Astronomy Exam 3
According to our theory of solar system formation, what are asteroids and comets? chunks of rock or ice that were expelled from planets by volcanoes the shattered remains of collisions between planets chunks of rock or ice that condensed after the planets and moons finished forming leftover planetesimals that never accreted into planets
leftover planetesimals that never accreted into planets
The planet in our solar system with the highest average surface temperature is __________. Neptune Earth Venus Mercury
Venus
What process created the elements from which the terrestrial planets were made?
nuclear fission in stars
Which of the following is not evidence for plate tectonics on Earth?
Existence of volcanoes
The major processes that heat the interiors of the terrestrial worlds are __________. (1) heat deposited as the planets were built from planetesimals; (2) heat of accretion; (3) heat that came from the gravitational potential energy of incoming planetesimals (1) heat deposited as the planets were built from planetesimals; (2) heat deposited as the planets underwent differentiation; (3) heat released by radioactive decay (1) heat of accretion; (2) heat from convection; (3) heat from thermal radiation (1) volcanism; (2) tectonics; (3) erosion
(1) heat depositedas the planets were built from planetesimals; (2) heat deposited as the planets underwent differentiation; (3) heat released by radioactive decay
Suppose you start with 1 kilogram of a radioactive substance that has a half-life of 10 years. Which of the following statements will be true after 20 years pass? You'll have 0.5 kilogram of the radioactive substance remaining. You'll have 0.25 kilogram of the radioactive substance remaining. You'll have 0.75 kilogram of the radioactive substance remaining. All the material will have completely decayed.
0.25 kilogram
Suppose you find a rock that contains 10 micrograms of radioactive potassium-40, which has a half-life of 1.25 billion years. By measuring the amount of its decay product (argon-40) present in the rock, you conclude that there must have been 80 micrograms of potassium-40 when the rock solidified. How old is the rock? 5.0 billion years 3.75 billion years 2.5 billion years 1.25 billion years
3.75 billion years
According to modern scientific dating techniques, approximately how old is the solar system? 14 billion years 10,000 years 4.5 billion years 4.6 million years
4.5 billion years
What is the Kuiper belt? a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets the most prominent ring of Saturn that is visible in photographs a region of the solar system that extends almost a fourth of the way to the nearest stars and contains a trillion comets with orbits going in all directions around the Sun a technical name for the asteroid belt
A region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets
A common natural example of a gas condensing into a solid is
Frost
Which jovian planet does NOT have rings? Uranus Neptune Jupiter All the jovian planets have rings.
All jovian planets have rings
What patterns can been seen comparing the terrestrial planets (Mercury, Venus, Earth, Mars) to the Jovian planets (Jupiter, Saturn, Uranus, Neptune)? The jovian planets are much more massive. 0% 0 The terrestrial planets are much more dense. 0% 0 The terrestrial planets are rocky and the jovian planets are gaseous. 3.7% 2 All of the above ( c ) 90.74% 49 A and C.
All of the above
Why does Earth have the youngest surface of all the terrestrial planets today? It is the largest terrestrial planet so its interior has not cooled too much. It is not so close to the Sun that it has lost its water and developed a thick lithosphere. It rotates rapidly. all of the above B and C
All of the above
Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction. The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise. The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise. All the planets orbit counterclockwise around the Sun.
All the planets orbit clockwise around the Sun
As you've seen, the nebular theory predicts that a cloud that gives birth to planets should have the shape of a spinning disk. Which observable property of our solar system supports this prediction? The orbit of Earth's Moon lies very close to the ecliptic plane. All the planets orbit the Sun in the same direction and in nearly the same plane. The four largest planets all have disk-shaped ring systems around them. There are two basic types of planets: terrestrial and jovian.
All the planets orbit the Sun in the same direction and in the nearly same plane
Which of the following is not a real difference between asteroids and comets? Asteroids orbit the Sun while comets just float randomly around in the Oort cloud. It is thought that comets are far more numerous than asteroids. Most asteroids are located much nearer to the Sun than most comets. Asteroids are made mostly of rock and comets are made mostly of ice.
