GEOL 109 Final Examm

Photo 4 This diagram plots the average temperature and age of various inner planets and Earth's Moon. Which curve is the correct curve for Earth? 1-5

1 Large planets will have the highest initial internal temperature and will cool more slowly. So the larger the planet the higher the internal temperature at any given time.

Photo 4 This diagram plots the average temperature and age of various inner planets and Earth's Moon. Which curve is the correct curve for Mercury? 1-5

4 Large planets will have the highest initial internal temperature and will cool more slowly. So the larger the planet the higher the internal temperature at any given time.

Photo 22 Carefully study this image of the Moon. Which letter labels a tectonic feature that formed by compression? A-D

A A is a wrinkle ridge formed by compression. The others are linear rilles, craters, or a mound.

Photo 26 One of these impact craters is on the Moon and the other is on Mercury. Which one is on Mercury? A or B

A Crater A has secondary impacts close to the rim, while B has secondary craters farther from the crater.

Photo 50A + 50B Which of these close up views is an image of part of Europa? A or B

A Europa has large fractures and polygons of ice, while Io has bright yellow and orange colors with volcanic features

Photo 37 Which letter is on a young volcanic plain in this colored shaded relief map along Mars' Great Escarpment? A-D

A Low viscosity, basaltic lava flows smooth out surfaces on planets by filling in cracks and craters and usually contain abundant wrinkle ridges.

Photo 3 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? A-H

A Magma oceans formed early in a terrestrial planets history and quickly disappeared.

Photo 51A-51D This set of photographs shows various landscapes on Io and Europa. Which image likely provides evidence that Io is still volcanically active? A-D

A The lobate lava flows spreading out from a common location as seen in A show Io is still volcanically active.

Photo 15 Which of these four lunar impact craters is the oldest? A-D

A The oldest crater is the most degraded one.

Photo 33 Examine this image of Mars carefully. Which feature is a small shield volcano? A-F

A Volcanic shields are low relief volcanoes that are reminiscent of Greek shields. These volcanoes are produced by low viscosity lava that cannot build up much topography.

Photo 47 These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Which of the images is of crater on Earth? A-D

A We know that crater A is on Earth because of the meandering river channel near the crater. Only Earth has river channels.

Photo 39 These diagrams show the history of Mars but they are not in the correct chronologic order. Put the events into the proper order with oldest first in your list and the youngest last in your list. A-F

A - Oldest D F B E C - Youngest

Photo 40 Study this colored topographic map of Venus and identify the following provinces using the letters on the map. highland, upland, lowland

A highland B An upland C A lowland A The uplands are large plateaus and encompass large areas (red) The highlands are domes that create topographic highs, they do not take up as much area as the uplands. The lowlands are the topographic lows marked as blue

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 Even though asteroids can get up to 1000 km in diameter, most are very small and are below 10 km wide.

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 a 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. The lithosphere is a mechanical subdivision (it is all solid). The crust is a compositional term (it is basaltic, in most cases).

Why is the Earth a dynamic planet, whereas the Moon and Mercury have undergone very little change during the last 3.5 billion years? (Select all that apply.) A. A major difference is that Earth is much larger than the other two. B. Because Earth is closer to the Sun than the Moon and Mercury, its hydrologic system has been more actively eroding the surface. C. Because Earth has a moon and the others do not, it has been tidally heated and kept warm and active for a long time. D. The Moon and Mercury lack atmospheres, but Earth has retained one, which has greatly modified the surface.

A. A major difference is that Earth is much larger than the other two. D. The Moon and Mercury lack atmospheres, but Earth has retained one, which has greatly modified the surface. There are two main ways a planet can be changed and be dynamic. The first is from internal heat, which drives volcanism and tectonism burying and destroying previous surface features. The second is presence of an atmosphere that can move sediment and reshape the surface by wind and flowing water.

On Earth and Mars, how is loess deposited? (Mark all that apply.) A. As a blanket which mantles the landscape. B. By the wind. C. As dust-sized particles. D. By running water. E. On the floors of their oceans.

A. As a blanket which mantles the landscape. B. By the wind. C. As dust-sized particles. Loess are dust-sized particles that are transported by wind and deposited as blankets on the Earth's surface.

Which of the following are true about planetary accretion? (Select all that apply.) A. As these particles accreted, the planets became hot as kinetic energy was converted to thermal energy. B. The planets grew larger and larger via repeated impact. C. The planets became internally differentiated to different degrees. D. The particles that accreted to form the planets were in orbit around the Sun.

A. As these particles accreted, the planets became hot as kinetic energy was converted to thermal energy. B. The planets grew larger and larger via repeated impact. C. The planets became internally differentiated to different degrees. D. The particles that accreted to form the planets were in orbit around the Sun. small particles that are orbiting the Sun collide into one another creating particles that get larger with each collision. Also during collision, the particles get hotter as kinetic energy is changed to thermal energy (think of rubbing your hands together). The thermal energy can almost completely melt the accreted material allowing the dense material (iron) to settle to the bodies center.

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. The differences in planetary bodies are always a result of what they are made of. The more silicates and metal the more dense the planetary body will be. The more ice, the less dense.

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. Helium and hydrogen were the most common elements present in the Solar Nebula. They are not present on the terrestrial planets because the inner planets were not large enough to have a enough gravity to hold onto these non-dense elements.

Photo 5 Study this graph of the size densities of the planets and some of their satellites. Each color represents a different class of planetary bodies. Which grouping represents the moons of the outer planets? A. Blue (lower left) B. Green (lower right) C. Grey (upper middle)

A. Blue (lower left) The moons of the outer planets are low density and small.

In what way is the history of Earth similar to the history of the Moon? A. Both "planets" once had heavily cratered surfaces. B. Both eventually developed plate tectonics. C. Both once had thick atmospheres of carbon dioxide and nitrogen. D. Both have magnetic fields to this day, shaped by convection of molten iron cores.

A. Both "planets" once had heavily cratered surfaces. Earth once had a heavily cratered surface, just like the Moon has today. None of the other answers have occurred on the Moon. The Moon did not develop plate tectonics, and is volatile poor not allowing an atmosphere to develop, nor does the Moon have a magnetic field or convection in a molten iron core; in fact the Moon may not even have a core.

Photo 64 How did the polygonal shapes on Pluto's Sputnik Planum form? A. By convection of ice below a rigid upper layer. B. By the flow of glacial ice from highlands to lowlands. C. By tectonic compression of the region to form reverse faults. D. By tectonic extension of the region to form normal faults E. By shrinkage of the ice layer that fills an old impact crater.

A. By convection of ice below a rigid upper layer. The shapes of the polygonal shapes within Sputnik Planitia and modelling show these cells form by convection of the basin's ice. The cell margins are the troughs and the downwelling section of the convection cell, while the center is the upward part of the convection cell.

What would have happened on Venus if it had been cool enough for liquid water to form? A. Carbonate minerals may have formed in the water and removed the carbon dioxide from the atmosphere. B. The high sulfur content of the atmosphere may have made the water acidic promoting extensive weathering. C. The greenhouse effect may have been even more intense.

A. Carbonate minerals may have formed in the water and removed the carbon dioxide from the atmosphere. Large bodies of liquid water and carbon dioxide in the atmosphere, can mix to precipitate carbonate minerals. Since Venus has a carbon dioxide-rich atmosphere, it can be assumed, if Venus had liquid water, there would be a lot of carbonate minerals on the surface.

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 Some comets have orbital periods of hundreds of thousands of years. The group of comets that occupies the outermost limits of the solar system is called the Oort cloud.

Photo 21 What was 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 Stress of wrinkle ridges is perpendicular to their long axis, so it is E-W here.

Which of the following Earth-like features have been identified on Titan? (Select all that apply.) A. Eolian dunes B. River channels C. Lakes or small seas D. A system of tectonics involving the large scale movement of lithospheric plates. E. A nitrogen-rich atmosphere F. Glaciers of flowing ice G. Linear ranges formed by contraction

A. Eolian dunes B. River channels C. Lakes or small seas E. A nitrogen-rich atmosphere F. Glaciers of flowing ice G. Linear ranges formed by contraction Surprisingly, Titan is very similar to the Earth and have many similar features. Out of this list, the only features we do not see on Titan are plate tectonics (only found on Earth) and continental glaciers. Like Earth, Titan has a nitrogen-rich atmosphere, dunes and rivers (though of different composition than Earth's), and mountain ranges formed by contraction. While the details of these features are different on Titan than Earth, the physical aspects are very similar.

What is the evidence that Ganymede and Callisto have more ice in their interiors than Io and Europa do? A. Ganymede and Callisto have lower densities. B. Ganymede and Callisto have large magnetic fields. C. Ganymede and Callisto have fewer impact craters because ice is so weak. D. Ganymede and Callisto have river channels formed when ice melted during impact.

A. Ganymede and Callisto have lower densities. As we have run into many times in this class, different materials have different densities. This fact helps us determine what planetary bodies are made of. If they are dense, they have rocky and metal material. If they body has a low density there is a lot of ice. Because Ganymeade and Callisto have lower densities than Io and Europa we can conclude Ganymeade and Callisto have more ice than the other Galilean moons.

The age of the surface of Europa is like which of the satellites of Jupiter? A. Io B. Ganymede C. Amalthea D. Callisto

A. Io Like Io, Europa has no craters indicating a similar surface age. The other moons have many craters.

Which statements are true for the Kuiper belt? (Select all that apply.) A. It contains many small icy objects in orbit around the Sun. B. It is another name for the asteroid belt. C. It extends halfway to the nearest star. D. The orbits formed a flattened disk in the outer solar system. E. Pluto is one of the bodies in the Kuiper belt. F. It is a semi-spherical cloud of orbiting bodies with highly inclined orbits.

A. It contains many small icy objects in orbit around the Sun. D. The orbits formed a flattened disk in the outer solar system. E. Pluto is one of the bodies in the Kuiper belt. The Kuiper Belt is a region beyond Neptune's orbit (30 to 50 AU) that is similar to the Asteroid Belt in many ways however, there are important differences between the two. Like the Asteroid Belt, the Kuiper Belt of leftover debris from the Solar Nebula that did not accrete into a planet. Instead of asteroids rich in rock and metals, Kuiper Belt Objects are rich in the volatile ices of water, nitrogen, methane, ammonia, and carbon monoxide. Pluto is one of these objects.

In what way is the magnetic field of Uranus distinctive? Choose all that apply. A. It has an unexpected orientation B. It is tilted compared to the spin axis C. It is irregular and may be experiencing a reversal. D. It is created by convection in its iron core. E. It is the strongest in the solar system

A. It has an unexpected orientation B. It is tilted compared to the spin axis C. It is irregular and may be experiencing a reversal. Every magnetic field in the Solar System is oriented in the same direction as the axis of the planet, except for Uranus' which, is tilted 60 degrees with respect to the planet's axial tilt. Perhaps this abnormal tilt is a result of a magnetic field reversal on Uranus.

In what way is the orbit of Triton distinctive? A. It is retrograde. B. Its spin axis is tilted almost 90 degrees so that it rolls like a ball around Neptune. C. It is highly elliptical. D. It is not tidally locked.

A. It is retrograde. Unlike almost all of the moons in the solar system, Triton revolves around Neptune in the opposite direction of the planet's spin (retrograde orbit).

If Venus is so close to Earth, why has it taken so long to understand what the solid surface of Venus is like? A. Its surface is buried beneath a very cloudy atmosphere. B. The temperature is so high the normal imagining is not possible. C. It is covered by a thick layer of water (an ocean). D. The radiation environment is so harsh that the cameras do not function.

A. Its surface is buried beneath a very cloudy atmosphere. The carbon dioxide atmosphere is too thick to visibly see through. Other light wavelengths (radar) are needed to pierce the atmosphere.

What is evidence that many of the outer moons of Saturn are captured rather than formed in orbit around Saturn? (Choose all that apply.) A. Many of them have highly inclined orbits. B. These outer moons are rocky and must have formed in the inner solar system before moving outward and being captured by Saturn. C. They are so big they could not have formed near Saturn which would have melted them. D. Many have retrograde orbits around Saturn.

A. Many of them have highly inclined orbits. D. Many have retrograde orbits around Saturn. Satellites that form with the planet orbit in the same direction as the planet rotates and revolves and along the equatorial plane of the planet. Captured satellites can have very different orbits than this and also very elliptical orbits. The physical characteristics of a captured satellite depend on what direction the object was moving.

Although both Mercury and Mars have similar gravity fields, Mars has an atmosphere whereas Mercury does not. What is a possible explanation? A. Mars is more volatile rich. B. Mercury's volatiles are frozen at its poles to form ice caps. C. Mercury has no volcanic activity but Mars has many volcanoes that belched gases to the surface. D. Because there was life on Mars that released gas to form the atmosphere.

A. Mars is more volatile rich. Because Mars accreted further from the Sun than Mercury, Mars has a greater amount of volatiles. These volatiles were outgassed and released past the surface of Mars where they were trapped by the gravity field of Mars.

Which kind of stars have the longest lifetimes (~10 billion years)? A. Medium-sized stars like our Sun. B. Large stars about 10 times larger than the Sun.

A. Medium-sized stars like our Sun. The larger the star, the faster the star uses its fuel.

Click on the possible explanations for Mercury's large core. Choose the two most likely. A. Mercury formed near the Sun in a zone that was oxygen-poor and rich in metallic iron. B. Mercury's magnetic field collected large masses of iron during accretion. C. During its early accretion, a large iron asteroid collided with Mercury and the iron sank to its core. D. A large impact stripped away the silicate shell from an already differentiated Mercury.

A. Mercury formed near the Sun in a zone that was oxygen-poor and rich in metallic iron. D. A large impact stripped away the silicate shell from an already differentiated Mercury. There are two main theories as to why Mercury has such a large iron core. The first is, Mercury accreted in a oxygen-poor area that allowed iron to remain in its metallic state allowing close to all of the iron to segregate in the core. The second hypothesis is a giant impact knocked off much of Mercury's mantle without affecting the core, so now the core is large compared to Mercury's diameter.

