Question 1

Nitrogen (N2) makes up about 95% of Titan's thick atmosphere. What gas makes up most of the remaining 5% of the atmosphere?

Accepted Answer

A) water vapor-H2O 
B) carbon dioxide-CO2 
C) methane-CH4 
D) nitrogen-N2 
A) water vapor-H2O 
B) carbon dioxide-CO2 
C) methane-CH4 
D) nitrogen-N2

Question 2

Earth-based observations of the motions of Jupiter's large satellites have resulted in measurements of the mass(es) of:

Accepted Answer

A) only Io. 
B) the two inner satellites. 
C) all four satellites. 
D) only Jupiter itself. 
A) only Io. 
B) the two inner satellites. 
C) all four satellites. 
D) only Jupiter itself.

Question 3

The four major satellites of Jupiter are collectively named after which early astronomer?

Accepted Answer

A) Copernicus 
B) Newton 
C) Ptolemy 
D) Galileo 
A) Copernicus 
B) Newton 
C) Ptolemy 
D) Galileo

Question 4

What does the surface of Europa, a satellite of Jupiter, look like?

Accepted Answer

A) It is entirely ice, with fractures and ridges going in every direction and no features more than about 100 m high. 
B) It is entirely ice, with light and dark areas containing many impact craters and parallel ridges up to about 1 km high. 
C) The surface is rocky and densely cratered, except for a few large, dark, relatively uncratered plains. 
D) We don't know; the surface is hidden below a dense layer of clouds. 
A) It is entirely ice, with fractures and ridges going in every direction and no features more than about 100 m high. 
B) It is entirely ice, with light and dark areas containing many impact craters and parallel ridges up to about 1 km high. 
C) The surface is rocky and densely cratered, except for a few large, dark, relatively uncratered plains. 
D) We don't know; the surface is hidden below a dense layer of clouds.

Question 5

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

Accepted Answer

A) from the breakup of ammonia into nitrogen and hydrogen, with the hydrogen being lost to space 
B) from microbes in the early atmosphere of Titan (when it was closer to the Sun) 
C) from having a presence since primordial times, when Titan first formed 
D) from outgassing through volcanic vents 
A) from the breakup of ammonia into nitrogen and hydrogen, with the hydrogen being lost to space 
B) from microbes in the early atmosphere of Titan (when it was closer to the Sun) 
C) from having a presence since primordial times, when Titan first formed 
D) from outgassing through volcanic vents

Question 6

Because of mutual gravitational forces between the satellites and the planet, the orbital periods of the three inner Galilean satellites of Jupiter are in the ratio:

Accepted Answer

A) 1:2:3. 
B) 1:10:100. 
C) 1:1:1-equal orbital periods. 
D) 1:2:4. 
A) 1:2:3. 
B) 1:10:100. 
C) 1:1:1-equal orbital periods. 
D) 1:2:4.

Question 7

How thick is the layer of surface ice on Europa thought to be?

Accepted Answer

A) a few meters 
B) several hundred meters 
C) 10 km 
D) 100 km 
A) a few meters 
B) several hundred meters 
C) 10 km 
D) 100 km

Question 8

Suppose you have calculated the speed of Ganymede in its orbit from Kepler's laws. You time the interval between when Ganymede first begins to disappear into Jupiter's shadow and when it is totally occulted by Jupiter. What can you calculate from this information?

Accepted Answer

A) the radius of the orbit of Ganymede 
B) the rotational period of Ganymede 
C) the orbital period of Ganymede 
D) the radius of Ganymede 
A) the radius of the orbit of Ganymede 
B) the rotational period of Ganymede 
C) the orbital period of Ganymede 
D) the radius of Ganymede

Question 9

The weak and variable magnetic field measured by the Galileo spacecraft on Europa is generated by:

Accepted Answer

A) its magnetized solid iron core. 
B) electrical currents between the satellite and Jupiter, through the conducting magnetosphere. 
C) the motion of molten iron in Europa's core. 
D) electrical currents in the ocean water, induced by Europa's motion through Jupiter's intense magnetic field. 
A) its magnetized solid iron core. 
B) electrical currents between the satellite and Jupiter, through the conducting magnetosphere. 
C) the motion of molten iron in Europa's core. 
D) electrical currents in the ocean water, induced by Europa's motion through Jupiter's intense magnetic field.