Asteroids orbit the Sun while comets just float randomly around in the Oort cloud
What is necessary for differentiation to occur in a planet? It must have metal and rock in it. It must be a mix of materials of different density. Material inside must be able to flow. All of the above B and C
B and C
Venus has a higher average surface temperature than Mercury. Why? Because its surface is heated by an extreme greenhouse effect. Because it is closer to the Sun. Because its surface is covered with hot lava from numerous active volcanoes. Because its slow rotation gives it more time to heat up in sunlight
Because its surface is heated by an extreme greenhouse effect
In what way is Venus most similar to Earth? Both planets have similar surface geology. Both planets have warm days and cool nights. Both planets have very similar atmospheres. Both planets are nearly the same size.
Both planets are nearly the same size
Most of the solar system's planets are made of rocks and minerals. are made of gas. orbit the Sun in the same direction. rotate in the same direction as they orbit the Sun. C and D
C and D
The nebular theory also predicts that the cloud will flatten into a disk as it shrinks in size. Which of the following best explains why the collapsing cloud should form a disk? Gravity pulls more strongly on material along the rotation axis than perpendicular to it, bringing this material downward into a disk. Colliding cloud particles exchange angular momentum and, on average, end up with the rotation pattern for the cloud as a whole. All collapsing objects tend to flatten into a disk, regardless of their rotation. As a star forms near the cloud center, its wind blows away material that is not aligned with its equator, thereby leaving an equatorial disk of material.
Colliding cloud particles exchange angular momentum and, on average, end up with the rotation pattern for the cloud as a whole
What is the likely origin of Earth's water and organic compounds?
Comets
Why was it advantageous for the Voyager mission to consist of flybys rather than orbiters? Each individual spacecraft was able to visit more than one planet. It was easier for data to be radioed back to Earth with flybys than orbiters. Spacecraft making flybys can return to Earth more quickly than orbiters. Flyby spacecraft can get closer to a planet than an orbiting spacecraft.
Each individual spacecraft was able to visit more than one planet
According to our modern science, which of the following best explains why the vast majority of the mass of our solar system consists of hydrogen and helium gas? All the other elements escaped from the solar nebula before the Sun and planets formed. Hydrogen and helium are the most common elements throughout the universe, because they were the only elements present when the universe was young. Hydrogen and helium are produced in stars by nuclear fusion. All the other elements were swept out of the solar system by the solar wind.
Hydrogen and helium are the most common elements throughout the universe, because they were the only elements present when the universe was young
Rank the following in order from lowest to highest melting point: iron, hydrogen, water, rock, methane
Hydrogen, methane, water, rock, iron
The solar system has two types of planets, terrestrial and jovian. According to the nebular theory, why did terrestrial planets form in the inner solar system and jovian planets in the outer solar system? All the planets started out large, but the Sun's heat evaporated so much material that the inner planets ended up much smaller. After the planets formed, the Sun's gravity pulled the dense terrestrial planets inward, leaving only jovian planets in the outer solar system. Denser particles of rock and metal sank into the inner solar system, leaving only gases in the outer solar system. Ices condensed only in the outer solar system, where some icy planetesimals grew large enough to attract gas from the nebula, while only metal and rock condensed in the inner solar system, making terrestrial planets.
Icy condensed only in the outer solar system, where some icy planetesimals grew large enough to attract gas from the nebula, while only metal and rock condensed in the sinner solar system, making terrestrial planets
How is Einstein's famous equation, E=mc 2, important in understanding the Sun? It explains why the Sun is so massive. It explains why the Sun's surface temperature is about 6,000°C. It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each second. It explains why the Sun has a magnetic field strong enough influence the atmospheres of the planets.
It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each second
Which of the following statements about the object called Eris is not true? It is slightly larger in mass than Pluto. It is thought to be the first example of a new class of object. It lies well beyond Pluto and Neptune. It orbits the Sun in the same general direction as the planets.
