Geology of Planets 109 Exam 1

The inner planets

A. Have about the same composition as the outer planets

B. Have about the same size as the outer planets

C. All have orbiting systems of rings

D. All have several moons

E. None of the above

E. None of the Above

Which statement is true for the outer planets of our solar system?

A. They produce enough internal energy to glow like the Sun.

B. They are largely made of hydrogen and helium.

C. They have solid surfaces just below a layer of clouds.

D. They lack systems of rings.

B. They are largely made of hydrogen and helium.

Water ice

A. is most abundant on the planets of the inner solar system

B. is most abundant on the moons of the outer planets

C. is unstable in the outer solar solar system because of the low pressure that exists there

D. is rare in the solar system

B. is most abundant on the moons of the outer planets

Which objects have orbits that take them the farthest from the Sun in our solar system?

A. Comets

B. Asteroids

C. Pluto and its moon Charon

D. Galilean satellites

A. Comets

What is a major difference between a moon and a planet?

A. Planets revolve around the Sun.

B. Moons do not have atmospheres.

C. Moons are smaller than any of the planets.

D. Except for Earth's moon, all other moons orbit the Sun between Mars and Jupiter.

A. Planets revolve around the Sun.

What is a major difference between planets and stars?

A. Planets are much smaller in diameter than the stars around which they revolve.

B. Planets do not generate energy through nuclear fusion.

C. Planets do not have systems of smaller bodies in orbits around them like many stars do.

D. Planets have solid surfaces, and stars do not.

B. Planets do not generate energy through nuclear fusion.

Which of the following is NOT a characteristic of the asteroid belt?

A. It consists of thousands of small bodies, all less than about 10 km in diameter.

B. The asteroids all occur inward toward the sun from Mercury.

C. Some asteroids appear to be rocky; some seem covered with lava; others seem to be metallic; and yet others may have water ice.

D. Many meteorites that fall on Earth come from the asteroid belt.

B. The asteroids all occur inward toward the sun from Mercury.

According to our best modern day evidence, how long ago was the Big Bang?

A. Too far back for us to have any idea.

B. About 14 billion years ago.

C. About 4.5 billion years ago.

D. About 65 million years ago.

B. About 14 billion years ago.

How are elements heavier than iron produced?

A. As the heaviest elements decay by radioactivity.

B. During a supernova explosion

C. By gravitational collapse of a star.

D. During the formation of a planetary nebula.

B. During a supernova explosion

What is the principal method of light element (up to Iron, atomic number 26) production?

A. radioactive decay of heavy elements

B. nuclear fusion

C. gravitational collapse

D. isotope reactivation

B. nuclear fusion

Supernovas are the result of

A. the explosive removal of a star's outer layers as hydrogen burning reaches a star's outer surface

B. collapse of a star with multiple burning shells

C. massive collisions of stars from the same nebula

D. carbon-burning

B. collapse of a star with multiple burning shells

How will the Sun's life probably end?

A. With the development of a black hole.

B. By a supernova explosion.

C. By passage through a T-Tauri stage.

D. With the formation of a planetary nebula.

D. With the formation of a planetary nebula.

Which of the following is NOT correct about the nebulas we see in the sky today?

A. They formed during the "Big Bang."

B. They are concentrations of interstellar gas and dust.

C. Many are the birth grounds of stars.

D. Some form when stars explode.

A. They formed during the "Big Bang."

Condensation in the solar nebula and accretion of planets is thought to have occurred about how many years ago?

A. 4,500 y

B. 4.500,000 y

C. 450,000,000 y

D. 4,500,000,000 y

D. 4,500,000,000 y

Which list contains the most volatile materials?

A. hydrogen, helium, argon, ammonia, methane

B. iron, nickel, and iron sulfide

C. tungsten (W), osmium (Os), and zirconium (Zr)

A. hydrogen, helium, argon, ammonia, methane

Most of the material in the solar nebula that condensed to form solids was made of what?

A. silicates that lacked water

B. silicates that contained water

C. carbonaceous material

D. iron

E. water ice

E. water ice

Why are the inner planets depleted (poor) in volatile elements?

