Question 1

If a collapsing interstellar cloud formed only a protostar without an accretion disk around it,what would happen?

Accepted Answer

A)   The forming protostar would be significantly less massive than it would have been otherwise.
B)   The forming protostar would be rotating too fast to hold itself together.
C)   Only Jovian planets would form around the protostar.
D)   Only terrestrial planets would form around the protostar.E) None of the above
F) A) and B)

Question 2

All planets orbit the Sun in the same direction.

Accepted Answer

A) True 
 B)False

Question 3

When astronomers began searching for extra-solar planets,they were surprised to discover Jupiter-sized planets much closer than 1 AU from their parent stars.Why is this surprising?

Accepted Answer

A)   These planets must have formed at larger radius where temperatures were cooler and then migrated inward.
B)   Jupiter-sized,rocky planets were thought to be uncommon in other solar systems.
C)   These planets must be the remnants of failed stars.
D)   Earth-like planets must be rarer than Jupiter-sized planets in other solar systems.E) B) and C)
F) C) and D)

Question 4

Conservation of angular momentum states that as a cloud of interstellar gas and dust collapses,the velocity of the particles increases.

Accepted Answer

A) True 
 B)False

Question 5

The primordial atmosphere of the Earth consisted of what type of chemical elements and from where did it originate? What chemical elements did the secondary atmosphere of the Earth consist of and from where did it originate?

Accepted Answer

The primary atmosphere consisted mostly ...

Question 6

To date astronomers have not yet detected Earth-size planets around normal stars.

Accepted Answer

A) True 
 B)False

Question 7

How do astronomers explain the basic difference in composition between the inner planets and the outer planets?

Accepted Answer

The inner planets (Mercury,Venus,Earth,a...

Question 8

Explain why most of the extra-solar planets astronomers have detected are so-called "hot Jupiters."

Accepted Answer

Current technology does not allow us to ...

Question 9

Our Solar System is likely unique among the stars in our Galaxy.

Accepted Answer

A) True 
 B)False

Question 10

What is the best method to use to detect Earth-sized extra-solar planets with the telescopes and instrumentation that exist today?

Accepted Answer

A)   Doppler shift
B)   transit
C)   direct imaging
D)   microlensingE) B) and C)
F) A) and D)

Question 11

Compare the orbital angular momentum of the Earth and Jupiter.Which is larger,and by how much? (Note that Jupiter's mass is 318 times that of the Earth,the semimajor axis of Jupiter's orbit is 5.2 AU,and Jupiter's orbital period is 12 years. )

Accepted Answer

The orbital angular momentum is equal to...

Question 12

Why do outer planets like Jupiter have huge gaseous atmospheres of hydrogen and helium while the inner planets do not?

Accepted Answer

A)   These gases were more abundant in the outer regions of the accretion disk where the outer planets formed.
B)   The outer planets grew massive quickly enough to gravitationally hold on to these gases before the solar wind dispersed the accretion disk.
C)   The inner planets were too close to the Sun,and solar winds blew away their original gaseous atmospheres.
D)   Frequent early collisions by comets with the inner planets caused most of their original atmospheres to dissipate.E) B) and D)
F) B) and C)

Question 13

The difference in composition between the giant planets and the terrestrial planets is most likely caused by the fact that

Accepted Answer

A)   the giant planets are much larger.
B)   only the terrestrial planets have iron cores.
C)   the terrestrial planets are closer to the Sun.
D)   the giant planets are made mostly of carbon.E) None of the above
F) C) and D)

Question 14

Over 330 extra-solar planets have been detected by direct imaging of the planets.

Accepted Answer

A) True 
 B)False

Question 15

Two competing models of the formation of giant gaseous planets suggest they form either from gas accreting onto a rocky core or from

Accepted Answer

A)   fragmentation of the accretion disk surrounding the protostar.
B)   the merger of two large planetesimals.
C)   an eruption of material from the protostar.
D)   materials condensing out of the solar wind.E) B) and C)
F) A) and D)

Question 16

What is the age of our solar system?

Accepted Answer

A)   4.5 billion years
B)   4.5 million years
C)   13.7 billion years
D)   13.7 million yearsE) A) and D)
F) A) and C)

Question 17

Current technology is sensitive enough to detect some extra-solar planets by a dip in brightness of the parent star as the planets pass between us and it.

