Deck 9: Small Bodies of the Solar System

Question 1

How can moons be more geologically active than planets?

A) Some moons have magnetic fields that are stronger than planets.
B) Some moons have a faster rotation rate than some planets.
C) The tidal stresses experienced by some moons can heat the interior.
D) Moons that are denser than the planets they orbit attract more colliding objects.

Answer 1

The tidal stresses experienced by some moons can heat the interior.

Question 2

What is the most common geological feature seen on moons?

A) craters
B) volcanoes
C) palimpsests
D) geysers

Answer 2

craters

Question 3

What are the possible geological states of a moon?

A) active today and active in the past
B) possibly active today
C) never active
D) active today; possibly active today; active in the past; never active.

Answer 3

active today and active in the past

Question 4

Where does Titan's thick,nitrogen-rich atmosphere (see the image below)come from?

A) photodissociation of methane in its atmosphere
B) frequent volcanic eruptions
C) cometary impacts over the age of the Solar System
D) photosynthesis of algae in oceans that lie beneath its icy surface

Question 5

What might cause a moon to be geologically active while its planet is not?

A) The moon may contain more magnetic material than the planet.
B) The moon's rotation is tidally locked to the planet.
C) Heating of the moon by its planet's heat of formation.
D) The moon orbital distance from the planet and/or other moons may cause tidal stresses that can heat its interior.

Question 6

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

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

Question 7

The varied colors found on Io's surface are due to the presence of various molecules containing:

A) sulfur.
B) silicon.
C) mercury.
D) magnesium.

Question 8

Which object has turned itself inside out numerous times,leading to lighter elements escaping,sulfur compounds composing the crust,and heavier elements making up the core?

A) Mercury
B) Titan
C) Pluto
D) Io

Question 9

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 Earth and Mars
D) carbonaceous chondrites

Question 10

Which of following is FALSE?

A) Pluto has five moons.
B) Pluto has a mass that is one-tenth of Earth's mass.
C) Pluto's orbit sometimes brings it closer to the Sun than to Neptune.
D) Pluto has a rocky core surrounded by a water-ice mantle.

Question 11

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 12

Which of the following can be used as an indicator of the age of a moon's surface?

A) surface brightness
B) crater density
C) volcanic activity
D) all of the above

Question 13

Which of the following moons is thought to have a vast ocean of water beneath its thin frozen surface?

A) Titan
B) Europa
C) Io
D) Callisto

Question 14

Which property of a moon might lead you to hypothesize it was a captured asteroid?

A) It is tidally locked.
B) Its orbital axis is tilted by 10° compared to the planet's rotational axis.
C) It rotates clockwise around the planet when viewed from the planet's north pole.
D) Its surface is very smooth and lacks craters.

Question 15

Titan's thick atmosphere (see the image below)is hypothesized to have been created when ultraviolet photons broke apart methane molecules,ultimately creating the observed smog-like conditions.This process,though,would likely remove all of the atmospheric methane in roughly 10 million years,yet we still see its presence today.How can this be?

A) Cometary impacts periodically bring new methane to Titan.
B) Ethane rains down out of the atmosphere, combines with surface rocks, and creates new methane.
C) Infrared photons give atmospheric molecules enough energy to recombine into methane.
D) Volcanoes on Titan periodically release new methane into the atmosphere.

Question 16

Most asteroids are closest in shape to:

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

Question 17

How do particles from Enceladus wind up in Saturn's E Ring?

A) Volcanoes erupt and expel silicates into space.
B) Water geysers erupt from the surface and expel particles into space.
C) Cosmic rays bombard the surface rock on Enceladus and expel particles into space.
D) A collision with a co-orbiting moon knocked rocky debris into orbit around Saturn.

Question 18

Eris and Ceres are examples of:

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

Question 19

Which moon gives rise to the particles that make up Saturn's E Ring?

A) Titan
B) Triton
C) Enceladus
D) Tethys

Question 20

Which of the following is NOT geologically active?

A) Callisto
B) Triton
C) Enceladus
D) Io

Question 21

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 22

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 23

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 24

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

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

Question 25

The most common type of meteorite is:

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

Question 26

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 27

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 28

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 29

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

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

Question 30

The likely source of comets that mostly have orbits of extreme tilt with respect to the ecliptic is:

A) the Kuiper Belt.
B) the Oort Cloud.
C) the asteroid belt.
D) the rings of Saturn.

Question 31

The minimum size of a meteoroid that is capable of surviving its passage through 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 32

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 that of any planet.
D) highly eccentric orbits.

Question 33

The type of meteorites most likely to have originated from the outer layers of differentiated planetesimals come from

A) comets.
B) C-type asteroids.
C) M-type asteroids.
D) S-type asteroids.

Question 34

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 35

Most comets originate:

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

Question 36

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 giant planet family
D) outside the Solar System

Question 37

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 38

The radiant of a meteor shower is:

A) the apparent vanishing point of the parallel orbital paths of meteoroids.
B) the location at which a meteor explodes in the atmosphere.
C) the radius of a meteoroid's orbit around the sun.
D) the radius of a meteoroid's orbit around the Earth.

Question 39

Cometary nuclei are most likely:

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

Question 40

The chronological description of an asteroidal fragment that falls to Earth would be:

A) meteor, meteorite, meteoroid.
B) meteorite, meteoroid, meteor.
C) meteoroid, meteor, meteorite.
D) meteor, meteoroid, meteorite.

Question 41

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

Question 42

Examine the figure below.How is it possible for the tails of a comet to move ahead of the comet itself?

Question 43

What are the two basic materials of which the moons in the Solar System are composed? For each type of material,name an example of a moon whose surface is composed primarily of that material.

Question 44

Two moons are observed to each have a large amount of cratering over their surfaces.However,one of the moons has portions of its surface that are darker than other portions.What might this suggest regarding the state of geologic activity of these moons?

Question 45

What material has been seen erupting from the surface (see the image below)of the icy moon Enceladus,and why?

Question 46

Phobos and Deimos,the two moons of Mars,are thought to have a unique origin.What is it?

Question 47

Why is Io,a moon that is smaller and farther from the Sun than our own Moon,still geologically active?

Question 48

Ganymede is one of the largest moons in the Solar System.It shows some terrain that is ancient and heavily cratered,younger terrain with less craters,but no terrain that is free of craters.Why would Ganymede's geological activity stop?

Question 49

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 50

Europa is a very interesting moon that NASA is considering visiting with a spacecraft in order to search for signs of life.What is it about this moon that makes it so interesting,and what surface features give us clues about its interior?

Question 51

If ultraviolet photons destroy methane,why does Titan have so much of it in its atmosphere?

Question 52

In the figure below,label each portion of the comet.

Question 53

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 54

The darkest asteroids are:

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

Question 55

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

Question 56

Why is the asteroid Ceres classified as a dwarf planet?

Question 57

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 58

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

Question 59

Why has planet formation essentially stopped in the solar system?

Question 60

Why are cometary dust tails curved along the orbit of a comet?

Question 61

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

Question 62

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 63

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

Question 64

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.