Which is the correct sequence of planets, based on increasing average radius of their orbits? A. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto B. Mercury, Venus, Mars, Earth, Jupiter, Saturn, Neptune, Uranus, Pluto C. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Uranus, Pluto D. Mercury, Earth, Venus, Mars, Jupiter, Saturn, Neptune, Uranus, Pluto

A. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto

Does Venus have a plate tectonic system like the Earth? (Mark all that apply.) A. No, the high surface temperature may prevent the lithosphere from becoming dense enough to subduct back into the mantle. B. No, Venus may lack a shallow asthenosphere. C. No, Venus is water-poor which makes the melting point of the mantle higher than on Earth. D. No, Venus is dominated by mantle plume convection instead. E. Yes, Venus and the Earth both have a system of plate tectonics.

A. No, the high surface temperature may prevent the lithosphere from becoming dense enough to subduct back into the mantle. B. No, Venus may lack a shallow asthenosphere. C. No, Venus is water-poor which makes the melting point of the mantle higher than on Earth. D. No, Venus is dominated by mantle plume convection instead. There are multiple reasons Venus does not have plate tectonics. Venus does not have a shallow asthenosphere for the plates to slide on because there is not water present to lower the melting temperature of the mantle. In addition, the high temperature of the surface makes the materials at the surface less dense, and perhaps they cannot subduct because of this. So, instead of plate tectonics, Venus' volcanism and tectonics are the result of mantle plumes.

Why did continents develop on Earth and not on the Moon, Mercury, or Mars? A. Only Earth has subduction zones. B. Only Earth has mid-ocean ridges. C. Only Earth has mantle plumes. D. Only Earth has a lithosphere thick enough to support them.

A. Only Earth has subduction zones. The continents are made of felsic materials, as we saw in the text, felsic magma is only produced at subduction zones. Since none of the other planets have subduction zones, there is not way for the planets to form continents.

What is a major difference between planets and stars? (Select all that apply.) 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.

A. Planets are much smaller in diameter than the stars around which they revolve. B. Planets do not generate energy through nuclear fusion. Planets have rings and systems of orbiting moons and some planets (the outer planets) lack solid surfaces.

What are the major differences between a moon and a planet? (Select all that apply.) A. Planets revolve around the Sun. B. Moons revolve around a Sun-orbiting planet. 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. B. Moons revolve around a Sun-orbiting planet. A few moons are actually bigger than Pluto and Mercury. By definition, moons (natural satellites) don't orbit the Sun but instead revolve around another planetary body. Some asteroids even have moons.

The most basic subatomic particles include which of the following? (Select all that apply.) A. Protons B. Neutrons C. Isotopes D. Ions E. Electrons

A. Protons B. Neutrons E. Electrons Protons, neutrons, and electrons are the basic subatomic particles that compose the elements. Ions are elements that has a positive or negative charge (lost or gained electrons). Isotopes are elements with varying number of neutrons.

It is very possible that Venus once had more water and has lost it to space over the millenia. A. True B. False

A. True It is possible Venus had water early on in the planet's history, and just like Earth outgassed water. However, because of the high surface temperature of Venus, the water would have not been stable and was expelled into space as a vapor.

Conditions on Venus are such that which of the following are true? Choose all that apply. A. Pure lead would be a liquid on its surface. B. Most of the CO2 is trapped in carbonate rocks (limestone). C. Precipitation of water as rain occasionally occurs. D. Sulfuric acid drips from the sky to cause intense weathering of rocks on the surface. E. The pressure is about 90 times that on Earth.

A. Pure lead would be a liquid on its surface. E. The pressure is about 90 times that on Earth. The greenhouse effect is so strong on Venus, it raises the surface temperature high enough to melt lead. And the atmosphere is much more dense than Earth. We know that carbon dioxide was not sequestered into limestones, because the carbon dioxide would be gone from the atmosphere. And since there is no water vapor on Venus, water cannot precipitate. While there is sulfuric acid in the atmosphere, it does not result in the weathering of rocks on the surface. The acid will evaporate before it reaches the surface.

On Ganymede, grooved terrain formed by which process? A. Tectonic disruption of heavily cratered terrain. B. Impact cratering. C. Hot spot volcanism. D. Planetary contraction.

A. Tectonic disruption of heavily cratered terrain. The grooved terrain formed by expansion of Ganymeade, causing rifts and grabens to develop within the cratered terrain, breaking up the previous crust. These rifts and grabens that formed subsequently filled with cryomagma (water magma) that then fractured. However, the grooved terrain began to form by extensional tectonics.

Which event drastically modified Earth's geologic history about 3.5 billion years ago? A. The advent of life. B. Beginning of a period of intense impact cratering. C. Outgassing of the atmosphere. D. The onset of mantle convection to form plumes and associated volcanoes.

A. The advent of life. Evidence for life is seen in rocks that are 3.5 billion years old.

Mars and Mercury differ substantially in what way(s)? Choose all that apply. A. The compositions of their atmospheres. B. Their densitites. C. The sizes of their cores. D. Their surface temperatures. E. The strength of their gravity fields.

A. The compositions of their atmospheres. B. Their densitites. C. The sizes of their cores. D. Their surface temperatures. As seen in this, and previous lessons, Mars is a much different planet than Mercury even though both are terrestrial planets. This shows that even generally, similar planets are not exactly alike and have undergone different histories and evolutions.

What is the probable origin of the smooth plains in the Northern Hemisphere of Mars? Choose all that apply. A. The depression probably started to form as a giant impact crater that covered half of the planet. B. The elevated highland started to form above a rising mantle plume and volcanic eruptions buried it. C. Sediment from a series of temporary seas smoothed it out. D. The crust in this region became so thick that it started to subside into the mantle. E. Eolian erosion carved the basin.

A. The depression probably started to form as a giant impact crater that covered half of the planet. C. Sediment from a series of temporary seas smoothed it out.

Which of the following statements about Venus is (are) true? Choose all that apply. A. The diameter of Venus is almost the same as that of Earth. B. It is the only planet without a natural satellite. C. The atmospheric gases create a large Greenhouse effect. D. Venus is heavily cratered like the moon.

A. The diameter of Venus is almost the same as that of Earth. C. The atmospheric gases create a large Greenhouse effect.

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. As we know, craters are formed by a body colliding with the surface of a planetary body. Atmospheres are not controlled by collision, but volatile content of the planet. The rings of Saturn are objects in orbit around Saturn, and therefore are not collisional. And water indicates Earth has water.

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. Just like someone being punched in the face, a planet being hit hard by a large object will move and become tilted. As a body accretes, the gravity makes the body spherical so one side cannot have more material than another. Other stars are too far away to make a near pass and capture a planet. if a planets spin axis changed with time, all of the planets would be tilted the same amount.

Photo 23 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 linear rilles are cut across by the wrinkle ridge. The others are not tectonic features.

Why is the history of Venus so different from that of Mars? A. Venus is significantly larger than Mars and cooled slowly. B. Venus is smaller than Mars and cooled more quickly. C. Venus lacks multiple impact craters because it is so far from the asteroid belt.

A. Venus is significantly larger than Mars and cooled slowly. Heat controls the geologic history of planets, and in turn, heat is controlled by how large the planetary body is. The larger the planet, the longer it stays warm, and the longer the planet can have active volcanism and tectonism.

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

A. The planet differentiated after accretion. Initially all the planets were homogeneous and accreted from materials of the same composition as meteorites. However, density differences of the various elements allowed segregation. Layers of varying composition formed, with each layer being a different composition than its average composition.

Photo 73 Why are the planetary bodies of the inner solar system different in composition from those of the outer solar system? (Select all that apply.) A. The planets formed in a thermal gradient around the ancient Sun. B. High-temperature solids could form near the ancient Sun. C. Low-temperature solids (ices) could only form near the Sun because pressure was higher there. D. Large icy cores attracted hydrogen and helium from the nebula. E. Dense objects were attracted more to the Sun and less dense ones moved outward.

A. The planets formed in a thermal gradient around the ancient Sun. B. High-temperature solids could form near the ancient Sun. D. Large icy cores attracted hydrogen and helium from the nebula.

What do the absolute ages of lunar rocks tell us about changes in the rate of impact cratering during 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 2 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.

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° to the eliptic. 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. All of the planets orbits are in the same plane as the Sun's equator (near enough). The orbits also form a disk shape. Therefore, the orbits cannot be spherical or tilted ninety degrees to the ecliptic (plane of the Sun's equator).

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. Chondrites are thought to be the oldest material in the Solar System and show the primeval composition of the solar nebula.

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 For an element to be in an atmosphere it must be volatile (condenses at cold temperatures) and low density (so it can rise above the planet's surface).

About how old are the lunar maria? A. They range in age from about 4.0 billion years old to at least 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 at least 2.5 billion years old. Radiometric ages show the basalts are 4.0 to 2.5 billion years old.

Why does Titan have an atmosphere rich in nitrogen and methane while the Galilean satellites of Jupiter lack atmospheres? A. Titan formed farther from the Sun where ammonia and methane ice were stable in the ancient accretion disk. B. Titan is big enough to have trapped nitrogen from the solar nebula. C. The Galilean satellites never became warm enough to out gas atmospheres. D. The galilean satellites of Jupiter once had thick, nitrogen-rich atmospheres, but they were swept away by Jupiter's intense magnetic field.

A. Titan formed farther from the Sun where ammonia and methane ice were stable in the ancient accretion disk. Titan formed in a location in the Solar Nebula that allowed ammonia and methane to condense as ices. The sublimation and disassociation of these molecules led to the development of an atmosphere. The galilean satellites do not have atmospheres because they condensed in a hot enough region (near Jupiter) for these volatile ices to develop.

Photo 57 What are the principal differences between Titan and the other satellites of Saturn? (Select all that apply.) A. Titan is the biggest moon of Saturn. B. Titan is the only moon that has a young surface with few impact craters C. Titan has liquids that flow and pond on its surface. D. The small size of Titan compared to the others is an important feature. E. Titan is the only moon with dunes.

A. Titan is the biggest moon of Saturn. C. Titan has liquids that flow and pond on its surface. E. Titan is the only moon with dunes. Titan is the largest moon of Saturn's. Because of its atmosphere, Titan can have liquids stable on its surface, unlike any of the other moons. This dense atmosphere also allows winds that are strong enough to pick up sediment and deposit them in dunes. Most of the unique features of Titan are related to its atmosphere.

Photo 63 These are images of two of Neptune's moons. In the photos, both are about the same size; in reality, one has a much larger diameter. Which one is larger? A. Triton B. Proteus

A. Triton We can tell Triton is actually larger because it is more spherical, the larger a planetary body gets the more spherical it becomes as its gravitational force overcomes the strength of the rock.

Would you be surprised if tomorrow's newspaper reported that a volcano was discovered erupting on Mercury? A. Yes, that is not expected to happen on Mercury today. B. No, Mercury is so hot because it is near the Sun that this would be expected. C. No, Mercury has such a large iron core that it has cooled very slowly and could still have volcanoes erupt on its surface. D. No, the tidal heating from the nearby Sun keeps it volcanically active.

A. Yes, that is not expected to happen on Mercury today. Mercury no longer has volcanic activity because its lithosphere is too thick for magmas to penetrate.

Photo 70 Is this comet near the Sun (within the orbit of Jupiter)? A. Yes. B. No, it is somewhere in the outer solar system.

A. Yes. A comet only develops a tail when it is near the Sun. Since this comet has a tail, it has to be near the Sun.

Both Neptune and Uranus have magnetic fields that ___________________. A. are tilted with respect to the axis of rotation B. are stronger than Jupiter's C. produced by convection of molten iron deep inside them D. have heated their satellites to the point of melting

A. are tilted with respect to the axis of rotation Like Uranus, Neptune's magnetic field is weak and at an angle to the axis of rotation. Are both of these planets in the middle of pole reversal? Or is there something else going on? Both of the planets being gas giants, they do not have a molten iron core to produce a magnetic field. And magnetic fields do not produce heat.

Which of the following is a major difference between Venus and Earth? A. atmospheric composition B. mass C. volume D. density E. gravity

A. atmospheric composition Though the size, density, gravity, and volume are near identical between the Earth and Venus. Venus does have some major differences from that of Earth, especially atmospheric composition. Earth's atmosphere is dominated by nitrogen and oxygen, while Venus' atmosphere is almost all carbon dioxide.

At one time the Moon may have _______________. A. been volcanically active B. been a satellite of Mars C. supported an integrated hydrologic system D. had a thick, O2-rich atmosphere

A. been volcanically active The Moon has no evidence of an atmosphere or hydrologic system. However, there are many lava flows and channels that show the Moon was volcanically active.

The lunar highlands, or terrae, 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 There are numerous craters that can be seen in the highlands of any planet wide image of the Moon.

The particles in the rings of Uranus are ______________________. A. dark and probably composed of darkened methane ice B. bright like the ice particles in the rings of Saturn C. dark like the ice particles in the rings of Saturn D. orbiting the planet outside the Roche limit.

A. dark and probably composed of darkened methane ice The particles that make up the rings of Uranus are really dark, some of the darkest objects every observed in the Solar System colored by decomposition of methane into carbon-rich residues.

Most of the mass of the solar nebula resided in materials which A. did not condense to form solids. B. condensed to form ice. C. condensed to form silicate materials. D. condensed to form metals.

A. did not condense to form solids. Most of the material in the Solar System (more than 99%) resides in the Sun and therefore, did not condense to form any solids.

Photo 74 Which statement is an accurate general history of cratering on a planet? A. early heavy cratering with declining intensity to the present B. initially light cratering, then intense bombardment, then light cratering to the present C. initially light cratering with increasing intensity to the present D. approximately constant rate of cratering

A. early heavy cratering with declining intensity to the present

Which of the following features are found on the Moon and Mercury? (Check all that apply) A. flood lavas B. dunes C. multiring basins D. impact craters E. faults related to contractions

A. flood lavas C. multiring basins D. impact craters E. faults related to contractions All but dunes are found on both the Moon and Mercury. Dunes do not exist because there is not atmosphere to move particles to form them.

What is the evidence for ground ice (or ground water) on Mars? Choose all correct answers. A. fluidized crater-ejecta patterns B. faulted plains C. chaotic (collapse) terrains D. the great Valles Marineris

A. fluidized crater-ejecta patterns C. chaotic (collapse) terrains Evidence of water on Mars is seen in impact features produced by melted water ice and the chaotic terrain produced by flowing water.

Which list is made of very volatile materials? A. helium (He), argon (Ar), ammonia (NH3), and methane (CH4) B. iron (Fe), nickel (Ni), and iron sulfide (FeS) C. tungsten (W), osmium (O), and zirconium(Zr) D. sodium (Na), potassium (K), and rubidium (Rb)—the alkalies

A. helium (He), argon (Ar), ammonia (NH3), and methane (CH4) Helium, argon, methane, and ammonia are very volatile elements and only condense at extremely cold temperatures.