It is thought to be the first example of a new class of object
According to our present theory of solar system formation, which of the following best explains why the solar nebula ended up with a disk shape as it collapsed? The law of conservation of energy. It flattened as a natural consequence of collisions between particles in the nebula. The force of gravity pulled the material downward into a flat disk. It was fairly flat to begin with, and retained this flat shape as it collapsed.
It flattened as a natural consequence of collisions between particles in the nebula
What's the leading theory for the origin of the Moon? It formed along with Earth. It formed from the material ejected from Earth in a giant impact. It split out of a rapidly rotating Earth.
It formed from the material ejected from Earth in a giant impact
According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size? Its mass, temperature, and density all increased. Its gas clumped up to form the terrestrial planets, nuclear fusion produced heavy elements to make the jovian planets, and central temperatures rose to more than a trillion Kelvin. Its mass did NOT increase. It got hotter, its rate of rotation increased, and it flattened into a disk.
It got hotter, its rate of rotation increases, and it flattened into a disk
Which of the following statements about Pluto is true? It has more in common with comets in the Kuiper belt than it does with terrestrial planets like Earth. Its mass is a little less than Earth's mass. It is the largest known object that is considered to be a dwarf planet. It is orbited by only one moon.
It has more in common with comets in the Kuiper Belt than it does with terrestrial planets like Earth
What do we mean by the frost line when we discuss the formation of planets in the solar nebula? It is the altitude in a planet's atmosphere at which snow can form. It marks the special distance from the Sun at which hydrogen compounds become abundant; closer to the Sun, there are no hydrogen compounds. It is another way of stating the temperature at which water freezes into ice. It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.
It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ices to condense
According to present understanding, which of the following statements about the solar wind is not true? It consists of charged particles blown off the surface of the Sun. It swept vast amounts of gas from the solar nebula into interstellar space. It helped in the transfer of angular momentum from the young Sun to particles that blew into interstellar space, which explains why the Sun rotates so slowly today. It is even stronger today than it was when the Sun was young.
It is even stronger today than it was when the Sun was young
In what way is Pluto more like a comet than a planet? It is made mostly of rock and ice. It has moons. It sometimes enters the inner solar system. It has a long tail.
It is made mostly of rock and ice
What feature of Venusian geology is largely unexplained?
It lacks plate tectonics
Why has NASA sent recent orbiters to Mars (such as Mars Reconnaissance Orbiter) on trajectories that required them to skim through Mars's atmosphere before settling into their final orbits? It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines. Each spacecraft also carried a lander, and the lander could only be dropped to the Martian surface when the spacecraft passed through the atmosphere. It allowed the spacecraft to collect samples of the atmospheric gas for return to Earth. It allowed the orbiters to get higher resolution pictures of the surface as it came close when skimming through the atmosphere.
It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines
Which describes our understanding of flowing water on Mars? It was never important. It was important once, but no longer. It is a major process on the Martian surface today.
It was once important, but no longer
Imagine that an alien spaceship crashed onto Earth. Which statement would most likely be true? It would crash in the ocean. All the evidence of the crash would be quickly whisked off by the U.S. military to Area 51 in Nevada. The aliens' home world is another planet in our own solar system. The crash would create a noticeable crater.
It would crash in the ocean
What is the Oort cloud? It is a great cloud of gas that resides far beyond the orbit of Pluto. It is another name for the cloud of gas from which our solar system was born. It's not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances. It is a giant storm in the atmosphere of Saturn.
It's not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances.
How would the solar system be different if the solar nebula had cooled, with a temperature half its actual value?
Jovian planets would have formed closer to Sun.
Suppose Venus rotated as fast as Earth. How would this change its relative levels of volcanism, tectonics, and erosion?
Levels of volcanism and tectonics would stay the same, but erosion levels would be higher
Recent evidence suggests that Mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic field like that of Earth?
