Question 1

As a comet enters the inner Solar System, its coma can grow to a large size, as large as some planets in a few cases.What causes this growth?

Accepted Answer

A)  Tidal forces from the inner planets pull material off the comet. 
B)  The comet moves at a higher velocity near perihelion and loose material is dislodged. 
C)  The comet's tectonic action is triggered by the Sun's strong gravity. 
D)  The rotation (spin) of the comet increases near perihelion due to angular momentum conservation. 
E)  The Sun's radiation heats the comet, allowing materials to sublimate into a cloud. 
A)  Tidal forces from the inner planets pull material off the comet. 
B)  The comet moves at a higher velocity near perihelion and loose material is dislodged. 
C)  The comet's tectonic action is triggered by the Sun's strong gravity. 
D)  The rotation (spin) of the comet increases near perihelion due to angular momentum conservation. 
E)  The Sun's radiation heats the comet, allowing materials to sublimate into a cloud.

Question 2

Why is it difficult to determine the sizes of dwarf planets, and what can be done to get accurate measurements?

Accepted Answer

Dwarf planets are far away,and the brigh

Question 3

In the early Solar System, when the Solar System had yet to be cleared of the debris out of which it formed, which type of object would have been most likely to deposit water onto Earth's surface?

Accepted Answer

A)  a comet 
B)  an asteroid 
C)  a Mars-sized protoplanet 
D)  Both comets and asteroids appear to be sources. 
E)  None, because water is not a major component of any of the objects above. 
A)  a comet 
B)  an asteroid 
C)  a Mars-sized protoplanet 
D)  Both comets and asteroids appear to be sources. 
E)  None, because water is not a major component of any of the objects above.

Question 4

Why does a comet usually have two tails, one that is straight and one that is curved? What materials compose each tail, and why do they have different shapes?

Accepted Answer

The straight tail is made of ionized gas

Question 5

Why do long-period comets usually put on a much more visually spectacular display than short-period comets?

Accepted Answer

Long-period comets have not passed perih

Question 6

The Lyrid meteor shower occurs every year on approximately April 21 because

Accepted Answer

A)  the Lyrae constellation is directly overhead at midnight. 
B)  Earth passes through a cloud of debris left behind by Comet Thatcher. 
C)  Earth passes through a cloud of debris left over from the Solar System's formation. 
D)  Earth undergoes a periodic volcanic eruption every April. 
E)  the Sun is located in the Lyrae constellation at noon. 
A)  the Lyrae constellation is directly overhead at midnight. 
B)  Earth passes through a cloud of debris left behind by Comet Thatcher. 
C)  Earth passes through a cloud of debris left over from the Solar System's formation. 
D)  Earth undergoes a periodic volcanic eruption every April. 
E)  the Sun is located in the Lyrae constellation at noon.

Question 7

The one orbital characteristic that both short- and long-period comets share is

Accepted Answer

A)  mostly prograde orbits. 
B)  orbits with completely random tilts. 
C)  mostly retrograde orbits. 
D)  orbital periods longer than any planet. 
E)  highly eccentric orbits. 
A)  mostly prograde orbits. 
B)  orbits with completely random tilts. 
C)  mostly retrograde orbits. 
D)  orbital periods longer than any planet. 
E)  highly eccentric orbits.

Question 8

Consider a small comet nucleus whose diameter is 1 km and mass is 5 * 1011 kg.It hits Earth head-on, traveling at a speed of 1,000 m/s.How many times larger or smaller is the comet's kinetic energy compared to that of a typical train pulling 20 boxcars whose total mass is
2 * 106 kg and speed is 25 m/s?

Accepted Answer

Kinetic energy is equal to 1/2mv^2</

Question 9

What does the existence of M-type asteroids tell us about their origin?

Accepted Answer

They were once the m

Question 10

Although most meteorites have ages around 4.5 billion years, a small subset has ages around 1.3 billion years.What caused the substantial difference in age between these two populations of meteorites?

Accepted Answer

A)  These meteorites just happened to form later than most meteorites. 
B)  Not all meteorites hit Earth in the early Solar System.We should expect to find younger meteorites as more meteors pass through the atmosphere. 
C)  The younger meteorites were created when a protoplanet collided with Earth, creating the Moon.The leftover fragments became meteorites. 
D)  These meteorites were thrown into space after an impact with Mars and afterward some happened to collide with Earth. 
E)  The younger ones are the result of comets repeatedly passing close to the Sun, melting their surfaces and making them appear younger. 
A)  These meteorites just happened to form later than most meteorites. 
B)  Not all meteorites hit Earth in the early Solar System.We should expect to find younger meteorites as more meteors pass through the atmosphere. 
C)  The younger meteorites were created when a protoplanet collided with Earth, creating the Moon.The leftover fragments became meteorites. 
D)  These meteorites were thrown into space after an impact with Mars and afterward some happened to collide with Earth. 
E)  The younger ones are the result of comets repeatedly passing close to the Sun, melting their surfaces and making them appear younger.

Question 11

Which type of comet is the most common?

Accepted Answer

A)  short-period 
B)  long-period 
C)  S-type 
D)  M-Type 
E)  There are approximately equal numbers of short- and long-period comets. 
A)  short-period 
B)  long-period 
C)  S-type 
D)  M-Type 
E)  There are approximately equal numbers of short- and long-period comets.