What is the origin of the features identified in question 2? A. icy volcanism and tidal heating B. impact melting C. collision with a passing comet D. heat released by radioactive decay of K, U, and Th

A. icy volcanism and tidal heating The observed features are icy volcanoes. They cannot be a result of a comet impact, or impact melting because they do not have the structures of impacts. Nor can the heat be formed by radioactive decay, because Enceladus would not have many radioactive elements to begin with, and its supply would be exhausted by now. The only logical source of heat for Enceladus and the production of icy volcanoes is tidal heating. The same process that keeps Io warm and volcanically active.

The Earth's oceanic crust is composed mostly of ____________________. A. igneous rocks of basaltic composition B. shales and limestome C. accumulations of salt deposited from sea water D. granite plutons formed at the mid-ocean ridge

A. igneous rocks of basaltic composition Earth's oceanic crust is formed at divergent plate boundaries. Here upwelling mantle partially melts and is extruded through fissures and creates the oceanic crust. The rocks that form by this process are basaltic in composition.

The largest dune fields on Mars are ____________________. A. in the polar regions B. in the equatorial canyons C. at the base of the Olympus Mons D. in Hellas Basin

A. in the polar regions The largest dune fields are seen in the polar regions of Mars.

The Roche limit _________________________. (Select all that apply.) A. is produced by tidal interaction between two planetary bodies B. changes with the distance between two planetary bodies C. governs the distance within which orbiting materials will not accrete together D. is the attention span of students during a slide show

A. is produced by tidal interaction between two planetary bodies C. governs the distance within which orbiting materials will not accrete together The Roche Limit is the distance from a planet that when closer than, the tidal forces exerted on the planetary body grow to large and break the body into fragments. This distance is determined by the large planet (Jupiter, Saturn, etc.) and is a hypothesis on how the rings of the outer planets are created.

The grooved terrain of Ganymede _______________. A. is younger than its cratered terrain B. is older than the cratered terrain C. forms only a small part of Ganymede's surface. D. developed as Earth-style plate tectonics developed

A. is younger than its cratered terrain Impact crater frequency shows the bright and grooved terrain is younger than the older, dark, cratered terrain. As seen from the global image of Ganymeade, the bright and grooved terrain is not restricted to a small area on the moon, but makes up a significant portion of it. Though the bright and grooved terrain may have some similarities to plate tectonics on Earth, the development process is not the same as plate tectonics. The grooved terrain formed as Ganymeade expanded as it froze, creating cracks for magma of water to extrude, and then fracture as expansion continued.

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 Lava flows, channels, and shield volcanoes are common volcanic landforms on the Moon. Stratovolcanoes and ash flow calderas are not seen because the Moon does not have enough internal volatiles to produce these landforms.

Mercury's smooth plains ____________________. A. may be similar in origin to the lunar maria B. are cut by large grabens or linear rilles C. are older than Caloris basin D. are probably thick deposits of dust

A. may be similar in origin to the lunar maria The smooth plains have few craters compared to the heavily cratered terrain and resemble the lunar maria.

Titan's atmosphere is rich in nitrogen (N2) and _____________. A. methane (CH4) B. carbon dioxide (CO2) C. has as much oxygen (O2) as the Earth's atmosphere D. Ammonia (NH3)

A. methane (CH4) Titan's atmosphere, in addition to nitrogen, has approximately 10% methane. The only reason there is not more methane in the atmosphere is because methane is stable on the surface in liquid form.

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 Chondrites are thought to be the oldest material in the Solar System and show the primeval composition of the solar nebula. Stony meteorites are common because they are from the surface of planetary bodies, and are therefore easy to knock off the surface.

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. The low density and composition (lack of water and other volatile elements) of the Moon suggests the Moon formed from a collision between a Mars-sized impactor and the Earth. This impact sent material out in orbit around the Earth and it accreted into the Moon.

A weak layer within Earth which behaves like a viscous fluid is _________________. (Mark all that apply.) A. the outer core B. the crust C. the lithosphere D. the asthenosphere E. the inner core

A. the outer core D. the asthenosphere There are two layers within the Earth that behave like a viscous fluid: the asthenosphere (which is partially molten because it is near its melting temperature) and the outer core which is totally liquid. The crust, lithosphere, and inner core are all solid (as evidenced by seismic waves).

Which of the following tectonic processes are thought to have occurred on Mercury? (Check all that apply) A. thrust faulting due to contraction of the planet B. thrust faulting due to expansion of the planet as it heated C. graben formation due to contraction D. graben formation due to extension

A. thrust faulting due to contraction of the planet D. graben formation due to extension Both extensional and contractional tectonics have occurred on Mercury. Extension produces grabens while contraction produces thrust faults. It is important to remember extension cannot produce thrust faults nor contraction produce grabens.

Photo 18 Which of the craters labeled in this image is a volcanic crater? A-D

B B is correct because a sinuous rille (volcanic in origin) is emanating from the crater.

Photo 20 This is an image of part of the Moon's maria. Which feature was produced by contraction? A-D

B Contraction forms lobate thrusts faults with a surface expression as seen in B. A is the basalt of the lunar maria, C are linear rilles that formed by extension, and D is the highlands.

Photo 25 Which image shows a feature that formed by contraction of Mercury's surface? A or B

B Contraction produces lobate features, while extension produces linear valleys.

Photo 49 This diagram shows the layered structure of Jupiter. Which letter labels the zone that consists of metallic hydrogen? A-D

B From the core outward we have a core of rock and ice, surround by a layer of water ice. Surrounding the water ice is a layer of metallic hydrogen with an atmosphere of molecular hydrogen. Layer B is the metallic hydrogen layer.

Photo 61 Which letter on this image of Ariel's surface labels an area that has evidence for late expansion and possible volcanism? A-D

B Grabens are the main evidence for expansion of a moon. the letter B is the only letter in a graben making it the correct answer.

Photo 62 Which letter on this image of Triton labels the youngest area of icy volcanism? A-D

B Icy volcanism, like basaltic volcanism, covers the surface making it smooth. Just like the area labelled B.

Photo 13 Which of the images below is the oldest surface of the Moon? A-C

B The amount of craters correlates with surface age. The more craters the older the surface.

Photo 48 These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Which of the images is of crater on the Moon? A-D

B The craters on the Moon are relatively simple, and do not have unique features associated with the craters that the other planets have.

Photo 10 On this photo of the Moon, which labeled section is the highlands? A-C

B The highlands are the "mountains" of the Moon and are brighter than the maria.

Photo 46 Which of the letters on this shaded relief map is a transform plate boundary? A-E

B Transform plate boundaries often offset segments of mid-ocean ridges.

Photo 42 Select the letter of the area of this radar image of Venus that has been shaped by Eolian processes. A-D

B Wind can produce a variety of features, including streaks, which are labelled as B. The others are tectonic or volcanic features.

Photo 41 Study these radar images of impact craters on Venus. Arrange their letters from smallest to largest. A-D

B - Smallest A D C - Largest Small craters are irregular and occur in clusters. With progressively larger craters have terraces, central peaks, and peak rings, and the largest are multiring basins

Photo 1 Put the following stages in the evolution of a medium-sized star in the correct time order, placing the first stage on the top and the last stage on the bottom. Don't use those that don't apply to a medium-sized star.

B First C D G A Last Medium stars condense into a protostar out of cosmic gas and dust. As the protostar gathers more debris it becomes a main sequence star. Near the end of its life the star will grow into a red giant, and finally the outer layers will be shed, creating a planetary nebula. Supernovas and black holes only form from large stars.

What is the Tharsis "bulge"? A. The elevated part of the polar ice cap of Mars. B. A large dome that was associated with the development of an extensive fracture system. C. The result of rebound in an impact basin. D. Weight gain associated with middle age. E. A large region elevated by crustal contraction when Mars was young.

B. A large dome that was associated with the development of an extensive fracture system. Multiple, large volcanoes sit a top the Tharsis "bugle". This bulge is associated with fractures that radiate away from the bulge. The presence of large volcanoes is evidence for an ancient mantle plume that may have risen in this location, lifting the crust and producing volcanism.

Photo 66 How did Pluto's Sputnik Planum form? A. A supervolcano eruption filled a subsided basin with pyroclastic material. B. A large impact basin was filled with weak nitrogen ice. C. A steam explosion excavated a crater which then filled with water ice. D. Planetary contraction pulled the center of the basin downward

B. A large impact basin was filled with weak nitrogen ice. Like many large basins in the Solar System (Imbrium Basin or Caloris Basin) Sputnik Planitia is suspected to have formed by a large impact that occurred early in Pluto's history. We know Pluto does not have the right composition to form a pyroclastic super volcano, nor is there a way to get water ice to turn into steam at Pluto's temperature, and we know planetary contraction does not form basins, but does form thrust faults.

How many meteorite impact craters have been identified on Earth? A. About 10 B. About 100 C. About 1,000 D. About 10,000 E. About 100,000

B. About 100 Because of Earth's active tectonic, volcanism, and hydrologic systems, most of the impact craters have been destroyed. However, they were not all destroyed and there are still a couple handfuls of impact craters.

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 2.5 billion years ago. E. About 65 million years ago at the end of the age of dinosaurs

B. About 14 billion years ago. As of 2015, our best estimate for when the Big Bang occurred is 13.8 billion years ago.

Why was it surprising to discover that Enceladus had the features you just identified? A. It is composed mostly of water ice. B. Because it is so small, young surfaces were not expected. It should have cooled long ago. C. It is so close to Saturn one would expect many craters. D. It lies so far from Saturn.

B. Because it is so small, young surfaces were not expected. It should have cooled long ago. Enceladus is small (like Mimas), and based on size, it should be geologically dead and saturated with craters, just like Mimas and even our Moon. But since there is young terrain, we know something more is going on here.

Why are comets thought to have originated in a different part of the solar nebula than asteroids? A. Because they are much smaller bodies. B. Because they are composed mostly of ices. C. Because many are associated with ring systems of the outer planets. D. Because many are associated with ring systems of the outer planets.

B. Because they are composed mostly of ices. The composition of planetary bodies is a good indicator of location of formation. Asteroids are rich in silicates and metals while comets are ice rich. These different compositions indicate comets formed in a different location than asteroids, and the ice rich composition suggests the comets formed in the outer solar system. Comets are rarely seen because they originate from far out in the solar system, very few make the long journey into the inner solar system.

How thick is Earth's lithosphere? A. Less than about 10 km thick. B. Between about 10 and 200 km thick. C. Between about 200 and 1000 km thick. D. Thicker than the Moon's lithosphere.

B. Between about 10 and 200 km thick. The lithosphere is the solid, outer shell of the Earth. It includes the crust and the solid mantle that is above the asthenosphere. It ranges in thickness from ~10 km at mid ocean ridges to 200 km below convergent continental margins.

How did the giant outer planets obtain their thick atmospheres? A. By degassing from their icy interiors. B. By collapse of nebular gas onto a protoplanet's icy core. C. By collection of gas swept into the outer solar system during the T-Tauri stage of the Sun's development. D. As the nebula cooled, the volatile gases condensed onto the planets.

B. By collapse of nebular gas onto a protoplanet's icy core. The "cores" of the giant planets grew large enough to have enough gravity to hold onto the light elements in the Solar Nebula. There was not degassing, or picking up gas by sweeping around the Solar System, or volatiles condensing onto the planet (because the nebula was already cold at this location.

How are the rings of Jupiter related to the small moons Adrastea and Metis? A. The magnetic fields of tiny Adrastea and Metis shepherd small chunks of ice into a narrow ring. B. Collisions at the surface of these bodies may send showers of small particles spiraling inward to Jupiter. C. Geysers of liquid water spew from the surface, freeze into droplets of ice, and go in orbit around Jupiter.

B. Collisions at the surface of these bodies may send showers of small particles spiraling inward to Jupiter. The moons Adrastea and Metis are so close to Jupiter's rings that it is suspected, impacts into these moons can send material towards Jupiter, some of which can be trapped in the ring of Jupiter. Perhaps this process replenishes Jupiter's ring enough that the ring never completely disappears.

Photo 8 What is the best explanation for this dome shaped mound on Ceres? A. The mound 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 morphology looks similar to volcanoes seen on Earth.

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 Only elements up to iron are made within stars. All heavier elements are created during the intense event of a supernova.

Photo 32 Note the long light-toned feature that extends diagonally across this image on Mars. Which phrase(s) best describe its possible origin? Choose all that apply. A. Viscous lava flows B. Low viscosity lava flow C. Basaltic lava flow D. Landslide tongue E. Silicic lava flow F. Glacier

B. Low viscosity lava flow C. Basaltic lava flow Just like on the Moon, basaltic (low viscosity) lava flows form long flows with lobate margins. Silicic, or high viscosity, lavas cannot produce this morphology because they do not form as readily. While will look like ice and landslides are not near as long or narrow.

Photo 43 What is the most likely cause of the sinuous feature that extends across this radar image of Venus? A. Erosion by running water. B. Erosion by hot flowing magma C. Erosion by hot, near-surface winds. D. Thrust faulting. E. Extensional faulting.

B. Erosion by hot flowing magma These features are formed by flowing lava that erodes down into the rock. The sinuous nature and small width of the channels suggest it is produced by flowing lava. We know they cannot form by water, because there is no water on Venus. The sinuous nature excludes extensional faulting, and there not being many, interconnected, sinuous faults excludes contractional faulting.

Which is true about our current understanding of extrasolar planets (exoplanets)? A. Exoplanets are very rare and only found around very old stars. B. Exoplanets are common and found around many different types of stars. C. Exoplanets are only found around planets with sizes similar to the Sun. D. Exoplanets are so far away, we don't know how many there might be.

B. Exoplanets are common and found around many different types of stars. Because stars condense out of a lot of material planets form around many stars, just like our Solar System. Recently, scientists have been able to discover many exoplanets around many stars.

Photo 67 What do the arrows in this image show? A. The directions of lava flow in a volcanic plain. B. Glacial flow directions C. Impact ejecta movement D. Flash flood deposits.

