Deck 12: Dwarf Planets and Small Solar System Bodies

Question 1

Pluto is the most massive member of the Kuiper Belt.

Answer 1

False

Question 2

Although asteroids are small individually, when combined they make up about a quarter of all the mass in the Solar System, excluding the Sun.

Answer 2

False

Question 3

Pluto is classified as a dwarf planet because:

A) it has not cleared out other bodies from its orbit
B) it is over 1,000 times smaller than the Earth's moon
C) it has no moons of its own
D) it has a unique chemical composition that is very different from other planets
E) it orbits just outside the Solar System

Answer 3

it has not cleared out other bodies from its orbit

Question 4

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

Question 5

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

Question 6

Eris is classified as an asteroid even though its mass is 28 percent larger than Pluto's mass.

Question 7

Some asteroids have moons just like planets do.

Question 8

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

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

Question 9

The dwarf planet Eris has a moon called Dysomia, which is much smaller in mass than Eris. If Dysomia has an orbital period of 16 days and orbits Eris at a distance of 40,000 km, then what is the mass of Eris?

A) 2 * 10¹³ kg
B) 2 *10²² kg
C) 2 * 10²⁸ kg
D) 2 *10³² kg
E) 2 * 10³⁵ kg

Question 10

Eris, Ceres, and Haumea are examples of:

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

Question 11

Pluto is composed primarily of rock.

Question 12

Most asteroids are found in orbit around the Sun between the orbits of Jupiter and Saturn.

Question 13

The mass of Pluto is approximately 100 times less than that of Earth.

Question 14

Astronomers can use the speed and direction of a cometary meteor's flight to identify its parent comet.

Question 15

Which of the following types of Solar System debris were NOT discovered until the age of telescopes?

A) comets
B) meteoroids
C) zodiacal dust
D) asteroids
E) all of the above

Question 16

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

Question 17

Which of following is FALSE?

A) Pluto has five moons.
B) Pluto has a mass that is 10 times less than the Earth's mass.
C) Pluto's orbit sometimes brings it closer to the Sun than Neptune.
D) Pluto was discovered by Clyde Tombaugh in 1930.
E) Pluto has a thin atmosphere.

Question 18

Cometary nuclei provide evidence that the ingredients necessary for the creation of life were present in the early solar nebula.

Question 19

Meteorites are more likely to come from asteroids than comets.

Question 20

The most common type of meteorites found are iron meteorites.

Question 21

Which group of asteroids regularly crosses Earth's orbit and thus might possibly collide with our planet?

A) the Amors
B) the Atens
C) the Kuiper Belt objects
D) the Trojans
E) all of the above

Question 22

Identify the object in the picture below.

A) an active comet
B) a meteor shower
C) a meteorite
D) an asteroid
E) zodiacal dust

Question 23

Suppose we discover a comet whose orbit was very highly eccentric, retrograde, had a very large tilt with respect to the ecliptic plane, and a period of 2,000 years. Where is the most likely place of origin for this comet?

A) the Kuiper Belt
B) the Oort Cloud
C) the asteroid belt
D) the Jovian family
E) outside the Solar System

Question 24

A comet having an orbit of 50 years would likely have come from the:

A) Atens family
B) Oort Cloud
C) Trojan family
D) zodiacal zone
E) Kuiper Belt

Question 25

Most asteroids are located between the orbits of:

A) Earth and Mars
B) Mars and Jupiter
C) Jupiter and Saturn
D) Neptune and Pluto
E) the Kuiper Belt and the Oort Cloud

Question 26

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

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 27

The most straightforward way to determine the mass of an asteroid is if it has:

A) a rocky composition
B) a moon
C) an orbit that lies between the Earth and Mars
D) carbonaceous chondrites
E) a magnetic field

Question 28

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

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) one-third the mass of the Moon

Question 29

Asteroids are primarily composed of:

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

Question 30

Most comets originate:

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 31

Most asteroids are:

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)

Question 32

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

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

Question 33

Which of the following does NOT describe comets in the Oort Cloud?

