Question 1

Explain the two primary reasons why the inner solar nebula was hotter than the outer solar nebula.

Accepted Answer

The inner solar nebula was hotter than t

Question 2

When you push your palms together and rub them back and forth, you are demonstrating one way of converting _________ energy into _________ energy.

Accepted Answer

A)  potential; thermal 
B)  kinetic; potential 
C)  thermal; kinetic 
D)  kinetic; thermal 
E)  potential; total 
A)  potential; thermal 
B)  kinetic; potential 
C)  thermal; kinetic 
D)  kinetic; thermal 
E)  potential; total

Question 3

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 that surrounds the protostar 
B)  the merger of two large planetesimals 
C)  planets stolen from another nearby protostar 
D)  materials condensing out of the solar wind 
E)  an eruption of material from the protostar 
A)  fragmentation of the accretion disk that surrounds the protostar 
B)  the merger of two large planetesimals 
C)  planets stolen from another nearby protostar 
D)  materials condensing out of the solar wind 
E)  an eruption of material from the protostar

Question 4

Consider four spheres of equal mass and size. Which has the most potential energy?

Accepted Answer

A)  a sphere on the top shelf of a bookshelf 
B)  a sphere rolling on the floor at the base of the bookshelf 
C)  a sphere sitting at rest on the floor at the base of the bookshelf 
D)  a sphere on the middle shelf of a bookshelf 
E)  a sphere that fell from the top shelf to the floor 
A)  a sphere on the top shelf of a bookshelf 
B)  a sphere rolling on the floor at the base of the bookshelf 
C)  a sphere sitting at rest on the floor at the base of the bookshelf 
D)  a sphere on the middle shelf of a bookshelf 
E)  a sphere that fell from the top shelf to the floor

Question 5

The primary atmospheres of the planets are made mostly of:

Accepted Answer

A)  carbon and oxygen 
B)  hydrogen and helium 
C)  oxygen and nitrogen 
D)  iron and nickel 
E)  nitrogen and argon 
A)  carbon and oxygen 
B)  hydrogen and helium 
C)  oxygen and nitrogen 
D)  iron and nickel 
E)  nitrogen and argon

Question 6

Explain why astronomers believe that the formation of planets is a natural by-product of star formation.

Accepted Answer

To explain the structure of the Solar Sy

Question 7

When astronomers began searching for extrasolar 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 radii 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)  It is different than in our Solar System. 
A)  These planets must have formed at larger radii 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)  It is different than in our Solar System.

Question 8

What is the most important factor in determining whether or not a planet will be rocky like terrestrial planets or gaseous like giant planets?

Accepted Answer

A)  the time at which the planet forms 
B)  the planet's radius 
C)  the planet's distance from the Sun 
D)  whether the planet has moons 
E)  the planet's internal temperature 
A)  the time at which the planet forms 
B)  the planet's radius 
C)  the planet's distance from the Sun 
D)  whether the planet has moons 
E)  the planet's internal temperature

Question 9

If an interstellar cloud having a diameter of 1016 m and a rotation period of a million years were to collapse to form a sphere that had the diameter of our Solar System, approximately 40 AU, what would its rotation period be? Assume the cloud's total mass and angular momentum did not change.

Accepted Answer

A)  1 million years 
B)  600 years 
C)  1 year 
D)  6 years 
E)  4 months 
A)  1 million years 
B)  600 years 
C)  1 year 
D)  6 years 
E)  4 months

Question 10

Astronomers believe that the "hot Jupiters" found orbiting other stars must have migrated inward over time:

Accepted Answer

A)  by slowly accreting large amounts of gas and increasing their gravitational pull 
B)  by losing their gas due to evaporation 
C)  by losing orbital angular momentum 
D)  after colliding with another planet 
E)  after a close encounter between their star and another star 
A)  by slowly accreting large amounts of gas and increasing their gravitational pull 
B)  by losing their gas due to evaporation 
C)  by losing orbital angular momentum 
D)  after colliding with another planet 
E)  after a close encounter between their star and another star

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

Briefly explain the four different observational methods we use to detect extrasolar planets. Which has detected the largest number of extrasolar planets to date?