B. Glacial flow directions Pluto's surface is rich in nitrogen ice that has the ability to flow at the conditions found on Pluto. These arrows indicate the direction of flowing, glacial nitrogen ice. There is no liquid to create flash flood deposits, impact ejecta deposits happen instantaneously and would not be going on currently. Nor can these features be lava flows, there are no volcanic edifices near this location (cryovolcanoes included).

Photo 5 Study this graph of the size densities of the planets and some of their satellites. Each color represents a different class of planetary bodies. Which grouping represents the outer planets? A. Blue (lower left) B. Green (lower right) C. Grey (upper middle)

B. Green (lower right) The outer planets have small densities and large diameters.

Photo 16 Examine this photograph of the nearside of the moon. How can you tell that Eratosthenes 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. Eratosthenes being on top of Imbrium's rim and lava flows shows it is younger.

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. The best way to get high concentration of iron is differentiation of planetary bodies. So these meteorites must have settled to the core of asteroids that were then broken up by a large impact.

Why is Jupiter so much larger than all of the terrestrial planets combined? A. It radiates a significant amount of energy like the Sun. B. It formed in the outer solar system where water ice was stable. C. It has low density. D. It has a large gravitational attraction.

B. It formed in the outer solar system where water ice was stable. Jupiter was able to get much larger than the terrestrial planets because there was more material to accrete from at Jupiter's location. This is a result of water ice becoming stable here. There was A LOT of water in the Solar Nebula, but it could not condense into a solid state until the water is cold enough (far enough away from the Sun). Jupiter grew large because of the presence of water ice, this in turn allowed Jupiter to have a strong gravitational attraction that allowed Jupiter to hold onto the hydrogen and helium from the Solar Nebula, leading to Jupiter's very low density.

Photo 16 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 from 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 from Copernicus cross over Eratosthenes crater. Copernicus' rays cut across Eratosthenes, and Copernicus' ejecta has not been degraded like the other crater.

In what way is Earth's atmosphere unique among the moons and planets? A. It has a nitrogen-rich (N2) atmosphere. B. It is rich in oxygen (O2). C. It is rich in carbon dioxide (CO2) because of animal life. D. It is rich in carbon dioxide (CO2) because of plant life. E. It has clouds and storms.

B. It is rich in oxygen (O2).

Jupiter is different from the terrestrial planets in what important way? A. It shows atmospheric perturbations. B. It radiates more energy than it receives from the Sun. C. It is denser. D. It has a rocky surface. E. None of the above.

B. It radiates more energy than it receives from the Sun.

Why is the present day Moon less dynamic than the planet Earth? (Select all that apply.) A. Its lithosphere is thin, preventing new landforms. B. Its lithosphere is thick. C. It cooled quickly because of its small size. D. It has no liquids flowing across its surface.

B. Its lithosphere is thick. C. It cooled quickly because of its small size. D. It has no liquids flowing across its surface. Having no atmosphere or fluids, and having cooled quickly forming a thick lithosphere, the Moon is now geologically dead with no geologic processes occurring on it besides the irregularly time impacts.

When comparing Jupiter and Saturn, which of the following is correct? (Select all that apply.) A. Jupiter has no rings. B. Jupiter is denser. C. Jupiter is smaller. D. Jupiter has more large satellites (those larger than the moon).

B. Jupiter is denser. D. Jupiter has more large satellites (those larger than the moon). Saturn has a lower density than Jupiter and has more satellites larger than 100 km in diameter than any other planet. Saturn is the second largest planet (behind Jupiter) and has more pronounced rings than Jupiter.

Photo 51A-51D This set of photographs shows various landscapes on Io and Europa. Which image shows that the surface of Europa has been tectonically deformed? A-D

D In image D we see large, criss-crossing fractures that are evidence of extensional tectonics.

Which is true about the most common volcanic rocks found on the Moon? A. They are of a type not found on Earth. B. Lunar volcanic rocks are similar to the most common volcanic rocks on asteroids and other terrestrial planets. C. Lunar volcanic rocks are high in silica and thus very viscous. D. Most were erupted explosively from stratovolcanoes like Mt. St. Helens.

B. Lunar volcanic rocks are similar to the most common volcanic rocks on asteroids and other terrestrial planets. Low viscosity basalt is the most common igneous rock on the terrestrial bodies and form lava flow channels, flows, and shield volcanoes.

About how old is the surface of Venus as judged from the abundance of meteorite impact craters? A. Thousands of years old. B. Millions of years old. C. Billions of years old. D. So varied in age that a single age cannot be given.

B. Millions of years old. Because there are few impacts, and even fewer large impacts, the surface is very young. On the order of millions of years old.

Does Mars have a plate tectonic system like Earth? A. Yes, it has mobile plates of lithosphere. B. No, it lacks a system of moving plates.

B. No, it lacks a system of moving plates.

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. No, it can only show relative dates. For example, it is younger than the surface it impacted on.

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 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. Radiometric ages are determined from radioactive elements in rocks.

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. Like the terrestrial planets, the Moon's core is most likely made of iron. And once had to convect for there to evidence for a past magnetic field in the rocks. Seismology shows the core of the Moon is very small, but does show the Moon is differentiated.

In which ways is the Oort cloud different than the Kuiper belt? (Select all that apply.) A. The Oort cloud is nearer the Sun than most of the Kuiper belt. B. The Oort cloud is spherical, not disk-shaped. C. The Oort cloud is disk-shaped, not spherical. D. Most long period comets come from the Oort cloud. E. The bodies in the Oort cloud are much richer in silicate minerals than those in the Kuiper belt.

B. The Oort cloud is spherical, not disk-shaped. D. Most long period comets come from the Oort cloud. The Oort Cloud is spherical while the Kuiper Belt is planar and in the plane of the ecliptic. The Oort Cloud is also the source of most comets while the Kuiper Belt is home to icy bodies like Pluto

Which of the following is involved in collisional accretion? A. The selective condensation of elements at different temperatures. B. The aggregation of planetismals when they impact one another. C. The hydrodynamic collapse of nebular gases. D. The gradual change of the gravitational constant.

B. The aggregation of planetismals when they impact one another. Collisional accretion is the gradual growing of material by colliding. This process does not have to do with materials changing their state from gas to solid (condensation), a nebula becoming smaller by collapse, or the gravitational constant changing (it is constant for a reason).

Which of the following are the characteristics of the asteroid belt? (Select all that apply.) A. It consists of thousands of small bodies, all less than about 10 km in diameter. B. The asteroids mark the transition from the rocky terrestrial planets to the outer planets. 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 mark the transition from the rocky terrestrial planets to the outer planets. 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. The largest asteroid Ceres is almost 1,000 km across. The asteroids are between Mars and Jupiter and have a wide array of compositions.

What are some important characteristics of the atmosphere of Jupiter? (Select all that apply.) A. Jupiter's atmosphere formed by outgassing of solids in its interior. B. The clouds are made of ices of ammonia (NH3) and water. C. The main gases in the atmosphere are ammonia and methane D. Jupiter's atmosphere formed by trapping nebula gas on to a large icy core. E. It is poor in carbon dioxide, unlike Mars.

B. The clouds are made of ices of ammonia (NH3) and water. D. Jupiter's atmosphere formed by trapping nebula gas on to a large icy core. E. It is poor in carbon dioxide, unlike Mars. Jupiter's atmosphere is mostly composed of the gases hydrogen and helium, however there are significant amounts of the ices ammonia and water. Unlike the terrestrial planets, the atmosphere of Jupiter did not form by outgassing of the planet, but by collapse of the nebular gases onto Jupiter's large rocky-ice core. And unlike Mars and Venus, Jupiter does not have any carbon dioxide in its atmosphere.

Which of the following are major differences between Io and Europa? A. Europa is much denser than Io. B. The composition of the surface materials. C. The age of their surfaces. D. Europa is much larger than Io.

B. The composition of the surface materials. The density of Io indicates Io is made of silicates, while the density of Europa indicates it is made of ice.

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. The giant outer planets are not large enough to sustain nuclear fusion like stars, but they are made of similar materials—hydrogen and helium. They have no solid surfaces and they commonly have rings.

Differences in the appearance of multiring basins on the Moon with those developed on Callisto are thought to be a result of which of the following? A. The volcanic origin of Callisto's basins. B. The difference in the behavior of ice and silicates when impacted. C. The lack of the differentiation of Callisto. D. Global contraction on Callisto, but not on the other bodies.

B. The difference in the behavior of ice and silicates when impacted. The difference between the multiring basins on the Moon and Valhalla stem from the different materials found on the surface on each of these satellites. The Moon is made of silicate rock while Callisto is made of water ice. These two materials have different physical properties from each other. This can cause differences in structures to occur from similar processes.

Photo 17 What process formed these sinuous valleys? A. Erosion by running water during the wet period 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. Sinuous valleys are made by the erosion of regolith by lava flows. The erosion is both mechanical (picks up particles) and thermal (melts particles). Erosion by water (or from melting ground ice) does not produce features with this morphology. They produce dendritic patterns. Lithospheric faulting produces straight lines, not sinuous.

What is the most likely explanation for Saturn's magnetic field? A. The magnetic field forms like Earth's—in a convecting core of molten iron. B. The magnetic field forms by convection in a shell of metallic hydrogen. C. The magnetic field forms by convection in the core of rock and ice driven by the great pressure of Saturn's interior. D. Saturn has no magnetic field. It isn't spinning fast enough. E. Saturn has no magnetic field. It has the wrong composition.

B. The magnetic field forms by convection in a shell of metallic hydrogen. Like Jupiter, Saturn does not have a iron core to generate a magnetic field in, but we know Saturn does have a magnetic field. The presence of this field can be explained by the same mechanism as we discussed for Jupiter. Convection in a metallic hydrogen shell.

Photo 60 The last 2 or 3 billion years of the histories of the small inner planets (like the Moon and Mercury) are dominated by contraction, whereas the late histories of the small icy satellites of Saturn and Uranus are dominated by expansion like that evidenced in Ariel. Why? A. The outer planet satellites have warmed and expanded over that time. B. The outer planet satellites have a lot of water ice that expands as it freezes. C. The outer planet moons are so small that gravity is not strong and they expand as a result. D. The outer planet satellites were hit by many more large impacts and these have fractured them.

B. The outer planet satellites have a lot of water ice that expands as it freezes. The difference in composition between terrestrial bodies and ice-rich bodies is the reason. As silicates and metals freeze they shrink and become more dense. As water freezes it expands and becomes less dense.

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 million years long. C. The planets started to accrete about the same time as the Sun, but then grew slowly over a period of about two billion years. D. The planets are a young feature of the Solar System forming only a few thousands of years ago.

B. The planets formed about the same time as the Sun in a relatively short period of time only a few million years long. Because of the amount of impact craters on many of the planetary bodies, and radiogenic dating we know the planets must be around 4.5 billion years old, the same age as the chondritic meteorites. These data suggest the planets formed concurrently with the Sun and completed forming relatively quickly.

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 Planets have different amounts of each element. Those planets with more dense elements will be denser than those without.

Which of the following is true about Saturn's rings? A. They are a series of solid disks spinning around Saturn like a hula hoop. B. The rings are composed of many small particles of water ice in orbit around Saturn. C. The rings have the same composition and brightness as the rings of Jupiter. D. Saturn is the only planet with rings in our solar system.

B. The rings are composed of many small particles of water ice in orbit around Saturn. Though the rings of Saturn may appear as solid disks surrounding the planet, and are in fact, made of billions of small chunks of ice that orbit Saturn.

What is the most important factor in the volcanic and tectonic evolution of Venus as compared to Mars? A. The distance Venus is from the Sun which elevates its surface temperature and makes its lithosphere thin. B. The size of Venus which makes it cool slower than Mars. C. The composition of Venus with higher concentrations of radioactive elements like potassium, uranium, and thorium.

B. The size of Venus which makes it cool slower than Mars. As we have discussed with Mercury and Mars (and terrestrial planets in general). The volcanic and tectonic evolution is determined by the planetary body's size. The larger the planet, the more heat it has, and the longer volcanic and tectonic activity will occur.

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. The inner planets are enriched in refractory elements and depleted in volatile elements because these planets formed near the Sun where it was too hot for volatile elements to condense, but was not too hot for condensation of refractory elements.

Which of the following is correct about the nebulas we see in the sky today? (Select all that apply.) 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.

B. They are concentrations of interstellar gas and dust. C. Many are the birth grounds of stars. D. Some form when stars explode. The nebulas we see today are concentrations of gas and dust that give rise to new stars. Some of these nebulas formed by supernovas.

Photo 46 Which of the letters on this shaded relief map is a convergent plate boundary? A-E

D Oceanic crust juxtaposed to continental crust always marks a convergent plate boundary.

Which of the following are correct about red giant stars? (Select all that apply.) A. These are very young stars that are cool because fusion has not started in them. B. They form as a star expands and the surface cools. C. They are among the stars with the hottest surfaces. D. They evolve from medium-sized stars. E. They evolve from large stars F. Heavy elements like uranium and thorium form in their interiors.

B. They form as a star expands and the surface cools. D. They evolve from medium-sized stars. Red giants form by expansion and cooling of the surface of a medium-sized star.

In what way is Io similar to Earth's Moon? (Select all that apply.) A. Both have heavily cratered surfaces. B. They have about the same density. C. Both have active volcanoes. D. Both are tidally locked with one face pointed toward their host planet. E. They are about the same size.

B. They have about the same density. D. Both are tidally locked with one face pointed toward their host planet. E. They are about the same size. The easiest way to answer this question is to think "what is the major difference between the Moon and Io?". The answer to this question is Io is still geologically active while the Moon is geologically dead. This is because Io experiences tidal forces with Jupiter that keeps Io warm. This results in Io having active volcanism that buries impact craters. So we would not mark A and C because only the Moon is heavily cratered and only Io has active volcanoes.

Triton, because of its small size and frigid surface, was thought to be an unlikely spot for recent geologic activity. What did Voyager 2 reveal? (Select all that apply.) A. This was true. B. Triton has many young surfaces and active "volcanic" vents. C. Triton has a dark surface ruptured by volcanic vents. D. Triton was probably heated by tidal activity.

B. Triton has many young surfaces and active "volcanic" vents. D. Triton was probably heated by tidal activity. Voyager 2 showed Triton is geologically complex, with young and old terrains, and large, smooth plains of cryovolcanically deposited material.

