Question 1

The internal structure of Mercury is a:

Accepted Answer

A)  dense iron core taking up almost half of the volume of the planet and a rocky mantle surrounding the core. 
B)  rocky core with a liquid (or perhaps frozen) water mantle and icy surface. 
C)  thick rocky mantle taking up most of the volume of the planet, overlaying a small but dense iron core. 
D)  rocky core surrounded by liquid metallic hydrogen and a hydrogen-helium atmosphere. 
A)  dense iron core taking up almost half of the volume of the planet and a rocky mantle surrounding the core. 
B)  rocky core with a liquid (or perhaps frozen) water mantle and icy surface. 
C)  thick rocky mantle taking up most of the volume of the planet, overlaying a small but dense iron core. 
D)  rocky core surrounded by liquid metallic hydrogen and a hydrogen-helium atmosphere.

Question 2

MOST of the craters on the Moon are thought to have been caused by:

Accepted Answer

A)  the collapse of volcanic domes, leaving central peaks in the craters. 
B)  volcanic activity, leaving behind volcano craters similar to those on Earth. 
C)  continuous bombardment throughout the Moon's life, including the present and recent past, by large and small asteroids. 
D)  intense bombardment by large and small bodies over some specific early period in the Moon's history. 
A)  the collapse of volcanic domes, leaving central peaks in the craters. 
B)  volcanic activity, leaving behind volcano craters similar to those on Earth. 
C)  continuous bombardment throughout the Moon's life, including the present and recent past, by large and small asteroids. 
D)  intense bombardment by large and small bodies over some specific early period in the Moon's history.

Question 3

The gas that is the major constituent of the atmospheres of Venus and Mars and a minor constituent of Earth's atmosphere is:

Accepted Answer

A)  oxygen. 
B)  water. 
C)  carbon dioxide. 
D)  nitrogen. 
A)  oxygen. 
B)  water. 
C)  carbon dioxide. 
D)  nitrogen.

Question 4

What is (or was)Pangaea?

Accepted Answer

A)  the original supercontinent that was formed when Earth's surface solidified 
B)  the most recent of a number of supercontinents that have formed since Earth's surface solidified 
C)  the name we give to the future supercontinent that will form if the continental plates continue to follow their present paths 
D)  the site of the international conference at which Wegener presented his theory 
A)  the original supercontinent that was formed when Earth's surface solidified 
B)  the most recent of a number of supercontinents that have formed since Earth's surface solidified 
C)  the name we give to the future supercontinent that will form if the continental plates continue to follow their present paths 
D)  the site of the international conference at which Wegener presented his theory

Question 5

Why do we believe Mars is so small?

Accepted Answer

A)  The material out of which a larger planet might have formed was already incorporated into Earth and Venus. 
B)  The material out of which a larger planet might have formed was scattered by the migration of the Jovian planets. 
C)  Tidal forces from Jupiter prevented material here from coalescing into a stable planet. 
D)  Like Mercury and perhaps Venus, it suffered a major collision in the early history of the solar system. 
A)  The material out of which a larger planet might have formed was already incorporated into Earth and Venus. 
B)  The material out of which a larger planet might have formed was scattered by the migration of the Jovian planets. 
C)  Tidal forces from Jupiter prevented material here from coalescing into a stable planet. 
D)  Like Mercury and perhaps Venus, it suffered a major collision in the early history of the solar system.

Question 6

The fraction of light reflected by a planet or other object is its:

Accepted Answer

A)  color index. 
B)  emissivity. 
C)  apparent magnitude. 
D)  albedo. 
A)  color index. 
B)  emissivity. 
C)  apparent magnitude. 
D)  albedo.

Question 7

Which planet rotates on its axis in a retrograde fashion,opposite to that of most of the planets and opposite to the direction of revolution of the planets?

Accepted Answer

A)  Mercury 
B)  Venus 
C)  Saturn 
D)  the Moon 
A)  Mercury 
B)  Venus 
C)  Saturn 
D)  the Moon

Question 8

The outer core of Earth is molten,but the inner core is solid.The reason is that the:

Accepted Answer

A)  inner core has a different composition than the outer core, with a higher melting point. 
B)  lower pressure in the inner core allows the material to freeze out of the molten rock. 
C)  melting point of the iron-nickel mixture is raised above the actual temperature by the extremely high pressure. 
D)  temperature is lower in the inner core than in the surrounding region. 
A)  inner core has a different composition than the outer core, with a higher melting point. 
B)  lower pressure in the inner core allows the material to freeze out of the molten rock. 
C)  melting point of the iron-nickel mixture is raised above the actual temperature by the extremely high pressure. 
D)  temperature is lower in the inner core than in the surrounding region.

