The Outer Planets Comins Chapter 9 Test Bank Docx - Discovering the Universe 14e Test Bank + Answers by Neil F. Comins. DOCX document preview.
Chapter 9: The Outer Planets
Section: Introduction
1. Which is the biggest planet in the solar system?
A) Earth
B) Neptune
C) Jupiter
D) Saturn
2. What is the mass of Jupiter compared with other objects in the solar system?
A) 20 times the mass of all other planets combined
B) half the mass of the Sun
C) as large as the mass of Saturn and Neptune combined
D) about two and a half times the mass of all other planets combined
3. Jupiter is sometimes described as a “failed star,” suggesting that if it had more mass it would have developed as a star rather than as a planet and that we would live in a binary star system. Is this possible? How many times more massive would Jupiter have to be for this development to have taken place?
A) Yes. Jupiter would need only about double its present mass.
B) Yes. Jupiter would need slightly less than 100 times its present mass.
C) Yes, but Jupiter would need thousands of times its present mass.
D) No. No amount of extra mass could make a planet into a star.
4. How much more massive would Jupiter need to be to generate energy by nuclear fusion in its interior?
A) 1000 times more massive
B) It already generates energy by nuclear fusion.
C) only about twice as massive; it is almost a star
D) 75 times more massive
5. How does the amount of radiation radiated from Jupiter compare with the amount of radiation it receives from the Sun?
A) Jupiter receives more radiation than it radiates because of the external energy required to maintain its powerful magnetic field.
B) These two are in balance, as they must be.
C) Jupiter radiates about twice as much energy as it receives from the Sun.
D) Jupiter radiates almost 75 times as much energy as it receives from the Sun.
6. Jupiter’s mass makes up what fraction of the total mass of the planets in the solar system?
A) 70 percent
B) 10 percent
C) 98 percent
D) 50 percent
Section: 9-1
7. How is the mass of Jupiter determined?
A) by observing Jupiter’s interaction with the Sun and using Kepler’s third law
B) by observing Jupiter’s interaction with its satellites and using Kepler’s third law
C) by multiplying Jupiter’s density by its volume
D) by observing Jupiter’s effect on the perihelion of Mercury
8. To compute the density of Jupiter, one obtains its mass from
A) Kepler’s third law and its size from Kepler’s second law.
B) its observed rotation period and its size from trigonometry.
C) Kepler’s third law and its size from trigonometry.
D) its gravitational redshift and its size from Kepler’s first law.
9. How do the moons of Jupiter behave when considered in terms of the relationship between the period P and radius a of their orbits around the planet?
A) Jupiter’s moons follow the Keplerian relationship P2 = ka3, where k is a constant that is different from that in the relation governing planetary motion around the Sun.
B) Jupiter’s moons do not obey the Keplerian relationship P2 = ka3 because their motion about Jupiter is affected by Jupiter’s motion about the Sun.
C) Jupiter’s moons obey the Keplerian relationship P2 = ka3 where k is the same as that for planetary motion around the Sun because it is a universal constant.
D) Jupiter’s moons do not obey the Keplerian relationship P2 = ka3 because they orbit Jupiter, not the Sun.
10. The mass of Jupiter compared with that of Earth is
A) about 300 times larger.
B) about 1/300 because of Jupiter’s low density.
C) several thousand times larger.
D) about 11 times as large.
11. Which of these objects rotates the MOST quickly around its own axis?
A) Venus
B) Earth’s Moon
C) Earth
D) Jupiter
12. When viewed from Earth, the apparent angular diameter of Jupiter appears to vary with time because
A) the amount of sunlight reaching Jupiter varies with time.
B) the absorption of radiation by interplanetary dust between Jupiter and Earth varies with time.
C) Jupiter is a fluid planet, and its size and brightness both pulsate with a long oscillation period.
D) the distance between Jupiter and Earth varies.
13. Which spacecraft recently dropped a probe into the atmosphere of Jupiter?
A) Ulysses
B) Voyager
C) Cassini
D) Galileo
14. What characteristic features are seen on the visible surface of Jupiter?
A) light and dark bands parallel to the equator
B) large volcanoes and a long, deep rift valley
C) bluish-green, almost featureless cloud layer
D) almost featureless white cloud surface
15. What is the physical appearance of Jupiter as seen from Earth or a spacecraft?
A) uniform bluish color with a high-level haze
B) solid ice surface, showing some craters that have been highly modified by ice flow
C) densely cratered surface with one large impact basin
D) series of dark belts and light zones parallel to the equator
16. Evidence of lava flow, either recent or ancient, is NOT found on
A) Jupiter.
B) Earth.
C) Earth’s Moon.
D) Mars.
17. The dark, reddish bands on Jupiter are called
A) streams.
B) zones.
C) voids.
D) belts.
18. What are the light-colored bands on Jupiter called?
A) belts
B) streams
C) plumes
D) zones
19. On which planet is the Great Red Spot found?
A) Mercury
B) Mars
C) Jupiter
D) Saturn
20. The existence of the Great Red Spot of Jupiter has been known since
A) the arrival at Jupiter of Voyager 1, with its imaging cameras, in 1979.
B) the time of Hooke and Cassini in the 1600s.
C) first light at the 200-inch telescope on Mount Palomar, in 1948.
D) the first flyby of a spacecraft, Pioneer 10, in December 1973.
21. What is the Great Red Spot?
A) dark, polar hood in the clouds of Titan, a satellite of Saturn
B) large storm on Neptune discovered by the Voyager spacecraft
C) lava lake on Io, a satellite of Jupiter
D) large and long-lived, possibly permanent storm on Jupiter
22. What is the Great Red Spot on Jupiter?
A) summit of a large mountain that rises above the upper cloud level
B) region over the south pole of Jupiter where ammonia compounds that absorb blue light have condensed in the colder atmosphere
C) area where charged particles from the satellite Io collide with Jupiter’s cloud tops
D) large, long-lived hurricanelike storm that is maintained by the differential rotation of Jupiter’s atmosphere
23. The Great Red Spot is
A) the top of a massive mountain penetrating through Jupiter’s clouds.
B) a temporary storm in Jupiter’s atmosphere, lasting a few months.
C) a large, long-lived storm system in Jupiter’s atmosphere.
D) the colored polar cap of Jupiter.
24. Jupiter’s Great Red Spot is a(n)
A) continent.
B) storm.
C) optical illusion.
D) hole in the clouds.
25. One distinctive feature that is visible on the “surface” of Jupiter through a telescope from Earth is
A) the Great Red Spot.
B) Olympus Mons.
C) the Cassini Division.
D) the northern auroral oval.
26. The lifetime of the Great Red Spot of Jupiter appears to be
A) well over 2000 years, from ancient Greek records.
B) about 2 to 4 weeks between successive appearances, similar to sunspots.
C) about one Jupiter orbital period between successive appearances because the spot is produced by tidal effects.
D) at least 300 years, from visual records.
27. The brown ovals seen in Jupiter’s atmosphere appear bright in an image taken in infrared radiation. Why is this?
A) The ovals are moving toward Earth, and the Doppler blueshift makes them appear brighter.
B) The ovals are moving away from Earth, and the Doppler redshift makes them appear brighter.
C) The ovals are high up in the Jovian atmosphere.
D) The ovals are deep within the Jovian atmosphere.
28. What is the dominant circulation pattern in Jupiter’s atmosphere (i.e., at the visible “surface”)?
A) alternating bands of eastward and westward flow parallel to the equator
B) air rising at the equator, flowing north and south toward the poles, then sinking and returning to the equator at a lower level
C) uniform eastward flow of the entire atmosphere, with occasional dark storms and turbulent swirls
D) isolated storms and turbulent swirls, with little overall flow pattern in any particular direction
29. The rotation period of Jupiter is
A) relatively short, on the order of 10 hours.
B) very short, on the order of 1 hour.
C) very long—several weeks—because of its great size and mass.
D) long, on the order of several days.
30. Which planet in the solar system has the fastest rotation?
A) Mercury
B) Uranus
C) Jupiter
D) Earth
31. Which feature of Jupiter leads to the confinement of its clouds in very narrow bands around the planet?
A) high gravitational field
B) powerful magnetic field
C) the large proportion of hydrogen and helium in its atmosphere
D) rapid rotation
32. Detailed observations of Jupiter’s rotation suggest that Jupiter
A) rotates in two separate parts, with equatorial regions rotating in a direction opposite to polar regions.
B) is slowing down noticeably at the present time.
C) rotates as a solid body, with equatorial and polar regions showing the same rotational period.
D) is not a rigid object because equatorial regions rotate faster than polar regions.
33. One interesting feature of Jupiter’s rotation is the fact that
A) the direction of Jupiter’s rotation is opposite to that of most of the planets and opposite to its direction of revolution around the Sun.
B) Jupiter’s rotation rate has slowed down significantly since it was first observed through telescopes in the 1600s.
C) regions of Jupiter at different latitudes appear to rotate at different rates.
D) Jupiter’s axis of rotation lies almost in the plane of its orbit.
34. Have astronomers observed differential rotation in the atmosphere of Jupiter?
A) No. The entire atmosphere rotates together.
B) Yes. The polar regions rotate slightly faster than the equatorial regions.
C) Yes. The equatorial regions rotate slightly faster than the polar regions.
D) Yes. The equatorial regions rotate much faster (approximately half the period) than the polar regions.
35. Which of these conclusions is correct on the basis of observations of the motions of Jupiter’s clouds?
A) The planet rotates differentially, with the equatorial regions rotating fastest while intermediate latitudes and polar regions rotate more slowly.
B) Intermediate-latitude regions rotate fastest while equatorial and polar regions rotate more slowly, as shown by the presence of bands and zones and locally rotating spots and ovals.
C) The planet rotates as a solid body because of its great mass and self-gravitation, with all regions having the same rotation speed.
D) The planet rotates differentially, with equatorial regions rotating slowest and rotation speed increasing toward both poles.
36. What is the overall composition, according to the number of atoms, of the outer atmospheric regions of Jupiter in terms of the relative numbers of atoms?
A) 75 percent hydrogen, 15 percent helium, and 10 percent everything else
B) hydrogen and helium only, with no other elements
C) 86 percent hydrogen, 13 percent helium, and 1 percent everything else
D) pure hydrogen
37. What are the MOST common molecules in Jupiter’s clouds?
A) ice crystals of water and carbon dioxide
B) liquid droplets of water and ammonia
C) ice crystals of methane, ammonia, and water vapor
D) water ice crystals
38. The composition of the clouds seen on Jupiter is
A) similar to the composition of Earth’s clouds throughout the whole atmosphere—water droplets and crystals of frozen water.
B) very different from the composition of Earth’s clouds: almost entirely ammonia and ammonium hydrosulfide crystals and almost no water.
C) similar to the composition of Earth’s clouds (water droplets and crystals of frozen water) in the higher levels but very different (ammonia crystals) in the lower levels.
D) similar to the composition of Earth’s clouds (water droplets and crystals of frozen water) in the lower levels but very different (ammonia crystals and other chemicals) in the higher levels.
39. Which of these chemicals is the MOST abundant in the outer atmosphere of Jupiter?
A) H2O (water vapor)
B) CH4 (methane)
C) NH3 (ammonia)
D) CO2 (carbon dioxide)
40. Which of these likely plays an important role in the banded structure on Jupiter’s visible “surface” as seen from Earth?
A) “sweeping” of Jupiter’s clouds through magnetic field lines from Jupiter’s magnetosphere
B) underlying rising and falling convection pattern stretched into bands by Jupiter’s rapid rotation
C) underlying north-south flow pattern stretched into bands by Jupiter’s rapid rotation
D) breaking up by underlying mountain ranges of the strong eastward flow caused by Jupiter’s rapid rotation
41. The high-speed winds observed on Jupiter occur mainly
A) in a northwest-southeast direction from the light zones toward the dark belts.
B) in a northeast-southwest direction from the dark belts toward the light zones.
C) from the poles toward the equator.
D) in the directions parallel to the equator.
42. What did the Cassini spacecraft recently observe about the belts, zones, and ovals in Jupiter’s atmosphere?
A) Cooler material (white ovals, dark belts) is generally rising.
B) Warmer material (brown ovals, white zones) is generally sinking.
C) White clouds have been seen rising in the dark belts.
D) Ovals occur in pairs, a white one and a brown one together.
43. What have planetary scientists observed about the evolution of the red spots and white and brown ovals in Jupiter’s atmosphere?
A) All of these seem to be permanent with no discernible changes over the 4 centuries of observing them.
B) Brown ovals routinely change into white ovals and then back into brown.
C) White ovals have been observed to merge to create a red spot.
D) The Great Red Spot seems too create and spin off other smaller red spots.
44. The predominant large-scale atmospheric circulation pattern on Jupiter is characterized by
A) strong winds blowing eastward at all latitudes so that the entire atmosphere rotates faster than the planet.
B) isolated cyclones (low-pressure areas) and anticyclones (high-pressure areas), similar to those on Earth.
C) strong winds blowing parallel to the equator but in opposite directions at different latitudes.
D) strong winds blowing westward at all latitudes so that the entire atmosphere rotates more slowly than the planet.
45. How thick are the cloud layers on Jupiter’s visible “surface”?
A) greater than 10,000 km, as seen through the dark ovals that represent holes in the cloud layers
B) about 1000 km
C) about 60 km
D) very thin, less than 10 km
46. Which of these correctly characterizes the composition of Jupiter’s cloud layers?
A) hard surface just under the cloud layers, contrary to the understanding of Jupiter’s atmospheric structure
B) no evidence at all of hydrogen in the atmosphere of Jupiter
C) vast quantities of invisible water vapor above the cloud layers
D) only traces of water vapor and many other chemical elements in the cloud layers that are very easily measured spectroscopically from Earth
47. Recent estimates suggest that the overall mass distribution between atomic components of Jupiter is
A) 50 percent hydrogen and 50 percent helium.
B) almost 100 percent hydrogen.
