Question 1

Are auroras known to exist on Ganymede?

Accepted Answer

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.

Question 2

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

Accepted Answer

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

Question 3

On which body has the aurora NOT been observed?

Accepted Answer

A)  Jupiter 
B)  Saturn 
C)  Ganymede 
D)  Callisto

Question 4

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

Accepted Answer

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 5

The effect of tidal forces caused by Triton on Neptune as it moves in its retrograde orbit will lead to Triton:

Accepted Answer

A)  spiraling outward from Neptune and eventual escape. 
B)  spiraling in toward Neptune to eventual destruction by differential tidal forces on the moon. 
C)  being captured by Pluto when next this planet passes inside the orbit of Neptune. 
D)  gradually moving from its elliptical orbit toward a perfectly circular orbit.

Question 6

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.

Accepted Answer

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, with Earth.

Question 7

Earth experiences an equinox every six months when the day and night are of equal length everywhere on the planet.Does Uranus experience equinox? If so,how often?

Accepted Answer

A)  No. 
B)  Yes, every six months just like Earth. 
C)  Yes, every 42 years. 
D)  Yes, every 84 years.

Question 8

Neptune's high cirrus clouds consist of:

Accepted Answer

A)  ammonia ice crystals. 
B)  crystals of water ice. 
C)  droplets of sulfuric acid. 
D)  methane ice crystals.

Question 9

Which effect 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?

Accepted Answer

A)  the out-of-balance force on the spin axes of planets from their moons, some of which are very massive 
B)  a major collision with another planet-like body 
C)  the steady force on one hemisphere of the planet from the highly directional solar wind 
D)  tidal distortion and deflection caused by neighboring planets

Question 10

The magnetosphere of Jupiter is:

Accepted Answer

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.

Question 11

How is nitrogen thought to have become the dominant gas in the atmosphere of the moon Titan,a satellite of Saturn?

Accepted Answer

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

Question 12

Approximately how thick (top to bottom)are Saturn's rings compared with the total width from inside to outside?

Accepted Answer

A)  about 1/50,000 of the width 
B)  about 1/1,000,000 of the width 
C)  about 1/10 of the width 
D)  about 1/2000 of the width

Question 13

As seen by an observer floating above the clouds of Uranus,where would the Sun be located in midsummer in the northern hemisphere?

Accepted Answer

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 the North Pole

Question 14

We normally determine the relative ages of planetary surfaces by counting craters.This technique works for some of Jupiter's Galilean moons but not for others.Where can we use it?

Accepted Answer

A)  all except Io 
B)  Ganymede and Callisto 
C)  only Ganymede 
D)  only Callisto

Question 15

The magnetic fields of Uranus and Neptune appear to originate in the:

Accepted Answer

A)  rocky cores of the planets. 
B)  liquid water-mineral 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.

Question 16

The "volcanoes" of Io,the innermost Galilean moon of Jupiter,MOST resemble in behavior which Earth-bound phenomenon?

Accepted Answer

A)  mountain volcanoes such as Mount St. Helens, exhibiting rare but devastating explosions that throw material high into the atmosphere 
B)  regularly spouting geysers in relatively flat hot springs areas 
C)  lava-flow volcanoes occurring on the tops of mountains, such as those on Hawaii 
D)  undersea volcanoes, where hot lava produces explosive boiling of the water

Question 17

What future awaits Triton,the largest satellite of Neptune?

Accepted Answer

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

Question 18

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

Accepted Answer

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 19

Which satellite of a planet in our solar system has a significant and dense atmosphere?

Accepted Answer

A)  Triton, a moon of Neptune 
B)  Io, a moon of Jupiter 
C)  Titan, a moon of Saturn 
D)  Earth's Moon

Question 20

What kind of ring or rings does Jupiter have?

Accepted Answer

A)  several thin dark rings made up of very fine dust particles 
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

Exam 7: The Outer Planets and Their Moons