A. Their constituents condensed at lower temperatures.

B. Their constituents condensed at high temperatures.

C. They formed from portions of the nebula depleted in these elements.

D. They are not depleted in volatiles.

E. Hydrogen is not stable inside the orbit of Mars.

B. Their constituents condensed at high temperatures.

Which of the following is NOT true about planetary accretion?

A. As these particles accreted, the planets became hot as kinetic energy was converted to thermal energy.

B. The planets grew larger and larger when the Sun ejected more and more materials.

C. The planets became internally differentiated to different degrees.

D. The particles that accreted to form the planets were in orbit around the Sun.

B. The planets grew larger and larger when the Sun ejected more and more materials.

When did the planets form?

A. The planets formed before the Sun and were then captured by its large gravity.

B. The planets formed about the same time as the Sun in a relatively short period of time, only a few millions years long.

C. The planets started to accrete about the same time as the Sun, but then grew slowly over a period of billions of years.

D. The planets are a young feature of the Solar System forming only a few thousand years ago.

B. The planets formed about the same time as the Sun in a relatively short period of time, only a few millions years long.

Which of these is evidence for planetary accretion?

A. The heavily cratered surfaces of the Moon and other planetary bodies.

B. The absence of atmospheres on the Moon and Mercury.

C. The rings of Saturn.

D. The abundance of water on Earth.

A. The heavily cratered surfaces of the Moon and other planetary bodies.

How did the giant outer planets obtain their thick atmospheres?

A. They degassing from their icy interiors.

B. The nebular gases collapsed onto a protoplanet's icy core.

C. Gas swept into the outer solar system collected during the T-Tauri stage of the Sun's development.

D. As the nebula cooled, the volatile gases condensed onto the planets.

B. The nebular gases collapsed onto a protoplanet's icy core.

Large planetary bodies failed to accrete in some parts of the Solar System and did not sweep their neighborhood clear of debris. Select the two most prominent zones of this debris.

A. between Venus and Earth

B. between Mars and Jupiter

C. between Uranus and Neptune

D. beyond Neptune

B. between Mars and Jupiter

D. beyond Neptune

Which of the following are characteristics of the orbits of the objects that accrete to make planets? (Select all that apply)

A. Their orbits form a flattened disk shape.

B. Their orbits form a spherical zone centered on the star.

C. Their orbits define an elliptical zone tilted about 90 degrees to the ecliptic.

D. They orbit in the equatorial plane (ecliptic) of the star.

A. Their orbits form a flattened disk shape.

D. They orbit in the equatorial plane (ecliptic) of the star.

The spin axes of some planets are tilted relative to the plane in which most orbit. What could have caused this?

A. The impact of a large object late in the history of accretion changed the spin.

B. More accretion occurred on one side of the planet than on the other and it tipped on its side.

C. These planets were probably captured from a passing star.

D. With the passage of time, the spin axis of a planet starts to tilt to one side.

A. The impact of a large object late in the history of accretion changed the spin.

In general, large planets cool

A. during core formation

B. before a lithosphere can form

C. more rapidly than small planets of similiar composition

D. more slowly than small planets of similar composition

D. more slowly than small planets of similar composition

Important sources of planetary heat include all the following except

A. accretion

B. core formation

C. tidal heating

D. decay of radioactive elements

E. the Big Bang

E. the Big Bang

Which of the following is not a mechanism of heat transport?

A. conduction

B.magnetism

C.convection

D.radiation

B.magnetism

The weak layer within a terrestrial planet which behaves like a viscous (resisting flow) fluid is

A. the crust

B. the lithosphere

C. the asthenosphere

D. the mantle

C. the asthenosphere

Consider two planets that are the same age. Which one will have the thicker lithosphere?

A. A large rocky planet

B. A large gas giant

C. A small rocky planet

D. A small gas giant

C. A small rocky planet

Why are the rocks found at the surface of a planet, say Mercury, so different in elemental composition from the meteoritic material from which it formed?

A. The planet differentiated after accretion.

B. Layers of different composition sequentially accreted to the planet.

C. Dissolution by water and upward transport of the soluble elements created distinctive outer layers.

D. Late stage condensation of mafic silicates from the nebula buried the surface.

A. The planet differentiated after accretion.

Study this thermal evolution diagram, which shows how the interior of a terrestrial planet should change with time. Which section of the diagram represents the asthenosphere?