Question 10

All of the following exist on Titan EXCEPT:

Accepted Answer

A) clouds. 
B) liquid water on the surface. 
C) rain. 
D) nitrogen in vapor form. 
A) clouds. 
B) liquid water on the surface. 
C) rain. 
D) nitrogen in vapor form.

Question 11

If we consider the formation of the jovian system as analogous to the formation of the solar system, the "snow line" in the jovian system would be:

Accepted Answer

A) inside the orbit of Io. 
B) between the orbits of Io and Europa. 
C) between the orbits of Europa and Ganymede. 
D) between the orbits of Ganymede and Callisto. 
A) inside the orbit of Io. 
B) between the orbits of Io and Europa. 
C) between the orbits of Europa and Ganymede. 
D) between the orbits of Ganymede and Callisto.

Question 12

Callisto, the outer Galilean satellite of Jupiter, has a surface consisting of:

Accepted Answer

A) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves. 
B) an ancient, icy crust covered with numerous craters and no surface cracks or groove belts that would indicate internal activity. 
C) rock, heavily cratered like the highlands of our Moon. 
D) a relatively young, icy crust covered with a network of streaks and cracks, and only a few impact craters. 
A) an icy crust showing two interlocking types of terrain, one ancient and heavily cratered, the other younger with systems of parallel grooves. 
B) an ancient, icy crust covered with numerous craters and no surface cracks or groove belts that would indicate internal activity. 
C) rock, heavily cratered like the highlands of our Moon. 
D) a relatively young, icy crust covered with a network of streaks and cracks, and only a few impact craters.

Question 13

As a result of measurements by the Galileo spacecraft, what is now believed to be the internal structure of Io?

Accepted Answer

A) a thick mantle of rock over a core of iron and iron sulfide 
B) a thick mantle of ice over a core of rock 
C) entirely or almost entirely rock, with no evidence of ice or a differentiated metallic core 
D) a thick crust of ice over a rocky mantle and a small, possibly molten, iron core 
A) a thick mantle of rock over a core of iron and iron sulfide 
B) a thick mantle of ice over a core of rock 
C) entirely or almost entirely rock, with no evidence of ice or a differentiated metallic core 
D) a thick crust of ice over a rocky mantle and a small, possibly molten, iron core

Question 14

Observations indicate that a large electric current flows through Europa, induced by Jupiter's magnetosphere sweeping over the planet. This requires an electrically conducting medium under the surface. In the case of Europa, this medium is believed to be:

Accepted Answer

A) liquid metallic hydrogen. 
B) molten iron. 
C) ionized water. 
D) a plasma of sulfur and sulfur dioxide. 
A) liquid metallic hydrogen. 
B) molten iron. 
C) ionized water. 
D) a plasma of sulfur and sulfur dioxide.

Question 15

Which one of the following changes would decrease volcanic activity on Io?

Accepted Answer

A) Increase the masses of Europa and Ganymede. 
B) Decrease the distances from Io to Europa and to Ganymede. 
C) Increase the distance from Jupiter to Io. 
D) Increase the mass of Jupiter. 
A) Increase the masses of Europa and Ganymede. 
B) Decrease the distances from Io to Europa and to Ganymede. 
C) Increase the distance from Jupiter to Io. 
D) Increase the mass of Jupiter.

Question 16

When Galileo first discovered the large moons of Jupiter in 1610, he called them:

Accepted Answer

A) Matthew, Mark, Luke, and John. 
B) the Medicean stars. 
C) the Papal Planets. 
D) the Galilean satellites. 
A) Matthew, Mark, Luke, and John. 
B) the Medicean stars. 
C) the Papal Planets. 
D) the Galilean satellites.

Question 17

In what way was methane, CH4, first discovered on Titan, the giant satellite of Saturn?

Accepted Answer

A) by chemical "sniffers" carried by Voyager 2 when it passed very close to Titan 
B) spectroscopically, by noting specific absorptions in reflected sunlight 
C) by detecting the light of burning methane spectroscopically, similar to that seen from oil or gas-well flares 
D) by noting the formation on its surface of colored "ice," characteristic of methane ice 
A) by chemical "sniffers" carried by Voyager 2 when it passed very close to Titan 
B) spectroscopically, by noting specific absorptions in reflected sunlight 
C) by detecting the light of burning methane spectroscopically, similar to that seen from oil or gas-well flares 
D) by noting the formation on its surface of colored "ice," characteristic of methane ice

Question 18

What have we learned about the atmospheres of the Galilean satellites of Jupiter?

