Deck 6: The Terrestrial Planets and Their Moons

Question 1

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

A) clockwise.
B) counterclockwise.
C) clockwise, except that of Venus.
D) counterclockwise, except that of Mercury.

Answer 1

counterclockwise.

Question 2

Which planet or planetary group occupies the next orbital position beyond Saturn?

A) Neptune
B) Uranus
C) Jupiter
D) asteroid belt

Answer 2

Uranus

Question 3

Which of the following is NOT a unit of density?

A) lb/(yd)³
B) Newton/m³
C) kg/m³
D) slug/(yd)³

Answer 3

Newton/m³

Question 4

A theory of the origin of the solar system must take into account all important general properties of the planets,which include three of the four properties listed.Which one is NOT an important general property of the planets?

A) The planets are grouped by size and composition into three general groups.
B) The magnetic fields of the planets are produced by a variety of mechanisms.
C) The terrestrial planets all orbit much closer to the Sun than do any of the Jovian planets.
D) All the planets orbit the Sun in the same direction and nearly in the same plane.

Question 5

The MOST noticeably elliptical planetary orbit is that of:

A) Mars.
B) Uranus.
C) Mercury.
D) Earth.

Question 6

In our solar system,which planet is a member of the terrestrial group?

A) Neptune
B) Saturn
C) Jupiter
D) Mars

Question 7

The average density of a planet is:

A) its total mass divided by its total volume.
B) the amount of mass in unit volume of the material on its surface.
C) another way of describing its total mass.
D) the mass of a unit volume (1 cubic meter) of the material at its core.

Question 8

The average density of the large,outer planets is:

A) close to the density of water.
B) much higher than the density of Earth rocks, due to the great gravitational compression of their interiors.
C) very much less than the density of water because of the amount of hydrogen they contain.
D) close to the density of basaltic rocks on Earth.

Question 9

Mass is:

A) weight.
B) the force with which an object pushes down on a scale.
C) the pressure on a unit of area.
D) a measure of the number and kind of particles an object possesses.

Question 10

Which one of the following is NOT used to designate a measure of mass?

A) slug
B) pound
C) Newton
D) kilogram

Question 11

The overall shape of the orbits of MOST of the planets in the solar system is:

A) perfectly circular.
B) parabolic.
C) slightly elliptical, but nearly circular.
D) elliptical, very elongated.

Question 12

Suppose the Hubble Space Telescope discovers a series of planets with the following characteristics moving around a star that resembles our Sun: spherical,solid surfaces; mean densities about four times that of water; radii about 4000 km; low-density atmospheres.How would these planets be classified in comparison with our solar system?

A) terrestrial planets
B) Jovian planets
C) cometary nuclei
D) asteroids

Question 13

Compared with the orbital distance of Earth from the Sun,the equivalent orbital distances for the outer planets are _____ times greater.

A) between 2 and 20
B) more than 10
C) between 2 and 5
D) more than 5

Question 14

What are the main characteristics of our solar system?

A) four small planets close to the Sun and four large planets far from the Sun
B) three small planets close to the Sun and five large planets far from the Sun
C) two large planets close to the Sun, three small planets next out, and four large planets farthest from the Sun
D) three small planets close to the Sun, four large planets far from the Sun, and one small planet farthest from the Sun

Question 15

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

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

Question 16

A core of rock and metal seems to be characteristic of:

A) the terrestrial planets only.
B) the Jovian planets only.
C) all the planets, except Jupiter and Saturn.
D) all the planets.

Question 17

MOST of the planets orbit the Sun on or close to the:

A) plane of the Milky Way Galaxy.
B) ecliptic plane.
C) plane containing both north and south celestial poles and the zenith at Greenwich, England.
D) equatorial plane.

Question 18

The CORRECT sequence of planets in our solar system from the Sun outward is:

A) Mercury, Earth, Venus, Mars, Jupiter, Saturn, Uranus, and Neptune.
B) Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
C) Mercury, Venus, Earth, Mars, Saturn, Uranus, Jupiter, and Neptune.
D) Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus, and Neptune.

Question 19

Suppose that observers using the Hubble Space Telescope detect around several solar-type stars the presence of planets with the following characteristics: low density,large size,fluid surfaces,rapid rotation.How would these planets be classified in terms of our solar system?