In the early 1980's, some planetary scientists suggested that Triton has a sea of liquid nitrogen. Voyager 2 showed that _____________________________. A. this sea is about 100 m deep B. Triton is too cold for liquid nitrogen C. Triton is too warm for liquid nitrogen D. Triton has no nitrogen

B. Triton is too cold for liquid nitrogen Triton is too cold for nitrogen to exist in its liquid state.

Large planetary bodies failed to accrete in some parts of the solar system and did not sweep their neighborhoods 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 Failure of large planetary bodies forming would leave behind a lot of material, smaller than planets, that did not accrete to form a planet. The two main areas of high amounts of small bodies are the asteroid belt (between Mars and Jupiter) and the Kuiper Belt (past the orbit of Neptune).

Many supernovas are the result of _____________________. A. the explosive removal of the star's outer layers as hydrogen burning reaches its surface B. collapse of a star with multiple burning shells C. condensation and accretion of the planets D. carbon-burning

B. collapse of a star with multiple burning shells Supernovas occur in nuclear fusion slows down tremendously in large stars. The star then collapses in on itself and ignites any unburned fuel causing a large explosion.

The Oort cloud _____________________. A. is another name for the ancient solar nebula B. contains the orbits of comets in the outer part of the solar system C. is not visible outside the orbit of Mars D. contains material ejected from the Sun that condenses to make icy comets

B. contains the orbits of comets in the outer part of the solar system The Oort cloud has never been directly observed, but is inferred from the highly elliptical orbits not within the ecliptic of comets. These orbits indicate a "cloud" of comets surrounds the solar system 1/10th of the way to the nearest star that is the source of many comets.

The tail of a comet __________________. A. is a permanent feature B. develops temporarily when the comet enters the inner solar system C. develops temporarily when the comet enters the outer solar system in an attempt to slow heat loss D. develops temporarily as material vaporizes when the comet passes through a planet's atmosphere

B. develops temporarily when the comet enters the inner solar system The tails of comets are temporary, only happening when the comet gets near enough to the Sun (within the inner solar system) that the ices begin to vaporize, forming the tail.

What causes the important differences between craters on the Moon and those on Mercury (the extent of the ejecta blanket and secondary cratering)? A. differences in the cratering rate B. different gravitational attractions on each planet C. crustal deformation D. the size of the meteorites impacting Mercury

B. different gravitational attractions on each planet Gravitational pull can effect the extent of crater ejecta and secondary craters. Both of these features will extend for greater distances on planetary bodies that have less gravity.

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 Central peaks occur in large craters on the Moon from impact. The have terraced walls on the side.

In contrast to Jupiter, Uranus and Neptune are thought to ________________________. A. have narrow ring systems B. have water ice in their interiors. C. be rocky bodies composed mostly of silicates D. have captured satellites which formed elsewhere in the solar system

B. have water ice in their interiors. While the interior of Jupiter has water ice, it has a much thicker layer and is dominated by different forms of hydrogen (metallic and molecular). Neptune does not have these hydrogen layers and instead, the interior is dominated by water ice.

The oldest types of terrains on both the Moon and Mercury are ________________________. A. smooth, flood lava plains B. heavily cratered terrain C. folded mountain belts D. characterized by sinuous rilles and linear rilles

B. heavily cratered terrain Heavily cratered terrain is older than terrain with less craters, since cratering rate has decreased with time.

Which of the following is not a mechanism of heat transport. A. conduction B. magnetism C. convection D. radiation

B. magnetism Heat can be convected (like boiling water), conducted (touching a stove), and radiated (the Sun shining). Magnetism is the attraction and repulsion between objects (magnets).

Water ice is __________________________. A. most abundant on the planets of the inner solar system B. most abundant on the moons of the outer planets C. unstable in the outer solar system because of the low pressure that exists there D. rare in the solar system

B. most abundant on the moons of the outer planets Water ice is stable and common on the moons of the outer planets and into the Kuiper belt. It is unstable in the near vacuum of the inner solar system because the temperature is too high.

Complete this sentence. Some of the satellites of Saturn ____________________. (Select all that apply.) A. are composed of materials that melt at high temperatures explaining the abundance of craters on all of their surfaces B. orbit closer to the planet than its famous rings C. also orbit Jupiter D. Have equatorial ridges formed by accumulation of ring materials

B. orbit closer to the planet than its famous rings D. Have equatorial ridges formed by accumulation of ring materials

In what way are the icy moons of Uranus different from those of Saturn? A. lower abundance of impact craters B. slightly higher densities C. uniformly larger sizes D. all have methane atmospheres

B. slightly higher densities The moons of Uranus are about the size of Saturn's intermediately sized moons. Like Saturn's moons, the moons of Uranus are made of rock and ice. However, these moons may have more rock than Saturn's as shown by higher densities of Uranus' moons.

On Earth, lithospheric plates converge at which plate boundary? A. oceanic ridges B. subduction zones C. transform faults

B. subduction zones Trenches form at the boundary between two converging, lithospheric plates.

What is one of the major causes of the high temperatures on the surface of Venus? A. high volcanic activity B. the greenhouse effect C. high radioactive element concentrations D. tidal heating

B. the greenhouse effect The high concentration of carbon dioxide, in the atmosphere, traps heat.

What is the evidence the highlands of the Moon are older than the low lands (maria)? A. the highlands have a thicker crust. B. the highlands have abundant impact craters. C. the highland craters lack obvious ejecta blankets. D. the highlands have few volcanic plains.

B. the highlands have abundant impact craters. The frequency of impact craters on a landform is the best way to determine if it is old or not. The highlands have many more impact craters than the maria suggesting the highlands are older.

As a dense particle in a planet moves toward the core, the loss of gravitational potential energy is converted to _________ energy. A. chemical B. thermal (heat) C. nuclear D. solar

B. thermal (heat)

The outflow channels on Mars are different from river systems on Earth in what way? A. they lack extensive transport systems B. they appear to come from below the surface and lack extensive collection systems C. they are proportionally smaller D. they are more sinuous E. they show numerous flow features

B. they appear to come from below the surface and lack extensive collection systems The lack of smaller tributaries connected with the large outflow channels suggest water did not flow from other places into a larger channel. Instead, the outlfow channels connection with chaotic terrain suggest the water came from melting large quantities of water ice in the chaotic terrain. This melting released huge volumes of water that produced the outflow channels.

The most volcanically active body in the solar system is ______________. A. Enceladus B. Earth C. Io D. Europa E. Jupiter

C. Io Io is the most actively volcanic body in the Solar System. This is evidenced by the fact that the spacecraft Voyager identified 11 volcanoes that had experienced recent volcanic activity. The chances of a spacecraft passing Earth and observing an erupting volcano are slim.

Photo 58 Which of the letters on this image of Titan's dunes labels a feature that is the strongest evidence for the movement of sand in the dunes? A (Small white feature) B C D

C C shows linear dunes that are very indicative of movement of sand particles. B and A are both hills with no dunes on their surfaces.

Photo 46 Which of the letters on this shaded relief map is a divergent plate boundary? A-E

C Divergent plate boundaries often occur in oceanic crust and produce grabens and normal faults.

Photo 52 Which letter in this image of Ganymede labels an area of grooved terrain? A-C

C Ganymeade is made up of two primary terrains: the dark cratered terrain and the bright, grooved terrain. C is the grooved terrain, we can determine this by seeing grooves within bright bands that cuts across darker terrain (A).

Photo 36 Mass movement commonly affect steep slopes on the planets. Which letter labels a landslide on Mars? A-E

C Landslides are a mass movement process that produces a deposit that look like tongues that stick out from mountainous terrain. These landslides result from debris flowing off of a topographically high area.

Photo 45 Which of the letters on this cross section of Earth labels where the mafic ocean crust is made? A-F

C Mafic oceanic crust is made at mid-ocean ridges, where upwelling mantle partially melts and the magma is erupted through a fissure.

Photo 55 Enceladus (500 km across) and Mimas (400 km across) are both small, icy moons with about the same diameter. Enceladus is shown here. Which letter labels a feature that makes Enceladus so different from Mimas? A-C

C Mimas is a geologically dead moon and saturated with craters. While Enceladus does have some heavily cratered terrain, it also has younger terrain shown at C.

Photo 46 These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Which of the images is of crater on Mars? A-D

C Some craters on Mars are very distinctive because of the pattern of fluidized ejecta surrounding them.

Photo 3 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? A-H

C The crust is the outer most layer of a planet.

Photo 9 On this photo of the Moon, which labeled section is one of the maria? A-D

C The maria are the dark, low lying basins.

Photo 11 Which of the craters below is the oldest? A-D

C The older craters are more degenerate, it is harder to see the details of old craters.

Photo 14 This graph shows impact crater sizes versus the numbers of craters per square kilometer for several different regions of the Moon. Which line corresponds to the youngest terrain? A-C

C This graph shows Mare Imbrium has the lowest crater frequency and therefore must be the youngest.

Photo 35 Which of the features is the result of tectonic contraction on Mars? A-F

C Contraction (shortening) produces, lobate and positive relief structures like wrinkle ridges.

Photo 48 These images show 5 stages in Earth's 4.6 billion year evolution. Using the dropdowns below, sort the images from youngest (present day) at the top, to oldest (primordial Earth) at the bottom. A-E

C - Youngest E A D B - Oldest Earth started off forming a primitive crust that was pelted by many impacts (B). Subsequently, small nuclei of continents began to form (D). These nuclei began to grow into large continents with a granitic composition and plate tectonics began (A). These continents collided and attached to one another to form the super continent known as Pangea (E). Ultimately, Pangea broke up, dispersing the continents and placing them in the locations we see today (C).

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 Asteroids can be very small and get up to 1000 km in diameter.

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 The thermal evolution of planets is only seen in the solid, silicate-rich terrestrial planets. As a planet cools its lithospheric thickness increases, since small planets cool faster than large planets a smaller planet will have a thicker lithosphere.

Why is Neptune blue? A. Because of the scattering of light by dust grains in its atmosphere. B. Because of reflection off an ocean of liquid water that lies just below the cloud layer. C. Because its atmosphere contains a significant proportion of methane. D. Because it has a high concentration of metallic hydrogen near the base of the clouds.

C. Because its atmosphere contains a significant proportion of methane. Neptune's atmosphere because of the presence of methane, which reflects blue light and absorbs red light.

The Moon's highland crust consists largely of plagioclase feldspar. Since no magma has that 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 from running water.

C. By flotation of plagioclase feldspar in a magma ocean. Plagioclase is less dense than mafic magma allowing plagioclase to float to the top of a magma ocean.

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. Earth was not large enough to trap gaseous elements in the Solar Nebula like the outer planets were. Instead, the volatiles in Earth were released from the hot interior.

Where does Jupiter's large magnetic field come from? A. It develops like Earth's field when convection happens in a layer of molten iron deep inside. B. All planets that spin have magnetic fields. C. Convection in a layer of ionized hydrogen may create the magnetic field. D. It is induced by the orbital motions of its moons and the ring system.

C. Convection in a layer of ionized hydrogen may create the magnetic field. As we have discussed previously, movement of a charged particles can produce a magnetic field. With the terrestrial planets a magnetic field is produced by convective motion of molten iron in the planets outer core. Since Jupiter does not have the same internal structure there must be a slightly different way the magnetic field develops. It occurs by convective motion of charged hydrogen in the metallic hydrogen layer of Jupiter.

How did the multiple rings of Valhalla on Callisto form? A. Collapse of a volcanic caldera. B. Domal upwarping of the lithosphere. C. Crustal breakage as impact shock waves traveled through the surface. D. Eruption of flowing ice outward from a surface fracture.

C. Crustal breakage as impact shock waves traveled through the surface. Valhalla is a large impact structure. It has multiple rings, just like the multiring basins on the Moon (though Valhalla has many more rings). These rings form as shock waves travel through the crust after impact.

Photo 7 Why are asteroids closer to Jupiter so much darker than those near Mars? 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. Asteroids closer to Jupiter are farther from the Sun and have more carbonaceous material.

Photo 5 Study this graph of the size densities of the planets and some of their satellites. Each color represents a different class of planetary bodies. Which grouping represents the inner planets? A. Blue (lower left) B. Green (lower right) C. Grey (upper middle)

C. Grey (upper middle) The inner planets are dense and small.

Photo 2 Think about the process of planetary accretion. Which statement best describes our current ideas about the rate of impact cratering in the inner solar system? A. The rates of meteorite bombardment steadily declined after the age of accretion. B. The rate of bombardment increased with time to reach its maximum today. C. Initially, the rate declined smoothly, but there was a later episode of heavy bombardment followed by resumption of the decline. D. Initially, the rate increased smoothly, but there was an episode of much lower impact rates followed by a resumption of the increase.

C. Initially, the rate declined smoothly, but there was a later episode of heavy bombardment followed by resumption of the decline. The impacted surface of the Moon, as well as modelling, show the impact frequency was high at the beginning of the Solar System. With time frequency decreased (because there was not as much material) until the orbits of the gas giants changed sending a high amount of material into the Solar System causing a spike in the frequency. Since the Late Heavy Bombardment the frequency has declined greatly.

A giant molecular cloud is best described by which statement? A. It is a hot mass of ionized gas that cannot collapse to form a star. B. It is the ejected shell from a dying red giant star. C. It is a cool mass of gas and dust that can be light years across. D. It is a cloud of gas and dust violently ejected from a supernova explosion.

C. It is a cool mass of gas and dust that can be light years across. A molecular cloud is a grouping of cool gas and dust. Not to be confused with a planetary nebula that forms from the death of a medium sized star.

Why does Mars lack a well-integrated hydrologic system? A. It is poor in water. B. It is too hot. C. It is too cold. D. It never differentiated.

C. It is too cold. No flowing water presently the vast amounts of water ice in the ground and polar regions suggest it is too cold for water to flow as a fluid on the surface today.

Why is it appropriate to call Uranus the "oddball" planet? A. It lacks a ring system. B. It has a density similar to terrestrial planets in spite of its gas-rich composition. C. Its spin axis is tipped from vertical by over 90 degrees. D. It revolves around the Sun in a retrograde direction.

C. Its spin axis is tipped from vertical by over 90 degrees. Uranus is very similar to the other gas giants. It has a faint ring system made of dark materials (making it hard to see), Uranus has a similar density, and it revolves around the Sun in the same direction. The biggest difference between Uranus and every other planet (excluding Pluto) is its extreme axial tilt (90 degrees).