C) 75 percent hydrogen, 24 percent helium, and 1 percent heavier elements.
D) 86 percent hydrogen, 13 percent helium, and 1 percent heavier elements.
48. Jupiter is significantly thicker through the equator than it is through the poles. The word used to describe such a planetary shape is
A) oblate.
B) obtuse.
C) oblique.
D) obese.
Section: 9-2
49. What is the basic structure of the planet Jupiter?
A) rocky core, liquid hydrogen mantle, gaseous atmosphere
B) rocky core, liquid methane and water mantle, gaseous atmosphere
C) entirely liquid hydrogen except for a thin gaseous atmosphere
D) rocky core, frozen water mantle, thin methane atmosphere
50. Jupiter’s core consists of rocky material like that from which the terrestrial planets formed. How does Jupiter’s core compare with Earth?
A) It constitutes the bulk of Jupiter’s mass, even though its radius is only a few percent of Jupiter’s.
B) It is considerably larger in mass than Earth but only a small fraction of Jupiter’s total mass.
C) Because most of the terrestrial materials were in the inner part of the solar nebula, Jupiter’s core is smaller than Earth in both size and mass.
D) Because of Jupiter’s enormous rate of spin, the core is not spherical. So, the size is difficult to compare to Earth, but the core’s mass appears to be smaller than Earth’s mass.
51. Which of these spacecraft did NOT visit Jupiter?
A) Galileo
B) Viking
C) Pioneer
D) Voyager
52. Which spacecraft was the MOST recent to reach Jupiter?
A) Hubble Space Telescope
B) Galileo
C) Pioneer
D) Voyager
53. What is the basic structure of the planet Jupiter?
A) rocky core overlaid by a thick mantle of liquid hydrogen, relatively thin gaseous atmosphere
B) small rocky core overlaid by a thin mantle of liquid hydrogen, thick gaseous atmosphere
C) large rocky core with a thin mantle of liquid hydrogen, thin gaseous atmosphere
D) rocky core, liquid hydrogen mantle, and gaseous atmosphere, all having about the same thickness
54. The internal structure of the two largest Jovian planets (from the center outward) is a(n)
A) iron-nickel core (from which the Jovian magnetic field arises), a semifluid rocky mantle, and a solid rocky crust covered by a thin atmosphere.
B) rocky core covered by a very thick gaseous hydrogen and helium layer.
C) rocky core, a liquid “ice” layer that may overlap with the rocky core, a liquid metallic hydrogen and helium layer, and an ordinary hydrogen and helium gaseous layer.
D) rocky core, a liquid methane mantle, and a gaseous methane atmosphere.
55. The overall interior structure of the Jovian planets is expected to be
A) three-layered: a rocky core covered by liquid metallic hydrogen and a thin gaseous hydrogen/helium atmosphere.
B) four-layered: a rocky core, a semifluid ice layer that may overlap with the rocky core, a liquid mantle of hydrogen, and a gaseous hydrogen and helium atmosphere.
C) two-layered: a large, solid, rocky core surrounded by an extensive gaseous atmosphere.
D) four-layered: a solid inner core, a liquid iron outer core, a semifluid rocky mantle, and a solid crust.
56. Which one of these does NOT contribute in a significant way to the energy radiated outward by Jupiter?
A) the decay of radioactive elements in the planet’s core
B) reflection of radiation absorbed from the Sun
C) magnetic energy released by Jupiter’s enormous magnetic field
D) gravitational potential energy released as Jupiter continues to contract
57. What is the Kelvin-Helmholtz mechanism?
A) the tidal flexing that causes Io to be geologically active
B) A satellite in a nonequatorial orbit will have its orbit gradually shifted toward the equatorial plane.
C) the release of gravitational potential energy as heat when a body contracts
D) the shift of the spectral peak to longer wavelengths as a body cools off
58. What material serves as the main electrical conductor in Jupiter’s interior?
A) liquid metallic helium
B) solid metallic hydrogen
C) liquid metallic hydrogen
D) a molten iron-nickel mixture
59. In what form is the hydrogen in the interior of Jupiter?
A) liquid metallic hydrogen, electrically conducting
B) gaseous molecular hydrogen (H2) electrically conducting
C) solid hydrogen, compressed to this state by the very high pressures
D) gaseous hydrogen because the pressures are never sufficient to condense it into liquid
60. Where in the solar system would one look for liquid hydrogen?
A) on the polar caps of Mars
B) on the surface of Venus, beneath the clouds
C) Nowhere, because it is not cold enough anywhere in the solar system to liquefy hydrogen
D) in the deep interiors of Jupiter and Saturn
61. The low average density of Jupiter (about 1300 kg/m3 compared with that of water, 1000 kg/m3) indicates that this planet is composed mainly of
A) hydrogen and helium in gaseous form only because low temperatures and great pressures are needed to liquefy these gases.
B) water, compressed somewhat by gravity, maybe in the form of ice.
C) methane, ammonia, and water, from spectroscopic observation of its atmosphere.
D) hydrogen, in liquid or gaseous form.
62. The Jovian planets have high masses and hence generate powerful gravitational fields, and yet they have low average densities. What does this fact indicate about their interiors?
A) The Jovian planets are composed almost entirely of ice crystals and dust.
B) The Jovian planets are composed almost entirely of water.
C) The interiors of the Jovian planets are hot and gaseous, like those of cool stars.
D) The Jovian planets are composed almost entirely of hydrogen and helium.
63. The deepest central sections of the interiors of Jupiter and Saturn are thought to be composed of
A) methane, ammonia, and water vapor.
B) liquid metallic hydrogen.
C) magnetized iron.
D) rock.
64. The magnetic field strength at Jupiter’s “surface” exceeds that at Earth’s equatorial surface by a factor of about
A) 20,000.
B) 1 million.
C) 14.
D) 2.
65. Strong radio radiation from Jupiter indicates the presence of
A) radio stations.
B) thunderstorms.
C) a strong magnetic field.
D) the Great Red Spot.
66. Jupiter has a magnetic field that is
A) much more powerful than that of Earth.
B) about the same strength and extent as that of Earth.
C) weak and variable, sometimes existing only above the Great Red Spot.
D) very weak, almost nonexistent.
67. What is the source of Jupiter’s intense magnetic field?
A) electric currents in ionized layers of Jupiter’s atmosphere
B) electric currents in Jupiter’s molten iron core
C) permanently magnetized iron core
D) electric currents in Jupiter’s liquid hydrogen layer
68. The material in the interior of Jupiter that is thought to be responsible for its powerful magnetic field is
A) solid magnetic and magnetized iron.
B) liquid metallic hydrogen.
C) “ices” of NH3 (ammonia), CH4 (methane), and H2O (water) that contain frozen-in magnetic fields.
D) molten iron and nickel.
69. The requirement(s) for the generation of a powerful magnetic field in a Jovian planet (e.g., Jupiter, Saturn) appear(s) to be a
A) liquid “metal” core and interior, and very slow rotation.
B) solid iron core forming a permanent magnet.
C) liquid “metal” interior and relatively rapid rotation.
D) solid interior throughout the planet and slow rotation.
70. What conditions are considered to be necessary for a planet to be able to generate an intense magnetic field?
A) ionized and electrically conducting layer in its atmosphere
B) electrically conducting material in its interior and slow rotation because rapid rotation will destroy a magnetic field
C) solid iron core into which a magnetic field was induced early in the planet’s history
D) relatively rapid rotation and electrically conducting material in its interior
71. The magnetosphere of Jupiter is
A) a region of charged particles extending along the orbit of the satellite Io, forming a ring around Jupiter.
B) the magnetized hydrogen in the inner regions of Jupiter just outside the solid core, where the planet’s magnetic field is produced.
C) a narrow layer in Jupiter’s atmosphere, just above the cloud tops, in which intense electric currents flow and generate the planet’s magnetic field.
D) a large space around Jupiter in which its magnetic field has excluded the solar wind but that is filled with high-energy charged particles.
72. The magnetosphere of Jupiter is
A) a narrow layer in which intense electric currents flow, just above the cloud tops in the planet’s atmosphere, generating the planet’s magnetic field.
B) the inner regions of Jupiter, just beyond the solid core, that contain liquid metallic hydrogen, where electric currents flow to produce the planet’s magnetic field.
C) a doughnut-shaped region similar to the Van Allen belts around Earth containing high-speed protons and electrons, whose motions produce the planet’s magnetic field.
D) a large cavity created and maintained within the solar wind stream by the planet’s magnetic field, filled with extremely hot, ionized plasma.
73. The shape and dimensions of the magnetosphere surrounding Jupiter are controlled by
A) the atoms of Jupiter’s outer atmosphere moving outward because of the rapid rotation of the planet, pressing against the solar wind.
B) the pressure of the solar wind against the outer atmosphere of Jupiter.
C) solar radiation pressure pushing against the planet’s outer atmosphere.
D) the opposing pressures of the ionized gas of the solar wind and the planet’s magnetic field.
74. If one could see the full extent of the magnetosphere of Jupiter from Earth, how big would it appear in the sky?
A) about 16 times larger than Jupiter itself
B) about as large as the full Moon
C) about twice as large as Jupiter itself
D) 16 times larger than the full Moon
75. If one could see Jupiter’s magnetosphere visually, how big would it appear?
A) Jupiter’s magnetosphere would be too small to be visible without a telescope.
B) Jupiter’s magnetosphere would be easily visible, many times larger than the full Moon.
C) Jupiter’s magnetosphere would cover essentially the entire sky whenever Jupiter was above the horizon.
D) Jupiter’s magnetosphere would be just big enough to see, almost at the limit of unaided-eye visibility.
76. How does the magnetosphere of Jupiter compare to that of Earth?
A) Jupiter’s magnetosphere is very similar to that of Earth.
B) Jupiter’s magnetosphere is much larger than that of Earth because of Jupiter’s large magnetic field and the weakness of the solar wind at Jupiter’s orbital distance from the Sun.
C) Jupiter has no detectable magnetic field and hence no magnetosphere.
D) Jupiter’s magnetosphere is much smaller than that of Earth because Jupiter’s magnetic field is much stronger than that of Earth.
77. Which of the Galilean moons of Jupiter are within Jupiter’s magnetosphere?
A) only Io; the others are well outside the magnetosphere.
B) only Io and Europa; the others are well outside the magnetosphere.
C) all except Callisto, which is well outside the magnetosphere
D) all four Galilean moons
78. Which of these has NOT been observed on Jupiter?
A) long-lived storms
B) auroras
C) particle-trapping regions in the magnetic fields like Earth’s Van Allen belts
D) currents in the atmosphere (like Earth’s jet stream) which can stretch from the pole to the equator
79. At what locations are auroras seen on Jupiter?
A) directly above both magnetic poles, with little extension from these regions toward the equator
B) only over the major spots in the atmosphere, such as the Great Red Spot, where the magnetic field of Jupiter is disturbed
C) in oval regions around Jupiter’s magnetic poles but only rarely, if ever, directly over these poles
D) along the equator, aligned with the dark bands and light zones
80. In which of these ways is there a similarity between Jupiter and Earth?
A) Jupiter and Earth display the same colors when viewed from space.
B) Auroras are produced by magnetospheres on both Jupiter and Earth.
C) The atmospheres of Jupiter and Earth contain the same constituency of gases.
D) Jupiter and Earth have similar average densities.
81. In 2018, measurements by the spacecraft Juno challenged which aspect of the understanding of Jupiter?
A) the extent of its rocky core
B) the strength of its magnetic field
C) the composition of its cloud layers
D) the age of its storms, such as the Great Red Spot
Section: 9-3
82. How did Comet Shoemaker-Levy 9 achieve lasting fame?
A) The comet became the first comet to be visited by spacecraft.
B) The comet crashed into Jupiter.
C) The comet exploded after passing too close to the Sun.
D) The comet just missed Earth, passing between the Moon and Earth.
83. Kepler’s third law for orbits around the Sun is a3 = P2 where the semimajor axis is in au, and the period P is in years. For objects in orbit around Jupiter, one must use a3 = 0.001 P2 because the mass of Jupiter in solar masses is approximately 0.001. The period for Comet Shoemaker-Levy 9 in its orbit around Jupiter was about 2 years. What was its maximum distance from Jupiter in this orbit (in u)?
A) 0.05
B) 0.16
C) 0.32
D) 0.48
84. What were the results of the impacts of the fragments of Comet Shoemaker-Levy 9 into Jupiter?
A) Holes punched through the clouds, and craters gouged Jupiter’s surface.
B) There were essentially no visible effects because the fragments plummeted deep below the cloud layers before being destroyed.
C) Rings of debris were flung into orbit around Jupiter’s equator.
D) Fireballs hotter than the Sun’s surface made dark splotches that lasted for months.
85. Which of these was NOT a result of Comet Shoemaker-Levy 9 impacting Jupiter?
A) The observable effects were delayed by several months after impact, because the resulting heat had to be convected through Jupiter’s atmosphere.
B) Friction with the atmosphere created enormous fireballs.
C) Carbon from the comet vaporized, leaving dark plumes.
D) Ripples created by the impact disturbed Jupiter’s atmosphere for months.
86. What effect did the fragments of Comet Shoemaker-Levy 9 have on the atmosphere of Jupiter?
A) The fragments created dark patches that lasted for months.
B) The fragments created white clouds of ammonia and water ice crystals that lasted for several days.
C) The fragments disrupted the atmospheric circulation of light and dark zones for almost a month.
D) The fragments had no lasting effect beyond the initial bursts of hot gas.
87. In the collisions of the fragments of Comet Shoemaker-Levy 9 with Jupiter, the pieces
A) were not able to penetrate deeply into Jupiter’s atmosphere; their impacts disturbed only the high atmosphere.
B) were able to penetrate through the atmospheric layers and the liquid metallic hydrogen region to reach the solid core because they were passing through only hydrogen.
C) skipped off the very high layers of Jupiter’s atmosphere and went back out into space because of their tangential approach angles.