A) asteroids
B) comet nuclei
C) terrestrial planets
D) Jovian planets

Question 20

The planetary orbit with the GREATEST inclination to the plane of the ecliptic is the orbit of

A) Earth.
B) Mercury.
C) Uranus.
D) Saturn.

Question 21

The planet whose average density is less than that of water is:

A) Neptune.
B) Jupiter.
C) Earth.
D) Saturn.

Question 22

Which statement is TRUE?

A) Earth is the biggest of the planets.
B) Jupiter has the highest average density of the planets.
C) The average mass of terrestrial planets is close to the average mass of the large, outer planets.
D) Earth is the most massive of the terrestrial planets.

Question 23

In order of increasing density,the Jovian planets are:

A) Jupiter, Saturn, Uranus, and Neptune.
B) Saturn, Uranus, Jupiter, and Neptune.
C) Neptune, Saturn, Uranus, and Jupiter.
D) Neptune, Uranus, Saturn, and Jupiter.

Question 24

The average density of which planetary group is close to that of water (1000 kg/m³)?

A) Mercury and Venus because they are close to the Sun
B) terrestrial planets because they are of relatively low mass and have been compressed very little by gravitational forces
C) asteroids because they are very small objects
D) large, outer planets because of their composition-hydrogen and helium

Question 25

The fraction of light reflected by a planet or other object is its:

A) color index.
B) emissivity.
C) apparent magnitude.
D) albedo.

Question 26

The SMALLEST of the terrestrial planets is:

A) Neptune.
B) Mars.
C) Ganymede.
D) Mercury.

Question 27

The LARGEST of the terrestrial planets is:

A) Venus.
B) Earth.
C) Mars.
D) Jupiter.

Question 28

The average density of the outer "giant" planets compared with the density of liquid water is:

A) slightly higher, about 1.2 times.
B) very high, greater than 10 times.
C) much lower.
D) about 5 times higher.

Question 29

Which planet in our solar system has the LARGEST mass?

A) Saturn
B) Earth
C) Uranus
D) Jupiter

Question 30

Earth has an average density of 5500 kg/m³,although the density of rock on its surface is about 3000 kg/m³.What conclusion can be reached about Earth's core from this observation?

A) Earth's core consists of lower-density material than surface rock.
B) Earth's core must be composed of material with density several times that of the surface material.
C) Earth's core must be very hot.
D) Earth's core is made of material far denser than surface rock.

Question 31

The low average density of the large,outer planets,which have high masses and hence high gravitational fields,is an indication of what fact about their interiors?

A) The large, outer planets have hot, gaseous interiors, similar to the interiors of cool stars.
B) The interiors of the large, outer planets are composed of water, methane, and ammonia.
C) The large, outer planets are composed mainly of very light elements, such as hydrogen and helium.
D) The interiors of the large, outer planets have not been condensed to liquid or solid form.

Question 32

The word albedo refers to the:

A) fraction of the surface or atmosphere of a planet that is covered by clouds.
B) ratio of infrared radiation to visible radiation emitted by a planet or other object.
C) amount of light absorbed by a planet or other object.
D) amount of light reflected by a planet or other object.

Question 33

The smallest of the planets is:

A) Venus.
B) Neptune.
C) Mercury.
D) Mars.

Question 34

Which planet in our solar system has the lowest average density?

A) Earth
B) Saturn
C) Uranus
D) Jupiter

Question 35

Which characteristic is NOT typical of our planetary system?

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 36

A curious fact about the structure of the planet Jupiter,compared with the structure of Earth,is that it has:

A) much greater mass and greater average density.
B) about the same mass but much higher density.
C) much greater mass but about the same density.
D) much greater mass but much lower average density.

Question 37

The smallest planet in our solar system is:

A) Mars.
B) Neptune.
C) Mercury.
D) Venus.

Question 38

The large,outer planets have high masses and hence generate powerful gravitational fields,and yet they have low average densities.What does this indicate about their interiors?

A) The interiors are hot and gaseous, like those of cool stars.
B) The interiors are composed mainly of water.
C) The interiors are composed mainly of very light elements, such as hydrogen and helium.
D) The interiors have not condensed to liquid or solid form.

Question 39

The planet with the greatest mean density is:

A) Mercury.
B) Earth.
C) Jupiter.
D) Neptune.

Question 40

Which planet is the LARGEST in our solar system?

A) Uranus
B) Jupiter
C) Earth
D) Saturn

Question 41

Billions of years ago,Earth's atmosphere was composed primarily of carbon dioxide.Where might you go on Earth to find a large fraction of this carbon dioxide today?

