C) critical density universe
  4. D) steady state universe
  5. E) All have an ultimate collapse.

Answer:  B

Diff: 1

Section Ref.:  17.3

 

62) With a Hubble constant of 70 km/sec/Mpc, the critical density would be

  1. A) 1.4 g/cc.
  2. B) 4 × 10-36g/cc.
  3. C) 9 × 10-27kg/m3.
  4. D) 6.23 × 10-23g/mole.
  5. E) 3 × 10-31g/cc.

Answer:  C

Diff: 1

Section Ref.:  17.3

 

 

63) If Ωo is less than one, then

  1. A) the universe is closed, and must recycle.
  2. B) the universe will expand forever.
  3. C) no matter could have existed.
  4. D) only dark energy exists in the universe.
  5. E) there is more matter than energy in the universe.

Answer:  B

Diff: 2

Section Ref.:  17.3

64) The presently accepted value of the Hubble constant gives an age of

  1. A) 4.5 billion years.
  2. B) 8-9 billion years.
  3. C) 14 billion years.
  4. D) 18 billion years.
  5. E) 22 billion years.

Answer:  C

Diff: 2

Section Ref.:  17.3

 

65) What is the meaning of a “closed” universe?

  1. A) The universe will expand forever.
  2. B) The universe will someday stop expanding and start to collapse.
  3. C) The universe will stop expanding in an infinite amount of time.
  4. D) The universe is in a steady-state.
  5. E) The universe will disappear into a white hole in time.

Answer:  B

Diff: 2

Section Ref.:  17.3

 

66) In the closed universe model, the geometry of spacetime in two dimensions resembles the surface of a

  1. A) flat piece of paper.
  2. B) saddle.
  3. C) cylinder.
  4. D) sphere.
  5. E) pyramid.

Answer:  D

Diff: 2

Section Ref.:  17.3

 

 

67) If the density of the universe is greater than critical, then

  1. A) there is more matter than energy.
  2. B) the universe is closed, gravity wins, and will shrink to the Big Crunch.
  3. C) the universe is flat, and Euclid is right.
  4. D) the universe will continue expanding forever.
  5. E) the universe will end up as nothing but black holes.

Answer:  B

Diff: 2

Section Ref.:  17.3

 

68) Studies from ________ led to the discovery of “dark energy.”

  1. A) Cepheid variables in the Virgo Cluster
  2. B) Type II supernovae in the Large Magellanic Cloud
  3. C) the gravitational lensing by MACHOs
  4. D) the COBE microwave ripples
  5. E) Type I supernovae at very large red shifts

Answer:  E

Diff: 2

Section Ref.:  17.4

69) According to the turn-off points of the oldest globular clusters, they are about

  1. A) 4.5 billion years old.
  2. B) 6.8 billion years old.
  3. C) 10 billion years old.
  4. D) 12 billion years old.
  5. E) 16 billion years old.

Answer:  D

Diff: 2

Section Ref.:  17.4

 

70) The expansion rate of the universe is

  1. A) increasing.
  2. B) decreasing.
  3. C) constant.
  4. D) different in different directions.
  5. E) independent of time.

Answer:  A

Diff: 2

Section Ref.:  17.4

 

 

71) In the critical density universe now proposed, the ratio of dark energy to matter is about

  1. A) 1 to 100.
  2. B) 1 to 1.
  3. C) 3 to 1.
  4. D) 10 to 1.
  5. E) 1 to 5.

Answer:  C

Diff: 3

Section Ref.:  17.4

 

72) The major players in the discovery of the cosmic microwave background were at

  1. A) Cal Tech and Mt. Palomar.
  2. B) Jet Propulsion Lab and MIT.
  3. C) Bell Labs and Princeton.
  4. D) Kitt Peak and the University of Arizona.
  5. E) Keck telescopes and the University of Hawaii.

Answer:  C

Diff: 1

Section Ref.:  17.5

 

73) What temperature has the Big Bang cooled to by now?

