Question 1

What is the Jeans instability?

Accepted Answer

A)  When a growing protoplanet becomes too large, it is more likely to be split apart by subsequent bombardment than to grow further. 
B)  If a solar nebula is too massive, it will continue to collapse to become a black hole and will not form planets. 
C)  If the disk of matter surrounding a solar nebula becomes too hot, it will dissipate, and planets will not form. 
D)  If a cloud of gas and dust is sufficiently dense, it will collapse due to its own gravity. 
A)  When a growing protoplanet becomes too large, it is more likely to be split apart by subsequent bombardment than to grow further. 
B)  If a solar nebula is too massive, it will continue to collapse to become a black hole and will not form planets. 
C)  If the disk of matter surrounding a solar nebula becomes too hot, it will dissipate, and planets will not form. 
D)  If a cloud of gas and dust is sufficiently dense, it will collapse due to its own gravity.

Question 2

Suppose that you were to go back in time and explore the solar nebula during the formation of the solar system.If you were to travel outward from the protosun,the first solid material you would encounter would be:

Accepted Answer

A)  dust-sized grains of rocky material. 
B)  dust-sized grains of frozen hydrogen, water ice, and rocky minerals. 
C)  snowflakes made of frozen water, methane, ammonia, and carbon dioxide. 
D)  snowflakes made of frozen hydrogen and helium. 
A)  dust-sized grains of rocky material. 
B)  dust-sized grains of frozen hydrogen, water ice, and rocky minerals. 
C)  snowflakes made of frozen water, methane, ammonia, and carbon dioxide. 
D)  snowflakes made of frozen hydrogen and helium.

Question 3

What is the origin of many of the bodies in the Kuiper belt and the Oort comet cloud?

Accepted Answer

A)  These bodies were part of the original solar nebula. Because they are so far from the rest of the solar system, these regions were undisturbed by the creation of the planets, and these objects have remained there ever since. 
B)  These distant objects have been captured from interstellar space by the Sun's gravitational pull. 
C)  The gravitational forces from Jupiter and Saturn flung planetesimals from regions closer to the Sun out into these regions. 
D)  Early in the history of the solar system, it is believed that these objects were pulled out of the Sun by a close encounter with a passing star. 
A)  These bodies were part of the original solar nebula. Because they are so far from the rest of the solar system, these regions were undisturbed by the creation of the planets, and these objects have remained there ever since. 
B)  These distant objects have been captured from interstellar space by the Sun's gravitational pull. 
C)  The gravitational forces from Jupiter and Saturn flung planetesimals from regions closer to the Sun out into these regions. 
D)  Early in the history of the solar system, it is believed that these objects were pulled out of the Sun by a close encounter with a passing star.

Question 4

Compared with Jupiter and Saturn,Uranus and Neptune contain proportionally more heavy materials,more ices,and less hydrogen.How do we account for this?

Accepted Answer

A)  Jupiter and Saturn migrated inward early during their formation, leaving substantial quantities of heavy materials and ices behind (to form Uranus and Neptune) but taking most of the hydrogen. 
B)  Neptune and Uranus were formed far out in the solar system, where the materials were different from those in the present location of the outer planets (where Jupiter and Saturn were formed). 
C)  The heavy materials are from asteroids flung outward by the inward migration of the gas planets, the ices are from icy masses that had spiraled in from far out in the solar system, and the deficit of hydrogen was caused by the prior formation of the gas planets. 
D)  The heavy materials and ices are from asteroids flung outward by the inward migration of the gas planets, and the hydrogen deficit is because the light gases were blown out of the solar system by the solar wind. 
A)  Jupiter and Saturn migrated inward early during their formation, leaving substantial quantities of heavy materials and ices behind (to form Uranus and Neptune) but taking most of the hydrogen. 
B)  Neptune and Uranus were formed far out in the solar system, where the materials were different from those in the present location of the outer planets (where Jupiter and Saturn were formed). 
C)  The heavy materials are from asteroids flung outward by the inward migration of the gas planets, the ices are from icy masses that had spiraled in from far out in the solar system, and the deficit of hydrogen was caused by the prior formation of the gas planets. 
D)  The heavy materials and ices are from asteroids flung outward by the inward migration of the gas planets, and the hydrogen deficit is because the light gases were blown out of the solar system by the solar wind.