Accepted Answer

The four different observational methods

Question 13

All planets orbit the Sun in the same direction.

Accepted Answer

A) True 
 B)False

Question 14

Explain why most of the extrasolar planets that astronomers first detected were so-called "hot Jupiters."

Accepted Answer

Originally technology did not allow us t

Question 15

Hundreds of extrasolar planets have been detected by direct imaging of the planets.

Accepted Answer

A) True 
 B)False

Question 16

What property of an extrasolar planet can be determined directly from the Doppler effect data shown in the figure below? What other properties of the planet can then be determined?

Accepted Answer

The period of repetition of the Doppler

Question 17

Explain how astronomers use the Doppler effect to detect the presence of extrasolar planets.

Accepted Answer

As a planet orbits a star, the gravitati

Question 18

How did the formation of our Moon differ from the formation of the Galilean moons of Jupiter?

Accepted Answer

Astronomers believe that the formation o

Question 19

The Moon probably formed:

Accepted Answer

A)  out of a collision between the Earth and a Mars-sized object 
B)  when the Earth's gravity captured a planetesimal 
C)  when the accretion disk around the Earth fragmented 
D)  when planetesimals collided to form a more massive object 
E)  when a piece of Earth broke off and entered orbit 
A)  out of a collision between the Earth and a Mars-sized object 
B)  when the Earth's gravity captured a planetesimal 
C)  when the accretion disk around the Earth fragmented 
D)  when planetesimals collided to form a more massive object 
E)  when a piece of Earth broke off and entered orbit

Question 20

Most planets currently found around other stars are:

Accepted Answer

A)  rocky in composition like terrestrial planets 
B)  2 to 10 MEarth, which is smaller than Neptune 
C)  2 to 10 MJupiter 
D)  located at distances much larger than Jupiter's distance from the Sun 
E)  similar in mass to the Earth 
A)  rocky in composition like terrestrial planets 
B)  2 to 10 MEarth, which is smaller than Neptune 
C)  2 to 10 MJupiter 
D)  located at distances much larger than Jupiter's distance from the Sun 
E)  similar in mass to the Earth

Exam 7: The Birth and Evolution of Planetary Systems

Explain the two primary reasons why the inner solar nebula was hotter than the outer solar nebula.

When you push your palms together and rub them back and forth, you are demonstrating one way of converting _________ energy into _________ energy.

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

Consider four spheres of equal mass and size. Which has the most potential energy?

The primary atmospheres of the planets are made mostly of:

Explain why astronomers believe that the formation of planets is a natural by-product of star formation.

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

What is the most important factor in determining whether or not a planet will be rocky like terrestrial planets or gaseous like giant planets?

If an interstellar cloud having a diameter of 1016 m and a rotation period of a million years were to collapse to form a sphere that had the diameter of our Solar System, approximately 40 AU, what would its rotation period be? Assume the cloud's total mass and angular momentum did not change.

Astronomers believe that the "hot Jupiters" found orbiting other stars must have migrated inward over time:

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.)

Briefly explain the four different observational methods we use to detect extrasolar planets. Which has detected the largest number of extrasolar planets to date?

All planets orbit the Sun in the same direction.

Explain why most of the extrasolar planets that astronomers first detected were so-called "hot Jupiters."

Hundreds of extrasolar planets have been detected by direct imaging of the planets.

What property of an extrasolar planet can be determined directly from the Doppler effect data shown in the figure below? What other properties of the planet can then be determined?

Explain how astronomers use the Doppler effect to detect the presence of extrasolar planets.

How did the formation of our Moon differ from the formation of the Galilean moons of Jupiter?

The Moon probably formed:

Most planets currently found around other stars are:

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

When you push your palms together and rub them back and forth, you are demonstrating one way of converting _ energy into _ energy.

If an interstellar cloud having a diameter of 10¹⁶ m and a rotation period of a million years were to collapse to form a sphere that had the diameter of our Solar System, approximately 40 AU, what would its rotation period be? Assume the cloud's total mass and angular momentum did not change.