A) nowhere, because most of the carbon dioxide has escaped into space
B) anywhere, because most of the carbon dioxide is still in the atmosphere, but nitrogen and oxygen have since been added to it
C) to extinct volcanoes, which are composed of rock from Earth's interior that absorbed the carbon dioxide earlier in Earth's history
D) to mountain ranges such as the Rocky Mountains of North America, which are composed largely of limestone

Question 42

"It has a cool,solid surface with an atmosphere of nitrogen and oxygen and clouds of water vapor." Which of the planets fits this description?

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

Question 43

The albedo of a piece of white paper is about:

A) minus one.
B) zero.
C) one.
D) two.

Question 44

The albedo of a piece of black velvet is about:

A) minus one.
B) zero.
C) one.
D) two.

Question 45

The terrestrial planet whose atmosphere is composed primarily of nitrogen is:

A) Mars.
B) Venus.
C) Jupiter.
D) Earth.

Question 46

What is the ratio of the number of oxygen to nitrogen molecules in Earth's lower atmosphere?

A) 1 oxygen molecule to every 4 nitrogen molecules
B) 4 oxygen molecules to every 1 nitrogen molecule
C) equal numbers of oxygen and nitrogen molecules
D) only 1 oxygen molecule to every 100 nitrogen molecules, or about 1%

Question 47

Which is the MOST abundant gas in Earth's atmosphere?

A) oxygen
B) nitrogen
C) hydrogen
D) carbon dioxide

Question 48

What were the dominant gases in Earth's second atmosphere?

A) nitrogen and oxygen
B) carbon dioxide and nitrogen
C) methane and ammonia
D) hydrogen and helium

Question 49

What is the ratio of nitrogen to oxygen in Earth's atmosphere?

A) 1 part nitrogen to 2 parts oxygen
B) 4 parts nitrogen to 1 part oxygen
C) 1 part nitrogen to 4 parts oxygen
D) equal parts nitrogen and oxygen

Question 50

The major constituents of Earth's atmosphere are:

A) 95% carbon dioxide and some water vapor.
B) about equal amounts of methane, ammonia, water vapor, and carbon dioxide.
C) 77% oxygen and 21% nitrogen.
D) 77% nitrogen and 21% oxygen.

Question 51

Roughly how much denser was Earth's second atmosphere (i.e.,how much gas was there in it?)compared with today's atmosphere?

A) the same density as the present atmosphere
B) 1/10 as dense
C) twice as dense
D) 100 times denser

Question 52

One or more satellites (or moons)orbit which planets?

A) all except the inner two planets and Uranus
B) only Earth, Jupiter, and Saturn
C) only Earth and the four large, outer planets
D) all except the inner two planets

Question 53

Why did Earth's earliest atmosphere,composed primarily of hydrogen and helium,not last long?

A) Hydrogen is highly reactive, and it soon became bound into chemical compounds in Earth's rocks.
B) Hydrogen and helium are light gases, and they soon escaped into space.
C) Biological activity very quickly combined the hydrogen with oxygen to form water.
D) The hydrogen soon became dissolved in Earth's oceans.

Question 54

Which object has the highest albedo?

A) Mercury
B) Venus
C) the Moon
D) Earth

Question 55

What were the dominant gases in Earth's earliest atmosphere after it first formed?

A) methane and ammonia
B) hydrogen and helium
C) nitrogen and oxygen
D) carbon dioxide and nitrogen

Question 56

Which planets do NOT have any natural satellites?

A) Mars and Venus
B) Mercury and Mars
C) Mercury, Venus, and Mars
D) Mercury and Venus

Question 57

The atmosphere that we are now breathing is the _____ atmosphere Earth has had.

A) third
B) second
C) seventh
D) first

Question 58

What happened to the first major atmosphere to develop on the early Earth,which consisted of hydrogen and helium?

A) The molecules reacted chemically with Earth's hot surface and were absorbed into the newly formed rocks.
B) The molecules were quickly absorbed into the ocean since they have high solubility in water.
C) The molecules combined chemically with one another to become molecules that were heavy enough for Earth's gravity to pull into the surface rocks, where they are now found.
D) The atmosphere drifted off into space as Earth's gravity was too weak to hold the light molecules of hydrogen and helium.