Mars's interior has cooled so much its molten core layer no longer undergoes convection
Among these five objects, ___ should cool the fastest and ___ should cool the slowest
Moon, Earth
Which of the following is not a major pattern of motion in the solar system? Nearly all comets orbit the Sun in same direction and roughly the same plane. All of the planets orbit the Sun in the same direction - counterclockwise as viewed from above Earth's north pole. The Sun and most of the planets rotate in the same direction in which the planets orbit the Sun. Most of the solar system's large moons orbit in their planet's equatorial plane.
Nearly all comets orbit the Sun in same direction and roughly the same plane
Could a solar system like ours have formed with the first generation of stars after the Big Bang?
No, there would not have been enough metals and rock to form terrestrial planets.
Which of these facts is NOT explained by the nebular theory?
Number of planets of each type (four terrestrial and four jovian).
Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars? the polar caps the southern highlands Valles Marineris Olympus Mons
Olympus Mons
Why are terrestrial planets denser than jovian planets? Only dense materials could condense in the inner solar nebula. The Sun's gravity gathered dense materials into the inner solar system. Actually, the jovian planets are denser than the terrestrial planets. Gravity compresses terrestrial planets to a higher degree, making them denser.
Only dense materials could condense in the inner solar nebula
What do we conclude if a planet has few impact craters of any size? The planet was never bombarded by asteroids or comets. Its atmosphere stopped impactors of all sizes. Other geological processes have wiped out craters.
Other geological processes have wiped out craters
In essence, the nebular theory holds that _________. our solar system formed from the collapse of an interstellar cloud of gas and dust nebulae are clouds of gas and dust in space The nebular theory is a discarded idea that imagined planets forming as a result of a near-collision between our Sun and another star. the planets each formed from the collapse of its own separate nebula
Our solar system formed from the collapse of an interstellar cloud of gas and dust
Rank the objects from left to right based on their average distance from the Sun, from farthest to closest.
Pluto, Saturn, Jupiter, Mars, Earth, Mercury
How do scientists determine the age of the solar system? Radiometric dating of Moon rocks. Radiometric dating of the oldest Earth rocks. Radiometric dating of meteorites Theoretical calculations tell us how long it has taken the planets to evolve to their present forms
Radiometric dating of meteorites
What is the primary reason that astronomers suspect that some jovian moons were captured into their current orbits? Some moons are surprisingly large in size. Some moons have orbits that are "backwards" (compared to their planet's rotation) or highly inclined to their planet's equator. Some moons have a composition that differs from the composition of the planets Astronomers have observed moons being captured.
Some moons have orbits that are "backwards" or highly inclined to their planet's equator
How do we know what the interior structure of the Earth is like?
Sound waves travel through the Earth and probe the interior.
Which of the following best explains why we can rule out the idea that planets are usually formed by near-collisions between stars? A near collision should have left a trail of gas extending out behind the Sun, and we see no evidence of such a trail. Studies of the trajectories of nearby stars relative to the Sun show that the Sun is not in danger of a near-collision with any of them. Stellar near-collisions are far too rare to explain all the planets now known to orbit nearby stars. A near collision might have created planets, but it could not have created moons, asteroids, or comets.
Stellar near-collisions are far too rare to explain all the planets now known to orbit nearby starts
Rank these objects based on size from largest to smallest
Sun, Jupiter, Earth, Mars, Mercury, Pluto
Rank these objects from left to right based on their mass. highest to lowest
Sun, Jupiter, Earth, Mars, Mercury, Pluto
Which of the following is not a major difference between the terrestrial and jovian planets in our solar system? Terrestrial planets orbit much closer to the Sun than jovian planets. Terrestrial planets contain large quantities of ice and jovian planets do not. Terrestrial planets are higher in average density than jovian planets. Jovian planets have rings and terrestrial planets do not.
Terrestrial planets contain large quantities of ice and jovian planets do not
Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets? Terrestrial planets will likely be located farther from the planetary system's star than any jovian planets. Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets. There is no way to know where terrestrial planets are likely to be.