D) penetrated very deeply into Jupiter’s atmosphere, reaching and disturbing the liquid metallic hydrogen region.
88. The 2009 impact site near the south pole of Jupiter’s atmosphere was noticeably different from the 1994 impacts. How?
A) The 2009 site was much larger, indicating a more massive impactor.
B) The 2009 site was surrounded by a halo of small impacts, indicating the impact by an asteroid rather than a comet.
C) The 2009 site was not surrounded by a halo of small impacts, thus indicating the impact by an asteroid rather than a comet.
D) The colors that developed at this site were different from those of the earlier impacts because of differences in temperature and composition of Jupiter’s atmosphere near the poles.
89. How many moons are now known to orbit Jupiter?
A) only 4, discovered by Galileo
B) 10
C) more than 60
D) none, just like Mercury and Venus
90. How many large, spherical moons are in orbit around Jupiter?
A) 11
B) 4
C) none
D) 16
91. The four giant moons of Jupiter were discovered by
A) Newton, in seventeenth-century England.
B) the Pioneer spacecraft, the first spacecraft to visit Jupiter.
C) Galileo, in seventeenth-century Italy.
D) Ptolemy, in ancient Greece.
92. How many moons of Jupiter were seen by Galileo?
A) none because he had no telescope and was unable to see them with the unaided eye
B) 4, with his new telescope
C) 28
D) only 1
93. By which collective name (after their discoverer) are the four major moons of Jupiter known?
A) “Ptolemic,” after Ptolemy
B) “Newtonian,” after Newton
C) “Copernican,” after Copernicus
D) “Galilean,” after Galileo
94. For how long has it been known that the planet Jupiter has moons?
A) since the first spacecraft flybys by Pioneer I in 1979
B) since 1948, when the Mount Palomar telescope was completed
C) since Galileo turned his telescope toward the sky in 1610
D) since the time of the ancient Greeks
95. Which of these early telescope observations provided strong evidence that led Galileo to conclude that the Copernican heliocentric model provided a better explanation for the solar system than the Greek geocentric model?
A) observations of a supernova
B) observation of moons orbiting another planet, Jupiter, rather than Earth
C) change in apparent angular size of the Moon as it orbits Earth
D) change with time in the angular size of Mars
Section: 9-4
96. Which satellite of Jupiter is volcanically active?
A) Europa
B) Io
C) Callisto
D) Ganymede
97. What causes Io to be so active geologically?
A) Its mantle has an unusually high density of long-term radioactive elements.
B) It is still contracting gravitationally and gives out energy via the Kelvin-Helmholtz mechanism.
C) It is in a highly eccentric orbit and thus is subjected to tidal flexing from Jupiter.
D) It is in a very circular orbit, but it is subjected to tidal flexing from Jupiter because of orbital perturbations from the other Galilean satellites.
98. Io is believed to be mostly rock and iron, much like Earth. How does its density compare to Earth’s density?
A) With the same basic composition, its density must be similar to Earth’s.
B) Io’s density is smaller because it has a mantle of sulfur that is not very dense.
C) Io’s density is greater because at its greater distance from the Sun its materials are colder and thus more dense than similar materials on Earth.
D) Earth’s density is larger because it experiences more gravitational compression, and the same materials at Earth’s core have a greater density than they would at Io’s core.
99. Which characteristic of Jupiter’s satellite Io makes it different from any other known satellite in the solar system?
A) Io has a permanent, dense atmosphere.
B) Io is volcanically active, with gas plumes and lava flows.
C) Io has geyserlike plumes of nitrogen gas.
D) Io’s surface is broken into heavily cratered and lightly cratered regions in a pattern similar to plate tectonics.
100. Io’s composition is believed to be similar to that of the terrestrial planets rather than to that of the giant planets, yet its density is intermediate between these two groups. Explain.
A) Like the Earth–Moon system, Io is believed to have formed from part of the mantle of Jupiter and thus has a density different from Jupiter as a whole.
B) The intense cold at Io’s distance from the Sun compresses its materials and increases its density.
C) The internal heat caused by its gravitational interaction with Jupiter causes Io to expand and decreases its density.
D) Io’s smaller mass causes its materials to be compressed less by its own gravity compared, for example, to Earth.
101. Earth, which is mostly rock and iron, has a density of 5515 kg/m3. Ganymede, Jupiter’s largest satellite, contains much water and water ice and has a density of 1940 kg/m3. Io has a density of 3570 kg/m3. What conclusions have astronomers drawn from this?
A) Io must be composed of some new material other than rocks, iron, water, or ice.
B) Io is composed of compressed water and water ice.
C) Io is mostly rock and iron, but because of its smaller mass it cannot compress the material as much as Earth can.
D) Since Io is smaller than Earth, it is expected to have a smaller density regardless of composition.
102. The white spots on Io’s surface
A) are a combination of water ice and carbon dioxide ice.
B) are actually openings into lava tubes like those found on the Moon.
C) are patches of crystallized sulfur dioxide flakes.
D) remain a mystery.
103. Jupiter’s satellite Io has numerous black spots on its surface. What are these spots?
A) volcanic vents
B) impact craters
C) collapsed features in an icy crust
D) debris from comets
104. The MOST geologically active object in the planetary system at the present time is
A) Io, a moon of Jupiter.
B) Earth’s Moon.
C) Triton, a moon of Neptune.
D) Mars.
105. The eruptions observed on Io are thought to MOST clearly resemble
A) impacts, a side effect of the many asteroids and comets captured by Jupiter.
B) geysers, where material is shot upward more or less continuously by the pressure of gas produced below the surface.
C) terrestrial mid-ocean ridges, where upwelling molten rock pushes the crust apart.
D) explosions, where material is thrown upward by a single burst and then falls back to the surface.
106. Which of these phenomena is NOT seen on Jupiter’s satellite Io?
A) lava flows
B) volcanic plumes
C) sulfur dioxide frost
D) impact craters
107. Why should an observer expect to see no craters, such as those on the Moon or Mars, on Io, the innermost Galilean moon of Jupiter?
A) The continuous water rainfall quickly erodes and washes away any trace of craters.
B) Volcanoes are continuously depositing new material onto the surface.
C) The liquid surface cannot maintain a crater, just as Earth’s oceans cannot.
D) The surface is always reentering the planet’s interior by subduction in rapid plate tectonic motion, similar to but faster than that on Earth.
108. Are the volcanoes of Io efficient replacers of the surface of this moon?
A) No. The volcanoes emit only gases that dissipate into space.
B) No. The volcanoes emit solid material, mostly sulfur, but this material only coats the surface with about 12 mm per century.
C) Yes. The volcanoes emit enough so that the whole surface is covered with about 1 m of new material per century.
D) Yes. The volcanoes emit enough to coat the whole surface with about 1 m of new material per year.
109. How would Interplanetary Travel Holidays, Inc., advertise a holiday on Jupiter’s satellite Io?
A) Greatest deep-sea diving beneath thick ice layers!
B) Glaciers galore for your hiking pleasure under star-studded skies!
C) Exquisite ethane lakes, hydrocarbons beyond your wildest dreams!
D) The largest number of volcanoes for your travel dollar anywhere in the solar system!
110. The major chemical constituent of the layers of material continuously being deposited on the surface of Io, the innermost moon of Jupiter, by “volcanic” action is
A) hydrogen.
B) sulfur.
C) silicate dust and rock.
D) water.
111. The “snow” that falls continuously on the surface of Io, the innermost Galilean moon of Jupiter, is composed of
A) ammonia crystals.
B) water crystals.
C) sulfur and sulfur dioxide.
D) methane crystals.
112. Which chemical or chemicals appear to play a prominent role in the “volcanoes” of Io?
A) water and steam
B) molten lava
C) methane and ammonia
D) sulfur and sulfur dioxide
113. Which gas is thought to be responsible for the tremendous eruptions of material from Jupiter’s innermost Galilean moon, Io, by providing the propulsive forces?
A) oxygen, O2
B) sulfur dioxide, SO2
C) carbon dioxide, CO2
D) steam, or heated water vapor
114. What is believed to be the source of the many colors seen on the surface of Io, the inner large satellite of Jupiter?
A) impurities in a water-ice crust
B) sulfur and sulfur compounds
C) phosphorus compounds
D) organic (carbon) compounds discolored by solar ultraviolet light
115. The very wide range of colors that are seen on the surface of Io results from
A) frozen ices of sulfur dioxide, water vapor, and carbon dioxide.
B) the wide range of temperatures, each region emitting its own blackbody spectrum.
C) different chemical compounds, each with its own characteristic color, emitted from the volcanoes.
D) various forms of sulfur, the color of which can vary widely following exposure to a variety of thermal conditions.
116. The required heating of the large Galilean moon Io of Jupiter in order to produce volcanic activity is probably caused by
A) tidal distortion by Jupiter and its other moons.
B) its original heat of formation.
C) nuclear fission within its interior.
D) radioactive elements in its surface.
117. The source of intense heating in the interior of Jupiter’s moon Io causing continuous and intense volcanic activity is
A) tidal flexing and distortion caused by Jupiter and the other large moons.
B) heat released by continuous shrinkage after creation, transforming potential gravitational energy to heat.
C) solar UV and visible radiation.
D) frictional heating as the solar wind impacts on the moon surface.
118. One of the MOST important sources of heat in the interiors of moons that orbit close to giant planets is
A) thermal energy from the moon’s parental planets.
B) continuous tidal distortion from the planet and other moons.
C) reflection of sunlight from the planet’s surface.
D) decay of radioactive elements within the moons.
119. The heating of the interior of Io, the innermost Galilean moon of Jupiter, is caused by
A) thermal heating from Jupiter because Jupiter emits more infrared radiation than it receives from the Sun.
B) continual bombardment by meteoroids attracted by Jupiter’s enormous gravitational pull.
C) continuous tidal distortion by Jupiter and the other moons.
D) the fact that Io moves inside Jupiter’s magnetosphere, where the temperature is as high as anywhere in the solar system.
120. Io, one of the major moons of Jupiter, is undergoing extensive volcanic activity associated with interior heating that is caused by
A) deposition of energy by particles from within Jupiter’s Van Allen belts.
B) original heat caused by gravitational condensation at the moon’s formation.
C) tidal distortion and internal friction because of flexing.
D) solar radiation and heat falling on the surface.
121. What is the heat source that causes the extensive volcanic activity observed on Jupiter’s satellite Io?
A) frictional heating by mantle convection and crustal tectonics
B) tidal stresses from Jupiter and Io’s companion moons
C) “primordial” heat remaining from when Io first formed
D) heat released by radioactivity in Io’s core and mantle
122. What is the internal structure of Io?
A) iron core overlaid by a molten mantle and rocky crust
B) core of rock overlaid by a thick mantle of water ice
C) entirely or almost entirely rock, with no evidence of ice or a differentiated metallic core
D) iron core overlaid by a rocky mantle and a deep ocean of liquid water
123. Io would probably be less active geologically if
A) its orbit were perfectly circular.
B) it were closer to Jupiter.
C) Europa and Ganymede were closer to it.
D) Jupiter did not rotate at such a high rate.
Section: 9-5
124. Which of the moons of Jupiter is characterized by an exceptionally smooth, icy surface, few craters, and many streaks and cracks?
A) Callisto
B) Io
C) Ganymede
D) Europa
125. Much of the surface of Europa resembles
A) the maria of the Moon.
B) the lunar highlands.
C) the oceans of Earth.
D) Earth’s polar regions.
126. Which of Jupiter’s Galilean moons appears to have current tectonic activity?
A) Io
B) Europa
C) Ganymede
D) Callisto
127. The surface of Europa, one of the Galilean moons of Jupiter, appears to be covered with
A) dark areas of older crust separated by lighter, grooved terrain.
B) a smooth layer of ice crossed by many cracks.
C) rugged mountain ranges and ancient volcanoes.
D) many ancient craters and maria.
128. Europa, one of the Galilean satellites of Jupiter, has a surface consisting of
A) a relatively young, icy crust covered with a network of streaks and cracks and only a few impact craters.
B) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves.
C) rock, heavily cratered like the highlands of the Moon.
D) an ancient, icy crust covered with numerous craters and no surface cracks or groove belts that would indicate internal activity.
129. Which of these phrases describes the surface of Europa, one of the giant moons of Jupiter?
A) entirely ice, with fractures and ridges going in every direction
B) entirely ice, with light and dark areas containing many impact craters and parallel ridges up to about a kilometer high
C) rocky and densely cratered, except for a few large, dark, relatively uncratered plains
D) The surface of Io is hidden below a dense layer of clouds, so its properties are unknown.
130. On which other world in the solar system does one find evidence of ice floes (now apparently frozen) similar in many respects to ice floes in Earth’s Arctic Ocean?
A) icy surface of Jupiter’s satellite Europa
B) Pluto, in the equatorial region facing most directly toward the Sun
C) tropical regions of Saturn’s satellite Titan
D) Mars, at the edges of the polar caps
131. What appears to be the relationship between the surface of Europa and its interior?
A) A solid ice layer extends from the surface to the rocky mantle.
B) A frozen ocean with one small, irregular “continent” overlays several mountain peaks rising above the ice.
C) A solid surface of ice overlays a layer of liquid water or slush.
D) A light, rocky surface and crust “floats” on a denser but partially molten layer of rock.
132. What appears to have caused the extensive cracking and streaking of the surface of Europa?
A) shrinking of the satellite as it cooled, producing extensive wrinkling
B) impacts by cometary debris breaking up the surface
C) expansion of the surface as the ice froze, bending and wrinkling the surface
D) tidal flexing by Jupiter and its other moons, which broke the surface and released water that immediately froze
133. What is the MOST probable physical mechanism to have caused the very long cracks and streaks that crisscross the surface of Europa, one of the moons of Jupiter?
A) Volcanic eruptions caused lava flows, which then froze in place.
B) The “cracks” are frozen rivers that, in warmer times, were flowing across the moon’s surface.