D

Study this thermal evolution diagram, which shows how the interior of a terrestrial planet should change with time. Which section of the diagram represents the crust?

C

Study this thermal evolution diagram, which shows how the interior of a terrestrial planet should change with time. Which section of the diagram represents the magma ocean?

E

Study this thermal evolution diagram, which shows how the interior of a terrestrial planet should change with time. Which section of the diagram represents the core?

B

Consider the interior structure of a planet. How is a lithosphere different from a crust?

A. A lithosphere is a mechanical subdivision, and crust is a compositional term.

B. A lithosphere is a chemical subdivision, and crust is a mechanical subdivision. 

C. A lithosphere is made of less dense rock that floats on the rigid crust.

D. A lithosphere is made of dense rock that floats on the rigid crust.

A. A lithosphere is a mechanical subdivision, and crust is a compositional term.

Where did the water in Earth's hydrosphere come from?

A. From a late bombardment by silicate asteroids.

B. From gradual trapping of water molecules in space by Earth's gravitational field after Earth formed.

C. From trapping gases from the primeval solar nebula.

D. From the volatiles released by volcanoes.

E. By condensation of refractory elements.

D. From the volatiles released by volcanoes.

What properties of the atmophile elements (hydrogen, helium, carbon, nitrogen, oxygen) allow them to generate atmospheres?

A. They are volatile elements.

B. They are refractory elements.

C. They form molecules with low densities

D. They form molecules with high densities.

E. They are all chalcophile elements as well.

A. They are volatile elements.

C. They form molecules with low densities

Which of the following is NOT a way that a planet's atmosphere can lose gas?

A. Escape to space

B. Formation of limestone or carbonate materials

C. Formation of polar ices

D. The process of outgassing

D. The process of outgassing

Why do the inner planets lack thick atmospheres of hydrogen and helium?

A. Because they are too small to have retained such gases. 

B. These elements were not present in the inner part of the solar nebula.

C. Because these elements did not condense to form solids.

D. Because they are efficiently outgassed from the interior of planets. 

A. Because they are too small to have retained such gases. 

How did Earth's atmosphere form?

A. By gradual trapping of volatiles from space by its gravitational field. 

B. By trapping gases from the primeval solar nebula. 

C. By gaseous exhalations from rocks deep inside. 

D. By condensation of refractory elements. 

C. By gaseous exhalations from rocks deep inside. 

Where are the inner planets

INNER PLANETS ARE THE GREY DOTS AT THE TOP

Where are the Icy moons

ICY MOONS ARE THE BLUE ON THE BOTTOM LEFT

Where are the giant planets

GIANT PLANETS ARE GREEN IN THE BOTTOM RIGHT

Why do the planets have different densities?

A. Planets get denser with age and some planets are younger than others. 

B. The planets have different mixtures of ice, silicates, iron, and gas 

C. The pressure of the interplanetary medium is higher near the Sun so that planets near the Sun have high densities.

B. The planets have different mixtures of ice, silicates, iron, and gas 

What is the age of most meteorites that fall to Earth?

A. Less than about 1 billion years old.

B. About 1.3 billion years old, the age of the late heavy bombardment.

C. Most are less than 1 billion years old, but a few are as old as 4.6 billion years.

D. Almost all have ages of about 4.6 billion years.

D. Almost all have ages of about 4.6 billion years.

Why are chondritic meteorites so important?

A. They are undifferentiated, and preserve evidence about the age and nature of condensation in the ancient solar nebula.

B. They contain a great abundance of metallic grains that can be extracted for a profit.

C. Most are thought to have crystallized on Mars.

D. Many are remnants of the Big Bang.

A. They are undifferentiated, and preserve evidence about the age and nature of condensation in the ancient solar nebula.

Most meteorites that fall to Earth are of which type?

A. stony meteorites

B. iron meteorites

C. stony-iron meteorites

D. from the Moon or Mars

A. stony meteorites

Which is true about iron meteorites?

A. They formed by the condensation of metallic elements from the solar nebula.

B. Iron meteorites formed during the internal differentiation of small asteroids.

C. They have nothing in common with stony meteorites.

D. Iron meteorites are the source of most iron ore on Earth.

B. Iron meteorites formed during the internal differentiation of small asteroids.

Some stony-iron meteorites appear to have ______________________.