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets
The Earth has far less identifiable impact craters than the Moon, because
The Earth has erosion and active geology which reforms the surface
Consider the following statement: "Rocky asteroids are found primarily in the asteroid belt and Kuiper belt while icy comets are found primarily in the Oort cloud." What's wrong with this statement? The Oort cloud has nothing to do with comets. The Kuiper belt contains icy comets, not rocky asteroids. Comets are not really icy. Asteroids are not really made of rock. The statement is accurate as written.
The Kuiper belt contains icy comets, not rocky asteroids
What is the giant impact hypothesis for the origin of the Moon? The Moon originally was about the same size as Earth, but a giant impact blasted most of it away so that it ended up much smaller than Earth. The Moon formed when two gigantic asteroids collided with one another. The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object. The Moon formed just like Earth, from accretion in the solar nebula.
The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object
Which of the following is not a line of evidence supporting the hypothesis that our Moon formed as a result of a giant impact? The Moon has a much smaller proportion of easily vaporized materials than Earth. Computer simulations show that the Moon could really have formed in this way. The Pacific Ocean appears to be a large crater - probably the one made by the giant impact. The Moon's average density suggests it is made of rock much more like that of the Earth's outer layers than that of the Earth as a whole.
The Pacific Ocean appears to be a larger crater- probably the one made by the giant impact
Which of the following statements about our Sun is NOT true? The Sun is a star. The Sun is made mostly of hydrogen and helium. The Sun's diameter is about five times that of Earth. The Sun contains more than 99 percent of all the mass in our solar system.
The Sun's diameter is about five times that of the Sun
The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system? The diameter of Earth's Moon is about 1/4 that of Earth. Saturn has no solid surface. Venus does not have a moon. Jupiter has a very small axis tilt.
The diameter of Earth's Moon is about 1/4 that of Earth
According to our present theory of solar system formation, which of the following statements about the growth of terrestrial and jovian planets is not true? Both types of planet begun with planetesimals growing through the process of accretion, but only the jovian planets were able to capture hydrogen and helium gas from the solar nebula. Swirling disks of gas, like the solar nebula in miniature, formed around the growing jovian planets but not around the growing terrestrial planets. The terrestrial planets formed inside the frost line of the solar nebula and the jovian planets formed beyond it. The jovian planets began from planetesimals made only of ice, while the terrestrial planets began from planetesimals made only of rock and metal.
The jovian planets began from planetesimals made only of ice, while the terrestral planets began from planetesimals made only of rock and metal
According to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size? The law of universal gravitation The law of conservation of energy The law of conservation of angular momentum Einstein's law E=mc2
The law of conservation of angular momentum
Which of the following is not generally true of all the terrestrial world lithospheres? The thickness of the lithosphere depends on interior temperature, with cooler interiors leading to thicker lithospheres. Rock in the lithosphere is stronger than rock beneath it. The lithosphere is broken into a set of large plates that float upon the softer rock below. The lithosphere extends from somewhere in the mantle all the way to the surface.
The lithosphere is broken into a set of large plates that float upon the softer rock below
Many meteorites appear to have formed very early in the solar system's history. How do these meteorites support our theory about how the terrestrial planets formed? Their appearance and composition matches what we observe in comets today, suggesting that they were once pieces of icy planetesimals. The meteorites appearance and composition is just what we'd expect if metal and rock condensed and accreted as our theory suggests. Their overall composition is just what we believe the composition of the solar nebula to have been: mostly hydrogen and helium. The meteorites sizes are just what we'd expect if metal and rock condensed and accreted as our theory suggests.
The meteorites appearance and composition is just what we'd expect if metal and rock condensed and accreted as our theory suggests
Consider only the observed patterns of motion in the solar system. Scientifically, which of the following possible conclusions is justified from the patterns of motion alone? The planets were not each born in a separate, random event. The planets started out quite small and grew to their current sizes as they gradually accreted more material. The planets were born from a giant cloud of gas that rotated in the same direction that the Milky Way Galaxy rotates. The planets were not born within the past million years, but instead they must have been born billions of years ago.