C) The “cracks” are actually the tops of gigantic greenhouses, built by inhabitants of Europa to protect their cucumber crops.
D) Tidal flexing by Jupiter and its moons cracked the icy surface, allowing subsurface fluids to gush out and freeze in place.
134. When Io passes between Jupiter and Europa, both moons experience gravitational stress. On Europa this is responsible for three of the features listed below. Which feature does NOT occur as a result of the gravitational flexing of Europa?
A) cracks on the surface
B) heat to keep subsurface water liquid
C) water geysers
D) lava/sulfur volcanoes
135. Which of these is NOT a reason that planetary scientists suspect that liquid water exists under the surface of Europa?
A) existence of cracks and fractures on the moon’s surface
B) existence of smooth areas apparently formed by fluid erupting onto the surface
C) lack of a magnetic field around Europa
D) discovery of lenticulae of rising, warmed ice
136. The ocean water that is believed to occur below the surface of Jupiter’s moon Europa is kept unfrozen by heat from
A) absorption at this level in the moon of solar UV and visible radiation.
B) radioactive decay of heavy elements in the moon’s core.
C) electric currents flowing in this conducting liquid, induced by the motion of the moon through Jupiter’s magnetic field.
D) tidal distortions of the moon by the combined gravity of Jupiter and the other moons.
137. Jupiter’s satellite Europa is believed to be made up of
A) a metallic core and a rocky mantle covered with a liquid water ocean whose surface is frozen.
B) a small, rocky core overlaid by a very thick layer of water ice.
C) ice and rock mixed throughout in roughly equal proportions.
D) solid rock throughout, the surface of which shows ancient craters.
138. Based on its average density of 2970 kg/m3 compared with that of water at 1000 kg/m3, what is the internal structure of Jupiter’s moon Europa thought to be?
A) almost entirely water in liquid form or as ice
B) large iron core, the rest rock
C) half rock, half water and ice
D) a metallic core of high density with one-quarter of its mass composed of water and ice
139. The very thin but measurable atmosphere of molecular oxygen around Jupiter’s moon Europa probably originates from
A) dissociation of water vapor by solar UV radiation.
B) the remnant gases from Jupiter that reside within its magnetosphere.
C) primitive plant life living in the extensive oceans underneath the icy surface, which has transformed carbon dioxide into oxygen.
D) volcanoes that have ejected this gas during recent eruptions.
140. What property is shared by Earth and Europa, one of Jupiter’s large moons?
A) Earth and Europa have both been shown to harbor intelligent life in their oceans.
B) Earth and Europa both have thick atmospheres of nitrogen and oxygen.
C) Earth and Europa both have oceans of liquid water.
D) Earth and Europa are about the same physical size.
141. Why was the Galileo spacecraft NOT just left floating in space when its mission ended?
A) The last part of the mission was a final probe of Jupiter’s atmosphere.
B) It was feared that Galileo might someday crash on Europa and contaminate its oceans with biological organisms from Earth.
C) It was feared that the new Cassini spacecraft might crash into it.
D) Galileo carried a nuclear reactor, and the spacecraft was destroyed to prevent possible radioactive contamination.
142. In which of these solar system bodies is plate tectonics still active?
A) Europa
B) Io
C) Mars
D) Venus
143. Which of these lists of planets and satellites of planets is in the correct order of increasing size?
A) Mercury, the Moon, Europa, Mars
B) Europa, Mercury, the Moon, Mars
C) Europa, the Moon, Mercury, Mars
D) the Moon, Europa, Mars, Mercury
Section: 9-6
144. Where in the universe would one look for Ganymede?
A) in the asteroid belt
B) around the planet Mars because it is one of the moons of Mars
C) on the Moon because it is one of the largest maria
D) near Jupiter because it is one of Jupiter’s moons
145. If the orbital period of Jupiter’s moon Ganymede is 7.15 days, what would be the view from a point on its surface at the equator?
A) Both the Sun and Jupiter would remain fixed in the sky above Ganymede.
B) Both Jupiter and the Sun would rise and set with a period of about 7.15 days.
C) The Sun, if visible, would always be at the same point in the sky, but Jupiter would rise and set with a period of about 7.15 days.
D) Jupiter, if visible, would always remain at the same point in the sky, but the Sun would rise and set with a period of a few days.
146. Which is the largest planetary satellite in the solar system?
A) Earth’s Moon
B) Neptune’s satellite Triton
C) Jupiter’s satellite Ganymede
D) Saturn’s satellite Titan
147. Ganymede, the largest Galilean moon of Jupiter, has
A) a larger radius than either the Moon or Earth.
B) a smaller radius than the Moon.
C) a larger radius than Mercury but smaller than Mars.
D) a larger radius than Mars but smaller than Earth.
148. The MOST massive planetary satellite in the solar system is
A) Jupiter’s satellite Europa.
B) Jupiter’s satellite Ganymede.
C) Earth’s Moon.
D) Saturn’s satellite Titan.
149. What features dominate the surface of Ganymede, one of Jupiter’s satellites?
A) craters, densely spread over the entire surface
B) volcanoes, lava lakes, and sulfur dioxide frost
C) many cracks and streaks and very few craters in an otherwise smooth, icy surface
D) old, dark, highly cratered polygons separated by younger, lighter, grooved terrain
150. Ganymede, one of the Galilean satellites of Jupiter, has a surface consisting of
A) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves.
B) rock, heavily cratered like the highlands of the Moon.
C) an ancient, icy crust covered with numerous craters and no surface cracks or groove belts that would indicate internal activity within the moon.
D) a relatively young, icy crust covered with a network of streaks and cracks and only a few impact craters.
151. The orbital periods of Io, Europa, and Ganymede are in the ratio 1:2:4. Is there any significance to this?
A) No. This is just a random coincidence of the manner in which these satellites condensed out of the primordial nebula around Jupiter.
B) Yes. This is the ordering predicted by Kepler’s third law.
C) Yes. Combined with the fact that these are all prograde orbits, this shows that these moons are not captured asteroids.
D) Yes. After completion of an orbit by Ganymede, all these moons will be in a line, creating tidal stresses on Io.
152. The surface of Ganymede, a Galilean satellite of Jupiter, is characterized by
A) bright, eroded, ancient terrain broken by darker, younger areas that show signs of tectonic activity in the past, such as water or slush volcanoes and faulting along subduction zones.
B) dark areas of ancient terrain and bright areas with almost no craters and many signs of recent tectonic activity, such as fracturing, ice raft creation, and eruptions of icy lava.
C) dark areas of ancient terrain and bright, younger areas with many-folded ridges that indicate tectonic activity on Ganymede in the distant past.
D) multicolored deposits of sulfur and sulfur compounds, with several lava lakes and active volcanic plumes.
153. The specific and unique property of water that was responsible for the large-scale surface features—dark polygons surrounded by heavily grooved and lighter terrain—on Ganymede’s surface is
A) its reflectivity when still wet compared to when it is fully frozen. Wet ice in the polygons appears darker.
B) the difference in reflectivities of ice and liquid water. The light ice network surrounds darker pools of liquid water.
C) the change in color of water ice with temperature, becoming darker in the centers of the colder polygons but lighter at their warmer edges.
D) the fact that it expands when it freezes. Water squeezed out from beneath old, dark ice expanded to produce the lighter, raised terrain.
154. The structure of Ganymede, a Galilean satellite of Jupiter, is thought to be
A) an iron core, a rocky mantle, and a liquid ocean with a dirty ice surface.
B) mostly or entirely rock, with no firm evidence of an iron core, and active volcanoes on its surface.
C) a large rocky core with a thin layer (100 km thick) of ice and water over it.
D) about half rock and half ice, with rock at the center and ice outside.
155. How are the relative ages of the different types of terrain on Ganymede estimated?
A) The smoother the surface, the older is the terrain.
B) The colder the surface, the older is the terrain.
C) The darker the coloration, the older is the terrain.
D) The denser the cratering, the older is the terrain.
156. What can be said about tectonic activity on Ganymede?
A) Active volcanoes give evidence of current tectonic activity.
B) Young, lightly cratered terrain separating older more heavily cratered regions suggests tectonic activity in the past.
C) An intrinsic magnetic field suggests current tectonic activity.
D) Ganymede has a subsurface liquid ocean. This requires tectonic activity to provide the heat to keep the ocean from freezing.
157. What appears to be the origin of the light, grooved terrain on the surface of Ganymede?
A) impacts by cometary debris
B) cracking of the surface caused by shrinkage of the moon as it cooled
C) cracking of the icy surface, releasing water that expanded as it froze into ice
D) flow of water on the solid surface of the moon at some time in the past, which subsequently shrank as it froze into this distinctive terrain
158. Even though Ganymede, one of the large Galilean satellites of Jupiter, and Earth are very different, they share one feature. What is it?
A) dense atmosphere
B) evidence of plate tectonic activity
C) thick rocky mantle and a large iron core under icy crust
D) active volcanoes
159. What is the mechanism that generates the variable component of Ganymede’s magnetic field?
A) variable electric currents in the conducting upper atmosphere of this moon
B) electric currents induced in the conducting ocean by Ganymede’s motion through Jupiter’s powerful magnetic field
C) spinning of the moon whose surface is electrically charged, which is equivalent to an electric current
D) spinning and permanently magnetized iron core within the liquid ocean
160. Which of these is NOT a reason that planetary scientists suspect Ganymede has a subsurface ocean?
A) It has a variable magnetic field.
B) Ganymede’s surface has evidence of past tectonic activity.
C) There is evidence of salts on the surface.
D) Ganymede is in synchronous rotation about Jupiter.
161. Are auroras known to exist on Ganymede?
A) No. It is much too cold for auroras to exist on Ganymede.
B) No. Ganymede is too far from the Sun to have appreciable numbers of solar charged particles interact with its magnetic field.
C) Yes. Charged particles from Jupiter’s magnetosphere interact with Ganymede’s atmosphere to produce auroras.
D) Yes. Sulfur ions from the Io torus interact with Ganymede’s magnetic field to produce a primarily yellow aurora.
Section: 9-7
162. What features dominate the surface of Callisto, one of Jupiter’s satellites?
A) volcanoes, lava lakes, and sulfur dioxide frost
B) old, dark, highly cratered polygons separated by younger, lighter, grooved terrain
C) many cracks and streaks and very few craters in an otherwise smooth, icy surface
D) large craters, densely spread over the entire surface
163. The structure of Callisto, the outer Galilean satellite of Jupiter, is thought to be
A) a mixed ice-rock interior surrounded by a liquid ocean and then a solid icy crust.
B) mostly or entirely rock, with no firm evidence of an iron core, and active volcanoes on its surface.
C) an iron core surrounded by a rocky mantle and an ice mantle and crust.
D) almost all water ice, in view of its low average density.
164. Which of these BEST describes the surface of Callisto, the outer Galilean moon of Jupiter?
A) very dark, rocky surface with a thin ice frost that occasionally disappears by evaporation when illuminated by the Sun
B) ammonia and methane ice surface with methane clouds above it, making the moon appear very bright
C) ice-covered and heavily cratered surface with a dark coating, maybe of meteoritic dust or hydrocarbon material, making the moon appear dark
D) sulfur-coated surface with molten sulfur lakes and active volcanoes
165. The surface of Callisto, the outer Galilean moon of Jupiter, can BEST be described as
A) relatively smooth, with many large impact craters and one large basin created by an asteroid impact.
B) relatively smooth, with many small craters but no evidence of large impacts.
C) rough and mountainous, with evidence of either volcanoes or geyserlike activity.
D) very smooth, with a network of streaks and cracks and very few craters.
166. Callisto, the outer Galilean moon of Jupiter, has a surface consisting of
A) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves.
B) rock, heavily cratered like the highlands of Earth’s Moon.
C) a relatively young, icy crust covered with a network of streaks and cracks and only a few impact craters.
D) a very dark and ancient icy crust covered with numerous craters, with no surface cracks or groove belts that would indicate internal activity.
167. Mercury has a large impact crater, the Caloris Basin, opposite which shock waves traveling through the planet created a region called the “jumbled terrain.” Callisto has a large impact crater, Valhalla. What does the surface of Callisto look like on the opposite side from Valhalla?
A) The surface is jumbled, like that on Mercury.
B) There is no jumbled terrain because the distance through Callisto is too great for a shock wave to travel.
C) The opposite side of Callisto has been cratered more recently, so it is not possible to determine if a jumbled terrain was formed opposite Valhalla.
D) There is no jumbled terrain because Callisto’s partially liquid interior damped out the shock waves.
168. Which of these does NOT accurately characterize Jupiter’s moon Callisto?
A) a subsurface ocean
B) a very large impact crater
C) a changing magnetic field
D) evidence of tectonic activity
169. Large scale geologic activity apparently never occurred on
A) Europa.
B) Io.
C) Callisto.
D) Ganymede.
170. The water in the ocean predicted to occur below the surface of Jupiter’s moon Callisto is heated above its freezing point by heat from
A) absorption of solar UV and visible radiation at this depth in the moon.
B) tidal distortions of the moon by the combined gravity of Jupiter and the other moons.
C) radioactive decay of heavy elements in the moon’s core.
D) electric currents flowing in this conducting liquid, induced by the motion of the moon through Jupiter’s magnetic field.
171. What is the pattern followed by the average densities of the Galilean moons of Jupiter with increasing distance from the planet?
A) Average density increases with distance from the planet.
B) Average density shows no pattern with distance; the highest-density moon is Ganymede, the largest moon.
C) Average density is the same for all moons because they were made from the same material.
D) Average density decreases with distance from the planet.
172. The inner two Galilean satellites of Jupiter differ from the outer two by having
A) much higher average densities and almost crater-free surfaces.
B) almost the same average densities but much older, more heavily cratered surfaces.
C) much lower average densities and heavily cratered surfaces.
D) almost the same average densities but much younger, less-cratered surfaces.
