Deck 8: The Giant Planets

Question 1

Each season is 42 years long on Uranus because:

A) they change on the timescale of Uranus's orbital period.
B) Uranus rotates so slowly.
C) Uranus's rotational axis is tipped by 45° relative to its orbital axis.
D) Hadley circulation is ineffective in transferring heat in Uranus's atmosphere.

Answer 1

they change on the timescale of Uranus's orbital period.

Question 2

As a group,the giant planets all rotate ________ terrestrial planets.

A) faster than
B) slower than
C) the same as
D) retrograde compared to

Answer 2

faster than

Question 3

The colors of the cloud bands on Jupiter and Saturn are due primarily to differences in their:

A) wind speeds.
B) chemical compositions.
C) altitudes.
D) temperatures.

Answer 3

chemical compositions.

Question 4

You could fit roughly ________ Jupiters across the diameter of the Sun and roughly ________ Earths across Jupiter's diameter.

A) 10; 100
B) 100; 10
C) 10; 10
D) 100; 100

Question 5

Uranus and Neptune are bluish green because they contain large amounts of:

A) ammonia.
B) methane.
C) water vapor.
D) hydrocarbons.

Question 6

Neptune and Uranus probably took longer to form than Jupiter and Saturn because the solar nebula was ________ at the radius of Neptune and Uranus.

A) rotating faster
B) composed of rockier planetesimals
C) not as dense
D) hotter

Question 7

A planet will have bands in its atmosphere like Jupiter and Saturn if:

A) Hadley circulation is the main effect governing the atmosphere.
B) the planet rotates slowly.
C) the wind speeds vary greatly with latitude.
D) the planet has a high temperature.

Question 8

You observe Neptune as it occults a background star when the relative velocity between Neptune and the Earth is 30 km/s,and the star crosses through the middle of the planet and disappears for 27.6 minutes.What is Neptune's diameter?

A) 5 × 104 km
B) 800 km
C) 4,000 km
D) 9 × 103 km

Question 9

________ has the most extreme seasons of any planet in the Solar System.

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

Question 10

The giant planet atmospheric vortices are created by a combination of the Coriolis effect and:

A) rapid rotation.
B) convection.
C) their strong magnetic fields.
D) Hadley circulation.

Question 11

All the giant planets except ________ experience seasons.

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

Question 12

The gas giants are composed primarily of:

A) hydrogen.
B) helium.
C) water.
D) ammonia.

Question 13

Why do we find methane ice clouds above water ice clouds in the atmospheres of Uranus and Neptune?

A) Methane ice clouds are lighter than water ice clouds.
B) Methane is far more plentiful than water on Uranus and Neptune.
C) Methane is in a liquid/gas state at lower temperatures than water.
D) All of the above are good reasons.

Question 14

The Great Red Spot,Jupiter's most prominent storm system,has a diameter that is ________ times Earth's diameter.

A) 2
B) 5
C) 10
D) 50

Question 15

The compositions of Uranus and Neptune differ primarily from those of Jupiter and Saturn in that the outer two planets contain more:

A) hydrogen.
B) helium.
C) water ice.
D) carbon dioxide.

Question 16

Why are Jupiter and Saturn not perfectly spherical?

A) They formed from the collision of two large planetesimals.
B) They rotate rapidly.
C) They have storms that develop preferentially along their equators.
D) They have very active auroras that heat the atmospheres along the poles.

Question 17

Band systems on Saturn,Uranus,and Neptune are most prominent when viewed in which wavelength regime?

A) visible
B) infrared
C) ultraviolet
D) X-ray

Question 18

Why are all clouds on Jupiter not white,as on Earth?

A) They are made of methane.
B) They are made of carbon dioxide.
C) There are impurities in their ice crystals.
D) For the same reason that we see colors in rainbows on Earth.

Question 19

If you could find a large enough ocean,which one of these planets would float in it?

A) Uranus
B) Saturn
C) Neptune
D) Mars

Question 20

Which of the giant planets was predicted to exist mathematically before it was ever seen through a telescope?