The planets were not born in a separate, random event
Which of the following does NOT provide evidence that Mars once had abundant liquid water on its surface? the presence of features that look like dried-up riverbeds the presence of very old craters that appear to have been eroded by rain the presence of canali, discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell the presence of "blueberries" made of the mineral hematite
The presence of canali, discovered in the late 1800s by Giovanni Schiaparellu and mapped by Percival Lowell
Why are there fewer large craters on the seafloor than on the continents?
The seafloor crust is younger than the continental crust
Based on your study of the Interactive Figure, which of the following is not one of the four major features of the solar system? Large bodies in the solar system have orderly motions. Several exceptions to the general trends stand out. Swarms of asteroids and comets populate the solar system. Planets fall into two major categories (terrestrial and jovian). The solar system contains eight planets plus dwarf planets (including Ceres, Pluto, and Eris).
The solar system contains eight plus dwarf planets
According to our present theory of solar system formation, how did Earth end up with enough water to make oceans? The water was mixed in the other materials in the planetesimals that accreted at our distance from the Sun. The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars. The water was formed by chemical reactions among the minerals in the Earth's core. Earth formed in the relatively narrow region of the solar nebular in which liquid water was plentiful.
The water was brought to the forming Earth by planetesimals that accreted beyond the orbit of Mars
About 2% of our solar nebula consisted of elements besides hydrogen and helium. However, the very first generation of star systems in the universe probably consisted only of hydrogen and helium. Which of the following statements is most likely to have been true about these first-generation star systems? Jovian planets in these first-generation star systems had clouds made of water and other hydrogen compounds. There were no comets or asteroids in these first-generation star systems. These first-generation star systems typically had several terrestrial planets in addition to jovian planets. Like the jovian planets in our solar system, the jovian planets in these first-generation systems were orbited by rings.
There were no comets or asteroids in these first-generation star systems
The region of our solar system between Mercury and Mars has very few asteroids, while the region between Mars and Jupiter has many asteroids. Based on what you have learned, what is the most likely explanation for the lack of asteroids between Mercury and Mars? It was too hot for asteroids to form in this part of the solar system. There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed. All the asteroids that formed between Mercury and Mars later migrated to the asteroid belt between Mars and Jupiter. Gravity was too weak to allow asteroids to form in this part of the solar system.
There were very few planetary leftovers in this region, because most of the solid material was accreted by the terrestrial planets as the planets formed
Why could the jovian planets grow to be much larger than the terrestrial planets?
They formed beyond the frost line where ices could condense, so they included hydrogen compounds.
Which planet is approximately halfway between Pluto's orbit and the Sun? Mars, the fourth planet from the Sun Jupiter, the fifth planet from the Sun Saturn, the sixth planet from the Sun Uranus, the seventh planet from the Sun
Uranus
Which planet listed below has the most extreme seasons? Mars Uranus Earth Jupiter
Uranus
Are there any exceptions to the rule that planets rotate with small axis tilts and in the same direction that they orbit the Sun? No. Venus is the only exception. Venus and Uranus are exceptions.
Venus and Uranus are the exceptions
What do we mean when we say that the terrestrial worlds underwent differentiation? The five terrestrial worlds all started similarly but ended up looking quite different. When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces. Their surfaces show a variety of different geological features resulting from different geological processes. They lost interior heat to outer space.