173. Which of these motions is characteristic of the four Galilean moons of Jupiter?
A) Each of the four Galilean moons keeps the same face toward the Sun at all times.
B) Each of the four Galilean moons keeps the same face toward Jupiter at all times.
C) The four Galilean moons orbit the planet in the opposite direction to its rotation—retrograde motion.
D) The four Galilean moons orbit the planet in a plane carrying them over both the north and south poles of Jupiter.
174. What is significant about the rotational and orbital motions of the Galilean moons of Jupiter in which they mimic the behavior of Earth’s Moon?
A) nonsynchronous rotation, with axes of rotation in any direction with respect to their orbital plane
B) nonsynchronous rotation, with independent periods of rotation and revolution and spin axes perpendicular to their orbit
C) synchronous rotation, with one face always pointed toward the planet
D) synchronous rotation, with one face always pointed toward the Sun
175. Brightness variations of Jupiter’s moons as they orbit the planet indicate that the relation between the spin around their axes and their orbital motions is that these moons
A) do not rotate at all while orbiting the planet.
B) rotate exactly once per orbital period.
C) rotate in a way that is controlled by the gravitational influence of the Sun, keeping one face toward the Sun to produce the observed brightness variations.
D) rotate on their axes independently of their orbital motion.
176. How many of the large, Galilean satellites are in synchronous rotation around Jupiter (always turning the same face toward Jupiter)?
A) inner two
B) only Io
C) all four
D) inner three
177. Which of the Galilean moons of Jupiter appear(s) to have experienced tectonic activity in the past?
A) Io only
B) Europa and Ganymede
C) Europa and Callisto
D) all four
178. The three outer Galilean satellites of Jupiter—Europa, Ganymede, and Callisto—all appear to have cores of rock. In addition to rocky material, the major constituent of these satellites seems to be ices of
A) water.
B) carbon dioxide.
C) ammonia.
D) methane.
179. The outer three Galilean moons of Jupiter differ from Io, the innermost Galilean moon, because they have surfaces of
A) smoothly polished rock.
B) carbon dioxide ice.
C) sulfur.
D) water ice.
180. On which one of Jupiter’s Galilean moons is there evidence of present tectonic activity?
A) Io
B) Europa
C) Ganymede
D) Callisto
181. What is the order of rotation periods for the Galilean moons, from shortest to longest? (Hint: All four moons are in synchronous orbits.)
A) Io, Europa, Ganymede, Callisto
B) Io, Ganymede, Europa, Callisto
C) Ganymede, Europa, Io, Callisto
D) Callisto, Ganymede, Europa, Io
Section: 9-8
182. What peculiar feature accompanies Io in its orbit around Jupiter?
A) torus or ring of ionized sulfur and oxygen atoms and electrons
B) cometlike tail of rocks and dust, shining by reflected sunlight
C) narrow ring of rocks and dust, Jupiter’s ring, at about Io’s orbital distance
D) auroral storm in the magnetosphere that always keeps pace with Io
183. The smaller (non-Galilean) moons of Jupiter all orbit the planet in
A) the prograde direction.
B) the retrograde direction.
C) directions that are prograde for some of the moons and retrograde for others.
D) orbits that cross over both poles of Jupiter.
184. What is the source of the particles that compose Jupiter’s rings?
A) These are particles that orbited Jupiter when it was formed but never coalesced into a satellite.
B) These particles were once a satellite, but it moved too close to Jupiter and was torn apart by the strong gravitational field.
C) Particles blasted by impacts off the four innermost moons of Jupiter form the rings.
D) The ring particles are captured from the asteroid belt by Jupiter’s strong magnetic field.
185. The material that composes the rings of Jupiter
A) consists mostly of boulder-size rocks.
B) remains constant over time.
C) is continually being ejected from the rings and being replenished from material from the Jovian moons.
D) is a very thin solid sheet that orbits the planet as a single object.
186. There is a torus of material around Jupiter surrounding the orbit of Io. This torus consists of
A) large chunks of material that never formed into a ring.
B) charged particles ejected from Io’s geysers.
C) fine dust particles, like the rings.
D) charged particles ejected from Jupiter’s aurorae.
187. Most if not all of Jupiter’s outermost “moons” appear to be
A) relatively small rocks or icy debris left over after the formation of the rest of the Jovian moons.
B) spherical, about the same size as and similar to Earth’s Moon or Mercury.
C) loosely bound collections of fine dust grains held together by electrical forces similar to static electricity on Earth.
D) small planetesimals captured by Jupiter.
188. Which of these is NOT a valid reason to believe that the outer satellites of Jupiter are captured planetesimals?
A) There was not enough material in the primordial nebula around Jupiter to form the large Galilean satellites as well as the 60 or so outer satellites. So, they must have been captured.
B) The outer satellites are irregular in shape.
C) The outer satellites are all less than 275 km in diameter.
D) The outer satellites are mostly in retrograde orbits.
189. What are the physical characteristics of the “other” (non-Galilean) moons of Jupiter?
A) only 10 to 20 km in diameter and spherical in shape
B) 500 to 1000 km in diameter and spherical in shape
C) less than 300 km in diameter and irregular in shape
D) all sizes up to 1500 km in diameter, the smaller ones irregular and the larger ones spherical
190. What is the location of the smaller moons of Jupiter compared with the orbits of the Galilean moons?
A) The smaller moons all orbit beyond Callisto.
B) The smaller moons occupy orbits over the full range, inside Io’s orbit, between the Galilean moons and outside Callisto’s orbit.
C) The orbital distances from Jupiter of the smaller moons are all less than that of Io.
D) Several of the smaller moons are inside Io’s orbit, and none orbit within the orbits of the Galilean moons and the rest are beyond Callisto.
191. What kind of ring or rings does Jupiter have?
A) a main ring made up of very fine dust particles as well as ringlets made up of larger debris
B) three wide, bright rings, composed of icy particles about 1 cm to 1 m in size
C) one narrow, dark ring composed of icy particles less than 1 mm in size
D) only a ring of glowing ions at Io’s orbital distance, no rings of solid particles
192. Does Jupiter have rings orbiting the planet?
A) Yes, a main ring composed of fine dust particles and three ringlets composed of larger debris.
B) No.
C) Yes, three very wide, bright rings and several faint, thin ones.
D) Yes, several thin dark rings of particles made up of or at least coated with methane ice.
193. A plasma torus has been discovered around Jupiter associated with each of these moons:
A) Io and Europa
B) Io and Ganymede
C) Europa and Ganymede
D) all four Galilean moons
194. Jupiter’s strong magnetic field
A) has no effect on Io.
B) is the main cause of the geologic activity on Io.
C) contains many charged particles that have been ejected from Io.
D) has caused Io to go around Jupiter in a synchronous orbit.
195. The source of the aurora seen around the magnetic poles of Jupiter is
A) water vapor evaporated from Europa, Ganymede, and Callisto and ionized by solar UV radiation.
B) dust from the rings of Jupiter ionized by friction between the different parts of the rings.
C) ionized material from a torus surrounding Jupiter along Io’s orbit and originating on Io.
D) electrons from the solar wind.
196. Aurorae are formed when charged particles, spiraling along magnetic field lines, collide with atoms in an atmosphere. Where are the charged particles that produce Jupiter’s aurorae believed to originate?
A) from the Sun, just like the particles that produce Earth’s aurora
B) from particles ejected from Io’s geysers
C) from debris knocked off the inner moons Adrastea and Metis
D) from Jupiter’s rings
Section: 9-9
197. Saturn, like Jupiter, is composed primarily of
A) gases.
B) liquids.
C) solids.
D) plasma.
198. “Visible features” on the surface of Saturn are
A) of a completely different pattern from those on Jupiter and more distinct.
B) similar in appearance to those on Jupiter but much less distinct.
C) similar to those on Jupiter but much more pronounced.
D) nonexistent because Saturn shows completely uniform cloud tops.
199. Which of these characteristics of Saturn’s atmosphere differs substantially from Jupiter’s atmosphere?
A) bands caused by rapid rotation
B) auroras
C) helium rain
D) convection
200. What is helium rain?
A) In Jupiter’s large gravitational field, helium is condensed to liquid and falls until it becomes liquid metallic hydrogen.
B) Titan’s thick atmosphere produces condensed helium, which falls like rain.
C) The cold temperatures in Saturn’s atmosphere cause helium to condense and to fall toward the interior like rain.
D) Helium gas from Jupiter is conducted along the intense magnetic field lines to fall as rain on Europa. Europa is colder because it does not have the internal heating experienced by Jupiter.
201. Like Jupiter, Saturn gives out more energy than it receives from the Sun. But unlike Jupiter, much of Saturn’s excess energy comes from
A) the Kelvin-Helmholtz mechanism.
B) radioactivity.
C) friction among the ring particles.
D) helium rain.
202. Saturn’s atmosphere does NOT show the same colorful contrast seen in Jupiter’s atmosphere because
A) Saturn has a similar circulation pattern to Jupiter’s, but it is obscured by a thick hazy atmosphere.
B) Saturn has counter-flowing eastward and westward winds, as does Jupiter, but it lacks the three differently colored cloud levels.
C) Saturn’s clouds and circulation pattern resemble those of Earth (individual cyclones and anticyclones) rather than the elongated cloud forms of Jupiter.
D) Saturn’s features are obscured by an upper cloud deck of methane ice crystals, whose distinctive absorption of red light results in Saturn’s blue color. Jupiter is too hot to have a methane atmosphere.
203. Other than the rings, how does the appearance of Saturn differ from that of Jupiter?
A) Saturn’s visible surface is basically featureless, with no hint of the belts and zones of Jupiter.
B) Saturn shows an ever-changing system of dark storms and light eddies, without the belts and zones of Jupiter.
C) There are belts and zones on Saturn, but they are very faint and hazy compared to Jupiter.
D) Saturn has many more belts and zones than Jupiter, with large storms distorting their shapes.
204. Aurorae has been observed on three of the bodies listed. Where has it NOT been observed?
A) Jupiter
B) Saturn
C) Ganymede
D) Callisto
205. The MOST prevalent constituent of the interior of Saturn is
A) rock.
B) hydrogen.
C) carbon dioxide.
D) nitrogen.
206. What is the mass of Saturn compared with the mass of Jupiter?
A) about 
the mass of Jupiter
B) about 1
times the mass of Jupiter
C) about 
the mass of Jupiter
D) almost the same mass
207. Which of these BEST describes the interior structure of Saturn?
A) rocky core, thick mantle of liquid metallic hydrogen and helium, thick layer of molecular hydrogen and helium, thin gaseous atmosphere
B) rocky core, thin mantle of liquid metallic hydrogen and helium, thick layer of molecular hydrogen and helium, relatively thin gaseous atmosphere
C) large iron core, molten rock mantle, thin gaseous atmosphere
D) large, liquid, metallic hydrogen core overlaid by a thick gaseous atmosphere
208. Saturn is less massive than Jupiter but has almost the same radius. Explain.
A) The smaller mass exerts less gravitational force and is unable to compress the material as much as in Jupiter.
B) Saturn is rotating faster than Jupiter, and the increased centrifugal force results in a larger size.
C) Saturn’s interior is hotter than that of Jupiter.
D) Saturn is composed of lighter material than Jupiter.
209. Which planet in the solar system has the lowest average density?
A) Mercury
B) Saturn
C) Uranus
D) Jupiter
210. Jupiter’s atmosphere has three prominent cloud layers: NH3 (ammonia), NH4SH (ammonium hydrosulfide), and H2O (water vapor). How do the cloud layers in the atmosphere of Saturn compare to this?
A) The two atmospheres are virtually identical.
B) The layers in Saturn’s atmosphere are very similar, but they are more spread out because of Saturn’s lesser gravity.
C) Saturn is much colder because it is farther from the Sun and because it does not give out as much energy from gravitational contraction as does Jupiter. This temperature difference has reversed the order of the layers in comparison with Jupiter.
D) Saturn is a very different planet, and its atmosphere does not resemble that of Jupiter at all.
211. The major components of the visible surfaces of the Jupiter and Saturn atmospheres, other than hydrogen and helium, have been found to be
A) dust and iron oxides.
B) CH4 (methane), NH3 (ammonia), and H2O (water).
C) N2 (nitrogen), O2 (oxygen), and CO2 (carbon dioxide).
D) H2O (water) and CO2 (carbon dioxide).
212. Figure 9-7 shows the three cloud layers of Jupiter and Saturn. What is the unlabeled blank space beneath these layers?
A) gaseous hydrogen
B) liquid hydrogen
C) solid metallic hydrogen
D) Rocks
Section: 9-10
213. The Roche limit around a planet is defined as the
A) distance beyond which the orbital velocity of a body in a Keplerian orbit is greater than the escape velocity, and matter is no longer captured by the planet.
B) distance inside which a solid satellite (e.g., a fragment of rock) will be pulled apart by tidal forces.
C) outer extent of the magnetic field of the planet, or the magnetospheric boundary.
D) distance at which a planet creates tides on its moon’s surface high enough to pull its moon apart.
214. Which planet has wide, bright rings that are easily visible from Earth?
A) Neptune
B) Venus
C) Jupiter
D) Saturn
215. What observation technique was being used when Saturn’s rings were originally discovered?
A) ground-based photography
B) momentary occultation of starlight as the planet moved in front of a star
C) spacecraft photography
D) visual observations through a telescope
216. The rings of Saturn are in which plane with respect to the planetary system?
A) orbital plane of Saturn around the Sun
B) equatorial plane of Saturn
C) plane inclined at an angle to both the orbital and equatorial planes of the planet and to the ecliptic plane, which is why they can be easily seen face-on from Earth
D) ecliptic plane
217. Saturn’s main ring system is tilted 27 degrees with respect to what?
A) the ecliptic
B) Saturn’s orbital plane
C) Saturn’s equatorial plane
D) the equatorial plane of the Sun
218. The rings of Saturn alternately appear very distinct and then almost disappear when viewed from Earth over a period of a few years because
A) Earth is very much closer to Saturn at opposition than at conjunction, so the rings are more easily seen at this time.