Saturn is the most similar in composition and internal structure to which of the planets below. A. Mercury B. Mars C. Jupiter D. Neptune

C. Jupiter The composition of Saturn is incredibly rich in hydrogen and helium, just like Jupiter. Mars and Mercury are terrestrial planets rich in silicates and metals. Neptune does have hydrogen and helium but it also has a lot of methane, which Saturn and Jupiter do not have.

Photo 68 The dark reddish regions on Charon's north pole result from what process? A. Impact of icy cometary objects with distinctive compositions. B. Landslides. C. Methane from Pluto condenses at Charon's poles. D. Deposits from geysers like those on Enceladus.

C. Methane from Pluto condenses at Charon's poles. The reddish material on Charon's north pole is compositionally similar to that of tholins and can be produced by photochemical reactions of methane. This methane is sourced from Pluto as it escapes the atmosphere. The methane can make its way to Charon and become deposited on the north pole during a Charon winter. As the pole moves into the sunlight, the methane reacts with the light and becomes refractory.

Where is Saturn's Roche limit for small icy bodies in orbit around it? A. Near the orbit of Tethys. B. In the Cassini Division. C. Near the outer edge of the rings. D. Near the inner edge of the rings. E. Just beyond the orbit of the outermost satellite.

C. Near the outer edge of the rings. The Roche Limit is near the outer edge of the rings. Closer to the planet than this, Saturn has the rings of broken fragments. Beyond this distance, Saturn's satellites are whole.

Pluto's atmosphere is tenuous and temporary, but what are it's major constituents? A. Hydrogen and helium inherited from the solar system. B. Carbon dioxide and oxygen released by volcanism as a secondary atmosphere. C. Nitrogen and methane that sublime from the most volatile ices on its surface. D. Water vapor that sublimes from its thick water ice crust.

C. Nitrogen and methane that sublime from the most volatile ices on its surface. The composition of Pluto's surface is reflected in the composition of the body's atmosphere. Pluto's surface ices of nitrogen and methane are so volatile and Pluto's surface temperature is so close to the ices sublimation temperature that small fluctuations in solar insolation can cause these ices to sublime into the atmosphere. Pluto is too small to have, gravitationally, held on to the hydrogen and helium of the Solar Nebula. Since Pluto is not a terrestrial planet, there was no volcanic outgassing carbon dioxide and no life to form free oxygen. While Pluto does have a thick water ice lithosphere, Pluto's surface temperature is too cold to allow sublimation of water ice.

Photo 54 What causes the Cassini Division, the 400 km wide break in the rings of Saturn? A. The tidal disruption of small bodies at this distance. B. The low temperature at this distance. C. Orbital resonance of the ring particles with the larger satellites. D. The presence of a ring shepherd in the gap.

C. Orbital resonance of the ring particles with the larger satellites. The gap appears to be the result of Mimas 2:1 resonance with the division. Clearing out the division by pulling the objects away from this location. Tidal disruptions would cause fragments to form here, and therefore is not correct. Perhaps, there are larger particles that sweep up smaller particles. But planetary scientists have not seen evidence for this.

Which of the following are major extensional features on Venus? A. The wide belts of ridges on the lowlands. B. The continental highland known as Ishtar Terra. C. Rift valleys and grabens associated with lithospheric domes.

C. Rift valleys and grabens associated with lithospheric domes. Rift valleys and grabens form by extension. While ridge belts are contractional and Isthar Terra is also contractional.

What do thermal models of Mercury's evolution suggest about its history? A. That it has developed a core in the last billion years or so. B. That it experienced global expansion to produce domical bulges. C. That it developed a metallic core early in its history. D. That its history is more like the Earth's than the Moon's.

C. That it developed a metallic core early in its history. The iron within Mercury separated out into a core early in the planet's history.

The two large volcanoes of Venus, Theia Mons and Rhea Mons, lie on the flanks of a structure similar to which of the following? A. A subduction zone like the one that formed Andes Mountains of South America. B. A volcanic chain over a "hot spot" like Hawaii. C. The East African Rift valley. D. An island arch such as Japan.

C. The East African Rift valley. Devana Chasma is an extenisonal feature. This is most similar to the East African Rift valley (also extensional). A subduction zone produces contractional features and thickens the crust. Volcanic hot spots form volcanic edifices. The island arc is also volcanic not tectonic.

What is the major difference between the composition of the Moon and Earth? A. The Moon is richer in volatile elements than Earth. B. The Moon is richer in iron than Earth. C. The Moon is poorer in water than Earth. D. The Moon has a lower H/He ratio than Earth.

C. The Moon is poorer in water than Earth. The Moon has less water than the Earth. This is seen in the absence of oceans, water ice, and explosive eruptions. We know the Moon is poorer in iron because it has a much smaller core than the Earth.

Which of the following statements are accurate descriptions of the atmosphere of Venus? A. It is cold and dry. B. It is the densest of all the planets. C. The Venusian atmosphere is rich in carbon dioxide. D. It is an inherited remnant of the gaseous solar nebula. E. It has abundant water vapor.

C. The Venusian atmosphere is rich in carbon dioxide. The composition of the Venusian atmosphere is ~96% carbon dioxide. It is a secondary atmosphere that formed by from outgassing. The composition and thickness of the atmosphere trap incoming heat, allowing the planet to become hot enough on the surface to melt lead. While Venus' atmosphere is incredibly dense (and the most dense of the inner planets), it is not the most dense. That title belongs to one of the Gas Giants.

What is the approximate age of the surface of Venus? A. Most of the surface of Venus is about the same age as the heavily cratered lunar highlands. B. The smooth volcanic plains of Venus are about the same age as the lunar maria. C. The average age of the surface is much younger than any of the Moon's major terranes.

C. The average age of the surface is much younger than any of the Moon's major terranes. Venus is a large planet and cooled slowly, unlike the small planetary bodies of the Moon and Mercury. The slow cooling would allow for volcanism and tectonic activity to occur and resurface Venus, or possibly, still.

How did the Chicxulub impact affect Earth? A. The impact did little to affect the Earth since about half of the crater was in the ocean. B. The impact appears to have triggered large outpourings of basaltic lava that filled the basin. C. The impact triggered a series of climate changes that led to the extinction of many species, including dinosaurs. D. The Gulf of Mexico was created by this huge impact.

C. The impact triggered a series of climate changes that led to the extinction of many species, including dinosaurs. The impact that formed Chicxulub crater was large enough to eject a vast amount of dust into the sky. This dust blocked incoming solar radiation and cooled the Earth, leading to the extinction of many creatures and plants. The impactor was not large enough to create the Gulf of Mexico, but it did impact near the gulf.

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 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.

Photo 28 How did these vast valleys on Mars form? A. The wide valleys formed as flood lavas crossed the surface. B. The valleys were carved by winds blowing off the Tharsis rise. C. The outflow valleys were eroded by liquid water. D. The valleys formed as glaciers eroded the landscape but then melted away.

C. The outflow valleys were eroded by liquid water. Flowing water erodes the landscape and produces sinuous stream channels that flow from higher elevation (left) to lower elevation (right).

Photo 56 Why are many of Saturn's moons shaped like this one (Phoebe), instead of being essentially spherical? A. They lie too far from the Sun to become spherical—a feature caused by more intense solar winds near the Sun B. These satellites lie too far from Saturn to be affected by its intense magnetic field. C. The size and hence the gravity field are not large enough to deform the irregular bodies into near spherical shapes. D. The irregular satellites have solid surfaces unlike the gaseous, but spherical moons.

C. The size and hence the gravity field are not large enough to deform the irregular bodies into near spherical shapes. As discussed early in the semester, to become spherical a planetary body needs to be large enough to have enough gravity to overcome the strength of the materials it accreted from.

Photo 76 What is the most important control on a planet's present level of geologic activity (especially volcanism and tectonism)? A. Its distance from the Sun. B. Its surface temperature. C. The thickness of its lithosphere. D. The composition of its atmosphere.

C. The thickness of its lithosphere.

The final days of comet Shoemaker Levy 9 were marked by which of the following? (Select all that apply.) A. The formulation of a planetary nebula. B. Its tidal breakup in orbit around the Sun. C. The vaporization of all of its ice and consequent disaggregation. D. Explosions in the atmosphere of Jupiter

C. The vaporization of all of its ice and consequent disaggregation. D. Explosions in the atmosphere of Jupiter The life of the comet Shoe Maker Levy 9 ended as it broke apart as all of its ice was vaporized and the multitude of remaining parts fell into Jupiter's atmosphere in a series of explosions.

Photo 30 What is the probable origin of the features shown in this image of the surface of Mars? A. Glaciers of flowing ice shaped this landscape. B. Volcanic processes shaped these landforms. C. These are dendritic channels eroded by liquid water. D. Vast floods of water caused these outflow channels. E. Sublimation of ground ice caused collapse of the surface. F. This is a dune shaped by the wind. G. This is part of the polar ice cap of Mars.

C. These are dendritic channels eroded by liquid water.

Folded mountain belts are important tectonic landforms. Which of the following statements is the most accurate description of folded mountain belts? A. They are found on all of the terrestrial planets. B. They are dominated by normal faults and grabens. C. They are found around the margins of highlands on Earth and Venus. D. They are produced by impact compression of thin lithospheres.

C. They are found around the margins of highlands on Earth and Venus. These features are not seen across all of the terrestrial planets. The sinuosity and intertwining of the ridge belts are a distinctive feature are evidence of contractional and not extensional tectonics. Thus, they are not dominated by normal faults but by thrust faults.

What is the evidence that the moons of Saturn are generally icy? A. They orbit near the icy rings of Saturn so they must also be icy. B. Their most common mineral is light-colored feldspar. C. They have densities less than 2.0 g/cm3. D. They are volcanically active like Io.

C. They have densities less than 2.0 g/cm3. The density of a planetary body is indicative of its composition. High density suggests a lot of metal and silicates, low density suggests a lot of ice. Since we have low densities for Saturn's moons we can conclude they are icy.

The banding of Jupiter's atmosphere is probably related to which of the following? A. Jupiter's atmosphere shows no banding. B. Reflection of the surface features. C. Turbulent winds in the atmosphere of this rapidly spinning planet. D. The composition of the atmosphere.

C. Turbulent winds in the atmosphere of this rapidly spinning planet. The bands of Jupiter (called "zones") are formed by turbulent winds in the atmosphere similar to the cyclones and anticyclones of Earth (rising and sinking gas). By looking at any image of Jupiter, we know the planet is indeed banded. Since Jupiter does not have a true surface and does have an incredibly thick atmosphere, we can deduce the bands are not a reflection of surface features.

Photo 44 What is the most likely cause of the radical tectonic features on this part of Venus? A. NW-SE extension B. E-W compression C. Vertical doming D. Vertical down-warping

C. Vertical doming Rising plumes can dome the crust and produce radial fractures. Other contractional or extensional features are usually linear and only form in one direction.

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. Because of the small sizes, volcanism would have occurred on asteroids long ago.

Photo 65 The tall mountains on Pluto are composed of what kind of ice? A. Methane B. Nitrogen C. Water D. Carbon dioxide E. Ammonia

C. Water At the surface temperatures of Pluto, the volatile ices listed above are too weak to support topography. These ices will flow under their own weight. On the other hand, water ice is incredibly strong, perhaps as strong as silicate rock at these low temperatures, and can build up high topography (4-5 km).

Considering the ways it forms, deforms, and crystallizes, glacial ice can be considered to be which of the following? A. regolith B. an igneous rock C. a metamorphic rock D. a sedimentary rock

C. a metamorphic rock Since the ice in glaciers deforms and recrystallizes without melting it is similar to metamorphic rocks. Unlike igneous rocks that come from melt or sedimentary (which come from fragments of previously eroded rocks) or regolith (dust)

Which of the following is a common process that occurred during the evolution of the satellites of Uranus? A. fluvial erosion by running water B. eolian erosion by strong, cold winds C. cracking as they expanded late in their histories D. the eruption of basaltic (silicate) lavas E. accretion from dense rocky materials

C. cracking as they expanded late in their histories As these ice-rich moons cool and the liquid water freezes, the water ice expands, and creates large fractures that cut across the moons surfaces. There is no running water, or atmosphere to cause erosion, and cool nature/composition of the moon does not allow basalt to form.

Large amounts of water (as gas or liquid) on Venus _________. A. lie in shallow oceans near its cool polar regions. B. probably never existed C. have probably been lost to space and by combination with surface materials. D. exist beneath the surface in shallow aquifers.

C. have probably been lost to space and by combination with surface materials. Since there is no water observed on Venus, and there most likely was (since we have water on Earth), the water must have been lost to space.

What is the most important source of energy that drives the circulation of Saturn's atmosphere? A. solar heating B. rotation C. heat released from the interior D. large storms in the outer atmosphere E. the large magnetic field

C. heat released from the interior Unlike the terrestrial planets, the motions within Saturn's atmosphere are caused by heat rising from the planet's interior. Perhaps, as a result of liquid hydrogen raining out from the atmosphere.

Photo 53 What is the most abundant of the gases comprising Saturn? A. nitrogen B. helium C. hydrogen D. ammonia

C. hydrogen Like Jupiter, hydrogen is the most abundant gas on Saturn.

The nucleus of a comet __________________. A. is small, bright, and composed of ices B. is large, bright, and composed of vapors and dust jetted from the core C. is small and dark D. has never been seen

C. is small and dark Comet Halley is a good, representative sample of comets. Like comet Halley, the nucleus of comets is dark. The reason why is shown in Figure 14.4, the surface of a comet's nucleus is coated in a dark, carbonaceous residue.

The T-Tauri phase of a star's history ______________________. A. strips away the atmosphere of any planet formed around it B. results in the production of planetary condensates C. is typified by extreme fluctuations in energy and a strong magnetic field D. is the result of stellar collapse

C. is typified by extreme fluctuations in energy and a strong magnetic field The T-tauri stage occurs near the end of a stars formation. During the T-tauri stage, the star gives up huge amounts of energy and has a strong magnetic field. The energy may clear away some of the loose debris surrounding the star, but it is not strong enough to strip away the atmosphere of formed planets

The surface of Io is thought to be less than a million years old because ________________. A. it is internally differentiated B. it is too close to Jupiter C. it has no impact craters D. volcanoes have been discovered on its surface

C. it has no impact craters As we have seen numerous times throughout the course of this class, the crater density on a planetary body reflects how old the surface is. Since Io has no impact craters, we can conclude the surface is very young.