A. formed by direct condensation from the solar nebula

B. formed during volcanic activity on small asteroids

C. fallen to Earth as the most abundant type of meteorite.

D. been formed at the core-mantle boundary of an asteroid

D. been formed at the core-mantle boundary of an asteroid

What is one evidence suggesting that SNC meteorites came from Mars?

A. their red colors

B. their low temperatures of formation

C. their young ages

D. they consist of sedimentary rocks

C. their young ages

What is the size range of asteroids?

A. 0 to 10 km across

B. 0 to 100 km across

C. 0 to 1000 km across

D. 0 to 10,000 km across

C. 0 to 1000 km across

Most asteroids are probably in which size range?

A. 0 to 10 km across

B. 0 to 100 km across

C. 0 to 1000 km across

D. 0 to 10,000 km across

A. 0 to 10 km across

What geologic process is most common on asteroids?

A. Volcanism

B. Erosion by running water

C. Erosion by wind

D. Tectonic fractures caused by contraction

E. Impact cratering

E. Impact cratering

Which of the following is most accurate about volcanic activity on the asteroids?

A. Volcanism never occurred because they are so small.

B. On a few asteroids, it is still going on today.

C. Volcanism occurred anciently on at least some asteroids.

D. Explosive volcanic eruptions propelled fragments to Earth, which we call meteorites.

C. Volcanism occurred anciently on at least some asteroids.

Why is there a density difference between Vesta and Ceres? (Select all that apply.)

A. Because Vesta is rich in silicates and metals.

B. Because Ceres has an outer shell of water ice.

C. Because Ceres is rich in silicates and metals.

D. Because Vesta has an outer shell of water ice.

E. Because Vesta is more strongly fragmented by impact than Ceres is.

A. Because Vesta is rich in silicates and metals.

B. Because Ceres has an outer shell of water ice.

Study this image of Vesta. What is the most likely cause of the linear ridges and grooves near its equator?

A. Fracturing caused by extension

B. Running water

C. Erosion by glacial ice

D. Near disruption by a large impact

D. Near disruption by a large impact

Why are asteroids closer to Jupiter (just off the right side of the images) so much darker than those near Mars (on the left)?

A. Solar radiation is stronger on the ones near Mars and has bleached them.

B. The asteroids near Mars have a higher content of water ice and are thus lighter in color.

C. Dark carbonaceous materials are common on the asteroids near Jupiter.

D. The asteroids near Mars are light because they have abundant light color feldspar.

C. Dark carbonaceous materials are common on the asteroids near Jupiter.

What is the best explanation for this dome shaped mound on Ceres?

A. The mound was formed by tectonic deformation.

B. Cryovolcanism (ice volcano).

C. It is the central peak of an impact crater.

D. Erosion of the other rocks away from a resistant mass of igneous rock.

B. Cryovolcanism (ice volcano).

The surface of the Moon can be divided into two general terrains. What are they?

A. bright and dark terrains

B. old and young terrains

C. high and low terrains

D. the maria and the terrae

E. all of the above

E. all of the above

The lunar highlands are typified by

A. closely spaced impact craters

B. basaltic lava flows

C. long anorthositic lava flows

D. a multitude of volcanic craters

A. closely spaced impact craters

The most important MINERAL in the upper mantle of the Moon is

A. iron

B. magnesium

C. olivine

D. peridotite

C. olivine

Which of the following statements about the Moon's core are correct? (Select all that apply)

A. The Moon's core is much larger than expected for a planet of its size.

B. The Moon's core is probably made of iron.

C. The Moon's core was once molten and convected to make a magnetic field.

D. As far as we can tell, the Moon is not differentiated, and has no core.

B. The Moon's core is probably made of iron.

C. The Moon's core was once molten and convected to make a magnetic field.

On this photo of the Moon, click on the largest Maria

is is the large circle thing on the left/ bottom leftish

On this photo of the Moon, click a part of the Highlands.

White/light parts

The energy of crater formation is expended in which of the following ways? Mark all that are correct.

A. slumping to create terraces

B. heat

C. rebound of the interior

D. fracturing of the bedrock

A. slumping to create terraces

B. heat

C. rebound of the interior

D. fracturing of the bedrock

Which of the following types of energy is mostly responsible for crater generation?