Question 12

Why do comets still exist in our Solar System? That is, why have they not all been vaporized away or impacted large bodies by now?

Accepted Answer

Comets are thought to be the leftover de

Question 13

All of the zodiacal dust in the Solar System combined is roughly equal in mass to

Accepted Answer

A)  a meteoroid. 
B)  a comet. 
C)  Jupiter. 
D)  the Moon. 
E)  a terrestrial planet. 
A)  a meteoroid. 
B)  a comet. 
C)  Jupiter. 
D)  the Moon. 
E)  a terrestrial planet.

Question 14

The "M" in "M-type" asteroid stands for

Accepted Answer

A)  magnesium. 
B)  Mars-orbiting. 
C)  metal. 
D)  major. 
E)  medium-sized. 
A)  magnesium. 
B)  Mars-orbiting. 
C)  metal. 
D)  major. 
E)  medium-sized.

Question 15

The mass of all the known asteroids combined is approximately equal to

Accepted Answer

A)  half the mass of Earth. 
B)  three times the mass of Earth. 
C)  twice the mass of Mars. 
D)  the mass of Mars. 
E)  less than one-third the mass of the Moon. 
A)  half the mass of Earth. 
B)  three times the mass of Earth. 
C)  twice the mass of Mars. 
D)  the mass of Mars. 
E)  less than one-third the mass of the Moon.

Question 16

The dwarf planet Eris is covered in methane ice, whereas the surface of Saturn's moon Enceladus is covered in water ice.Why does methane exist in ice form on Eris but not Enceladus?

Accepted Answer

Eris is located much farther from the Su

Question 17

List the names of the known dwarf planets and their approximate location in the Solar System.

Accepted Answer

As of printing,there are five

Question 18

Currently the surface of the dwarf planet Eris is covered with ________, which makes it have what may be the highest albedo of any object in the Solar System.

Accepted Answer

A)  methane ice 
B)  water ice 
C)  nitrogen ice 
D)  sulfur dioxide ice 
E)  carbon dioxide ice 
A)  methane ice 
B)  water ice 
C)  nitrogen ice 
D)  sulfur dioxide ice 
E)  carbon dioxide ice

Question 19

Eris, Ceres, and Haumea are examples of

Accepted Answer

A)  asteroids. 
B)  dwarf planets. 
C)  meteoroids. 
D)  comets. 
E)  meteor showers. 
A)  asteroids. 
B)  dwarf planets. 
C)  meteoroids. 
D)  comets. 
E)  meteor showers.

Question 20

Where are asteroids found?

Accepted Answer

A)  only between Mars and Jupiter 
B)  only inside Earth's orbit, halfway to the Sun 
C)  only in the farthest reaches of the Solar System, beyond Pluto 
D)  throughout the entire Solar System 
E)  only in orbital resonances in Jupiter's orbit 
A)  only between Mars and Jupiter 
B)  only inside Earth's orbit, halfway to the Sun 
C)  only in the farthest reaches of the Solar System, beyond Pluto 
D)  throughout the entire Solar System 
E)  only in orbital resonances in Jupiter's orbit

Exam 12: Dwarf Planets and Small Solar System Bodies

As a comet enters the inner Solar System, its coma can grow to a large size, as large as some planets in a few cases.What causes this growth?

Why is it difficult to determine the sizes of dwarf planets, and what can be done to get accurate measurements?

In the early Solar System, when the Solar System had yet to be cleared of the debris out of which it formed, which type of object would have been most likely to deposit water onto Earth's surface?

Why does a comet usually have two tails, one that is straight and one that is curved? What materials compose each tail, and why do they have different shapes?

Why do long-period comets usually put on a much more visually spectacular display than short-period comets?

The Lyrid meteor shower occurs every year on approximately April 21 because

The one orbital characteristic that both short- and long-period comets share is

What does the existence of M-type asteroids tell us about their origin?

Although most meteorites have ages around 4.5 billion years, a small subset has ages around 1.3 billion years.What caused the substantial difference in age between these two populations of meteorites?

Which type of comet is the most common?

Why do comets still exist in our Solar System? That is, why have they not all been vaporized away or impacted large bodies by now?

All of the zodiacal dust in the Solar System combined is roughly equal in mass to

The "M" in "M-type" asteroid stands for

The mass of all the known asteroids combined is approximately equal to

The dwarf planet Eris is covered in methane ice, whereas the surface of Saturn's moon Enceladus is covered in water ice.Why does methane exist in ice form on Eris but not Enceladus?

List the names of the known dwarf planets and their approximate location in the Solar System.

Currently the surface of the dwarf planet Eris is covered with ________, which makes it have what may be the highest albedo of any object in the Solar System.

Eris, Ceres, and Haumea are examples of

Where are asteroids found?

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Formation of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Planetary Moons and Rings

Taking the Measure of Stars

Our Starthe Sun

The Interstellar Medium and Star Formation

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

Galaxies

The Milky Waya Normal Spiral Galaxy

The Expanding Universe

Cosmology

Large-Scale Structure in the Universe

Life

Filters