Question 59

The albedo of Mercury is about 0.1.This means that:

A) Mercury reflects 9/10 of the sunlight falling on it.
B) 1/10 of Mercury's surface is cloud-covered.
C) Mercury is visible only 1/10 of the time.
D) Mercury reflects 1/10 of the sunlight falling on it.

Question 60

Moons have been discovered around:

A) all the planets.
B) just the terrestrial planets.
C) just the Jovian planets.
D) all the planets, except those nearer to the Sun than Earth is.

Question 61

Which major constituent of the atmospheres of Venus and Mars is present in only very small amounts in Earth's atmosphere?

A) methane, CH₄
B) carbon dioxide, CO₂
C) nitrogen, N₂
D) oxygen, O₂

Question 62

The large amount of free oxygen in Earth's present atmosphere is primarily a result of:

A) out-gassing by volcanoes and other geological processes.
B) biological processes such as photosynthesis.
C) splitting of carbon dioxide into carbon and oxygen by solar ultraviolet light.
D) carbon dioxide becoming dissolved in the oceans, releasing oxygen.

Question 63

Where did the majority of the large amount of carbon dioxide (CO₂)from the second major atmosphere to form on the early Earth end up?

A) as nitrogen oxides and carbon, after chemical reactions with the majority component of the atmosphere, the nitrogen molecules
B) in plant life, where it was transformed into solid carbon and gaseous oxygen
C) dissolved in the oceans and, via the shells of living creatures, in the limestone of many mountain ranges
D) still in the atmosphere, though the quantity of nitrogen and oxygen has since risen to make these constituents the most abundant and relegate carbon dioxide to a minor constituent

Question 64

Photosynthesis in plants on Earth maintains a balance between which of the two atmospheric gases?

A) carbon dioxide and water vapor
B) oxygen and water vapor
C) nitrogen and oxygen
D) oxygen and carbon dioxide

Question 65

In what crucial way is the atmosphere of Earth very different from the atmospheres of Venus and Mars?

A) Earth's atmospheric temperature is relatively cool, whereas both Venus and Mars have very high atmospheric temperatures.
B) Methane (CH₄) gas is present in large quantities on Venus and Mars, but it is only a trace gas on Earth.
C) Hydrogen (H) gas makes up a large fraction of the atmospheres of both Venus and Mars, but it is absent from Earth's atmosphere.
D) Carbon dioxide (CO₂) gas is the dominant component in the atmospheres of Venus and Mars, but it is only a minor constituent in Earth's atmosphere.

Question 66

The molecular oxygen in Earth's present atmosphere was most probably produced:

A) at the formation of Earth and has always been present.
B) from volcanic eruptions as the primitive Earth cooled down.
C) from volcanoes, by out-gassing.
D) by biological activity such as photosynthesis from living things.

Question 67

The presence of oxygen in Earth's atmosphere is thought to result directly from what type of process?

A) volcanic eruptions
B) out-gassing of the oceans
C) original condensation of interplanetary gas clouds
D) biological activity of plants and animals

Question 68

Photosynthesis is a chemical process that takes place in green plants.What is its effect on our atmosphere?

A) Photosynthesis consumes carbon dioxide from our atmosphere but produces carbon dioxide at the end of the process and thus has little effect on our atmosphere.
B) Photosynthesis consumes carbon dioxide from our atmosphere and produces oxygen.
C) Photosynthesis consumes oxygen from our atmosphere and produces carbon dioxide.
D) Photosynthesis consumes both water vapor and carbon dioxide from our atmosphere and produces nitrogen.

Question 69

An "ozone hole" is:

A) a region centered on the equator where ozone levels are always very low because of destruction by direct sunlight.
B) a region of the stratosphere, often above the South Pole, where ozone levels occasionally drop to very low levels.
C) the name given to small pits or holes on the aluminum surface of an aircraft, etched by the corrosive ozone encountered in the stratosphere and requiring regular maintenance.
D) a permanent region of very low ozone content in the stratosphere centered over the south pole that has been there for thousands of years; the resulting transparency to UV radiation accounts for the lack of life-forms there.

Question 70

Earth's atmosphere differs from those of near-neighbor planets Venus and Mars in one important respect:

A) Earth's atmosphere has a much larger fraction of carbon dioxide than has either of the other two atmospheres.
B) The atmospheric temperature at the surface of Earth is much higher than those of the other two planets.
C) Earth's atmosphere has a significant fraction of oxygen.
D) Earth's atmosphere has a higher pressure than have the other two planetary atmospheres.