A. potential energy

B. thermal energy

C. kinetic energy

D. radiogenic energy

C. kinetic energy

Which of the following is not a feature formed by impact on the Moon?

A. overturned crater rim

B. rays of ejecta around the crater

C. terraces on the side of the crater

D. sinuous rilles

D. sinuous rilles

Craters with central peaks generally

A. are the smallest of all craters

B. have terraced walls

C. do not occur on the Moon

D. form as a result of volcanic activity

B. have terraced walls

Which of the following is least important for the appearance of an impact crater developed on the surface of a planet?

A. the size of the planet

B. the size of the impacting body

C. the nature of the surface material (target)

D. the presence of an atmosphere

E. the presence of a magnetic field

E. the presence of a magnetic field

Click on the oldest crater

Arrange these impact craters from smallest (on top) to largest (on bottom).

the ones that are most defined are smallest

Why do impact craters make good geologic time indicators? (Select all that apply)

A. They are laterally extensive (they cover large areas).

B. They are produced instantaneously, marking a single point in time.

C. Their features change with time as a result of degradation.

A. They are laterally extensive (they cover large areas).

B. They are produced instantaneously, marking a single point in time.

C. Their features change with time as a result of degradation.

Do the principles of superposition and cross cutting relations tell us how old a particular crater or surface is in number of years (the absolute age)?

A. yes

B. no

B. no

What is the basis for our understanding of the absolute time scale of the Moon?

A. By counting the number of impact craters on a surface, we can calculate the age of the surface.

B. Rock samples brought back from the Moon have been dated using radiometric techniques to give their absolute ages.

C. By carefully mapping the lava flows on the Moon we can calculate its absolute age.

D. The ages of the rocks on the surface can be measured using spectrometers on orbiting spacecraft.

B. Rock samples brought back from the Moon have been dated using radiometric techniques to give their absolute ages.

What do the absolute ages of lunar rocks tell us about changes in the rate of impact cratering throughout the Moon's history?

A. The rate of impact on the Moon has declined dramatically with time so that modern impact rates are much lower than they once were.

B. The rate of impact on the Moon has increased regularly.

C. The rate of impact has been about the same throughout its long history.

D. The rate of impact has declined over the first two billion years of the Moon's history, but has been increasing ever since.

A. The rate of impact on the Moon has declined dramatically with time so that modern impact rates are much lower than they once were.

How old are the oldest rocks found so far on the Moon?

A. The oldest rocks are 4.8 billion years old and older than any other body in the solar system.

B. The oldest rocks are quite young. None exceed 500 million years old.

C. The oldest rocks found so far on the Moon are about 4.5 billion years old.

D. The oldest rocks on the Moon are about 2.5 billion years old.

C. The oldest rocks found so far on the Moon are about 4.5 billion years old.

The surface of the Moon can be divided into two general terrains. What are they?

A. bright and dark terrains

B. old and young terrains

C. high and low terrains

D. the maria and the terrae

E. all of the above

E. all of the above

How old are the oldest rocks found on the Moon?

A. The oldest rocks are 4.8 billion years old and older than any other body in the solar system.

B. The oldest rocks are quite young. None exceeded 500 million years old.

C. The oldest rocks found on the Moon so far are about 4.5 billion years old.

D. The oldest rocks on the Moon are about 2.5 billion years old. The ages of all rocks formed before this have been reset by extensive impact

C. The oldest rocks found on the Moon so far are about 4.5 billion years old.

Examine this photograph of the nearside of the Moon. What shows that the crater Copernicus is younger than Eratosthenes? (Select all that apply)

A. Big impact craters are younger than small ones.

B. It has fresh rays of impact ejecta radiating from it.

C. The rays of Copernicus cross over Eratosthenes crater.

D. Copernicus is a much more degraded impact crater.

B. It has fresh rays of impact ejecta radiating from it.

C. The rays of Copernicus cross over Eratosthenes crater.

Examine this photograph of the nearside of the Moon. How can you tell that Eratosthenes crater is younger than Imbrium basin? (Select all that apply).

A. Eratosthenes is much smaller and therefore younger than Imbrium.

B. Imbrium is buried by smooth lava plains, but Eratosthenes is not.

C. Eratosthenes has bright rays, but Imbrium does not.

D. Eratosthenes formed on the rim of Imbrium.

B. Imbrium is buried by smooth lava plains, but Eratosthenes is not.

D. Eratosthenes formed on the rim of Imbrium.

Sort the lunar time periods chronologically by placing the youngest period on top and the oldest on the bottom. 