B) the solar wind occasionally blows away the ring particles when the Sun is particularly active.
C) the ice crystals from which they are made melt and refreeze as the planet approaches and recedes from the Sun.
D) the plane of the rings is tilted with respect to the ecliptic plane and thus appears edge-on at times.
219. In 2004 the bottoms of Saturn’s ring were visible from Earth. In 2019, what will an Earth-based observer see? (Saturn’s orbital period is 29 years.)
A) The rings will be edge-on and thus not visible.
B) The bottoms will again be visible.
C) The tops of the rings will be visible.
D) It is not possible to predict this so far in advance.
220. Suppose an observer is viewing the rings of Saturn from Earth, and they are seen edge-on. How long must the observer wait until the rings are again edge-on? (Saturn’s orbital period is 29 years.)
A) 6 months
B) 1 year
C) 14.5 years
D) 29 years
221. The rings of Saturn orbit the planet as
A) a solid body.
B) five separate, solid rings.
C) individual particles, all with periods shorter than the periods of the large moons of Saturn.
D) individual particles, all with periods longer than the periods of the large moons of Saturn.
222. The physical structure of Saturn’s rings is
A) a thin solid ring structured from ice and rock.
B) a sequence of many thousands of separate ringlets consisting of ice particles and ice-coated rock.
C) hot, ionized gas from the planet’s magnetosphere.
D) a thin but extensive gas cloud over the equator.
223. Kepler’s third law relates the period P and the semimajor axis a of an orbit. For a circular orbit, P = 2πa/v, so it is possible also to relate the speed at which the particle orbits, v, to a. The result is
A) as a increases, both P and v increase.
B) as a increases, P increases but v decreases.
C) as a increases, P decreases but v increases.
D) as a increases, both P and v decrease.
224. The size distribution of particles in the rings of the Jovian planets is
A) from pebble-sized fragments to objects a few meters in diameter, with significant amounts of fine dust in and above some rings.
B) from 10 m to 1 km across, with no smaller components.
C) a mixture of gas (mostly hydrogen) and dust grains, none larger than about 1 mm across.
D) only dust and smokelike particles.
225. What size are the particles making up Saturn’s rings?
A) a few micrometers in diameter (dust grains)
B) up to about 1 mm in diameter (“snowflakes”)
C) up to about 10 cm in diameter
D) up to about 10 m in diameter
226. The particles in Saturn’s rings are composed of
A) rocks with the reflectivity of dark asphalt.
B) iron and nickel.
C) ammonia and methane ice, possibly with rocky centers.
D) water ice or rock coated with water ice.
227. What is the composition of Saturn’s rings?
A) particles of methane and ammonia ice
B) sodium and sulfur ions
C) small grains of rock
D) water ice or ice-coated rock
228. Which of these techniques is NOT used to determine the size of the particles that make up the rings of Saturn?
A) studying the fraction of visible light reflected from the rings
B) studying the fraction of radio waves reflected from the rings
C) studying the colors of the rings
D) measuring the orbital periods of the particles in the rings
229. Which observational fact leads scientists to the conclusion that the particles making up Saturn’s rings are ice or ice-covered rocks?
A) high albedo, or reflectivity, of the ring material
B) distribution of their sizes; water ice is only strong enough to form the objects of the sizes detected in the rings
C) spectrum of the reflected light, which shows features unique to water ice
D) thin layer of haze above and below the rings originating from evaporated water vapor
230. What is the typical thickness of Saturn’s rings?
A) 15 km
B) 1.5 km
C) 300 m
D) 10 m
231. What is the MOST striking feature of the dimensions of the rings of Saturn?
A) The cross-section of the rings in a latitudinal direction appears to be circular.
B) The thickness of the rings means that the shadow they cast on the planet extends over 10° in latitude.
C) The radius of the rings is such that the rings extend out beyond the orbits of all of the planet’s moons.
D) The rings are extremely thin compared to their lateral extent.
232. Approximately how thick (top to bottom) are Saturn’s rings compared with the total width from inside to outside?
A) about 10-7 of the width
B) about 10-6 of the width
C) about 10-3 of the width
D) about 1/10 of the width
233. The rings of Saturn are seen by
A) emitted light from the molecules of the material of the rings, such as methane, ammonia, and water vapor.
B) reflected and scattered sunlight.
C) reflected light from Saturn because they can be seen at night.
D) fluorescence, a glow produced by photochemistry when material is irradiated by solar UV light and/or high-speed cosmic particles.
234. What basic optical process makes the rings of Saturn visible to observers on Earth?
A) absorption of sunlight, making the rings appear dark against the bright sunlit planet
B) refraction of sunlight by ice crystals
C) self-emission of light from atoms of the ring material under UV excitation
D) scattering of sunlight
235. The particles in Saturn’s rings
A) move in circular orbits; the outer particles move fastest.
B) revolve in different directions depending on the distance from the planet; the reversal of this direction is at the Cassini division.
C) all move as if they were one solid disk.
D) move in circular orbits; the inner particles move fastest.
236. How does the orbital period P of particles moving around in the rings of Saturn depend on the distance r of the particles from the center of the planet?
A) P2 is proportional to r3.
B) P is constant for all r because the rings move as a solid disk.
C) P is proportional to 1/r2
D) P increases directly with r.
237. Which of these sentences describes the motions of the particles in the rings of Saturn?
A) Each of the particles moves in an almost circular Keplerian orbit around the planet.
B) The particles move in randomly oriented elliptical orbits and collide frequently with one another.
C) The particles move in zigzag patterns within the ring system because of interaction with the major moons.
D) The particles all move in concert as if they were a solid sheet because of electrostatic interaction.
238. In the rings of Saturn, there are two main rings, the outer A ring and the inner B ring. How do the particles in these rings move relative to each other?
A) Particles in the A ring move more slowly than those in the B ring.
B) Speeds of the particles in all rings are the same because mutual gravitational forces between them ensure that they move as a solid disk.
C) Speeds of the particles vary because of attraction by the Sun, so A particles sometimes move faster and at other times B particles move faster.
D) Particles in the A ring move faster than particles in the B ring because they are farther from the planet.
239. Sometime in the future, a crewed space mission to Saturn might place an observer in a spacecraft within Saturn’s ring system. What relationship between the motions of the ring particles and the motion of the spacecraft would the observer see?
A) All particles would be moving with the same orbital speed and would fly in formation with the spacecraft because the motions of particles and spacecraft are governed by gravity.
B) Particles closer to the planet would overtake the spacecraft, while particles farther from the planet would be overtaken by the spacecraft, following Kepler’s laws.
C) The particles would be moving in ellipses and would therefore sometimes move ahead of the spacecraft and at other times fall behind the spacecraft, even colliding with it occasionally.
D) Particles orbiting farther from the planet would be traveling faster and would overtake the spacecraft, while particles closer to the planet would be moving slower and would be overtaken by the spacecraft.
240. What is the Cassini division?
A) boundary between the bright B ring and the faint C ring in Saturn’s rings
B) layer of relatively clear air separating Saturn’s upper cloud deck from the middle cloud deck
C) wide, dark gap between Saturn’s A and B rings
D) division between the two dark equatorial belts of Jupiter
241. Where is the Cassini division found in the solar system?
A) between two major ring systems around Saturn
B) between two band systems on the visible “surface” of Jupiter
C) between two major groups of asteroids in the asteroid belt
D) between the terrestrial and the Jovian planets, occupied by the asteroid belt
242. The Cassini division is
A) the gap between terrestrial and Jovian planets.
B) a gap between two groups of asteroids in the asteroid belt.
C) a gap between two specific mountain ranges collectively called Cassini on the Moon.
D) a gap in the rings of Saturn, seen from Earth.
243. How is the Cassini division created and maintained in Saturn’s rings?
A) A small moon orbits within the division, clearing particles from the gap.
B) An intense region of high-energy electrons in Saturn’s magnetosphere at that distance has eroded the particles from the gap.
C) The rings simply formed that way in the ancient past.
D) One of Saturn’s satellites exerts a resonant pull on particles in the division, clearing a gap.
244. The major gaps in the rings of Saturn are MOST likely to be caused by
A) beams of charged particles, similar to Earth’s Van Allen belts, in Saturn’s magnetosphere that clear out this region.
B) mutual gravitational interactions between the multitude of particles in the rings.
C) the intervention of a massive body that moved through the rings in their early history, leaving the gaps.
D) gravitational forces from Saturn and/or its moons that deflect the paths of particles that stray into the gaps.
245. Why is the F ring much narrower than the main rings?
A) The ring is in a stronger part of Saturn’s gravitational field and cannot spread out any farther.
B) The ring is constrained by Saturn’s strong magnetic field.
C) Two shepherd satellites focus the particles into a narrow ring.
D) There are not enough particles available to make a wider ring.
246. Two tiny but significant satellites that follow nearly identical orbits around Saturn are called shepherd moons because they
A) clear particles from the Cassini division.
B) trail streams of gases behind them, like comet tails.
C) lift dust particles up into “spokes” above the rings.
D) concentrate particles into the narrow F ring of Saturn.
247. The gravitational effect that confines the particles of the F ring of Saturn to a narrow orbit is the
A) major gravitational distortion caused by the neighboring planet Jupiter.
B) pressure of the solar wind upon these particles.
C) gravitational influence of two small shepherding satellites in orbits adjacent to the ring.
D) gravitational effects of the major moons of Saturn, such as Mimas and Enceladus.
248. The physical mechanism that is thought to control the motion and position of material in the narrow F ring around Saturn is the
A) effect of the planet’s intense magnetic field on the material.
B) confining gravitational interaction between this material and two shepherd satellites.
C) effect of sunlight focused on this material by the planet’s atmosphere.
D) complex gravitational interaction between the major moons of Saturn and the F ring material.
249. The main gravitational effect that organizes the particles in the rings of Saturn into specific narrow orbits is
A) the complex gravitational effects of the planet and the Sun on the ring particles.
B) perturbations by neighboring planets, such as Jupiter and Neptune.
C) collisions between the ring particles and the major moons of the planets.
D) gravitational perturbations by the moons orbiting the planet.
250. The Saturnian satellite Pan moves along the Encke gap. Suppose a rock is orbiting within the gap at an orbital radius slightly smaller than that of Pan. Which one of these passages correctly describes the interaction between Pan and the rock?
A) Pan catches up to and passes the rock. As it does so, Pan pulls back on the rock, slowing it and causing it to move in an orbit with a larger radius.
B) Pan catches up to and passes the rock. As it does so, Pan pulls the rock forward, making it move faster and causing it to move in an orbit with a smaller radius.
C) The rock catches up to and passes Pan. As it does so, Pan pulls the rock forward, making it move faster and causing it to move into an orbit with a larger radius.
D) The rock catches up to and passes Pan. As it does so, Pan pulls back on the rock, slowing it and causing it to move into an orbit with a smaller radius.
251. While Saturn’s rings are very thin, some particles escape away from the ring’s orbital plane. Why?
A) interactions with Saturn’s magnetic field
B) collisions with nearby comets
C) interactions with the solar wind
D) volcanic activity on Saturn’s moons
252. Saturn’s rings probably formed through
A) asteroid impacts on Saturn’s moons during the Late Heavy Bombardment.
B) the breakup of a satellite that spiraled too close to the planet.
C) stripping of Saturn’s atmosphere by the solar wind.
D) the capture of many comets within the planet’s Roche limit.
253. The dark spokes in Saturn’s rings are MOST likely a result of
A) gravitational interactions with Jupiter.
B) clearing of nearby ice particles by moonlets.
C) Saturn’s magnetic field.
D) resonances with Saturn’s larger moons.
Section: 9-11
254. Around which object does Titan orbit?
A) Saturn
B) Pluto
C) Jupiter
D) Neptune
255. The size of Saturn’s moon Titan is
A) about the same as the size of the moons of Mars.
B) intermediate between the sizes of Mercury and Mars.
C) intermediate between the sizes of Mars and Earth.
D) intermediate between the size of Mercury and the size of Earth’s Moon.
256. Saturn’s moon Titan is DIFFERENT from all other moons of the planets because
A) continuously erupting volcanoes are observed on it.
B) lakes of water with floating icebergs are seen on its surface.
C) its orbit carries it directly over both poles of the planet.
D) it possesses a thick atmosphere.
257. What characteristic of Saturn’s satellite Titan makes it DIFFERENT from any other known satellite in the solar system?
A) Titan is volcanically active.
B) Titan has geyserlike plumes of nitrogen gas on its surface.
C) Titan has a permanent and dense atmosphere.
D) The surface of Titan is broken into heavily cratered and lightly cratered regions in a pattern similar to plate tectonics.
258. Which is the only satellite in the solar system known to possess a permanent, dense atmosphere?
A) Titan
B) Charon
C) Callisto
D) Ganymede
259. Which of these satellites of planets in the solar system has a significant and dense atmosphere?
A) Triton, a moon of Neptune
B) Io, a moon of Jupiter
C) Titan, a moon of Saturn
D) Earth’s Moon
260. Which of the moons of the giant planets is known to have a significant and dense atmosphere?
A) Europa, a moon of Jupiter
B) Titan, a moon of Saturn
C) Triton, a moon of Neptune
D) Io, a moon of Jupiter
261. What is the appearance of Saturn’s satellite Titan when viewed from space?
A) The surface is not visible under a featureless cloud cover.
B) A smooth surface of ice is crisscrossed with innumerable streaks and cracks.
C) Volcanoes, lava flows, and sulfur dioxide frost are seen over the whole surface.
D) Dark islands of methane ice are seen in a bright ethane sea, covered by occasional clouds.
262. The composition of the atmosphere of Titan, a satellite of Saturn, is mostly
A) methane with small quantities of other gases.
B) nitrogen, methane, and other hydrocarbons.
C) carbon dioxide with small quantities of other gases.