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

Question 21

Why would a planet's rings reflect 50 percent of the sunlight they receive?

A) They are made of ice.
B) They are made of silicate rock.
C) They are made of iron.
D) They are very old.

Question 22

The fact that Jupiter's radius is contracting at a rate of 1 mm/year results in:

A) differential convection that powers Jupiter's Great Red Spot.
B) Jupiter's rotation rate slowing down with time.
C) Jupiter's shape being noticeably oblate.
D) Jupiter radiating more heat than it receives from the Sun.

Question 23

The Roche Limit is reached when:

A) the internal pressure of a gas giant planet is enough to compress its core.
B) ring particles closest to a planet fall into its atmosphere.
C) the tidal stress becomes greater than the surface gravity.
D) a ring particle reaches escape velocity.

Question 24

How does the thickness of Saturn's bright ring system compare to its diameter?

A) It's about 10 times thinner.
B) It's about 1,000 times thinner.
C) It's about 100,000 times thinner.
D) It's about 10 million times thinner.

Question 25

Uranus and Neptune do not have bands as distinct as those on Jupiter and Saturn because Uranus and Neptune:

A) have wind speeds that vary more smoothly from the equator to the poles.
B) are composed entirely of hydrogen and helium and lack more complex molecules.
C) are much closer to the Sun and much colder.
D) rotate 10 times slower.

Question 26

Where do Uranus's and Neptune's high magnetic fields originate?

A) molten rocky cores
B) salty oceans
C) large magnetospheres
D) metallic hydrogen layers

Question 27

All the giant planets radiate more energy into space than they receive from the Sun EXCEPT:

A) Jupiter.
B) Saturn.
C) Uranus.
D) Neptune.

Question 28

If the flux of sunlight on a planet suggested its temperature should be 200 K,but its actual temperature was 220 K,then how much more energy does this planet emit relative to the energy it receives from its parent star?

A) 5.3 times more energy
B) 2.2 times more energy
C) 1.1 times more energy
D) 1.5 times more energy

Question 29

The strongest magnetic fields in the Solar System are found on which planet?

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

Question 30

The different colors of auroras are due to:

A) temperature differences in the giant planet atmosphere.
B) fluctuations in the magnetic field.
C) variations in atmospheric pressure.
D) the composition of the giant planet atmosphere.

Question 31

Why can water exist in the hot interiors of the giant planets?

A) The pressure is high enough to prevent the water from becoming vapor.
B) Some of the metallic hydrogen in the core mixes with oxygen.
C) Regions of the interior are cooler than the surrounding regions.
D) Water released from moons via cryovolcanism is absorbed.

Question 32

We refer to some of the inner regions of Jupiter and Saturn as metallic hydrogen because they:

A) are as dense as lead.
B) are solid.
C) provide support for the upper layers of hydrogen and helium.
D) efficiently conduct electricity.

Question 33

If you monitor Jupiter's atmosphere and you see a storm move from a longitude of 60° west to a longitude of 80° west over 6 days,what is the wind speed at this storm's latitude on Jupiter? Note that these positions are measured on a coordinate system that rotates with the planet's interior.(The radius of Jupiter is 7.2 × 10⁴ km.)

A) 700 m/s
B) 300 m/s
C) 100 m/s
D) 50 m/s

Question 34

Of the giant planets,only Jupiter and Saturn have thick inner layers of:

A) liquid rock.
B) solid rock.
C) molecular and metallic hydrogen.
D) liquid methane.

Question 35

Which of the giant planets does NOT have rings?

A) Jupiter
B) Saturn
C) Uranus
D) Neptune
E) All of the giant planets have rings

Question 36

How do Saturn's shepherd moons help maintain the stability of Saturn's rings?

A) Their magnetic fields confine the rings' orbits.
B) Their gravity periodically captures solar system debris and adds it to the ring system.
C) They periodically collide with larger ring objects, pulverizing them.
D) Their gravitational interactions with ring material maintains the orbital stability of the rings.