Accepted Answer

A) None of these satellites has a permanent atmosphere. 
B) Only Ganymede, the largest, has a permanent atmosphere of CO2. 
C) Callisto has a thin atmosphere of CO2, whereas Ganymede has a thin atmosphere of O2. 
D) Ganymede and Callisto have thin atmospheres, whereas Io has a thick atmosphere of sulfur compounds. 
A) None of these satellites has a permanent atmosphere. 
B) Only Ganymede, the largest, has a permanent atmosphere of CO2. 
C) Callisto has a thin atmosphere of CO2, whereas Ganymede has a thin atmosphere of O2. 
D) Ganymede and Callisto have thin atmospheres, whereas Io has a thick atmosphere of sulfur compounds.

Question 19

Which Galilean satellite shows evidence of tectonic activity?

Accepted Answer

A) Io 
B) Europa 
C) Ganymede 
D) Callisto 
A) Io 
B) Europa 
C) Ganymede 
D) Callisto

Question 20

Why does the innermost Galilean satellite of Jupiter, Io, not show a cratered surface, as expected from the appearance of equivalent-sized objects like the Moon, Mercury, and Mars?

Accepted Answer

A) The large gravitational force generated by Jupiter has diverted most objects away from Io. 
B) The surface is completely covered by an ocean of water, partly frozen into ice, which will obviously not show craters. 
C) Volcanic action recoats the surface regularly and continuously. 
D) Dust storms triggered by heating from Jupiter have quickly filled in any craters. 
A) The large gravitational force generated by Jupiter has diverted most objects away from Io. 
B) The surface is completely covered by an ocean of water, partly frozen into ice, which will obviously not show craters. 
C) Volcanic action recoats the surface regularly and continuously. 
D) Dust storms triggered by heating from Jupiter have quickly filled in any craters.

Exam 13: Jupiter and Saturns Satellites of Fire and Ice

Nitrogen (N2) makes up about 95% of Titan's thick atmosphere. What gas makes up most of the remaining 5% of the atmosphere?

Earth-based observations of the motions of Jupiter's large satellites have resulted in measurements of the mass(es) of:

The four major satellites of Jupiter are collectively named after which early astronomer?

What does the surface of Europa, a satellite of Jupiter, look like?

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

Because of mutual gravitational forces between the satellites and the planet, the orbital periods of the three inner Galilean satellites of Jupiter are in the ratio:

How thick is the layer of surface ice on Europa thought to be?

Suppose you have calculated the speed of Ganymede in its orbit from Kepler's laws. You time the interval between when Ganymede first begins to disappear into Jupiter's shadow and when it is totally occulted by Jupiter. What can you calculate from this information?

The weak and variable magnetic field measured by the Galileo spacecraft on Europa is generated by:

All of the following exist on Titan EXCEPT:

If we consider the formation of the jovian system as analogous to the formation of the solar system, the "snow line" in the jovian system would be:

Callisto, the outer Galilean satellite of Jupiter, has a surface consisting of:

As a result of measurements by the Galileo spacecraft, what is now believed to be the internal structure of Io?

Observations indicate that a large electric current flows through Europa, induced by Jupiter's magnetosphere sweeping over the planet. This requires an electrically conducting medium under the surface. In the case of Europa, this medium is believed to be:

Which one of the following changes would decrease volcanic activity on Io?

When Galileo first discovered the large moons of Jupiter in 1610, he called them:

In what way was methane, CH4, first discovered on Titan, the giant satellite of Saturn?

What have we learned about the atmospheres of the Galilean satellites of Jupiter?

Which Galilean satellite shows evidence of tectonic activity?

Why does the innermost Galilean satellite of Jupiter, Io, not show a cratered surface, as expected from the appearance of equivalent-sized objects like the Moon, Mercury, and Mars?

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

The Nature of Light

Optics and Telescopes

Comparative Planetology I: Our Solar System

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

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Nitrogen (N₂) makes up about 95% of Titan's thick atmosphere. What gas makes up most of the remaining 5% of the atmosphere?

In what way was methane, CH₄, first discovered on Titan, the giant satellite of Saturn?