Question 71

One of the major differences between Earth and its neighboring planets Venus and Mars is the lack of large quantities of carbon dioxide in its atmosphere near the surface of the planet.If all these planets were originally formed with significant quantities of this gas in their atmospheres,where is a significant fraction of this carbon dioxide on Earth at the present time?

A) concentrated high in the atmosphere, where it contributes to the greenhouse effect
B) dissociated by solar UV light into carbon and oxygen, which now exist in abundance as separate chemicals
C) no longer on Earth but lost into space because it is such a light gas
D) dissolved in seawater, a situation that cannot arise on Venus or Mars

Question 72

Which statement about Earth is TRUE?

A) The oxygen in Earth's atmosphere was created by the evaporation of seawater and its dissociation into hydrogen and oxygen by solar UV light.
B) Earth has always had an oxygen-rich atmosphere, which was one reason that life could develop on Earth.
C) Out-gassing by volcanic eruptions converted the carbon-dioxide-rich atmosphere into an oxygen-rich atmosphere, thus creating conditions in which life could develop.
D) Life developed in a carbon-dioxide-rich atmosphere and then converted it into an oxygen-rich atmosphere.

Question 73

What is the MOST significant fact about the oxygen in Earth's atmosphere?

A) Oxygen is the most abundant gas in Earth's atmosphere.
B) Oxygen is very chemically reactive.
C) The oxygen in Earth's atmosphere exists not as pure oxygen, but only in chemical combination with hydrogen in water, carbon in carbon dioxide, and nitrogen in nitrogen oxides.
D) Oxygen is the heaviest molecule in Earth's atmosphere.

Question 74

What are ozone holes?

A) small voids on Earth's ozone layer that occur randomly over the entire planet
B) regions of larger-than-normal ozone concentration that appear over the poles
C) regions of smaller-than-normal ozone concentration that appear over the poles
D) seasonal drops in ozone density scattered around the equator

Question 75

Which process was NOT important in helping to remove carbon dioxide from Earth's early atmosphere?

A) biological activity
B) dissolving of carbon dioxide into the oceans
C) sedimentation of carbon compounds on the ocean floors
D) escape of carbon dioxide into space

Question 76

One of the major differences between Earth and its neighboring planets Venus and Mars is the lack of large quantities of CO₂ in its atmosphere.If all three planets were originally formed with significant quantities of this gas in their atmospheres,where is the majority of this CO₂ on Earth at the present time?

A) dissociated by UV and visible sunlight into carbon and oxygen that now exist in abundance as separate chemicals
B) concentrated low in the atmosphere near Earth's surface, where it contributes to the greenhouse effect
C) locked up in solid form within the polar caps
D) locked up in carbonate and carbon-rich rocks and minerals formed in the sea and on Earth's surface

Question 77

What is the current status of Earth's ozone layer?

A) The ozone layer is being irreversibly depleted and will probably disappear entirely within the next 200 years.
B) The ozone layer has been distorted-too thin at the poles and too thick over the equatorial regions.
C) The ozone layer has been somewhat depleted, but if left alone, it could restore itself in a century.
D) The ozone layer has become too thick and is moving downward toward the surface, where its heating qualities contribute to global warming.

Question 78

In which way are Venus and Mars alike and yet both markedly different from Earth?

A) Venus and Mars are both perpetually shrouded in clouds.
B) Venus and Mars both have either active or extinct volcanoes on their surface.
C) The atmospheres of Venus and Mars are both made up primarily of carbon dioxide.
D) The surface temperatures of Venus and Mars are both much higher than that of Earth.

Question 79

Billions of years ago,Earth's atmosphere was composed primarily of carbon dioxide.What happened to much of this carbon dioxide?

A) It is still in the atmosphere.
B) It dissolved into Earth's oceans.
C) It was broken down into carbon and oxygen by solar ultraviolet light.
D) It was lost to space.

Question 80

Ozone in the stratosphere performs an important task that protects life on Earth.What is it?

A) Ozone absorbs the solar wind as it streams into Earth, thereby protecting life from dangerous ionizing radiation.
B) Ozone absorbs much of the dangerous solar ultraviolet light.
C) Ozone acts as a disinfectant, killing dangerous viruses and bacteria that drift in all the time from space before they can reach Earth.
D) Ozone absorbs infrared radiation, thereby providing a comfortable atmospheric temperature on the surface of Earth.