Deck 7: The Outer Planets and Their Moons

Question 1

To compute the density of Jupiter,we obtain 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.

Answer 1

Kepler's third law and its size from trigonometry.

Question 2

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 fly-by of a spacecraft, Pioneer 10, in December 1973.

Answer 2

the time of Hooke and Cassini in the 1600s.

Question 3

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

Answer 3

series of dark belts and light zones parallel to the equator

Question 4

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.

Question 5

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

Question 6

Evidence of lava flow,either recent or ancient,is NOT found on:

A) Jupiter.
B) Earth.
C) Earth's Moon.
D) Mars.

Question 7

When is the BEST time to observe Jupiter from Earth?

A) when Jupiter is high above our southern horizon at sunrise or sunset
B) when Jupiter is at maximum eastern or western elongation and farthest away from the Sun in Earth's sky at sunrise or sunset
C) when Jupiter is at opposition and hence the closest to Earth
D) when Jupiter is at conjunction and hence at its brightest because it appears closest to the Sun

Question 8

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 it 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.

Question 9

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) twice the mass of all other planets combined

Question 10

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, as it is almost a star at its present mass
D) 75 times more massive

Question 11

Which object rotates the MOST quickly around its own axis?

A) Venus
B) Earth's Moon
C) Earth
D) Jupiter

Question 12

Jupiter's mass makes up what fraction of the total mass of the planetary system,excluding the Sun?

A) 70%
B) 10%
C) 98%
D) 50%

Question 13

Which is the BIGGEST planet in the solar system?

A) Earth
B) Neptune
C) Jupiter
D) Saturn

Question 14

At what point in its orbit does Jupiter appear to be brightest when viewed from Earth?

A) opposition
B) Jupiter's brightness does not vary with orbital position because of its almost circular orbit.
C) when the Earth-Jupiter line is at right angles to the Sun-Jupiter line
D) conjunction

Question 15

On which planet is the Great Red Spot found?

A) Mercury
B) Mars
C) Jupiter
D) Saturn

Question 16

Which spacecraft recently dropped a probe into the atmosphere of Jupiter?

A) Ulysses
B) Voyager
C) Cassini
D) Galileo

Question 17

What are the light-colored bands on Jupiter called?

A) belts
B) streams
C) plumes
D) zones

Question 18

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

Question 19

At what configuration does Jupiter appear to be faintest when viewed from Earth?

A) conjunction
B) when the Earth-Jupiter line is at a right angle to the Jupiter-Sun line
C) Jupiter's apparent brightness does not vary with orbital position because it has an almost circular orbit.
D) opposition

Question 20

The dark,reddish bands on Jupiter are called:

A) streams.
B) zones.
C) voids.
D) belts.

Question 21

Which conclusion 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.

Question 22

Jupiter is significantly thicker through the equator than it is through the poles.The word we use to describe such a planetary shape is:

A) oblate.
B) obtuse.
C) oblique.
D) obese.

Question 23

What is the overall composition of the outer atmospheric regions of Jupiter in terms of the relative numbers of atoms?

A) 75% hydrogen, 15% helium, and 10% everything else
B) hydrogen and helium only, with no other elements
C) 86% hydrogen, 13% helium, and 1% everything else
D) pure hydrogen

Question 24

Have we 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.

Question 25

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 us, and the Doppler blueshift makes them appear brighter.
B) The ovals are moving away from us, 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.

Question 26

Which planet in our solar system has the FASTEST rotation?

A) Mercury
B) Uranus
C) Jupiter
D) Earth

Question 27

What is the Great Red Spot?

A) a dark, polar hood in the clouds of Titan, a satellite of Saturn
B) a large, anticyclonic storm on Neptune discovered by the Voyager spacecraft
C) a lava lake on Io, a satellite of Jupiter
D) a large and long-lived, possibly permanent storm on Jupiter

Question 28

Jupiter's Great Red Spot is probably a(n):

A) continent.
B) storm.
C) optical illusion.
D) hole in the clouds.

Question 29

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.

Question 30

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.

Question 31

The composition of the clouds we see 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.

Question 32

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, with light and dark ovals between the flows
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

Question 33

Which chemical is the MOST abundant in the outer atmosphere of Jupiter?

A) H₂O (water vapor)
B) CH₄ (methane)
C) NH₃ (ammonia)
D) CO₂ (carbon dioxide)

Question 34

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.