Question 5

Why did the temperature start to rise at the center of the solar nebula?

Accepted Answer

A)  Supernova explosions were stirring up the material there and causing turbulence. 
B)  The nebula was contracting, which increased the speed of the atoms moving in it. 
C)  Fusion reactions were beginning in the core, releasing tremendous amounts of heat. 
D)  Massive stars nearby were heating the nebula with their ultraviolet radiation. 
A)  Supernova explosions were stirring up the material there and causing turbulence. 
B)  The nebula was contracting, which increased the speed of the atoms moving in it. 
C)  Fusion reactions were beginning in the core, releasing tremendous amounts of heat. 
D)  Massive stars nearby were heating the nebula with their ultraviolet radiation.

Question 6

The composition of a typical asteroid is:

Accepted Answer

A)  rock and metal. 
B)  ice with a liquid water core. 
C)  rock and ice. 
D)  pure ice, or perhaps ice with dust-sized grains of rock mixed in. 
A)  rock and metal. 
B)  ice with a liquid water core. 
C)  rock and ice. 
D)  pure ice, or perhaps ice with dust-sized grains of rock mixed in.

Question 7

Which characteristic is NOT typical of our planetary system?

Accepted Answer

A)  The spin axes of most of the planets are aligned to within 30° to the perpendicular of the orbital plane. 
B)  The orbits of most of the planets are almost circular. 
C)  Most of the planets orbit the Sun in the same direction. 
D)  The physical size of most of the planets is about the same. 
A)  The spin axes of most of the planets are aligned to within 30° to the perpendicular of the orbital plane. 
B)  The orbits of most of the planets are almost circular. 
C)  Most of the planets orbit the Sun in the same direction. 
D)  The physical size of most of the planets is about the same.

Question 8

What process had the greatest influence on the features of the Moon during the first billion years of its existence?

Accepted Answer

A)  erosion by an early, short-lived atmosphere 
B)  volcanoes 
C)  impacts from space 
D)  mountain-building from geological activity 
A)  erosion by an early, short-lived atmosphere 
B)  volcanoes 
C)  impacts from space 
D)  mountain-building from geological activity

Question 9

In our solar system,which planet is NOT a member of the terrestrial group?

Accepted Answer

A)  Venus 
B)  Jupiter 
C)  Mercury 
D)  Mars 
A)  Venus 
B)  Jupiter 
C)  Mercury 
D)  Mars

Question 10

The mass of the solar nebula that began contracting to form the solar system was estimated to be:

Accepted Answer

A)  one solar mass, the same as the mass of the solar system today. 
B)  only a fraction of a solar mass because additional mass has since been attracted from nearby objects. 
C)  several solar masses. 
D)  thousands of solar masses to allow for the mass energy radiated away since the formation. 
A)  one solar mass, the same as the mass of the solar system today. 
B)  only a fraction of a solar mass because additional mass has since been attracted from nearby objects. 
C)  several solar masses. 
D)  thousands of solar masses to allow for the mass energy radiated away since the formation.

Question 11

Which was the MOST probable time sequence for the formation of the solar system?

Accepted Answer

A)  The Sun contracted first as a gas ball, and the planets and moons formed shortly afterward by accretion and condensation. 
B)  The Sun formed first, the planets were spun off from the Sun, and the moons in turn were spun off from the planets. 
C)  The planets formed first out of a cold nebula of gas and dust, followed by the Sun, which formed when the gas had become much hotter. 
D)  The Sun formed initially, and the planets and major moons were captured much later as they drifted by the Sun. 
A)  The Sun contracted first as a gas ball, and the planets and moons formed shortly afterward by accretion and condensation. 
B)  The Sun formed first, the planets were spun off from the Sun, and the moons in turn were spun off from the planets. 
C)  The planets formed first out of a cold nebula of gas and dust, followed by the Sun, which formed when the gas had become much hotter. 
D)  The Sun formed initially, and the planets and major moons were captured much later as they drifted by the Sun.