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 The motion of the impactor creates the crater. radiogenic, potential, and thermal energy do not cause the holes.

Graben formation is usually associated with which process? A. catastrophic flooding B. lithospheric contraction C. lithospheric extension D. lithospheric cooling E. dust storms

C. lithospheric extension Grabens are fractures that form from expansion and extension of the lithosphere.

Which "planet's" interior stayed warm longer? A. Vesta B. the Moon C. Mercury D. Mars

D. Mars

Impact craters on Venus that are larger than about 30 km in diameter are __________. A. rare because of the planet's dense atmosphere B. abundant on the cratered highland of Ishtar Terra C. not common because of the planet's dynamic interior and young surface D. not visible because of the low resolution of current images

C. not common because of the planet's dynamic interior and young surface The surface of Venus is too young to have large craters. They would have been destroyed.

The most important mineral in the upper mantle of the Moon is _______. A. iron B. magnesium C. olivine D. peridotite

C. olivine Olivine is a common mineral in all of the terrestrial planets mantle.

A "star" that shines, but not as a result of nuclear reactions, is called a __________. A. T-Tauri star B. nebula C. protostar D. supernova E. planetismal

C. protostar Protostars shine because of the heat produced by friction as debris collapses onto the forming star. The T-tauri stage of a star begins with the onset of nuclear fusion. A nebula shines because of surrounding stars and planetismals do not shine at all.

Which of these geologic features are not found on all of the following planets—Mercury, Mars, and Earth? (Choose all that apply) A. impact craters B. tectonic landforms C. sand dunes D. volcanoes E. river valleys

C. sand dunes E. river valleys We have not seen either of the features on Mercury or the Moon. Both are too dry and cold to have had or have flowing water and no atmosphere to produce dunes.

What is the weak layer within a terrestrial planet that behaves like a viscous (flowing) fluid? A. the crust B. the lithosphere C. the asthenosphere D. the mantle

C. the asthenosphere The asthenosphere is the partially molten, and viscously behaving layer in a terrestrial planet. The crust is the upper most section of a terrestrial planet that is made of basaltic or felsic composition. The lithosphere is a subdivision of a planet that consists of the crust and solid mantle. The mantle is a section ultramafic rock in a terrestrial body.

Which of the following are true about mid-ocean ridges? (Select all that apply.) A. a site of deep earthquakes B. the equivalent of a subduction zone C. the site of the production of oceanic crust D. becomes progressively younger toward Iceland E. has abundant extensional normal faults

C. the site of the production of oceanic crust E. has abundant extensional normal faults Mid-ocean ridges are a type of divergent plate boundary. Here oceanic crust is formed as two oceanic plates move away from one another, and upwelling mantle partially melts, then solidifies as basalt. This makes a thin layer of crust, and because it is thin, only shallow earthquakes occur here. Because they are divergent there are many extensional faults within mid-ocean ridges.

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 Young meteorites must have undergone differentiated processes to have a young formation age. Only planets are large enough to have still had these processes going on recently.

Photo 69 Comets glow in the night sky because __________________________. A. they produce energy by cold fusion B. they produce energy by thermonuclear fusion C. they reflect the light from the Sun D. the coma consists of ionized gasses that interact with the Sun's magnetic field.

C. they reflect the light from the Sun Comets do not produce energy on their own, however, they do glow (as seen in Figure 14.2). Comets glow because of the light reflected from Sun.

Examples of highly refractory materials are ____________________________. A. argon (Ar), ammonia (NH3), and methane (CH4) B. iron (Fe), oxygen (O2), carbon (C), and sulfur (S) C. tungsten (W), osmium (Os), and zirconium (Zr) D. sodium (Na), potassium (K), and rubidium (Rb)—the alkalies

C. tungsten (W), osmium (Os), and zirconium (Zr) Refractory elements are those that condense at high temperatures. Volatile elements condense at low temperatures.

Using the dropdown boxes below, sort the lunar time periods chronologically by placing the youngest period on top and the oldest on bottom. Imbrian, Copernican, Eratosthenian, Nectarian

Copernican (youngest) Eratosthenian Imbrian Nectarian (oldest)

Photo 12 Using the drop-down boxes below, arrange these impact craters from smallest (on top) to largest (on bottom). Crater A - Crater D

Crater D (smallest) Crater A Crater B Crater C (largest) With increasing size a craters morphology changes from bowl shaped, to terraced, to a central peak, to a peak ring/s.

Photo 45 Which of the letters on this cross section of Earth labels where the silicic continental crust is made? A-F

D Continental crust is made at convergent plate boundaries. Where the under riding plate induces partial melting of the mantle wedge, creating magmas with andesitic to rhyolitic compositions.

Photo 46 These images show impact craters on the Moon, Mars, Venus, and Earth. Each has distinctive features because of the geologic processes that affect the surface. Which of the images is of crater on Venus? A-D

D Craters on Venus have bright material that surrounds and flows away from the crater.

Photo 22 Carefully study this image of the Moon. Which letter labels a tectonic feature that probably formed by extension? A-D

D D is a linear rille that looks like a valley that has been pulled apart.

Photo 34 Which part of this image of Mars has evidence of tectonic extension? A-D

D Extension of the lithosphere produces linear valleys in the crust.

Photo 62 Which letter on this image of Triton marks an area that has a composition like Earth's atmosphere? A-D

D Triton's polar ice cap is dominated by nitrogen ice. D is this ice cap as shown in figure 12.13. Also, look for the dark streaks that are present within the ice cap.

Photo 3 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? A-H

D asthenosphere is depleted as it freezes into a planets lithosphere.

Photo 24 Using the drop-down boxes below, arrange these images in the proper order to show the evolution of the Moon from 4.5 billion years ago to today in four different stages. Put the first stage (long ago) at the bottom and the fourth stage (today) at top. A-D

D (4th Stage, Today) B A C (1st Stage, Long ago)

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 Ages from meteorites suggest condensation occurred 4.5 billion years ago.

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. Most meteorites are very old (4.6 billion years ago) because most small, really old material never accreted to a major planet.

Pluto is considered to be a dwarf planet by some astronomers. Why? A. Because it is not big enough to have developed a nearly spherical shape. B. Because it generates heat by nuclear fusion deep in its core. C. Because its orbit is elliptical and inclined. D. Because it has not cleared its orbital path of debris.

D. Because it has not cleared its orbital path of debris. The current definition of a planet can be stated as: a planet is spherical, does nut does not generate nuclear fusion, orbits the Sun, and has cleared its orbit. Images from New Horizons show Pluto is spherical and does not undergo nuclear fusion. Pluto's orbit is elliptical and inclined, but the definition of a planet does not address this concern. Pluto is not considered a planet because there is still debris in Pluto's orbit; Pluto has not cleared out its orbit.

Which gas was most efficiently removed from the Earth's atmosphere since the advent of life? A. Oxygen—O2 B. Helium—He C. Nitrogen—N2 D. Carbon Dioxide—CO2 E. Water—H2O

D. Carbon Dioxide—CO2 The first forms of life on Earth were single-celled organisms that breathed in carbon dioxide, by photosynthesis, and produced free oxygen.

Which features of Mars indicate a distinctive geologic process that doesn't operate on Mercury or the Moon? A. Linear rilles caused by tectonic activity. B. Volcanic plains and volcanoes. C. Wrinkle ridges caused by tectonic processes. D. Domal upwarps of the lithosphere and associated fractures caused by mantle plumes.

D. Domal upwarps of the lithosphere and associated fractures caused by mantle plumes. Formation of lithospheric domes but rising mantle plumes are not seen on the Moon or Mercury, while Mars has several.

What explains the number of impact craters that have been identified on Earth? (Select all that apply.) A. Earth is so large that it has many meteorite impact craters on the surface. B. Earth formed 4.6 billion years ago and so it has accumulated many impact craters on its surface. C. Earth has only a few impact craters because it is shielded heavily by the Moon. D. Earth has few impact craters because its ancient surface has been extensively modified by erosional processes. E. Earth has few impact craters because many were obliterated by subduction, mountain building, and volcanism.

D. Earth has few impact craters because its ancient surface has been extensively modified by erosional processes. E. Earth has few impact craters because many were obliterated by subduction, mountain building, and volcanism. Because of Earth's active tectonic, volcanism, and hydrologic systems, most of the impact craters have been destroyed.

Where did the water in Earth's hydrosphere come from? A. From a late bombardment by icy comets. B. From gradual trapping of water molecules in space by Earth's gravitational field. 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. Water was trapped within the materials that created the Earth. As these materials heated up, the volatile water escaped from the rock and was released on the surface via volcanoes.

Which of the following are common features on the icy satellites of Saturn? A. Large shield volcanoes like those on Mars. B. Multiring impact features like those on Callisto and Ganymede. C. Integrated hydrologic systems with rivers and oceans. D. Global rifts apparently caused by expansion. E. Thick atmospheres of carbon dioxide

D. Global rifts apparently caused by expansion. A common feature of ice rich satellites are large rifts caused by extensional tectonics. This occurs because solid water takes up more volume than liquid water. So when the liquid water freezes, the planet expands forming rifts and grabens.

Where are the oldest rocks on Earth found? A. At points farthest from an ocean ridge. B. At points farthest from a subduction zone. C. In Hawaii. D. In its continental shields.

D. In its continental shields. The oldest rocks on Earth are found on continental shields because they are not disturbed in this location. At the fartherest point from a mid-ocean ridge, the plate is subducting and being destroyed. And vice versa, at the farthest point from a subduction zone the rocks are being created at a mid-ocean ridge, therefore they are young. Hawaii has rocks being created right now, so most of them are very young.

Which of the following statements is true about Europa? A. Europa has no water ice at its surface and is dominated by silicates. B. Europa has abundant craters and large impact basins. C. It is composed of ice throughout. D. It has crisscrossing stripes and fractures.

D. It has crisscrossing stripes and fractures. The images of Europa show long, linear fractures that extend across the icy surface.

Suppose that a new planet has been discovered between Venus and Earth. It is about the size of Earth's Moon. Which of the following statements about it is probably true? A. It would be covered with a thin layer of water ice. B. It should have a very active tectonic system. C. It will have numerous active volcanoes. D. It should be intensely cratered and lack a thick atmosphere. E. It should have a thick, oxygen-rich atmosphere.

D. It should be intensely cratered and lack a thick atmosphere.

Which planetary body has (basically) no magnetic field today? A. Earth B. Jupiter C. Mercury D. Mars

D. Mars Though Mars is larger than Mercury it does not have a present magnetic field. There is evidence within martian rocks that show there was one in the past, but there is not an active one today.

Photo 6 Study this image of Vesta. What is the most likely cause of the linear ridges and grooves near equator of Vesta? 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

Which describes the Moon's history better? A. The Moon has been expanding since it formed because of radioactive decay. B. The Moon has been shrinking since it formed because it is cooling. C. The Moon has not experienced a change in dimensions, D. The Moon first expanded slightly because of heating and has since been contracting.

D. The Moon first expanded slightly because of heating and has since been contracting. When refractory materials are hot and liquid they take up more space than the solid equivalent. Since the Moon started out mostly molten it initially expanded. But as most of the magma solidified it contracted as the solid version of magma is more dense.

What sets the composition of the moons of the outer planets apart from the inner planets? A. The moons of the outer planets have abundant hydrogen and helium -- like the planets around which they revolve. B. The moons of the outer planets are dominated by nitrogen ice. C. The moons of the outer planets generally have more iron metal and are denser than those of the inner planets. D. The moons of the outer planets generally have lower densities.

D. The moons of the outer planets generally have lower densities. The moons of the outer planets are too small to retain atmospheres of hydrogen and helium and are dominantly water ice rather than nitrogen ice, which is only stable in the far outer reaches of the solar system.

Which of the following best describes the orbital evolution of the planets in our solar system according to the Nice Model? A. The orbits of the planets have been more or less the way they are today for over 4.5 billion years. B. The orbits of the inner planets were once much closer to the Sun than they are now and they have slowly moved outward by centripetal forces. C. Earth, Mars, and Venus formed in the outer solar system, but they have slowly spiraled inward to their present orbits near the Sun. D. The orbits of the outer planets changed significantly about 3.9 billion years ago as Uranus and Neptune moved outward from the Sun.

D. The orbits of the outer planets changed significantly about 3.9 billion years ago as Uranus and Neptune moved outward from the Sun. As mentioned above, the orbits of the gas giants changed dramatically 3.9 billion years ago. The orbits extended farther form the Sun (especially Neptune and Uranus) and the orbits of Neptune and Uranus switched. The inner planets orbits remained unaffected.

Photo 71 What is the origin of the light-colored streaks extending from the surface of comet Churyumov-Gerasimenko? A. The streaks are small volcanic eruptions like those on Io. B. The streaks are just light reflected off the surface to form rays. C. The streaks were formed as material was ejected from the surface by a small impact. D. The streaks are plumes of dust and gas ejected from the interior as the Sun heats it.

D. The streaks are plumes of dust and gas ejected from the interior as the Sun heats it. Because comets are so small, they do not have any internal energy to produce volcanism, so these streaks are the result of a different process. As comets get near the Sun they heat up. This increase in heat, vaporizes the interior ices into gas that is released through surficial cracks and produces these streaks.

Photo 29 What is the probable origin of the features shown in this image of the surface of Mars? A. Glaciers of flowing ice shaped this landscape. B. Volcanic processes shaped these landforms. C. These are dendritic channels eroded by liquid water. D. These features are dunes shaped by the wind. E. This is part of the polar ice cap of Mars. F. Sublimation of ground ice caused collapse of the surface. G. Vast floods of water caused these outflow channels.

D. These features are dunes shaped by the wind.

Which of the following is true about the subdued crater palimpsests on Ganymede? A. They formed as the planet froze and expanded. B. They are more abundant in the grooved terrain than in the cratered terrain. C. Palimpsests were produced by ionic deformation within the ice. D. They were produced as the icy lithosphere flowed to fill in an impact crater.

D. They were produced as the icy lithosphere flowed to fill in an impact crater. By definition, palimpsests are remnants of old craters that have been modified by ice flow, causing the crater to be smoothed out and the topography erased. These craters are similar to ghost craters on the terrestrial planets (such as Mercury and the Moon) where basalt lava flows covered the original crater.