Question 35

Which feature of Jupiter leads to the confinement of its clouds in very narrow bands around the planet?

A) a high gravitational field
B) a powerful magnetic field
C) convection currents and upwelling in its atmosphere
D) rapid rotation

Question 36

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.

Question 37

What is the Great Red Spot on Jupiter?

A) the summit of a large mountain that rises above the upper cloud level
B) a region over the south pole of Jupiter where ammonia compounds that absorb blue light have condensed in the colder atmosphere
C) an area where charged particles from the satellite Io collide with Jupiter's cloud tops
D) a large, long-lived anticyclonic storm that is maintained by the differential rotation of Jupiter's atmosphere

Question 38

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.

Question 39

What is the composition of 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
D) water-ice crystals

Question 40

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.

Question 41

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.

Question 42

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

Question 43

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

Question 44

What was the MOST surprising result that the Galileo probe found when it penetrated the atmosphere of Jupiter?

A) a hard surface just under the cloud layers, contrary to our 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

Question 45

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 is larger than Earth in both size and mass.
B) It is considerably larger in mass, but Jupiter's gravity has compressed it to about Earth's size.
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.

Question 46

Which spacecraft did NOT visit Jupiter?

A) Galileo
B) Viking
C) Pioneer
D) Voyager

Question 47

In what form is the hydrogen in Jupiter's interior?

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

Question 48

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.

Question 49

Where in the solar system would you 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

Question 50

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

Question 51

Which spacecraft was the MOST recent to reach Jupiter?

A) the Hubble Space Telescope
B) Galileo
C) Cassini
D) Voyager

Question 52

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

Question 53

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, 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.

Question 54

What did Cassini 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.

Question 55

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, 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.

Question 56

Recent estimates suggest that the overall mass distribution among atomic components of Jupiter is:

A) 50% hydrogen and 50% helium.
B) almost 100% hydrogen.
C) 71% hydrogen, 24% helium, and 5% heavier elements.
D) 86% hydrogen, 13% helium, and 1% heavier elements.

Question 57

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).

Question 58

What causes 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

Question 59

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.

Question 60

What have we 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 four centuries we have been 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.

Question 61

Kepler's third law for orbits around the Sun is a³ = P²,where the semi-major axis a is in AU and the period P is in years.(See section 2-5 in Discovering the Essential Universe,6th ed.).For objects in orbit around Jupiter we 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 two years.What was its maximum distance from Jupiter in this orbit (in AU)?

A) 0.05
B) 0.16
C) 0.32
D) 0.48

Question 62

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

Question 63

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.

Question 64

If we 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) sbout twice as large as Jupiter itself
D) 16 times larger than the full Moon

Question 65

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.

Question 66

The temperature in the core of Jupiter is:

A) as hot as the temperature of the Sun's core, but it is composed of rock, so nuclear fusion will not occur.
B) as hot as the temperature of the Sun's core, and because Jupiter's core is mostly hydrogen, nuclear fusion occurs at a low rate to produce excess heat on Jupiter.
C) cooler than the temperature of the Sun's surface, meaning that no nuclear fusion can take place.
D) hotter than the temperature of the Sun's surface but cooler than the temperature of the Sun's core, so nuclear fusion cannot take place.

Question 67

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

Question 68

Strong radio radiation from Jupiter indicates the presence of:

A) radio stations.
B) thunderstorms.
C) a strong magnetic field.
D) the Great Red Spot.

Question 69

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.

Question 70

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.

Question 71

If we 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, several times larger than the full Moon.
C) Jupiter's magnetosphere would cover essentially our 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.

Question 72

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

Question 73

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.

Question 74

The outer cores of Jupiter and Saturn are made of "ices" that are actually in the liquid state.Why are they not solid?

A) The pressure in the outer cores of Jupiter and Saturn is too great.
B) The temperature in the outer cores of Jupiter and Saturn is too high.
C) The material of the ices is hydrogen and helium, which cannot exist in a solid form.
D) The constant agitation caused by the planets' rotation prevents the formation of a solid.

Question 75

Which characteristic has NOT been observed on Juipter?

A) lightning
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) that can stretch from the pole to the equator

Question 76

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.

Question 77

Which process 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

Question 78

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.

Question 79

What is the Kelvin-Helmholtz mechanism?

A) the tidal flexing which causes Io to be geologically active
B) a satellite in a non-equatorial 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

Question 80

How does the magnetosphere of Jupiter compare with 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.