Question 9

If you were watching the sunrise on Mercury when Mercury was near perihelion,what would you see? (See Figure 6-44,Comins,Discovering the Essential Universe,6th ed.)

Accepted Answer

A)  The Sun would rise slowly, gradually speed up over a period of a few days, then slow down again. 
B)  The Sun would rise, cross the sky, and set again, all in a few days, then spend the rest of Mercury's "year" below the horizon. 
C)  The Sun would rise, stop, turn back toward the east, stop, and then continue westward. 
D)  The Sun would rise, slowly come to a standstill, then start rising again. 
A)  The Sun would rise slowly, gradually speed up over a period of a few days, then slow down again. 
B)  The Sun would rise, cross the sky, and set again, all in a few days, then spend the rest of Mercury's "year" below the horizon. 
C)  The Sun would rise, stop, turn back toward the east, stop, and then continue westward. 
D)  The Sun would rise, slowly come to a standstill, then start rising again.

Question 10

Which fact first gave Alfred Wegener the idea that continents have drifted and are still drifting over Earth's surface?

Accepted Answer

A)  The ocean floors were much younger than the continents, indicating that they were still being formed. 
B)  The shapes of the east coasts of North and South America fit nicely against those of the west coasts of Europe and Africa. 
C)  A system of mountains and faults running up the middle of the Atlantic seafloor showed evidence that the crust was spreading apart there. 
D)  Volcanoes and earthquakes were localized into a well-defined "ring of fire" around the Pacific Ocean and other areas. 
A)  The ocean floors were much younger than the continents, indicating that they were still being formed. 
B)  The shapes of the east coasts of North and South America fit nicely against those of the west coasts of Europe and Africa. 
C)  A system of mountains and faults running up the middle of the Atlantic seafloor showed evidence that the crust was spreading apart there. 
D)  Volcanoes and earthquakes were localized into a well-defined "ring of fire" around the Pacific Ocean and other areas.

Question 11

What is pressure?

Accepted Answer

A)  force times the area over which the force acts 
B)  force times the distance over which the force acts 
C)  same as force but expressed in different units 
D)  force divided by the area over which the force acts 
A)  force times the area over which the force acts 
B)  force times the distance over which the force acts 
C)  same as force but expressed in different units 
D)  force divided by the area over which the force acts

Question 12

Which statement is the BEST explanation for the origin of the Moon?

Accepted Answer

A)  The Moon was created in its orbit around Earth by the same process that produced Earth, namely the collision of planetesimals that had formed by condensation and accretion of gas and dust. 
B)  The Moon was created by the process described in (
A) , but at some other location in the solar system. 
C)  While Earth was semi-molten early in its formation, a chunk of material was flung out of it. It went into orbit and evolved to become the Moon. 
D)  The Moon was created by the process described in (
C) , except that the ejection was caused by the impact of some large object on Earth. 
A)  The Moon was created in its orbit around Earth by the same process that produced Earth, namely the collision of planetesimals that had formed by condensation and accretion of gas and dust. 
B)  The Moon was created by the process described in (
A) , but at some other location in the solar system. 
C)  While Earth was semi-molten early in its formation, a chunk of material was flung out of it. It went into orbit and evolved to become the Moon. 
D)  The Moon was created by the process described in (
C) , except that the ejection was caused by the impact of some large object on Earth.

Question 13

Which theory about the origin of the Moon is now believed to be CORRECT?

Accepted Answer

A)  Earth and the Moon formed together, already orbiting each other. 
B)  The Moon formed separately in a different part of the solar nebula and was later captured by Earth. 
C)  Earth was spinning so rapidly while still molten that a piece spun off to form the Moon. 
D)  An object about the size of Mars crashed into Earth, and debris from the collision formed the Moon. 
A)  Earth and the Moon formed together, already orbiting each other. 
B)  The Moon formed separately in a different part of the solar nebula and was later captured by Earth. 
C)  Earth was spinning so rapidly while still molten that a piece spun off to form the Moon. 
D)  An object about the size of Mars crashed into Earth, and debris from the collision formed the Moon.

Question 14

Which spacecraft and technique has given us our most extensive information about the overall surface of Venus?