Question 12

A gas and dust cloud will not necessarily collapse because it normally experiences a balance between its internal gas pressure and:

Accepted Answer

A)  kinetic energy. 
B)  friction. 
C)  gravity. 
D)  electrostatic repulsion. 
A)  kinetic energy. 
B)  friction. 
C)  gravity. 
D)  electrostatic repulsion.

Question 13

The region at the farthest limits of the solar system in which a large number of objects composed of rock and ice circle the Sun in a roughly spherical region is called the:

Accepted Answer

A)  outer solar system. 
B)  asteroid belt. 
C)  Kuiper belt. 
D)  Oort comet cloud. 
A)  outer solar system. 
B)  asteroid belt. 
C)  Kuiper belt. 
D)  Oort comet cloud.

Question 14

The birthplace of the Sun and planets (and of other stars and maybe their planets)is thought to have been in:

Accepted Answer

A)  cool gas and dust clouds. 
B)  the centers of supernova explosions. 
C)  black holes dotted about the universe. 
D)  the centers of galaxies. 
A)  cool gas and dust clouds. 
B)  the centers of supernova explosions. 
C)  black holes dotted about the universe. 
D)  the centers of galaxies.

Question 15

Comets are typically:

Accepted Answer

A)  gaseous bodies from which some of the gas is pushed out by the Sun to form a long tail. 
B)  slushy mixtures of liquid and ice. 
C)  chunks of rock that are generally a few tens of kilometers in diameter. 
D)  chunks of ice that begin to vaporize if they pass close to the Sun. 
A)  gaseous bodies from which some of the gas is pushed out by the Sun to form a long tail. 
B)  slushy mixtures of liquid and ice. 
C)  chunks of rock that are generally a few tens of kilometers in diameter. 
D)  chunks of ice that begin to vaporize if they pass close to the Sun.

Question 16

Which physical parameter more than any other most probably controlled the early evolution of the planetary system and dictated the characteristics of the planets that eventually formed?

Accepted Answer

A)  the mix of chemical constituents 
B)  overall rotation of the nebula 
C)  temperature distribution in the nebula 
D)  the density of hydrogen gas in the nebula 
A)  the mix of chemical constituents 
B)  overall rotation of the nebula 
C)  temperature distribution in the nebula 
D)  the density of hydrogen gas in the nebula

Question 17

The manner in which the large,outer planets formed in our solar system was MOST likely the:

Accepted Answer

A)  gravitational condensation of hydrogen, helium, and dust in eddies or vortices in the outer solar nebula. 
B)  gravitational condensation of hydrogen and helium gas, followed by the capture of planetesimals. 
C)  accretion of planetesimals to form a core, followed by the gravitational capture of hydrogen and helium gas. 
D)  accretion of cold planetesimals containing large quantities of hydrogen and helium. 
A)  gravitational condensation of hydrogen, helium, and dust in eddies or vortices in the outer solar nebula. 
B)  gravitational condensation of hydrogen and helium gas, followed by the capture of planetesimals. 
C)  accretion of planetesimals to form a core, followed by the gravitational capture of hydrogen and helium gas. 
D)  accretion of cold planetesimals containing large quantities of hydrogen and helium.

Question 18

Pluto is in a 2:3 resonance orbit with Neptune.What does this mean?

Accepted Answer

A)  During the time that Neptune orbits the Sun three times, Pluto orbits it twice. 
B)  During the time that Neptune orbits the Sun twice, Pluto orbits it three times. 
C)  Neptune rotates on its axis three times while Pluto rotates twice about its axis. 
D)  Neptune's mean orbital radius is 2/3 of Pluto's mean orbital radius. 
A)  During the time that Neptune orbits the Sun three times, Pluto orbits it twice. 
B)  During the time that Neptune orbits the Sun twice, Pluto orbits it three times. 
C)  Neptune rotates on its axis three times while Pluto rotates twice about its axis. 
D)  Neptune's mean orbital radius is 2/3 of Pluto's mean orbital radius.

Question 19

Viewed from a position above the north pole of the Sun,the direction of the motion of the planets in their orbits is:

Accepted Answer

A)  clockwise. 
B)  counterclockwise. 
C)  clockwise, except for the direction of Venus. 
D)  counterclockwise, except for the direction of Mercury. 
A)  clockwise. 
B)  counterclockwise. 
C)  clockwise, except for the direction of Venus. 
D)  counterclockwise, except for the direction of Mercury.