Accepted Answer

A) True 
 B)False

Question 18

Comets and asteroids are

Accepted Answer

A)   other names for moons of the planets.
B)   primarily located within 1 AU of the Sun.
C)   all more massive than Earth's moon.
D)   material left over from the formation of the planets.E) A) and B)
F) B) and C)

Question 19

What is the ratio of the orbital angular momentum of the Earth compared to its spin angular momentum? Note that the Earth has a radius of 6,000 km,and 1 AU is  .

Accepted Answer

A)   70
B)   640
C)   25,000
D)   4 millionE) B) and D)
F) All of the above

Question 20

How much material in an accretion disk goes into forming the planets,moons,and smaller objects?

Accepted Answer

A)   Most of it
B)   Roughly half of it
C)   A small amount of it
D)   Barely any at allE) A) and B)
F) B) and C)

Exam 6: The Birth and Evolution of Planetary Systems

The difference in composition between the giant planets and the terrestrial planets is most likely caused by the fact that

Correct AnswerverifiedShow Answer

When astronomers began searching for extra-solar planets,they were surprised to discover Jupiter-sized planets much closer than 1 AU from their parent stars.Why is this surprising?

Correct AnswerverifiedShow Answer

How do astronomers explain the basic difference in composition between the inner planets and the outer planets?

Correct AnswerverifiedThe inner planets (Mercury,Venus,Earth,a...View AnswerShow Answer

Conservation of angular momentum states that as a cloud of interstellar gas and dust collapses,the velocity of the particles increases.

Correct AnswerverifiedShow Answer

Why do outer planets like Jupiter have huge gaseous atmospheres of hydrogen and helium while the inner planets do not?

Correct AnswerverifiedShow Answer

Comets and asteroids are

Correct AnswerverifiedShow Answer

Current technology is sensitive enough to detect some extra-solar planets by a dip in brightness of the parent star as the planets pass between us and it.

Correct AnswerverifiedShow Answer

What is the best method to use to detect Earth-sized extra-solar planets with the telescopes and instrumentation that exist today?

Correct AnswerverifiedShow Answer

The primordial atmosphere of the Earth consisted of what type of chemical elements and from where did it originate? What chemical elements did the secondary atmosphere of the Earth consist of and from where did it originate?

Correct AnswerverifiedThe primary atmosphere consisted mostly ...View AnswerShow Answer

All planets orbit the Sun in the same direction.

Correct AnswerverifiedShow Answer

What is the age of our solar system?

Correct AnswerverifiedShow Answer

Over 330 extra-solar planets have been detected by direct imaging of the planets.

Correct AnswerverifiedShow Answer

Compare the orbital angular momentum of the Earth and Jupiter.Which is larger,and by how much? (Note that Jupiter's mass is 318 times that of the Earth,the semimajor axis of Jupiter's orbit is 5.2 AU,and Jupiter's orbital period is 12 years. )

Correct AnswerverifiedThe orbital angular momentum is equal to...View AnswerShow Answer

If a collapsing interstellar cloud formed only a protostar without an accretion disk around it,what would happen?

Correct AnswerverifiedShow Answer

What is the ratio of the orbital angular momentum of the Earth compared to its spin angular momentum? Note that the Earth has a radius of 6,000 km,and 1 AU is .

Correct AnswerverifiedShow Answer

Explain why most of the extra-solar planets astronomers have detected are so-called "hot Jupiters."

Correct AnswerverifiedCurrent technology does not allow us to ...View AnswerShow Answer

How much material in an accretion disk goes into forming the planets,moons,and smaller objects?

Correct AnswerverifiedShow Answer

Two competing models of the formation of giant gaseous planets suggest they form either from gas accreting onto a rocky core or from

Correct AnswerverifiedShow Answer

Our Solar System is likely unique among the stars in our Galaxy.

Correct AnswerverifiedShow Answer

To date astronomers have not yet detected Earth-size planets around normal stars.

Correct AnswerverifiedShow Answer

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The inner planets (Mercury,Venus,Earth,a...
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The primary atmosphere consisted mostly ...
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The orbital angular momentum is equal to...
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Current technology does not allow us to ...
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