Accepted Answer

A)  photography from the Space Shuttle at UV wavelengths that can penetrate the Venusian clouds 
B)  photography by the four Viking spacecraft (two landers and two orbiters) 
C)  photography by the Venera landers of the former Soviet Union 
D)  radar mapping by the Magellan orbiter. 
A)  photography from the Space Shuttle at UV wavelengths that can penetrate the Venusian clouds 
B)  photography by the four Viking spacecraft (two landers and two orbiters) 
C)  photography by the Venera landers of the former Soviet Union 
D)  radar mapping by the Magellan orbiter.

Question 15

There are half a dozen large maria on the side of the Moon facing Earth and only one small mare on the far side.Which explanation is the MOST likely?

Accepted Answer

A)  Earth's larger mass attracted many heavy bombardment particles. Some of those that missed Earth hit the near side of the Moon. 
B)  Originally, there were probably as many large maria on the far side as on the near side. But subsequent bombardments erased most of them on the far side, while the near side was shielded from such bombardments by Earth's presence. 
C)  We believe that the Moon was formed elsewhere in the solar system, so we have no clue to its very early history-including this asymmetry in the maria. 
D)  The crust on the far side is thicker (because of Earth's pull on the Moon's core), and thus it was more difficult for lava to flow into large craters on the far side. 
A)  Earth's larger mass attracted many heavy bombardment particles. Some of those that missed Earth hit the near side of the Moon. 
B)  Originally, there were probably as many large maria on the far side as on the near side. But subsequent bombardments erased most of them on the far side, while the near side was shielded from such bombardments by Earth's presence. 
C)  We believe that the Moon was formed elsewhere in the solar system, so we have no clue to its very early history-including this asymmetry in the maria. 
D)  The crust on the far side is thicker (because of Earth's pull on the Moon's core), and thus it was more difficult for lava to flow into large craters on the far side.

Question 16

What is the MOST important reason for Earth's need of the ozone layer?

Accepted Answer

A)  The ozone layer protects Earth from the solar wind. 
B)  The ozone layer allows long-distance radio communication by reflecting radio waves to Earth's surface. 
C)  The ozone layer shields Earth from harmful solar ultraviolet radiation. 
D)  The ozone layer provides a convenient dumping site for chlorofluorocarbon chemicals, which are harmful to life. 
A)  The ozone layer protects Earth from the solar wind. 
B)  The ozone layer allows long-distance radio communication by reflecting radio waves to Earth's surface. 
C)  The ozone layer shields Earth from harmful solar ultraviolet radiation. 
D)  The ozone layer provides a convenient dumping site for chlorofluorocarbon chemicals, which are harmful to life.

Question 17

Because Mercury has no appreciable atmosphere,its surface shows extreme temperature changes between night and day,with a range of about:

Accepted Answer

A)  600 K. 
B)  900 K. 
C)  20 K. 
D)  60 K. 
A)  600 K. 
B)  900 K. 
C)  20 K. 
D)  60 K.

Question 18

What evidence does a planetary geologist use to identify a "young" crater on Mercury?

Accepted Answer

A)  observation of few, if any, smaller overlapping craters within it or on its rim 
B)  infrared and photographic results showing evidence of water released recently from the permafrost by the impact 
C)  observation of a lighter-colored central region; an older crater would have acquired a layer of dark dust over time 
D)  observation of a sharper rim and central peak compared with older craters; old craters would have suffered significant erosion by wind and dust 
A)  observation of few, if any, smaller overlapping craters within it or on its rim 
B)  infrared and photographic results showing evidence of water released recently from the permafrost by the impact 
C)  observation of a lighter-colored central region; an older crater would have acquired a layer of dark dust over time 
D)  observation of a sharper rim and central peak compared with older craters; old craters would have suffered significant erosion by wind and dust

Question 19

There are traces of oxygen in Mercury's atmosphere.The source of this is believed to be:

Accepted Answer

A)  the evaporation of polar ice. 
B)  the remnants of the primordial solar nebula. 
C)  outgassing from within the planet. 
D)  a continual rain of ice-coated cometary fragments into the atmosphere of Mercury. 
A)  the evaporation of polar ice. 
B)  the remnants of the primordial solar nebula. 
C)  outgassing from within the planet. 
D)  a continual rain of ice-coated cometary fragments into the atmosphere of Mercury.

Question 20

Why is the Moon in a synchronous orbit around Earth,always keeping the same face toward Earth?