A) long period
B) pristine condition
C) cold temperatures
D) randomly directed orbits
E) flattened distribution

Question 34

The darkest asteroids are:

A) M-type
B) S-type
C) C-type
D) A-type
E) Q-type

Question 35

Carbonaceous chondrite meteorites are fragments of which type of asteroid?

A) A-type
B) C-type
C) M-type
D) Q-type
E) S-type

Question 36

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

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

Question 37

Until spacecraft flew by asteroids, scientists did not have a good idea of what they looked like. Which of the following missions was the first to fly by an asteroid?

A) NEAR Shoemaker
B) Rosetta
C) Galileo
D) Dawn
E) Stardust

Question 38

Iron meteorites are fragments of which type of asteroid?

A) A-type
B) C-type
C) M-type
D) Q-type
E) S-type

Question 39

Most asteroids are closest in shape to:

A) a potato
B) a banana
C) a hot dog
D) a stick
E) a baseball

Question 40

Remnants of volcanic activity on the asteroid Vesta indicate that members of the asteroid belt:

A) were once part of a single protoplanet that was shattered by collisions
B) have all undergone significant chemical evolution since formation
C) occasionally grow large enough to become differentiated and geologically active
D) were once a part of a young Mars
E) used to be volcanic moons orbiting other planets

Question 41

In 1994, dozens of fragments of Comet Shoemaker-Levy 9 collided with:

A) Jupiter
B) the Earth
C) Neptune
D) the Moon
E) Saturn

Question 42

With a semimajor axis of 18 AU, Comet Halley has a period of:

A) 7 years
B) 16 years
C) 32 years
D) 67 years
E) 76 years

Question 43

Identify the object in the picture below.

A) an active comet
B) a meteor shower
C) a meteorite
D) an asteroid
E) zodiacal dust

Question 44

The minimum size of a meteoroid that is capable of surviving its passage through the Earth's atmosphere and hitting the ground is about as big as:

A) a car
B) a house
C) a basketball
D) a grain of sand
E) your fist

Question 45

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

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

Question 46

A large meteor shower will often occur once a year because:

A) Earth typically has one large volcanic eruption every year
B) the Earth's orbit passes through the Apollo asteroid belt
C) the Sun goes through a yearly solar cycle
D) Jupiter routinely disturbs the orbits of asteroids in the Jovian belt
E) the Earth passes through the debris left behind by a specific comet

Question 47

Antarctica is the best hunting ground for meteorites for all of the following reasons EXCEPT:

A) the ground is covered with ice
B) more meteorites fall there than on other locations on Earth
C) few native rocks are found on the glaciers
D) meteorites are protected from weathering and contamination there
E) by searching at different depths in the ice you can determine the history of impacts over time

Question 48

When a comet comes close to the Sun, its volatile ice sublimates and transforms directly from the solid to _________ phase.

A) liquid
B) crystalline
C) energized
D) gas
E) ionized

Question 49

The Perseid meteor shower will occur:

A) every month
B) every year
C) every 4 years
D) every 76 years
E) every 132 years

Question 50

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

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

Question 51

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

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

Question 52

A recent estimate finds that approximately 800 meteorites with mass greater than 0.1 kg strike the surface of the Earth each day. If a house covers an area of roughly 100 m², then what is the probability that your house will be struck by a meteorite in your 100-year lifetime? Note that the radius of the Earth is 6,400 km.

A) 1 in 1 *10⁴
B) 1 in 2 *10⁵
C) 1 in 4* 10⁶
D) 1 in 6 *10⁷
E) 1 in 8 * 10⁸

Question 53

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

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

Question 54

Comet Halley is unique because:

A) it was the first comet whose return was predicted
B) it is a member of the Jovian family, but has a retrograde orbit
C) its period is less than a human lifetime
D) it was successfully visited by a spacecraft
E) it was the brightest comet ever observed by humans

Question 55

Consider a meteoroid with a diameter of 10 cm and a mass of 2 kg that hits the Earth head-on while traveling at a speed of 25,000 m/s. How many times larger or smaller is the meteoroid's kinetic energy compared to that of a typical train whose mass is 2 * 10⁶ kg and speed is 25 m/s?