Question 20

The composition of matter in the universe can be summarized by which statement?

Accepted Answer

A)  All but 2% of the mass of the universe is hydrogen and helium. 
B)  All but 2% of the mass of the universe is hydrogen. 
C)  Two percent of the mass of the universe is hydrogen and helium; the rest is of heavier elements. 
D)  About half of the mass of the universe is in the form of rocks, molecules, and planetary material. 
A)  All but 2% of the mass of the universe is hydrogen and helium. 
B)  All but 2% of the mass of the universe is hydrogen. 
C)  Two percent of the mass of the universe is hydrogen and helium; the rest is of heavier elements. 
D)  About half of the mass of the universe is in the form of rocks, molecules, and planetary material.

What is the Jeans instability?

Suppose that you were to go back in time and explore the solar nebula during the formation of the solar system.If you were to travel outward from the protosun,the first solid material you would encounter would be:

What is the origin of many of the bodies in the Kuiper belt and the Oort comet cloud?

Compared with Jupiter and Saturn,Uranus and Neptune contain proportionally more heavy materials,more ices,and less hydrogen.How do we account for this?

Why did the temperature start to rise at the center of the solar nebula?

The composition of a typical asteroid is:

Which characteristic is NOT typical of our planetary system?

What process had the greatest influence on the features of the Moon during the first billion years of its existence?

In our solar system,which planet is NOT a member of the terrestrial group?

The mass of the solar nebula that began contracting to form the solar system was estimated to be:

Which was the MOST probable time sequence for the formation of the solar system?

A gas and dust cloud will not necessarily collapse because it normally experiences a balance between its internal gas pressure and:

The region at the farthest limits of the solar system in which a large number of objects composed of rock and ice circle the Sun in a roughly spherical region is called the:

The birthplace of the Sun and planets (and of other stars and maybe their planets)is thought to have been in:

Comets are typically:

Which physical parameter more than any other most probably controlled the early evolution of the planetary system and dictated the characteristics of the planets that eventually formed?

The manner in which the large,outer planets formed in our solar system was MOST likely the:

Pluto is in a 2:3 resonance orbit with Neptune.What does this mean?

Viewed from a position above the north pole of the Sun,the direction of the motion of the planets in their orbits is:

The composition of matter in the universe can be summarized by which statement?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Exoplanets

The Terrestrial Planets and Their Moons

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 4: Formation of the Solar System and Other Planetary Systems

What is the Jeans instability?

Suppose that you were to go back in time and explore the solar nebula during the formation of the solar system.If you were to travel outward from the protosun,the first solid material you would encounter would be:

What is the origin of many of the bodies in the Kuiper belt and the Oort comet cloud?

Compared with Jupiter and Saturn,Uranus and Neptune contain proportionally more heavy materials,more ices,and less hydrogen.How do we account for this?

Why did the temperature start to rise at the center of the solar nebula?

The composition of a typical asteroid is:

Which characteristic is NOT typical of our planetary system?

What process had the greatest influence on the features of the Moon during the first billion years of its existence?

In our solar system,which planet is NOT a member of the terrestrial group?

The mass of the solar nebula that began contracting to form the solar system was estimated to be:

Which was the MOST probable time sequence for the formation of the solar system?

A gas and dust cloud will not necessarily collapse because it normally experiences a balance between its internal gas pressure and:

The region at the farthest limits of the solar system in which a large number of objects composed of rock and ice circle the Sun in a roughly spherical region is called the:

The birthplace of the Sun and planets (and of other stars and maybe their planets)is thought to have been in:

Comets are typically:

Which physical parameter more than any other most probably controlled the early evolution of the planetary system and dictated the characteristics of the planets that eventually formed?

The manner in which the large,outer planets formed in our solar system was MOST likely the:

Pluto is in a 2:3 resonance orbit with Neptune.What does this mean?

Viewed from a position above the north pole of the Sun,the direction of the motion of the planets in their orbits is:

The composition of matter in the universe can be summarized by which statement?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Exoplanets

The Terrestrial Planets and Their Moons

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