  1. A) about 3,000 K
  2. B) 5,800 K
  3. C) about 300 K
  4. D) just over 2.7 K
  5. E) 1.4 K

Answer:  D

Diff: 2

Section Ref.:  17.5

74) The discovery of the cosmic microwave background was important because

  1. A) it established a firm center of the universe.
  2. B) it was experimental verification of a prediction from the Big Bang theory.
  3. C) it proved that astronomy at radio wavelengths was possible.
  4. D) its detection was a major advance in microwave testing.
  5. E) it showed the universe must be closed, with more than the critical density here.

Answer:  B

Diff: 2

Section Ref.:  17.5

 

 

75) How does the energy of the cosmic microwave background compare to the energy radiated by all the stars and galaxies that ever existed?

  1. A) They are very close to being equal.
  2. B) 73% cosmic background, 27% starlight
  3. C) about ten times more from the Big Bang than from stars and galaxies
  4. D) The starlight now dominates the background, as your eyes show clearly.
  5. E) We have no way of comparing matter and energy this way.

Answer:  C

Diff: 3

Section Ref.:  17.5

 

76) Concerning dark energy, we do know

  1. A) that it is created when matter annihilates anti-matter.
  2. B) its density remains constant over time, so it is not important in the early universe.
  3. C) combined with dark matter, it will ultimately produce a closed universe.
  4. D) that it was revealed with Type II supernovae distances in the late 1990s.
  5. E) that it makes up 90% of all the matter and energy in the whole universe.

Answer:  B

Diff: 3

Section Ref.:  17.5

 

77) What key event happened during the decoupling epoch?

  1. A) Pairs of neutrons and protons were created.
  2. B) Electrons and positrons were created.
  3. C) Expansion cooled the universe enough that protons could capture electrons in orbit.
  4. D) Dark energy accelerated the cosmos on to infinity.
  5. E) The universe underwent a brief period of very rapid expansion.

Answer:  C

Diff: 2

Section Ref.:  17.6

 

78) The Big Bang formed

  1. A) only hydrogen.
  2. B) only helium.
  3. C) hydrogen and helium, but very little else.
  4. D) all elements up to iron.
  5. E) all elements found in nature now.

Answer:  C

Diff: 2

Section Ref.:  17.6

 

79) Before the decoupling,

  1. A) the universe was transparent to radiation.
  2. B) the universe was opaque to radiation.
  3. C) protons and electrons combined to form atoms.
  4. D) there was more helium than hydrogen.
  5. E) deuterium produced electrons and positrons.

Answer:  B

Diff: 2

Section Ref.:  17.6

 

80) Most of the deuterium formed right after the Big Bang

  1. A) is still around today.
  2. B) broke down into electrons and neutrons.
  3. C) turned into dark matter.
  4. D) quickly burned into helium nuclei.
  5. E) was found in the globular clusters.

Answer:  D

Diff: 2

Section Ref.:  17.6

 

81) Why didn’t elements heavier than helium form in the first minutes of creation?

  1. A) The first generation of stars used them up too quickly to observe them.
  2. B) There was not enough matter in the universe at that time.
  3. C) When He-4 was formed, the expansion cooled the cosmos below 100 million K.
  4. D) The electrons slowed down enough to be captured into orbits by protons.
  5. E) Only Type I supernovae can produce iron and heavier elements.

Answer:  C

Diff: 3

Section Ref.:  17.6

 

82) The 3 K background radiation represents

  1. A) the Big Bang itself.
  2. B) the time of decoupling.
  3. C) the formation of the first galaxies.
  4. D) the outer edge of the universe.
  5. E) formation of the first quasar.

Answer:  B

Diff: 3

Section Ref.:  17.6

 

 

83) The best answer to both the flatness and horizon problems is

  1. A) the Steady State Theory.
  2. B) the GUT theory.
  3. C) the inflationary epoch.
  4. D) dark energy.
  5. E) decoupling.