Accepted Answer

A)  There is a strong magnetic attraction between the two bodies that keeps the Moon turned toward Earth. 
B)  The Moon must rotate on its axis at the same rate it orbits Earth to conserve angular momentum. 
C)  As the Moon rotates, friction between the Moon's large liquid interior and its mantle has slowed the rate of rotation until it just matches the orbital rate. Over time, it will slow further, and then the Moon will no longer be in a synchronous orbit. 
D)  When the Moon was molten and experienced chemical differentiation, the gravitational pull of Earth caused large tides. The friction created as Earth's gravity attempted to keep the high tide bulge pointed toward Earth resulted in the Moon's rotation being slowed, causing it always to face Earth. 
A)  There is a strong magnetic attraction between the two bodies that keeps the Moon turned toward Earth. 
B)  The Moon must rotate on its axis at the same rate it orbits Earth to conserve angular momentum. 
C)  As the Moon rotates, friction between the Moon's large liquid interior and its mantle has slowed the rate of rotation until it just matches the orbital rate. Over time, it will slow further, and then the Moon will no longer be in a synchronous orbit. 
D)  When the Moon was molten and experienced chemical differentiation, the gravitational pull of Earth caused large tides. The friction created as Earth's gravity attempted to keep the high tide bulge pointed toward Earth resulted in the Moon's rotation being slowed, causing it always to face Earth.

The internal structure of Mercury is a:

MOST of the craters on the Moon are thought to have been caused by:

The gas that is the major constituent of the atmospheres of Venus and Mars and a minor constituent of Earth's atmosphere is:

What is (or was)Pangaea?

Why do we believe Mars is so small?

The fraction of light reflected by a planet or other object is its:

Which planet rotates on its axis in a retrograde fashion,opposite to that of most of the planets and opposite to the direction of revolution of the planets?

The outer core of Earth is molten,but the inner core is solid.The reason is that the:

If you were watching the sunrise on Mercury when Mercury was near perihelion,what would you see? (See Figure 6-44,Comins,Discovering the Essential Universe,6th ed.)

Which fact first gave Alfred Wegener the idea that continents have drifted and are still drifting over Earth's surface?

What is pressure?

Which statement is the BEST explanation for the origin of the Moon?

Which theory about the origin of the Moon is now believed to be CORRECT?

Which spacecraft and technique has given us our most extensive information about the overall surface of Venus?

There are half a dozen large maria on the side of the Moon facing Earth and only one small mare on the far side.Which explanation is the MOST likely?

What is the MOST important reason for Earth's need of the ozone layer?

Because Mercury has no appreciable atmosphere,its surface shows extreme temperature changes between night and day,with a range of about:

What evidence does a planetary geologist use to identify a "young" crater on Mercury?

There are traces of oxygen in Mercury's atmosphere.The source of this is believed to be:

Why is the Moon in a synchronous orbit around Earth,always keeping the same face toward Earth?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters

Exam 6: The Terrestrial Planets and Their Moons

The internal structure of Mercury is a:

MOST of the craters on the Moon are thought to have been caused by:

The gas that is the major constituent of the atmospheres of Venus and Mars and a minor constituent of Earth's atmosphere is:

What is (or was)Pangaea?

Why do we believe Mars is so small?

The fraction of light reflected by a planet or other object is its:

Which planet rotates on its axis in a retrograde fashion,opposite to that of most of the planets and opposite to the direction of revolution of the planets?

The outer core of Earth is molten,but the inner core is solid.The reason is that the:

If you were watching the sunrise on Mercury when Mercury was near perihelion,what would you see? (See Figure 6-44,Comins,Discovering the Essential Universe,6th ed.)

Which fact first gave Alfred Wegener the idea that continents have drifted and are still drifting over Earth's surface?

What is pressure?

Which statement is the BEST explanation for the origin of the Moon?

Which theory about the origin of the Moon is now believed to be CORRECT?

Which spacecraft and technique has given us our most extensive information about the overall surface of Venus?

There are half a dozen large maria on the side of the Moon facing Earth and only one small mare on the far side.Which explanation is the MOST likely?

What is the MOST important reason for Earth's need of the ozone layer?

Because Mercury has no appreciable atmosphere,its surface shows extreme temperature changes between night and day,with a range of about:

What evidence does a planetary geologist use to identify a "young" crater on Mercury?

There are traces of oxygen in Mercury's atmosphere.The source of this is believed to be:

Why is the Moon in a synchronous orbit around Earth,always keeping the same face toward Earth?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Astrobiology

Filters