When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces
What are the basic requirements for a terrestrial world to have a global magnetic field? a core that has a molten layer and a mantle that has convection a metal core and rapid rotation a metal core, a rocky mantle, and sufficiently rapid rotation a core layer of molten, convecting material and sufficiently rapid rotation
a core layer or molten, convecting material and sufficiently rapid rotation
In Part A, you found that Planet Z should not have strong winds and violent storms. What single change to Planet Z's characteristics would cause it to have strong winds and violent storms? a smaller size a faster rotation rate a larger axis tilt a greater distance from its star
a faster rotation rate
Based on its surface features, the most important event on Venus in the past billion years or so was _______. the impact of an unusually large asteroid that left a deep scar on one side of the planet the onset of mantle convection, which caused Venus's lithosphere to split into plates like those on Earth a global "repaving" that erased essentially all the surface features that had existed earlier the eruption of a giant volcano that formed one of Venus's "continents"
a global "repaving" that erased essentially a;; the surface features that had existed earlier
In Part A, you found that Planet Z should not have polar ice caps or liquid water. What single change to Planet Z's characteristics would allow it to have these things? a larger size a smaller size a larger axis tilt a greater distance from its star
a greater distance from its star
In Part A, you found that Planet Z should not have seasons. What single change to Planet Z's characteristics would cause it to have seasons? a larger axis tilt a greater distance from its star a faster rotation rate a smaller size
a larger axis tilt
In the context of plate tectonics, what is a subduction zone? a place where a seafloor plate is sliding under a continental plate a place where two continental plates are colliding a place where two plates are pulling apart a place where two plates are slipping sideways against one another
a place where a seafloor is sliding under the continental plate
Jovial Planets:
accreted from icy planetesimals, ejected icy planetesimals that are now Oort cloud comets, formed in a region of the solar system with lower orbital speeds, formed in regions cold enough for water to freeze, large moons formed, in surrounding disks of material
Terrestrial Planets:
accreted from planetesimals of rock and metal surfaces dramatically altered during the heavy bombardment
What evidence is there for past liquid water is on Mars? channels that look like dry riverbeds eroded crater rims and erased craters Spirit and Opportunity rovers have found mineral evidence of water ice in Mar's polar caps all of the above
all of the above
Which terrestrial planets have had volcanic activity at some point in their histories? only Earth Earth and Mars all of them
all of them
Where would you expect terrestrial planets to form in the solar nebula? within the inner 0.3 AU anywhere between 0.3 AU and the frost line anywhere outside 0.3 AU anywhere outside the frost line
anywhere between 0.3 AU and the frost line
From center to surface, which of the following correctly lists the interior layers of a terrestrial world? mantle, core, crust core, crust, lithosphere core, mantle, crust mantle, crust, core
core, mantle, crust
You have found that Planet Z should have active tectonics and volcanism and an atmosphere produced by volcanic outgassing. What single factor explains why the planet should have these characteristics? Planet Z closely orbits its star. lacks axis tilt. has a large size for a terrestrial planet. has a slow rotation rate.
has a large size for a terrestrial planet
he most abundant ingredient of the Sun and Jupiter is: ionized metal. hydrogen. ammonia.
hydrogen
The solar nebula was 98 % ... rock and metal. hydrogen compounds. hydrogen and helium.
hydrogen and helium
What is Jupiter's main ingredient? rock and metal hydrogen compounds hydrogen and helium
hydrogen and helium
Which of the following types of material can condense into what we call ice at low temperatures? metal hydrogen and helium rock hydrogen compounds
hydrogen compounds
When you zoom in on the section labeled "Southern Highlands," which geologic processes are most clearly evident? volcanism and erosion impact cratering and erosion impact cratering and volcanism tectonics and erosion volcanism and tectonics
impact cratering and erosion
The processes responsible for virtually all surface geology are _________. convection, conduction, and radiation impact cratering, volcanisms, tectonics, and erosion accretion, differentiation, and radioactive decay eruptions, lava flows, and outgassing
impact cratering, volcanisms, tectonics, and erosion
Today, scientists have a theory (the nebular theory) that explains all the major characteristics of the solar system. In science, we expect a theory like this not only to explain the observed characteristics of our solar system but also to __________. make testable predictions about other solar systems predict which planets have life predict some major change that will eventually occur in our own solar system
make testable predictions about other solar systems
The cores of the terrestrial worlds are made mostly of metal because ______. over billions of years, convection gradually brought dense metals downward to the core the terrestrial worlds as a whole are made mostly of metal metals sunk to the centers a long time ago when the interiors were molten throughout the core contained lots of radioactive elements that decayed into metals
metals sunk to the centers a long time ago when the interiors were molten throughout
Compared to terrestrial planets, jovian planets are __________. more massive and higher in average density more massive and lower in average density less massive and lower in average density less massive and higher in average density
more massive and lower in average density
Large moons orbit their planets in the same direction the planet rotates: half of the time. most of the time. rarely.