Answer:  C

Diff: 2

Section Ref.:  17.7

84) In the Grand Unified Theory, the superforce was

  1. A) only dark energy.
  2. B) a union of the weak and electromagnetic forces.
  3. C) a union of all matter and energy.
  4. D) a union of the strong and weak nuclear, and electromagnetic forces.
  5. E) was only in effect at low energies.

Answer:  D

Diff: 3

Section Ref.:  17.7

 

85) The satellite that found the ripples in the cosmic background that led to galaxies is

  1. A) SOHO.
  2. B) the Hubble Space Telescope.
  3. C) the Chandra X-Ray Observatory.
  4. D) COBE.
  5. E) the Compton Gamma Ray Observatory.

Answer:  D

Diff: 2

Section Ref.:  17.8

 

86) In 1992, COBE observations revealed

  1. A) that the universe had less than the critical density, so was open.
  2. B) the microwave background radiation is not isotropic, but centered on Virgo.
  3. C) the dark matter in the universe is normal (baryonic), so the universe is closed.
  4. D) there are small ripples in the microwave background, the seeds of galaxies.
  5. E) the existence of dark energy.

Answer:  D

Diff: 2

Section Ref.:  17.8

 

 

87) The tiny ripples in the background radiation COBE found are due to

  1. A) a gravitational redshift caused by growing dark clumps.
  2. B) different velocities of the edge of the universe.
  3. C) reddening by interstellar dust clouds in our galaxy.
  4. D) variations in the speed of different wavelengths of light.
  5. E) bubble-like nature of space.

Answer:  A

Diff: 3

Section Ref.:  17.8

 

88) In the cosmological principle, ________ implies that matter and energy are randomly distributed in space.

Answer:  homogeneity

Diff: 1

Section Ref.:  17.1

 

89) In the cosmological principle, ________ implies that the direction the observer faces makes no difference on the grandest scale.

Answer:  isotropy

Diff: 2

Section Ref.:  17.1

90) The assumption that from any place in the universe the observer would measure the same physical properties we observe is called the ________.

Answer:  cosmological principle

Diff: 2

Section Ref.:  17.1

 

91) ________ paradox asks why the sky is dark at night.

Answer:  Olbers’s

Diff: 1

Section Ref.:  17.2

 

92) The critical number for the rate of universal expansion and age of the Big Bang is ________.

Answer:  Hubble’s constant

Diff: 1

Section Ref.:  17.2

 

93) The hot, dense universe shortly after the Big Bang is referred to as the ________.

Answer:  primeval fireball

Diff: 1

Section Ref.:  17.2

 

94) The relation between the Doppler shift of galaxies and their distances is called ________.

Answer:  Hubble’s law

Diff: 2

Section Ref.:  17.2

 

95) The closed universe is compared to the surface of a ________ in spacetime.

Answer:  sphere

Diff: 2

Section Ref.:  17.3

 

96) The infinite, open universe has a geometry compared to the surface of a ________.

Answer:  saddle

Diff: 2

Section Ref.:  17.3

 

97) The universe’s density, compared to the critical density, determines the ________ of space.

Answer:  shape or geometry

Diff: 2

Section Ref.:  17.3

 

98) The latest observations suggest the ratio of matter to energy is about ________.

Answer:  1 to 3, or 27/73

Diff: 3

Section Ref.:  17.3

 

99) The critical density must include both matter and ________.

Answer:  energy

Diff: 1

Section Ref.:  17.4

100) Since the finding of dark energy, almost all data supports a(n) ________ universe.

Answer:  open or critical or flat

Diff: 1

Section Ref.:  17.4

 

101) Einstein’s ________ constant has been revived to help us explain dark energy.

Answer:  cosmological

Diff: 2

Section Ref.:  17.4

 

102) The discovery of dark energy increased support for the ________ universe.

Answer:  open or critical or flat

Diff: 2

Section Ref.:  17.4

 

103) The inclusion of all known dark matter still increased the density to only ________ of the critical density.