D) methane, ammonia, and water vapor.
263. The atmosphere of Titan appears to include all of these EXCEPT significant amounts of
A) hydrogen.
B) nitrogen.
C) methane.
D) ethane.
264. Two bodies in the solar system known to have atmospheres primarily of nitrogen are
A) Saturn and Titan.
B) Saturn and Ganymede.
C) Earth and Titan.
D) Earth and Ganymede.
265. The major constituent of the atmosphere of Titan (the largest moon of Saturn) is
A) water vapor, H2O.
B) nitrogen, N2.
C) carbon dioxide, CO2.
D) methane, CH4.
266. What is(are) the main constituent(s) of the atmosphere of Titan, a satellite of Saturn?
A) ammonia and methane
B) nitrogen and oxygen
C) nitrogen and methane
D) carbon dioxide
267. How is nitrogen thought to have become the dominant gas in the atmosphere of the moon Titan, a satellite of Saturn?
A) from the breakup of ammonia by solar UV into nitrogen and hydrogen; the light hydrogen atoms are then lost to space
B) from outgassing through volcanic vents; nitrogen is the predominant gas from such vents
C) Nitrogen has been present from primordial times, when Titan first formed.
D) from the collision with the surface of Titan of comets rich in nitrogen in liquid and solid form
268. Which chemical in the atmosphere of Titan (a moon of Saturn) plays the same role that water plays on Earth by producing “rain,” “snow,” and “ice” at the temperature encountered on Titan?
A) nitrogen, N2
B) ammonia, NH3
C) ethane, C2H6
D) oxygen, O2
269. What would be a typical weather forecast on Titan, Saturn’s largest moon?
A) turbulent winds in an ammonia, methane, and water vapor atmosphere, with dense clouds of ammonia compounds and water ice
B) dust storms and high winds in a thin carbon dioxide atmosphere
C) occasional sulfur clouds and sulfur dioxide fog from volcanic eruptions
D) hydrocarbon fog and ethane rain in a dense nitrogen atmosphere
270. Which of these was NOT detected by the Huygens-Cassini mission on the surface of Titan?
A) a heavily cratered surface
B) numerous lakes of liquid hydrocarbons
C) evidence of methane rainfall
D) running streams of hydrocarbons
271. Which one of these features has NOT been found on Titan?
A) lakes and rivers of liquid methane
B) evidence of plate tectonics
C) sand dunes
D) significant atmospheric oxygen
272. Which one of these features has NOT been found on the surface of Titan?
A) drifting lakes
B) sand dune-like features
C) a high mountain range
D) water on the surface
273. The interior of Titan appears to include all of these EXCEPT
A) rocks.
B) ice.
C) high levels of radioactivity.
D) liquid water.
274. The surface temperature of Titan, the largest moon of Saturn, is on average
A) 178 K (195°C).
B) 273 K (0°C).
C) 368 K (+95°C).
D) 95 K (–178°C).
275. How would Interplanetary Travel, Inc., advertise a holiday on Titan, one of the satellites of Saturn?
A) Exquisite ethane lakes, hydrocarbons beyond your wildest dreams, no shortage of fuel!
B) Hot and dry—never rains—beautiful sulfurous skies!
C) The largest number of volcanoes for your travel dollar anywhere in the solar system!
D) Hot days and cool nights under cloudless skies but dust storms a possibility—bring your own oxygen supply!
276. Which spacecraft visited Saturn in 2004 to image both the planet and its moons and to send a probe onto one of its moons?
A) Voyager, on its next flyby of Saturn
B) Cassini
C) Hubble Space Telescope
D) Huygens
Section: 9-12
277. Scarps are long lines of cliffs believed to have formed when the surface of the body cooled and shrank. They have been observed on all of these EXCEPT
A) Mercury.
B) Earth.
C) the Moon.
D) Rhea.
278. Rhea is locked into a synchronous orbit by the strong gravitational pull of Saturn. This suggests that its orbital eccentricity is close to
A) 0
B) 1/2
C) 1
D) B
279. The Cassini spacecraft observed an unusual feature on Rhea. What was it?
A) a large volcano
B) scarps (long lines of cliffs)
C) plate tectonics
D) a satellite in orbit around Rhea
Section: 9-13
280. Which of these is NOT a reason to suspect liquid water on Enceladus?
A) It possesses a magnetic field.
B) Most of the moon’s southern hemisphere is free of craters.
C) There are cracks on the surface less than 1000 years old.
D) It possesses a thin atmosphere.
281. Which of these features does Saturn’s satellite Enceladus probably NOT possess?
A) molten lava flowing from active volcanoes
B) liquid water under its surface
C) thin atmosphere
D) a magnetic field
282. To generate a planetwide magnetic field requires a body to rotate and to contain some liquid that is electrically conductive. What is believed to be the source of the magnetic field of Enceladus?
A) molten nickel-iron, as on Earth
B) salty ice water
C) liquid metallic hydrogen, as on Saturn
D) Enceladus is too small to generate its own magnetic field, so this must be an induced field, caused by the presence of Saturn.
283. Which one of these features has NOT been found on Enceladus?
A) jets of ice water shooting into the atmosphere
B) a uniformly and heavily cratered surface
C) stripes of recently formed material
D) a magnetic field
284. Tidal flexing from Saturn appears to be responsible for interior heating of Enceladus. Some consequences of this internal heating include all of these EXCEPT
A) ice water jets.
B) a large area of smooth terrain.
C) a magnetic field.
D) the absence of seasons on Enceladus.
Section: 9-14
285. The spacecraft that successfully photographed Uranus on a 1986 flyby mission was
A) Viking.
B) Voyager.
C) Magellan.
D) Galileo.
286. What is the visual appearance of Uranus from space?
A) perpetually covered with yellowish, sulfur-rich clouds
B) blue-green with distinct white, high-altitude clouds and dark storms
C) blue-green and featureless
D) reddish belts and light zones parallel to the equator
287. What are the MOST abundant gases in the atmosphere of Uranus?
A) carbon dioxide, nitrogen, and oxygen
B) hydrogen and helium, with traces of methane
C) methane and water that form clouds, which are easily visible from Earth
D) nitrogen and ammonia
288. What gives Uranus its blue-green coloration?
A) impurities of phosphorus and sulfur in the otherwise white ice crystals of water, methane, and ammonia
B) emission by blue and green spectral lines of ethane and propane
C) absorption of red light by methane gas
D) absorption of blue and green light by ammonia gas
289. As photographed by Voyager 2, the atmosphere of Uranus shows
A) light zones and dark belts circling the planet parallel to the equator.
B) dark, whirlpool-like features and high, white clouds of methane ice crystals.
C) a pinkish haze due to scattering from silicate dust particles.
D) a faint haze over the north pole, but it is otherwise featureless.
290. The infrared camera of the Hubble Space Telescope was able to see through the haze layers of the atmosphere of Uranus to show
A) a system of Jupiterlike bands and zones above which are giant and constantly changing methane clouds.
B) a deeper but somewhat structured haze layer consisting of methane and ethane gases.
C) light zones and dark reddish belts circling the planet parallel to the equator, interspersed with dark spots and light ovals.
D) volcanoes on the planet’s surface spewing out vast quantities of sulfurous gases into the atmosphere.
291. The rotation axis of which planet is tilted at 98° from the vertical to its orbit?
A) Neptune
B) Earth
C) Venus
D) Uranus
292. The major planet whose spin axis lies almost in its orbital plane is
A) Neptune.
B) Uranus.
C) Mars.
D) Mercury.
293. By what angle is the rotation axis of Uranus tilted from the vertical to its orbit?
A) 98°
B) almost 180°
C) less than 2°
D) 25° (almost the same as Earth’s tilt)
294. As seen by an observer floating above the clouds of Uranus, where would the Sun be located in midsummer in the northern hemisphere?
A) directly over a line of latitude 25° south of the equator
B) directly over a line of latitude 25° north of the equator
C) almost directly above the equator
D) almost directly above its north pole
295. Uranus is tilted on its side with its rotation axis almost in the plane of its orbital motion around the Sun. As a result, seasonal variations in temperature on Uranus are
A) nonexistent.
B) much less extreme than seasonal variations in temperature on Earth.
C) about the same as on Earth.
D) much more extreme than seasonal variations in temperature on Earth.
296. The expected seasonal changes on Uranus because of its orbital and spin-axis alignments, compared with those on Earth, are
A) the same.
B) absent because of the alignment of the spin axis.
C) very much exaggerated.
D) much less.
297. Earth experiences an equinox when the day and night are of equal length everywhere on the planet. Does Uranus experience an equinox? If so, how often? (The orbital period of Uranus is 84 years.)
A) No.
B) Yes, every 6 months just like Earth.
C) Yes, every 42 years.
D) Yes, every 84 years.
298. Seasonal variations over a full Uranian year at a particular point on Uranus would
A) not be present at any point on the planet because dense clouds shield it from climate changes.
B) be nonexistent because such variations at any point on the planet will be smoothed out during its long “year” by the planet’s rapid rotation.
C) be almost nonexistent because Uranus moves in an almost perfectly circular orbit and its distance from the Sun remains constant.
D) be extreme because its spin axis is nearly in its orbital plane.
299. Which of these effects is now thought to be the MOST likely cause for the inclinations of spin axis of several of the planets such as Uranus (and even Earth) to their orbital planes?
A) out-of-balance force on the spin axes of planets from their moons, some of which are very massive
B) major collision with another planetlike body
C) steady force on one hemisphere of the planet from the highly directional solar wind
D) tidal distortion and deflection caused by neighboring planets
300. Which planets rotate about their axes in a retrograde direction?
A) Venus and Uranus
B) Uranus and Neptune
C) Mercury and Uranus
D) Venus and Neptune
301. What is believed to be the basic structure of the interior of Uranus?
A) rocky core, thick layer of highly compressed liquid water, thick outer layer of liquid hydrogen, thin gaseous atmosphere
B) rocky core, thick layer of liquid water covered by a thin gaseous atmosphere
C) rocky core, thick layer of liquid metallic hydrogen, thin gaseous atmosphere
D) iron core, thick layer of rock, solid icy surface covered by a thin gaseous atmosphere
302. The interior of Uranus has three layers. These do NOT include
A) liquid hydrogen and helium.
B) liquid metallic hydrogen.
C) compressed liquid water.
D) rocks and metals.
303. The surprising fact about the magnetic field of Uranus compared with the magnetic field of Earth or Jupiter is that
A) its axis is precisely aligned with the spin axis of the planet.
B) it is extremely small and localized in specific regions of the planet.
C) it is much more intense than that of any other planet.
D) its axis makes a larger angle to the planet’s spin axis than that of any other planet.
304. One of the characteristics of the magnetic field of Uranus is that its axis
A) is tilted almost 60° to the axis of planetary rotation and is offset from the planet’s center.
B) is aligned almost parallel to the planet’s axis of rotation but is offset from the planet’s center.
C) is aligned almost exactly along the planet’s axis of rotation, through the center of Uranus.
D) passes through the center of Uranus but is tilted almost 60° from the axis of rotation.
305. Of these characteristics of the magnetic field of Uranus, which one is NOT unusual when compared to other magnetic fields in the solar system?
A) The magnetosphere wobbles considerably as the planet rotates.
B) The strength of the magnetic field is less than that of Earth’s field.
C) The center of the field is well removed from the center of Uranus.
D) The magnetic field axis is 59 degrees from the planet’s rotation axis.
306. Because of the large angle between the magnetic axis of Uranus and its rotation axis, its magnetosphere wobbles considerably as the planet rotates. Astronomers use this wobble to determine the
A) strength of the magnetic field.
B) interior rotation speed of the planet.
C) rotation speed of the atmosphere.
D) density of the planet.
307. The interior rotation of Uranus is considerably slower than the rotation rate of the clouds on its surface. How have astronomers measured the interior rotation rate?
A) by measuring the differential rotation between the poles and the equator
B) The moons have locked into synchronous rotation at the same rate.
C) by measuring the wobble of the magnetosphere
D) by measuring the speeds of the cloud layers at different depths and extrapolating to the surface
Section: 9-15
308. The rings of Uranus were
A) predicted theoretically because of the planet’s similarity to Saturn.
B) first discovered while observing the occultation of a star by the Uranian system.
C) first discovered by Voyager 2 on its flyby in 1986.
D) first observed by Galileo.
309. How were the first rings of Uranus discovered?
A) from Earth, when each ring momentarily blocked the light from a background star
B) by the Ulysses spacecraft when observing from above the Sun’s north pole
C) by Voyager 2 during its pass through the Uranian system
D) by the Hubble Space Telescope, observing in infrared light
310. The ring system around Uranus was originally discovered by what observation technique?
A) infrared observation from the IRAS spacecraft in Earth orbit
B) observation by the cameras aboard the Voyager 1 spacecraft
C) occultation of light from a star as Uranus (and the rings) passed in front of it
D) radar reflection from the particles in the rings
311. What scientific method was first used to discover the rings around Uranus?
A) X-ray photography from the Einstein satellite
B) spacecraft exploration of the planet
C) direct photography of the rings from Earth
D) occultation of a star as the planet and rings moved in front of it
312. The rings of Uranus are
A) intrinsically very bright, with 70 percent reflectivity, but they are hard to detect because they are very narrow.
B) wide, dense, and very bright, with 70 percent reflectivity.
C) broad, diffuse, and almost transparent, made up of almost nothing bigger than dust particles.
D) narrow and very dark.
313. The particles in the Uranus ring system differ from those in the Saturn ring system in which important way?
A) The particles of the Uranus ring system move as a solid ring held together by static electricity, not in Keplerian orbits, as do the Saturnian ring particles.
B) The particles of the Uranus ring system reflect much more sunlight than do the particles of the Saturnian ring material.
C) The average sizes of the particles of the Uranus ring system are larger; the particles of the Saturnian system are only snowflake or dust-grain size.