Based on what we know today, which of the following is most like Pluto in its size, composition, and density? A. Mercury B. the Earth's Moon C. Europa D. Triton E. Neptune

D. Triton Triton, like Pluto, is small (2,700 km in diameter compared to Pluto's 2,377 km), rich in nitrogen ice, and has a water ice lithosphere and a rocky core. Mercury is much larger than Pluto and is a terrestrial planet with a silicate and metal composition. Europa and Earth's Moon are also rich in silicates and poor in ices. Neptune is a gas giant, larger than Pluto and of a different composition.

Why does the interior of Uranus appear to lack a layer of metallic hydrogen like those in Saturn and Jupiter? A. Uranus is too far from the Sun and the temperature is consequently too low. B. Uranus doesn't have enough hydrogen to make the transition to metallic state. C. The magnetic field of Uranus is too weak to make the hydrogen convert to its metallic form. D. Uranus is too small and the internal temperature and pressure are not high enough for metallic hydrogen.

D. Uranus is too small and the internal temperature and pressure are not high enough for metallic hydrogen. Uranus is not large enough to produce the extreme pressure needed to form a metallic hydrogen layer.

Which of the following objects is most like Earth in size and composition? A. Mercury B. Ida C. Mars D. Venus E. Neptune

D. Venus Venus is nearly the same diameter and composition to Earth. Neptune is large and compositionally very different, and the others are rocky like Earth, but significantly smaller.

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 Outgassing is the processes of moving volatiles from the interior to above the surface. This process introduces gas into the atmosphere, it does not take away gas.

What are some of the main reasons Venus and Earth have such different histories? A. Venus is a much smaller planet so it cooled more quickly than Earth and preserves heavily cratered terrain. B. Because Venus is so close to the Sun, the atmosphere of Venus was blown away during the T-Tauri stage of the Sun's evolution, but Earth was able to keep one. C. The giant Chicxulub impact heated Earth dramatically and started plate tectonics, but Venus has not had any large young impacts. D. Venus was hot enough that liquid water never precipitated on its surface to make oceans.

D. Venus was hot enough that liquid water never precipitated on its surface to make oceans. Venus and Earth have different histories because the Earth developed oceans while Venus was too hot for liquid eater to precipitate. We know that Venus and Earth are nearly identical in size, which suggests they are cooling at about the same rate and so both will have active volcanism and tectonism to create a young surface. Venus has such a thick atmosphere of carbon dioxide we cannot see to the surface, so we know the T-Tauri state of the Sun did not blow away the atmosphere. While we may not know exactly why plate tectonics began on Earth and not on Venus, we know a giant impact could not have initiated it because all terrestrial bodies have experienced large impacts.

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. Our Sun is too small to go out in a giant explosion or form a block hole. Instead it will die a gentle death of its outer layers floating into space to create a planetary nebula.

Which of the following is not usually associated with a terrestrial subduction zone? A. a trench B. one lithospheric plate moving under another C. andesite—rhyolite volcanism and stratovolcanoes D. basaltic shield volcanoes

D. basaltic shield volcanoes Subduction zones are located where two plates are colliding (converging) together. The more denser of the two plates will move underneath the less dense plate, and this location is usually marked by a trench. The lower trench will induce partial melting of the mantle wedge, creating magmas with compositions between andesite and rhyolite. However, this tectonic process never produces basaltic shield volcanoes.

Karst topography is produced _______________. A. by glacial melt waters B. because rocks behave differently at high pressure C. because groundwater is abundant in tropical climes D. because limestone is relatively soluble in water E. by collapse of the roofs of lava tubes

D. because limestone is relatively soluble in water Karsts form by ground water dissolving limestones, since limestones are soluble.

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 The mantle of planets is made of silicate material (such as olivines) while the core is made of iron. So it is likely the stony-iron meteorites are from the transition zone of mantle to core.

Jupiter is composed mainly of ____________. A. hydrogen, lithium, and sodium B. rocky silicate materials C. water ice D. hydrogen and helium

D. hydrogen and helium The incredibly low density of Jupiter (1.3 g/cm3) indicates a very different composition than any of the dense, terrestrial planets. While Jupiter does have core of rock and water ice, the amount of these materials is far less than the hydrogen and helium contained in Jupiter's atmosphere.

In general , large planets cool _____________________. A. during core formation B. before a lithosphere can form C. more rapidly than small planets of similar composition D. more slowly than small planets of similar compositions

D. more slowly than small planets of similar compositions Large planets cool more slowly than large planets because they have a smaller surface area/mass ratio. As we learned in a previous lesson, core formation adds heat to the planetary body. The formation of a lithosphere is a result of cooling, as a planet cools its lithosphere thickens. Therefore a planet cannot cool before a lithosphere forms.

What is the principal method of light element (up to iron, atomic number 26) production? A. radioactive decay of heavy elements B. gravitational collapse of a star C. isotope reactivation D. nuclear fusion

D. nuclear fusion Elements up to iron are constructed by nuclear fusion within stars.

Martian valley networks are ____________________________________. A. related to the development of highland volcanic centers B. related to huge catastrophic floods C. developed by wind erosion D. restricted in occurrence to the oldest parts of Mars

D. restricted in occurrence to the oldest parts of Mars Water flows from higher to lower elevation. This means, on Mars, the water channels will flow from the southern highlands to the northern lowlands.

Which of the following is not a feature formed by impact on the Moon? A. overturned flap on the crater rim B. radiating arms of ejecta around the crater C. terraces on the side of the crater D. sinuous rilles

D. sinuous rilles Sinuous rilles are volcanic landforms, they do not form by impact like the other listed features.

Photo 72 Which of the following is most important in keeping water a liquid on Earth? A. the size of Earth B. the biosphere C. the original composition of the planet D. the distance from the Sun

D. the distance from the Sun

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 a magnetic field E. the presence of an atmosphere

D. the presence of a magnetic field The size of the impactor and nature of surface materials determine the physical aspects of an impact crater. An atmosphere would produce friction slowing down and breaking the impactor. However, a meteorite can travel through a magnetic field as if it was not there.

The presence of oxygen (O2) in a planet's atmosphere is strong evidence for ___________________. A. an ancient surface B. a young surface C. loss of CO2 to space D. the presence of living organisms E. the T-Tauri stage in the Sun's evolution

D. the presence of living organisms The only process we know of that produces free oxygen is photosynthesis.

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 E. similar to other horsey lavas

D. very fluid The low topography of the mare basalts shows the lava was very fluid (similar to motor oil). We know the mare is not older than the highlands because the mare has less craters. Since there are no explosive landforms we know they basalts did not have water. The crust is never thicker than the lithosphere.

Photo 19 Which letter marks the youngest lava flow that crosses this part of the lunar maria? A-G

E E has very defined, lobate edges. The other letters are not lava flows.

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. All of the above are incorrect.

E. All of the above are incorrect. The outer planets are ice-hydrogen-helium mixtures, larger than the inner planets, and have rings and moons. They contrast with the inner planets in each of these aspects.

Compared to Jupiter, Saturn has a yellowish tint. What gives it this color? A. Sulfur in the clouds B. Methane in the atmosphere C. Metallic hydrogen in the interior D. Molecular hydrogen in the atmosphere E. Crystals of ammonia ice in the clouds

E. Crystals of ammonia ice in the clouds Like the presence of methane makes the atmosphere of Neptune greenish blue, crystals of ammonia ice in Saturn's clouds give Saturn its yellowish color.

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 Asteroids are very small and therefore do not have internal heat to produce volcanic or tectonic activity, nor do they have atmospheres and so cannot have erosion of water or air. However, they have undergone (and are still undergoing) cratering.

Photo 59 What do the features in this image imply about the geologic history of Titan? /> A. It has an ancient surface. B. Glaciers of moving nitrogen ice have carved intricate channels. C. Mountains formed by north-south contraction. D. Landslides have shaped the surface on a large and small scale. E. Rivers of liquid have flowed across the surface and eroded it. F. Huge floods of lava drained across its surface.

E. Rivers of liquid have flowed across the surface and eroded it. The dendritic pattern of this feature suggests the flowing of liquids in the form of rivers. These dendritic patterns are very similar to those seen in rivers on Earth.

Photo 31 What is the probable origin of the features shown in this image of the surface of Mars? A. This is a dune shaped by the wind. B. These are dendritic channels eroded by liquid water. C. Volcanic processes shaped these landforms. D. This is part of the polar ice cap of Mars. E. Sublimation of ground ice caused collapse of the surface. F. Glaciers of flowing ice shaped this landscape. G. Vast floods of water caused these outflow channels.

E. Sublimation of ground ice caused collapse of the surface.

What were the most common solids that condensed from the solar nebular gases? A. They were silicates that lacked water. B. They were silicates that contained water. C. They consisted of carbonaceous material. D. They were made of iron. E. They were water ice.

E. They were water ice. Water ice is the most common condensate in the Solar System. It may not be the most common in the inner Solar System, but the asteroid belt and beyond contains a vast amount of water ice.

The only satellite of Jupiter or Saturn known to have a substantial atmosphere is _________________. A. Ganymede B. Triton C. Io D. Rhea E. Titan

E. Titan Only Titan has an atmosphere, and its composition is nitrogen-rich.

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 surface of the Moon is made up of two terrains. The maria, which is low, young, and dark. And the highlands terrae, which is high, old, and bright.

Radar images of Venus show all of the following except __________. A. mountain chains B. volcanoes C. rift valleys D. plains E. river valleys

E. river valleys Radar images do not show any dendritic valleys nor any evidence for liquid water on Venus.

Important sources of planetary heat include all of the following except _______________. A. accretion B. core formation C. tidal heating D. decay of radioactive elements E. the Big Bang

E. the Big Bang Planetary heat comes from many sources that have to do with the formation, differentiation, and gravitational interactions. The Big Bang does not fall into these categories and occurred so long ago the heat is not an important factor in planets.

Which of the following planetary bodies has the oldest surface? A. Venus B. Mars C. Mercury D. Earth E. the Moon

E. the Moon

The absence of large folded mountain systems on the Moon, Mars, and Mercury is evidence that the lithospheres of these planets ___________________. A. have been highly mobile in recent times B. are younger than that of Earth C. are older than that of Earth D. have histories similar to that of Earth's E. thickened "rapidly" as these worlds cooled.

E. thickened "rapidly" as these worlds cooled.

Photo 38 What was the sequence of events that shaped this part of Mars? Put the following descriptions into the proper order with the oldest on bottom and youngest at the top. Not all descriptions apply and should be left out. Compressional tectonics Development of shield volcanoes Eolian deposition Formation of rampart crater Eruption of lava plains Intense impact cratering Extensional tecontics Erosion by running water

Formation of rampart crater - Youngest Extensional tectonics Eruption of lava plains Development of shield volcanoes - Oldest

Photo 27 This is a colored topographic map of Mars, with high elevations in brown and white and low elevations in blue. Match the letters with the correct geologic province. A-E Valles Marineris, the cratered highlands, the youngest plains, the volcanoes of the Tharsis bulge, an ice sheet

Valles Marineris: D the cratered highlands: B the youngest plains: A the volcanoes of the Tharsis bulge: C an ice sheet: E

Photo 75 Why aren't running water and erosion important geologic agents on all planets? (Select all that apply.) A. Some planets lack solid surfaces. B. Some planets are too cold. C. Some planets have the wrong composition for water to exist. D. Some planets are too hot.

all answers A. Some planets lack solid surfaces. B. Some planets are too cold. C. Some planets have the wrong composition for water to exist. D. Some planets are too hot.

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

all answers A. They are laterally extensive (they cover large areas). B. They are produced instantaneously. C. Their features change with time as a result of degradation. Impact craters are fantastic for determining relative time since they can cover large areas, the degrade with time, and are produced quickly.

What are some of the ways that the advent of life modified Earth's atmosphere/hydrosphere and the geologic processes which act on its surface? (Select all that apply.) A. Using energy from the Sun, organisms consumed carbon dioxide and released oxygen into the atmosphere. B. The oxygen produced by living things oxidized (weathered) the minerals and rocks at the surface. C. The evolution of creatures that make shells of calcium carbonate helped remove carbon dioxide from the atmosphere. D. Large quantities of dissolved iron were removed from the ocean to form delicately banded iron-rich sediments.

all answers A. Using energy from the Sun, organisms consumed carbon dioxide and released oxygen into the atmosphere. B. The oxygen produced by living things oxidized (weathered) the minerals and rocks at the surface. C. The evolution of creatures that make shells of calcium carbonate helped remove carbon dioxide from the atmosphere. D. Large quantities of dissolved iron were removed from the ocean to form delicately banded iron-rich sediments. The advent of life effected Earth in many ways. Life released free oxygen into the atmosphere and consumed carbon dioxide by the process of photosynthesis. This free oxygen has (and continues) to oxidize the rocks and minerals on the surface. Removed carbon dioxide from the atmosphere by breathing and creating shells of calcium carbonate, this allowed Earth to have a moderate surface temperature in opposition to Venus. Oxidizing of iron in the ocean removed the iron from the ocean by causing the precipitation of banded iron-rich sediments.

Which of the following are important components of a comet? (Select all that apply.) A. Water ice B. Silicate materials like olivine C. Methane D. Ammonia E. Carbon dioxide and carbon monoxide

all answers A. Water ice B. Silicate materials like olivine C. Methane D. Ammonia E. Carbon dioxide and carbon monoxide As described in figure 14.2, comets contain water ice, methane, ammonia, carbon dioxide/monoxide, and rocky material (meaning silicates).

Which of the following are important differences between the nature of the martian hemispheres (north and south)? (Mark all that apply) A. ages B. number of young volcanoes and volcanic plains C. elevations D. the number of impact craters

all answers A. ages B. number of young volcanoes and volcanic plains C. elevations D. the number of impact craters The nothern and southern hemispheres are very different in almost every aspect. Including ages, crater density, volcanic activity, and elevations.

Which of these factors control the Earth's hydrologic system? (Mark all that apply.) A. gravity B. solar energy C. topography D. temperature

all answers A. gravity B. solar energy C. topography D. temperature All of these factors help control the hydrosphere. Topography and gravity bring water down in streams to the ocean, while solar energy and temperature determine if water will evaporate or condense and precipitate.

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. seismic (earthquake) waves D. fracturing of the bedrock

all answers A. slumping to create terraces B. heat C. seismic (earthquake) waves D. fracturing of the bedrock Impacts establish shock (seismic) waves that pass through the interior, they can break up rock and cause slumping, and even melt (or vaporise) rock.