Answer:  20-30%

Diff: 2

Section Ref.:  17.4

 

104) If Ωo is exactly one, then the geometry of the universe is ________.

Answer:  flat or Euclidean

Diff: 2

Section Ref.:  17.4

 

105) In 1998 came the discovery of ________, which seems to overwhelm even gravity and all the dark matter in the final fate of the cosmos.

Answer:  dark energy

Diff: 2

Section Ref.:  17.4

 

106) The satellite most critical to the study of the formation and structure of the universe is ________, which detected the ripples that led to galaxies.

Answer:  COBE

Diff: 1

Section Ref.:  17.5

 

107) The microwave background we now observe dates back to ________ of matter and energy at 3,000 K.

Answer:  decoupling

Diff: 1

Section Ref.:  17.5

 

108) The universe we live in now is said to be ________ dominated.

Answer:  dark energy

Diff: 2

Section Ref.:  17.5

109) The discovery of the ________ at Bell Labs strongly supported the Big Bang.

Answer:  3 K or cosmic microwave background radiation

Diff: 2

Section Ref.:  17.5

 

110) When the universe was several hundred thousand years old, matter and energy decoupled, allowing the ________ radiation to escape, expand and cool off.

Answer:  cosmic microwave background

Diff: 2

Section Ref.:  17.5

 

111) Prior to decoupling, all matter was ________, with free electrons and nuclei.

Answer:  ionized

Diff: 1

Section Ref.:  17.6

 

 

112) When decoupling occurred ________ formed.

Answer:  hydrogen atoms

Diff: 2

Section Ref.:  17.6

 

113) After the decoupling, the universe was ________ to radiation.

Answer:  transparent

Diff: 2

Section Ref.:  17.6

 

114) The primordial nucleosynthesis was sped up by the abundance of ________ in the universe once the temperature dropped below a billion K.

Answer:  deuterium

Diff: 3

Section Ref.:  17.6

 

115) Helium production ceased when the universe was about ________ minutes old, and did not resume until the first generation of stars formed.

Answer:  15

Diff: 3

Section Ref.:  17.6

 

116) At a temperature of ________, protons and neutrons combined to form deuterium and start cosmic nucleosynthesis.

Answer:  900 million K

Diff: 3

Section Ref.:  17.6

 

117) The universe is dominated by dark ________.

Answer:  energy

Diff: 1

Section Ref.:  17.7

118) The ________ epoch happened when the superforce separated into the electromagnetic, strong, and weak forces, with a tremendous release of pressure.

Answer:  inflationary

Diff: 2

Section Ref.:  17.7

 

119) The ________ epoch explains the isotropy of the cosmic microwave background mapped by COBE.

Answer:  inflationary

Diff: 2

Section Ref.:  17.7

 

 

120) The COBE data, combined with computer simulations, strongly supported the ________ Epoch, showing how ripples in the background radiation could collapse into galaxies over time.

Answer:  Inflationary

Diff: 2

Section Ref.:  17.8

 

121) What is the study of cosmology?

Answer:  The study of large scale structure and evolution of the universe.

Diff: 1

Section Ref.:  17.1

 

122) State the cosmological principle.

Answer:  The universe is both homogeneous and isotropic on the grand scale.

Diff: 1

Section Ref.:  17.1

 

123) Does the universe have an edge or a center?

Answer:  No. According to the cosmological principle, things look the same everywhere.

Diff: 2

Section Ref.:  17.1

 

124) Is the cosmological red shift really a velocity of a given galaxy?

Answer:  No, it is a measure of how fast the entire universe is expanding in spacetime, with the galaxy just taken along for the ride.

Diff: 2

Section Ref.:  17.2

 

125) Relate the age of the universe to the Hubble constant.

Answer:  Inverting the Hubble constant and putting all distances in kilometers, gives us the age of the universe in seconds, assuming that Ho has never changed.

Diff: 2

Section Ref.:  17.2

 

126) Discuss the value of Ho if the universe were closed and starting to collapse.