D) The particles of the Uranus ring system reflect much less sunlight than do the particles in Saturn’s rings.
314. MOST of the satellites of Uranus orbit the planet in
A) the plane of the ecliptic and therefore almost at right angles to the plane of Uranus’s equator.
B) various directions, each one reflecting the satellite’s trajectory at the time it was captured by Uranus.
C) the plane of the planet’s equator and therefore approximately in the plane of the ecliptic.
D) the plane of the planet’s equator and therefore in a plane almost at right angles to the ecliptic.
315. Miranda is a satellite of
A) Pluto.
B) Neptune.
C) Uranus.
D) Jupiter.
316. Which one of these descriptions of Miranda, one of the satellites of Uranus, is correct?
A) heavily cratered, icy surface with deformation and flowing due to heating in some regions
B) icy, frost-covered surface with vents of rising gas visible in the northern hemisphere
C) icy surface with chaotically varied terrain
D) rocky surface with active volcanoes
317. Miranda, a satellite of Uranus,
A) shows active geysers and resurfacing due to water flows.
B) has a thick atmosphere containing methane, nitrogen, and hydrocarbons.
C) shows an ancient surface uniformly covered with impact craters.
D) appears to have been reassembled from separate parts after being shattered by an impact.
318. Which planetary satellite shows strong evidence of disruption by an impact at some time in its history and of subsequent partial reassembly and reshaping by self-gravity?
A) Callisto
B) Io
C) Triton
D) Miranda
319. The unusual surface terrain on Uranus’s satellite Miranda is believed to have originated
A) in tectonic plate motion.
B) when an impactor struck the body and remained embedded.
C) in a powerful internal explosion that occurred early in Miranda’s history.
D) when large blocks of ice and rock were lifted off the surface in an impact and then settled back.
Section: 9-16
320. The discoverer of the planet Uranus was
A) William Herschel.
B) Galileo Galilei.
C) Clyde Tombaugh.
D) Edmund Halley.
321. How was Neptune discovered?
A) accidentally, by an astronomer taking photographs for an all-sky survey
B) accidentally, by an astronomer studying the sky visually through a telescope
C) by a careful application of Newton’s laws to the somewhat irregular motions of Uranus
D) by a careful search with the Hubble Space Telescope
322. Which planet was discovered by applying Newton’s laws to the motion of another planet?
A) Neptune
B) Uranus
C) Mercury
D) Mars
323. Which is the eighth planet from the Sun (in order of increasing mean distance or semimajor axis)?
A) Saturn
B) Jupiter
C) Neptune
D) Uranus
324. The spacecraft that photographed Neptune on a 1989 flyby mission was
A) Viking.
B) Voyager 2.
C) Magellan.
D) Galileo.
325. What is the visual appearance of Neptune from space?
A) reddish belts and light zones parallel to the equator with large red spots
B) blue-green and featureless
C) perpetually covered with yellowish, sulfur-rich clouds
D) blue-green with white, high-altitude clouds and dark storms
326. Which planet is characterized by a blue-green appearance and white, high-altitude methane clouds surrounding dark storms?
A) Jupiter
B) Saturn
C) Uranus
D) Neptune
327. The Great Dark Spot (not the same as the Great Red Spot) was found on which planet or moon?
A) Mars
B) Jupiter
C) Neptune
D) Miranda, a moon of Uranus
328. The Great Dark Spot on Neptune, photographed by Voyager 2 during its flyby of the planet, is considered to be a
A) region of upwelling gas in Neptune’s atmosphere, above a hot spot on its surface, possibly a volcano.
B) storm system probably centuries old, like Jupiter’s Great Red Spot.
C) volcanic caldera.
D) relatively short-lived storm system.
329. The Great Dark Spot on Neptune
A) disappeared sometime between the Voyager flyby in 1989 and when the Hubble Space Telescope photographed Neptune in 1994.
B) came into existence sometime between the Voyager flyby in 1989 and when the Hubble Space Telescope photographed Neptune in 1994.
C) was the short-lived result of a comet crash in 1995.
D) has been visible through telescopes since at least as far back as 1665.
330. How did the Great Dark Spot, observed on Neptune, compare to Jupiter’s Great Red Spot?
A) The Great Dark Spot was much smaller in relation to Neptune’s size.
B) The Great Dark Spot wandered over Neptune’s surface, whereas the Great Red Spot remains relatively fixed.
C) The Great Dark Spot disappeared after a few years.
D) The Great Dark Spot was matched by a similar spot on the opposite side of the planet, whereas the Great Red Spot is solitary.
331. Neptune’s predominantly blue appearance is caused by
A) preferential scattering away from the planet of the blue end of the solar spectrum, in a similar process to that operating in Earth’s atmosphere.
B) auroral emissions caused by solar wind particles exciting the atoms and molecules in Neptune’s high atmosphere.
C) the fact that solar light has lost much of its red light by scattering in the interplanetary medium at the distance of Neptune.
D) absorption of the red end of the spectrum of reflected sunlight by the methane in its atmosphere.
332. Neptune’s high cirrus clouds consist of
A) ammonia ice crystals.
B) crystals of water ice.
C) droplets of sulfuric acid.
D) methane ice crystals.
333. At the time of the Voyager flybys of Neptune, the patterns and motions of its atmosphere MOST closely resembled those of which other planet?
A) Venus, with rapidly moving clouds of sulfuric acid droplets and a thick carbon dioxide atmosphere
B) Jupiter, with clouds and rotating spots
C) Saturn, with indistinct cloud bands and no large spots
D) Uranus, with no distinct features seen through a deep high-altitude haze
334. One distinct difference between the two otherwise similar planets, Uranus and Neptune, is
A) the almost featureless visible image of Uranus, compared to distinctly seen storms and clouds on Neptune.
B) the absence of an internal magnetic field and surrounding magnetosphere at Neptune.
C) belts and zones on Uranus, visible through haze, compared to the totally cloud-enshrouded Neptune.
D) the absence of moons around Neptune.
335. Compared to Earth, Jupiter, and Saturn, the magnetic fields of Uranus and Neptune
A) have axes that are tilted a long way from the spin axis of the planets.
B) have axes that are aligned almost exactly with the planet’s spin axis.
C) are nonexistent because Uranus and Neptune have no magnetic fields.
D) are much more powerful, dominating the motions of clouds on these planets.
336. Which one of these statements about all four of the giant planets is true?
A) The giant planets are almost entirely made up of hydrogen and helium; only about 1 percent of the planets’ mass is made up of heavier elements.
B) The giant planets are thought to have substantial rocky cores.
C) Liquid metallic hydrogen makes up a large part of the interiors of the giant planets.
D) The spin axes of the giant planets are all approximately perpendicular to their orbital planes.
337. Which planets are believed to have a thick layer of water mixed with ammonia and methane in their interiors?
A) Saturn, Uranus, and Neptune
B) Saturn and Neptune
C) Uranus and Neptune
D) Saturn and Uranus
338. The magnetic fields of Uranus and Neptune appear to originate in the
A) rocky cores of the planets.
B) liquid water-ammonia mixture in the mantles of the planets.
C) layer of liquid hydrogen and helium in the outer parts of the planets.
D) methane in the atmospheres of the planets.
339. The electrically charged particles that produce electric currents and therefore magnetic fields when they move inside Uranus and Neptune are
A) electrons flowing through metallic iron in the planet’s cores.
B) molecules such as ammonia (NH3), which become ionized when in solution in water.
C) liquid metallic hydrogen under immense pressure.
D) electrically conducting iron atoms in the molten cores.
340. Uranus and Neptune resemble each other in many ways. However, which of these statements is NOT correct?
A) Both planets (probably) have three layers: rocky core, watery mantle, and thick hydrogen-helium atmosphere.
B) Both planets appear basically featureless in photographs from Voyager 2.
C) Both planets have magnetic field axes tilted at large angles from their rotation axes.
D) A system of rings circles both planets.
341. Which of these statements correctly describes how Neptune differs from Uranus?
A) Neptune rotates quite rapidly (16 hours), whereas Uranus rotates very slowly (243 days).
B) A number of storms and ice clouds are visible in Neptune’s atmosphere, whereas Uranus’s atmosphere appears almost featureless.
C) Neptune is circled by a system of narrow, dark rings, whereas the rings of Uranus are wide, like those of Saturn.
D) Neptune’s magnetic axis is closely aligned with its rotation axis, whereas for Uranus the two axes are at a large angle to each other.
Section: 9-17
342. Does Neptune have rings orbiting the planet?
A) Yes, three very thin rings composed of fine dust particles.
B) Yes, three very wide, bright rings and several faint, thin ones made up of dark rocky material
C) No
D) Yes, a system of dark rings of particles coated in chemically modified methane ice
343. Why are the rings of Neptune dark?
A) Although the particles have highly reflective surfaces, there are very few particles in the rings.
B) The rings are composed of small, dark rock particles.
C) The particles are composed of methane ice that has been darkened by radiation damage.
D) The particles have highly reflective surfaces, but the rings are far from the Sun, where there is little light.
344. Which planet has a system of smaller moons with highly elliptical orbits and one large moon that orbits in a retrograde direction?
A) Jupiter
B) Neptune
C) Saturn
D) Uranus
345. Triton, the giant moon of Neptune, differs from all other major moons of the planets because
A) its orbit is very elliptical.
B) it orbits faster than the rotation of the planet.
C) it orbits in a retrograde direction, opposite to the planet’s rotation.
D) its orbit takes it over the planet’s poles.
346. Which property of Triton, the largest moon of Neptune, makes it significantly different from all other major moons in the solar system?
A) atmosphere of nitrogen and oxygen and water clouds
B) orbit at right angles to the equator of the mother planet
C) extremely dark, smooth surface; consequently, it was not discovered until very recently
D) orbit direction opposite to the rotation and revolution of the mother planet
347. What features characterize the visible surface of Triton, Neptune’s largest moon?
A) ice heavily cratered by ancient impacts
B) wrinkled surface, frozen lakes, and plumes of nitrogen gas
C) dense atmosphere permanently shrouded in clouds
D) lava flows, volcanoes, and sulfur dioxide frost
348. Triton, the largest satellite of Neptune, has a
A) surface of ice with frozen lakes, plumes of escaping gas, and few craters.
B) surface of ice in which ancient, densely cratered regions are surrounded by interconnecting systems of parallel ridges.
C) thick atmosphere that hides the surface from view.
D) densely cratered surface of ice with at least one very large ringed structure, indicating an ancient asteroid impact.
349. Which planetary satellites are known to have plumes of gas escaping through their surfaces?
A) Earth’s Moon, Europa, and Miranda
B) Io and Triton
C) Ganymede and Charon
D) Io and Titan
350. The plumes that were seen rising from the surface of Triton, Neptune’s largest satellite, are believed to be
A) nitrogen gas driven through fissures from beneath the surface by radioactive heat.
B) volcanic ash from eruptions similar to but much smaller than Earthbound eruptions.
C) sulfur dioxide from geysers heated by tidal stresses.
D) water, methane, and ammonia ice crystals above volcanic vents.
351. A striking characteristic on Triton, the largest satellite of Neptune, is
A) a brightness variation: one hemisphere is as bright as ice and the other hemisphere is as dark as asphalt.
B) plumes of nitrogen gas rising from the icy surface, possibly as a result of radioactive heating.
C) an interconnecting network of parallel grooves, indicating tectonic activity in geologically recent times.
D) a crater so large that the impact that created it must have come close to shattering the satellite.
352. How would Interplanetary Travel, Inc., advertise a holiday to Neptune’s satellite Triton?
A) The largest number of volcanoes for your travel dollar anywhere in the solar system!
B) Skate on frozen nitrogen lakes all morning, bask beside nitrogen geysers in the afternoon!
C) Hot and dry—never rains—beautiful sulfurous skies!
D) Exquisite ethane lakes, hydrocarbons beyond your wildest dreams, no shortage of fuel!
353. What future awaits Triton, the largest satellite of Neptune?
A) probable destruction from impact by Pluto
B) gravitational capture by Pluto
C) escape from Neptune after billions of years, as Triton gradually spirals outward
D) tidal breakup as it spirals closer to Neptune
354. If one were to observe Neptune a quarter of a billion years in the future, what significant change would be seen?
A) The planet would have shrunk considerably as gravity continues to compress it.
B) Triton would be gone and the ring system would be considerably enhanced.
C) Triton’s retrograde orbit would have become prograde.
D) The rings will have disappeared.
355. The effect of tidal forces caused by Triton on Neptune as it moves in its retrograde orbit will lead to Triton
A) spiraling outward from Neptune with an eventual escape.
B) spiraling in toward Neptune to eventual destruction by differential tidal forces on the moon.
C) being captured by Pluto when this dwarf planet next passes inside the orbit of Neptune.
D) gradually moving from its elliptical orbit toward a perfectly circular orbit.
356. Eruptions of material into space have been seen to occur from within the bodies of all of these moons EXCEPT
A) Europa.
B) Enceladus.
C) Io.
D) Triton.
357. The rotation periods for the Jovian planets Jupiter, Saturn, Uranus, and Neptune are
A) somewhat shorter than that of Earth, between 10 to 20 hours.
B) reasonably long, on the order of several Earth days.
C) much shorter than that of Earth, between 1 and 2 hours.
D) very long, on the order of years, because of the sizes of these planets.
358. In order of increasing density, the Jovian planets are
A) Neptune, Uranus, Saturn, and Jupiter.
B) Saturn, Uranus, Jupiter, and Neptune.
C) Neptune, Saturn, Uranus, and Jupiter.
D) Jupiter, Saturn, Uranus, and Neptune.
359. Rings of dust and icy particles are found around
which planets?
A) only Saturn
B) all four of the terrestrial planets
C) all four of the Jovian planets
D) only planets that do not have moons
360. Which of these would be UNCHANGED if Earth had been formed metal-poor?
A) smaller magnetic field
B) less gravity at Earth’s surface
C) much higher and lower tides
D) less volcanic activity