A) The meteoroid's kinetic energy is equal to that of the train.
B) The meteoroid's kinetic energy is 1,000 times less than that of the train.
C) The meteoroid's kinetic energy is 1,000 times greater than that of the train.
D) The meteoroid's kinetic energy is 10⁶ times greater than that of the train.
E) The meteoroid's kinetic energy is 10⁹ times greater than that of the train.

Question 56

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

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 57

Why does the dust tail separate from the ion tail?

A) The dust is not ionized, so it is not affected by the solar wind.
B) Dust cannot sublimate as ice can, so it cannot form a tail as easily.
C) The dust tail forms on the leading side of the nucleus, whereas the gas tail forms on the opposite side.
D) Dust particles are more massive than ions, so their accelerations are less.
E) The dust tail has the opposite charge as the ion tail.

Question 58

The nuclei of a comet is mostly:

A) solid ice
B) solid rock
C) liquid water
D) a porous mix of ice and dust
E) frozen carbon dioxide

Question 59

Meteor showers appear as if they are coming from one particular place in the sky because:

A) that is the direction in which the comet is coming toward us
B) that is the direction in which the comet is moving away from us
C) that is the direction toward which Earth is traveling
D) that is the direction Earth just passed
E) that is the location in the sky from which the meteors originate

Question 60

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

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

Question 61

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?

Question 62

Which of the following likely helps replenish the zodiacal dust in the vicinity of Earth the most?

A) comets
B) asteroids
C) the Moon
D) volcanoes on Earth
E) tornados on Earth

Question 63

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

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

Question 64

Do icy cometary nuclei melt and move from solid to liquid phase as they are warmed by the radiation from the Sun?

Question 65

Identify the object in the picture below.

A) a meteor
B) a chondrite meteorite
C) an achondrite meteorite
D) an iron meteorite
E) an asteroid

Question 66

The most common type of meteorites are:

A) stony meteorites
B) iron meteorites
C) achondrite meteorites
D) stony-iron meteorites
E) carbonaceous chondrite meteorites

Question 67

Meteorites contain clues to all of the following EXCEPT:

A) the age of the Solar System
B) the temperature in the early solar nebula
C) changes in the rate of cratering in the early Solar System
D) the composition of the primitive Solar System
E) the physical processes that controlled the formation of the Solar System

Question 68

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?

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 69

Identify the object in the picture below.

A) an active comet
B) a meteor shower
C) a meteorite
D) an asteroid
E) zodiacal dust

Question 70

How is it possible for the tail of a comet to actually move ahead of the comet itself?

Question 71

Assume the larger circle shown below is the Sun, and the smaller circle is the head of a comet. If the comet is moving AWAY from the Sun, draw and label the two tails onto the comet.

Question 72

Comets have highly eccentric orbits, with eccentricities of 0.95-0.99 being common. Suppose a certain comet has an eccentricity of 0.99. If the semimajor axis of its orbit is 2,500 AU, what will be its distance at perihelion and at aphelion? Is this most likely a Kuiper Belt object or an Oort Cloud comet? (Note: For an ellipse, a(1+e) is the distance from one focus to the farther edge of the long axis and a(1 - e) is the distance from the same focus to the closer edge of the long axis.)

Question 73

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

Question 74

Name three properties of the dwarf planets Pluto and Eris that are similar.

Question 75

Which group of meteorites represents the conditions in the earliest stages of the formation of the Solar System?

A) chondrites
B) achondrites
C) icy meteorites
D) iron meteorites
E) stony-iron meteorites

Question 76

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

Question 77

Give examples of a C-type asteroid and an S-type asteroid that have been observed by spacecraft. What did we learn about each type?

Question 78

In its 1986 trip around the Sun, it was estimated that Comet Halley lost approximately 100 billion kg of material. The total mass of the nucleus was estimated to be 3*10¹⁴ kg. Assuming the mass loss rate is constant with each passage, and assuming the nucleus remains intact until there is nothing left, how many more times will we see Comet Halley? Explain why your answer is an upper limit.

Question 79

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

Question 80

In the early universe, 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?

A) comets
B) asteroids
C) a Mars-sized protoplanet
D) a rogue moon
E) none, because water is not a major component of any of the objects above