Question 1

Comet nuclei, absent their tails, are very dark because:

Accepted Answer

A)  they are made of water ice 
B)  they have iron and nickel mixed with ice 
C)  they have organic molecules mixed with ice 
D)  they are covered in rock 
E)  they are too cold to emit any light 
A)  they are made of water ice 
B)  they have iron and nickel mixed with ice 
C)  they have organic molecules mixed with ice 
D)  they are covered in rock 
E)  they are too cold to emit any light C

Question 2

Approximately how often does a spectacularly active, visible comet appear?

Accepted Answer

A)  once a year 
B)  once every 5 years 
C)  once every 10 years 
D)  once every 50 years 
E)  once every 1,000 years 
A)  once a year 
B)  once every 5 years 
C)  once every 10 years 
D)  once every 50 years 
E)  once every 1,000 years C

Question 3

Most asteroids are:

Accepted Answer

A)  very large ($\gt$ 100 km) 
B)  large (30-100 km) 
C)  medium (10-30 km) 
D)  small (1-10 km) 
E)  very small ($\lt$ 1 km) 
A)  very large ($\gt$ 100 km) 
B)  large (30-100 km) 
C)  medium (10-30 km) 
D)  small (1-10 km) 
E)  very small ($\lt$ 1 km) D

Question 4

Consider three comets that have orbital periods of 10, 100, and 1,000 years. Where would each of these comets likely originate, in the Oort Cloud or the Kuiper Belt? If you wanted to study material that was the best example of pristine Solar System material, which would you study?

Accepted Answer

For all objects, including comets, that

Question 5

All short-period comets have periods less than or equal to 20 years.

Accepted Answer

A) True 
 B)False

Question 6

All meteorites are remnants of planetesimals that never coalesced to form a planet.

Accepted Answer

A) True 
 B)False

Question 7

Asteroids are primarily composed of:

Accepted Answer

A)  hydrogen and helium 
B)  ice and dust 
C)  rock 
D)  iron 
E)  methane 
A)  hydrogen and helium 
B)  ice and dust 
C)  rock 
D)  iron 
E)  methane

Question 8

Like meteoroids and asteroids, cometary nuclei in the Oort Cloud undergo frequent collisions that often send them into the inner Solar System.

Accepted Answer

A) True 
 B)False

Question 9

Most comets originate:

Accepted Answer

A)  near Earth and Venus in the early Solar System 
B)  far from the planets, many thousands of AU from the Sun 
C)  from the region between the orbits of Jupiter and Neptune 
D)  between the Sun and Mercury 
E)  between the orbits of Mars and Jupiter 
A)  near Earth and Venus in the early Solar System 
B)  far from the planets, many thousands of AU from the Sun 
C)  from the region between the orbits of Jupiter and Neptune 
D)  between the Sun and Mercury 
E)  between the orbits of Mars and Jupiter

Question 10

Some asteroids have moons just like planets do.

Accepted Answer

A) True 
 B)False

Question 11

In November 2005, the Japanese spacecraft Hayabusa brought back sample from which type of object for the first time?

Accepted Answer

A)  comet 
B)  asteroid 
C)  moon 
D)  terrestrial planet 
E)  gas giant planet 
A)  comet 
B)  asteroid 
C)  moon 
D)  terrestrial planet 
E)  gas giant planet

Question 12

Looking at the figure below, identify the two tails.

Accepted Answer

The top tail is pointing directly away f

Question 13

The nucleus of the typical comet is approximately _________ in size.

Accepted Answer

A)  10 km 
B)  1,000 km 
C)  100 m 
D)  10 m 
E)  1 cm 
A)  10 km 
B)  1,000 km 
C)  100 m 
D)  10 m 
E)  1 cm

Question 14

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 15

Pluto is the most massive member of the Kuiper Belt.

Accepted Answer

A) True 
 B)False

Question 16

Pluto has a density that is roughly equal to two times that of:

Accepted Answer

A)  a feather 
B)  water 
C)  lead 
D)  a rock 
E)  air 
A)  a feather 
B)  water 
C)  lead 
D)  a rock 
E)  air

Question 17

Which of the following comets has NOT been visited by spacecraft?

Accepted Answer

A)  Halley 
B)  Wild 2 
C)  Tempel 1 
D)  Hartley 2 
E)  Shoemaker-Levy 9 
A)  Halley 
B)  Wild 2 
C)  Tempel 1 
D)  Hartley 2 
E)  Shoemaker-Levy 9

Question 18

The meteoroids in the Leonids meteor shower, which occurs every November, come from:

Accepted Answer

A)  dust in the star-forming Leo nebula 
B)  dust melted off Comet Tempel-Tuttle 
C)  debris from the collision of Comet Shoemaker-Levy 9 
D)  zodiacal dust 
E)  dust blown off of Earth's surface 
A)  dust in the star-forming Leo nebula 
B)  dust melted off Comet Tempel-Tuttle 
C)  debris from the collision of Comet Shoemaker-Levy 9 
D)  zodiacal dust 
E)  dust blown off of Earth's surface

Question 19

While most meteorites have ages around 4.5 billion years, a small subset have 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 the 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 the 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 20

Meteorites are more likely to come from asteroids than comets.

Accepted Answer

A) True 
 B)False

Exam 12: Dwarf Planets and Small Solar System Bodies

Comet nuclei, absent their tails, are very dark because:

Approximately how often does a spectacularly active, visible comet appear?

Most asteroids are:

Consider three comets that have orbital periods of 10, 100, and 1,000 years. Where would each of these comets likely originate, in the Oort Cloud or the Kuiper Belt? If you wanted to study material that was the best example of pristine Solar System material, which would you study?

All short-period comets have periods less than or equal to 20 years.

All meteorites are remnants of planetesimals that never coalesced to form a planet.

Asteroids are primarily composed of:

Like meteoroids and asteroids, cometary nuclei in the Oort Cloud undergo frequent collisions that often send them into the inner Solar System.

Most comets originate:

Some asteroids have moons just like planets do.

In November 2005, the Japanese spacecraft Hayabusa brought back sample from which type of object for the first time?

Looking at the figure below, identify the two tails.

The nucleus of the typical comet is approximately _________ in size.

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

Pluto is the most massive member of the Kuiper Belt.

Pluto has a density that is roughly equal to two times that of:

Which of the following comets has NOT been visited by spacecraft?

The meteoroids in the Leonids meteor shower, which occurs every November, come from:

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

Meteorites are more likely to come from asteroids than comets.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

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