Answer:  In the contractive phase, Ho would be negative and all galaxies would blue shift towards each other.

Diff: 3

Section Ref.:  17.3

127) What would the geometry of a universe at the critical density be?

Answer:  This would be a flat universe and follow Euclid’s geometry.

Diff: 1

Section Ref.:  17.4

 

 

128) Is the Hubble constant really constant?

Answer:  No, with the influence of dark energy, it will gradually increase, speeding up the cosmic expansion to a final flat cosmos.

Diff: 2

Section Ref.:  17.4

 

129) If the density is less than critical, which fate of the universe awaits us?

Answer:  Gravity cannot slow the expansion enough, and the universe will be open and expand forever.

Diff: 2

Section Ref.:  17.4

 

130) How would the geometry of a universe with Ωo greater than 1 differ from one with Ωo less than 1?

Answer:  If Ωo is greater than 1, the geometry of space is positive and could be likened to the surface of a sphere. If Ωo is less than 1, the geometry is negative and space is saddle-shaped.

Diff: 2

Section Ref.:  17.3

 

131) How does dark energy affect the expansion of the universe?

Answer:  Dark energy is accelerating the expansion of the universe, making it likely that it will expand forever.

Diff: 2

Section Ref.:  17.4

 

132) Contrast the original and present uses of the Cosmological Constant.

Answer:  Originally Einstein added it to General Relativity to stabilize a presumably static universe against either contraction or expansion, for astronomers then thought the universe static. Today we apply the cosmological constant to the wild card of dark energy to explain the acceleration of the expansion, overpowering gravity.

Diff: 3

Section Ref.:  17.4

 

133) When dark matter was first discovered, some astronomers thought that Ωo was greater than one from the extra gravity, favoring what type of universe?

Answer:  This would have favored a closed or spherical universe that would eventually collapse back on itself.

Diff: 2

Section Ref.:  17.4

 

134) Why was the 1978 Nobel Prize in Physics given to Penzias and Wilson from Bell labs?

Answer:  They discovered the 3 K background radiation that is a remnant of the Big Bang.

Diff: 2

Section Ref.:  17.5

 

135) What role did Princeton astronomers play in the research on the Big Bang?

Answer:  Even before Bell Labs found it, they predicted the existence of the cosmic microwave background radiation.

Diff: 2

Section Ref.:  17.5

 

136) Why were elements heavier than helium not produced during the Big Bang?

Answer:  Once helium was formed from deuterium, the temperature and pressure dropped too low for fusion to produce the heavier elements.

Diff: 2

Section Ref.:  17.6

 

137) Why do population II stars contain almost nothing but hydrogen and helium?

Answer:  This first generation of stars must be made of the elements produced in primordial nucleosynthesis, which had time only to turn 25% of the hydrogen into helium.

Diff: 3

Section Ref.:  17.6

 

138) Regular atoms did not show up in the universe until when?

Answer:  A few hundred thousand years after the Big Bang, when decoupling allowed the energy to escape, and cooled off the matter until electrons could orbit protons at temperatures of less than 3000 K.

Diff: 2

Section Ref.:  17.6

 

139) Why was the separation of the superforce into three forces so important?

Answer:  The pressure release created the inflationary epoch, when the universe expanded by a factor of 1050 times, solving the horizon problem.

Diff: 3

Section Ref.:  17.7

 

140) What satellite revealed the most about cosmology, and why was it so effective?

Answer:  COBE is the “Cosmic Observer of the Background Energy”, and focused on the structure of the microwave cosmic background; its discovery of ripples in 1992 showed how the seeds of galaxies were sown in the early universe. The WMAP spacecraft made much more detailed measurements of the cosmic microwave background, confirming and extending COBE’s results.

Diff: 3

Section Ref.:  17.8

 

141) Why did Hubble conclude the universe must be expanding?