Question 37

Despite the high temperatures deep in the interiors of giant planets,their cores remain liquid because:

A) they are under very high pressures.
B) gravitational potential energy is being converted into thermal energy in the cores.
C) they are composed of heavy materials like rock and water.
D) their rotations are rapid compared to those of the terrestrial planets.

Question 38

If you monitor Saturn's atmosphere and you see a storm at a longitude of 0° west on one day and at a longitude of 90° west 3 days later,what is the average wind speed on Saturn at this storm's latitude? Note that these positions are measured on a coordinate system that rotates with the planet's interior.(The radius of Saturn is 6 × 10⁷ meters.)

A) 720 m/s
B) 120 m/s
C) 360 m/s
D) 540 m/s

Question 39

Saturn's rings may have originated from:

A) cometary material captured by Saturn's gravity.
B) the destruction of a moon or planetoid from tidal stresses within the Roche limit.
C) material released from Saturn during a collision with a planet-sized object.
D) material released from volcanic activity on Saturn.

Question 40

The fastest zonal winds are found on:

A) Jupiter and Saturn.
B) Saturn and Neptune.
C) Uranus and Neptune.
D) Jupiter and Uranus.

Question 41

How has Jupiter retained a significant portion of its heat since it formed?

Question 42

Explain why it was difficult for the Voyager space probe to detect Jupiter's ring system as it was approaching the planet but easy for it to detect the rings once it had passed behind Jupiter.

Question 43

Based on the flux of sunlight that it gets,Jupiter should have a temperature of 109 K.However,its temperature is observed to be 124 K.How much more energy is Jupiter radiating out into space compared to what it gets from the Sun?

Question 44

What causes the horizontal bands on Jupiter and Saturn to have different colors? How can they be used to probe different altitudes in their atmospheres?

Question 45

What is the ratio of Jupiter's volume to that of Earth's if both planets can be modeled as spheres and Jupiter's radius is 11 times that of Earth's?

Question 46

Examine the figure below.Why are winds on the giant planets far faster than those on Earth?

Question 47

If Saturn's rotational period is 11 hours and its radius is 6 × 10⁷ meters,what is the average speed of a cloud in its atmosphere that is rotating with Saturn? (Neglect differential speeds due to winds.)

Question 48

Suppose Neptune moves with an average orbital speed of 3.5 km/s.If it takes Neptune 4 hours to pass directly in front of a star,what is Neptune's diameter? Give Neptune's radius in units of Earth diameters,where the diameter of Earth is 12,800 km.

Question 49

On which of the giant planets do we think we can find deep oceans of water? Why do we think this?

Question 50

Define cloud cannibalism.Where is it observed in the Solar System?

Question 51

How does the discovery of Neptune relate to the discovery of extrasolar planets?

Question 52

Why do astronomers hypothesize that Saturn has such prominent rings,and does the observed total mass in the ring system support this theory?

Question 53

Rings of giant planets are very thin compared to their diameters mainly because:

A) of collisions between ring particles.
B) moons that tidally disrupt have small diameters.
C) energy is conserved when a moon tidally disrupts.
D) the planets have large tidal forces.

Question 54

What gives rise to the large magnetic fields of Uranus and Neptune? How does this source help explain why the axes of their magnetic fields are misaligned and significantly offset from their rotational axes?

Question 55

How can water exist as liquid at temperatures higher than its boiling point?

Question 56

Particles that make up the rings of Uranus and Neptune are composed of:

A) rocky material from tidally disrupted moons.
B) organic material that has darkened because of bombardment by cosmic rays.
C) icy material from tidally disrupted comets.
D) all of the above

Question 57

If Saturn's orbital period is 30 years and the obliquity is 26°,how long is it from the first day of spring to the first day of autumn on Saturn?

Question 58

What clues do the differences in the masses of the giant planets give about conditions in the early Solar System?

Question 59

Why are auroras visible mostly at the north or south magnetic poles of the giant planets?

Question 60

Jupiter's rings are made of material from:

A) its largest, innermost moons.
B) its upper atmosphere.
C) only Io.
D) only its retrograde moons.

Question 61

Explain how tidal stress can rip apart objects.

Question 62

Why do we suspect that the inner planets do not have rings?