1. Copernican

2. Eratosthenian

3. Imbrian

4. Nectarian

1. Copernican

2. Eratosthenian

3. Imbrian

4. Nectarian

Which of these images of the Moon shows the oldest surface? They are all about the same time scale and 200 km across. 

This graph shows impact crater size versus the number of craters per square kilometer for different regions of the Moon. Click on the line that corresponds to the youngest terrain.

LIGHT BLUE LEFT LINE IS YOUNGEST

Which of these four lunar impact craters is the oldest?

THE CRATER RIGHT ABOVE A

Landforms produced by lunar volcanism include which of the following? (Select all that apply.)

A. lava flows

B. low shield volcanoes

C. stratovolcanoes

D. ash flow calderas

E. lava channels

A. lava flows

B. low shield volcanoes

E. lava channels

What process formed these sinuous valleys?

A. Erosion by running water during the wet part of the Moon's history.

B. The eruption of lava flows.

C. Lithospheric faulting.

D. Melting of ground ice.

B. The eruption of lava flows.

Mare basalts are characteristically ________. 

A. rich in volatile elements like water

B. thicker than the lithosphere

C. older than the lunar highlands

D. very fluid

D. very fluid

Which is true about the most common volcanic rocks on the Moon?

A. They are of a type not found on Earth.

B. They are very similar to the most common volcanic rocks on asteroids and other terrestrial planets.

C. They are high in silica and thus very viscous.

D. Most were erupted explosively from stratovolcanoes like Mt. St. Helens.

B. They are very similar to the most common volcanic rocks on asteroids and other terrestrial planets.

Click on the volcanic crater in this image.

top right head of the worm thingy

Click on the youngest lava flow that crosses this part of the lunar maria.

click right below the line that goes diagonally from the top right to bottom left, click right half of the screen

About how old are the lunar maria?

A. They range in age from about 4.0 billion years old to about 2.5 billion years old.

B. They are about the same age as the ocean basins on Earth which are less than 175 million years old.

C. They formed over a brief interval of time in response to an episode of heavy bombardment about 60 million years ago when Earth's dinosaurs became extinct.

D. The maria are among the oldest features on the Moon--all are more than 4 billion years old.

A. They range in age from about 4.0 billion years old to about 2.5 billion years old.

This is an image of part of the Moon's maria. Click on the feature that was produced by contraction. contractional feature

any of the valley in the v shape on the right side

What is the orientation of the stress that created the wrinkle ridges in this image? North is upward.

A. Compression from W-E

B. Compression from N-S

C. Extension from W-E

D. Extension from N-S

A. Compression from W-E

Carefully study this image of the Moon. Click on the tectonic feature that is formed by compression.

raised valley things, top left

Carefully study this image of the Moon. Click on a tectonic feature that was probably formed by extension.

raised cut-looking things at the bottom

In the picture below, which is the oldest tectonic feature?

A. The linear rille.

B. The wrinkle ridge.

C. The lunar maria.

D. The impact craters.

A. The linear rille.

The presently favored theory for the origin of the Moon calls for which of the following scenarios?

A. the impact of a large body into the Earth.

B. the accretion of the Moon at the same time as the Earth was growing.

C. the rapid spin of the early Earth to throw some material out.

D. the gravitational capture of the Moon after it formed elsewhere in the solar system.

A. the impact of a large body into the Earth.

What is the major difference between the composition of the Moon and Earth?

A. The Moon is richer in volatile elements than the Earth.

B. The Moon is richer in iron than the Earth.

C. The Moon is poorer in water than the Earth.

D. The Moon has a lower H/He than the Earth.

C. The Moon is poorer in water than the Earth.

The Moon's highland crust consists largely of plagioclase feldspar. Since no magma has the composition, how was plagioclase concentrated in the crust?

A. By deposition from the gases of the solar nebula

B. By impact from plagioclase feldspar-rich meteorites

C. By flotation of plagioclase feldspar in a magma ocean

D. By eruption of lava

E. By deposition by running water

C. By flotation of plagioclase feldspar in a magma ocean