Answer:  He found the universe was not static, that the most distant galaxies showed us the highest recessional velocities and red shifts. He believed this was most easily understood by having all of spacetime itself expand, taking the galaxies with it.

Diff: 2

Section Ref.:  17.2

142) Galaxies in all directions appear to be red shifted, as if rushing away from us in the center of the universe. How does the cosmological principle handle this problem?

Answer:  It is not just us, but everyone, everywhere who witnesses the same cosmological red shift, as all space and time expand in the Big Bang. Since space itself is expanding, there is no preferred direction and no center to the universe.

Diff: 2

Section Ref.:  17.2

 

143) Why were Type I supernovae so critical in discovering dark energy?

Answer:  These brilliant explosions are consistent standard candles, visible out to billions of light years. Instead of finding the most distant galaxies slowing down as expected in a closed universe, the supernovae were even more distant than expected, as dark energy kept the universe forever expanding.

Diff: 2

Section Ref.:  17.4

 

144) Can either normal or dark matter stop the universal expansion?

Answer:  No, normal matter adds up to only about 1-3% of that to reach the critical density. Dark matter is perhaps 10 times more abundant, but it still adds up to only 20-30% of the mass needed for closure.

Diff: 2

Section Ref.:  17.4

 

145) Contrast the roles of dark matter and dark energy in the fate of the cosmos.

Answer:  At first, the discovery of much dark matter seemed to increase the role of gravity, giving us more than the critical density and closing the Big Bang. But dark energy acts against gravity, speeding up the expansion into at least a flat universe in the future.

Diff: 3

Section Ref.:  17.4

 

146) Quasars are far more luminous than Type I supernovae; why not use them to calibrate Ho and the age of the universe?

Answer:  Quasars vary over a period of weeks in brightness, and vary a great deal in luminosity from object to object. We need a uniform, consistent “standard candle”, and the run-away detonation of a 1.4 solar mass white dwarf in a Type I supernova gives us just the desired combination of luminosity and consistency.

Diff: 3

Section Ref.:  17.4

 

147) Fusion in giant stars takes us all the way to iron before a Type II supernova occurs. Why did it stop with helium in the far more energetic Big Bang?

Answer:  The expansion of the Big Bang cooled the temperature to below 100 million K by the time the helium abundances could have allowed carbon production to start.

Diff: 2

Section Ref.:  17.6

 

 

148) Why was deuterium so critical in the primordial nucleosynthesis?

Answer:  Formed at 900 million K, when protons and neutrons fused, it was the critical link to forming both He-3 and finally He-4 in the first few minutes of creation.

Diff: 3

Section Ref.:  17.6

149) Briefly describe the order of creation of normal matter in the Big Bang.

Answer:  Radiation originally filled the entire universe. There was sufficient energy for photons to transform into stable protons and neutrons. As temperatures dropped, electrons and positrons were formed next. Meanwhile, the protons and neutrons fused to make deuterium, and deuterium fusion led to helium production in the first few minutes. As the temperature fell still more, this production ceased, and finally at decoupling, electrons began to orbit the protons to form neutral hydrogen atoms.

Diff: 3

Section Ref.:  17.6

 

150) How does the cosmic background radiation relate to the Big Bang?

Answer:  After the Big Bang the universe was filled with only radiation. It was a radiation dominated universe. After protons and neutrons formed the universe was opaque to radiation. Photons couldn’t travel far without interacting with an electron. So nothing was visible. At the time of the decoupling, the universe become transparent to radiation and photons could travel with scattering off electrons except at very specific wavelengths. The artifact of this period of decoupling, when photons were first able to travel great distances, is the 3 K cosmic background radiation.

Diff: 3

Section Ref.:  17.6

 

151) Describe the separation of the superforce and the effect it had on the universe.

Answer:  The superforce separated into the electromagnetic, weak, and strong forces. At this time a tremendous pressure built up that caused the universe to expand rapidly, causing parts of space that had been right next to each other to become widely separated. This is called the period of inflation.

Diff: 3

Section Ref.:  17.7

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