Deck 12: Dwarf Planets and Small Solar System Bodies

Question 1

Pluto is the largest member of the Kuiper Belt.

Answer 1

False

Question 2

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

Answer 2

False

Question 3

Although asteroids are small individually,when combined they make up a significant fraction of the total mass of the planets.

Answer 3

False

Question 4

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

Question 5

All short period comets have period < 20 years.

Question 6

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

Question 7

The surface of the dwarf planet Eris has very high albedo and is covered with

A) methane ice.
B) water ice.
C) surfur dioxide.
D) frozen carbon dioxide.

Question 8

Meteorites are more likely to come from asteroids than comets.

Question 9

The average density of a comet is approximately one-quarter times the density of water.

Question 10

Pluto is composed mostly of rock.

Question 11

Which of following is FALSE?

A) Pluto has three moons.
B) Pluto has a mass that is 1/10 times 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.

Question 12

Some asteroids have moons just as planets do.

Question 13

Eris and Ceres are examples of

A) asteroids.
B) dwarf planets.
C) comets.
D) meteor showers.

Question 14

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

A) Comets
B) Meteorites
C) Asteroids
D) All of the above

Question 15

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

Question 16

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

Question 17

The most common type of meteorites found are iron meteorites.

Question 18

Pluto has a density that is roughly equal to that of

A) a feather.
B) water.
C) a rock.
D) a hammer.

Question 19

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

Question 20

The mass of Pluto is approximately 1 percent times the mass of the Earth.

Question 21

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

A) the ground is covered with ice in Antarctica.
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.

Question 22

The darkest asteroids are

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

Question 23

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

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

Question 24

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.

Question 25

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)
B)
C)
D)

Question 26

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

A) Long period
B) Pristine condition
C) Randomly directed orbits
D) Flattened distribution

Question 27

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) gas
D) ionized

Question 28

Most asteroids are closest in shape to

A) a potato.
B) an orange.
C) a stick.
D) a baseball.

Question 29

The mass of all the known asteroids combined would be as much as

A) half the mass of Earth.
B) three times the mass of Earth.
C) the mass of Mars.
D) one-third the mass of the Moon.

Question 30

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

A) Chondrites
B) Achondrites
C) Iron meteorites
D) Stony-iron meteorites

Question 31

Which of the following is the BRIGHTEST part of a comet?

A) Its nucleus
B) Its coma
C) Its ion tail
D) Its dust tail

Question 32

Which group of asteroids regularly crosses Earth's orbit and thus represents a known collision threat to our planet?

A) The Amors
B) The Atens
C) The Trojans
D) All of the above

Question 33

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.

Question 34

Most asteroids are

A) very large .
B) large .
C) medium .
D) small .

Question 35

What must an asteroid have in order for us to determine its mass?

A) A rocky composition
B) A moon
C) An orbit that lies between the Earth and Mars
D) Carbonaceous chondrites

Question 36

Comet Halley has a period of

A) 7 years.
B) 16 years.
C) 32 years.
D) 76 years.

Question 37

Cometary nuclei are most likely

A) solid ice.
B) rocky.
C) porous.
D) uniform.

Question 38

The most common type of meteorites are

A) stony meteorites.
B) iron meteorites.
C) stony-iron meteorites.
D) carbonaceous chondrite meteorites.

Question 39

Which group of meteoroids is more likely to have compositions indicative of those in the early Solar System?

A) Asteroidal meteoroids
B) Cometary meteoroids
C) Both groups are equally likely
D) Neither group: All meteoroids have undergone significant chemical evolution

Question 40

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.

Question 41

The meteoroids in the Orionid meteor shower,which occurs every October,come from

A) dust in the star-forming Orion nebula.
B) dust melted off Comet Halley.
C) debris from the collision of Comet Shoemaker-Levy 9.
D) zodiacal dust.

Question 42

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

Question 43

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.

Question 44

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 is more massive than ions,so it accelerates less.

Question 45

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 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 times greater than that of the train.

Question 46

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 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
B) 1 in
C) 1 in
D) 1 in

Question 47

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 grain of sand.
D) your fist.

Question 48

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

Question 49

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

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

Question 50

You find a blackened rock lying on top of the snow.You find that it is fairly dense and suspect it might be a meteorite.You take it to a lab,and they find that its age is 1.3 Gyr.Is this a meteorite? Why,or why not?

Question 51

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

Question 52

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.

Question 53

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 Jovian family
D) Outside the Solar System

Question 54

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 55

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

A) mostly prograde orbits.
B) orbits with completely random tilts.
C) orbital periods longer than any planet.
D) highly eccentric orbits.

Question 56

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

Question 57

Give the definitions of meteoroid,meteor,and meteorite,and clearly explain how they differ.

Question 58

The Perseid meteor shower will occur

A) every month.
B) every year.
C) every 4 years.
D) every 76 years.

Question 59

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

A) Jupiter.
B) the Earth.
C) the Moon.
D) Saturn.

Question 60

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

A) Trojan family.
B) Oort Cloud.
C) Zodiacal zone.
D) Kuiper Belt.

Question 61

Why does a comet usually have two tails,one which is straight and one that is curved? What materials compose each tail and why do they have different shapes?

Question 62

Consider a small comet nucleus,whose diameter is 1 km and mass is ,hitting the Earth head-on,traveling at a speed of 1,000 m/s.How many times larger or smaller is the comet's kinetic energy compared to that of a typical train pulling 20 boxcars whose total mass is and speed is 25 m/s?

Question 63

Comets have highly eccentric orbits,with eccentricities of 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, is the distance from one focus to the farther edge of the long axis and is the distance from the same focus to the closer edge of the long axis.]

Question 64

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 65

Let's say that you discovered a comet in the outer Solar System that had an average albedo of 0.6.If its surface was composed of a mixture of organic substances,which had an albedo of 0,and ice,which had an albedo of 1.0,then what percent of its surface is covered by organic substances?

Question 66

If you can model the mass in Comet Halley as a sphere 5 km in radius,what is its density if it contains of mass? How does that density compare to that of water ?

Question 67

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

Question 68

Describe two modern-day events when comets or asteroids collided with a planet.Cite the planet,give the approximate year when the collision occurred,and describe the major consequences of the collision.

Question 69

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 .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.