most of the time
Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is ______. much smaller much larger just slightly less about the same
much larger
What substances existed as solid flakes within the inner 0.3 AU of the solar system before planets began to form? none only rocks and metals only hydrogen compounds only hydrogen and helium gases
none
Now consider why the observed patterns of motion lead to the conclusion that the planets were not born in separate, random events. The reason for this conclusion is that, if the planets had been born in separate, random events, we would expect that __________. there would be many different types of planets, rather than just two major types planets would orbit at much higher speeds than they actually do planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane none of the planets would have ended up with moons
planetary orbits would have many different orientations and directions, rather than all being in the same direction and in the same plane
Jovian Planet Characteristics
primarily composed of hydrogen, helium, and hydrogen compounds, low average density, extensive ring systems, numerous orbiting moons
What is the longest-lasting internal heat source responsible for geological activity? accretion radioactive decay sunlight
radioactive decay
Which of the following best describes the lunar maria? relatively smooth, flat plains on the Moon densely cratered regions on the Moon mountainous regions on the Moon frozen oceans of liquid water on the Moon
relatively, smooth, flat plains on the Moon
The Caloris Basin on Mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that
the Caloris Basin formed toward the end of the solar systemʹs period of heavy bombardment
What substances were found within the inner 0.3 AU of the solar system before planets began to form? nothing at all only rocks and metals only hydrogen compounds only hydrogen and helium gases rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________. only rocks and metals only ices rocks, metals, and ices rocks, metals, ices, and hydrogen and helium gases
rocks, metals, ices, and hydrogen and helium gases
Which of a planet's fundamental properties has the greatest effect on its level of volcanic and tectonic activity? size distance from the Sun rotation rate
size
Mars has two moons that are most similar in character to: Earth's Moon particles in the rings of Saturn comets. small asteroids
small asteroids
Terrestrial planet characteristics
small size, rocky surface, located within the inner solar system
Assuming that features you see on Mars are similar to features found on Earth, what would a casual inspection of the interactive photo of Mars lead you to suspect about water on Mars? Abundant surface water is found in large, brownish pools inside craters. There are numerous small streams flowing with water. Surface water only exists as frozen ice. No surface water currently exists in any form.
surface water only exists as frozen ice
Which of the following is NOT an example of tectonics? the gradual disappearance of a crater rim as a result of wind and rain the slow movement of Earth's lithospheric plates the formation of a cliff when the lithosphere shrinks the stretching of the crust by underlying mantle convection
the gradual disappearance of a crater rim as a result of wind and rain
Observations show that interstellar clouds can have almost any shape and, if they are rotating at all, their rotation is not perceptible. However, as shown in the animation, the nebular theory predicts that a cloud will rotate rapidly once it shrinks to a small size. What physical law explains why a cloud will rotate rapidly as it collapses? the law of conservation of energy the law of conservation of angular momentum the universal law of gravitation Kepler's second law Newton's third law of motion
the law of conservation of angular momentum
The nebular theory also predicts that the cloud should heat up as it collapses. What physical law explains why it heats up? the universal law of gravitation Newton's third law of motion the law of conservation of angular momentum Kepler's second law the law of conservation of energy
the law of conservation of energy
According to our theory of solar system formation, which law best explains why the central regions of the solar nebula got hotter as the nebula shrank in size? Newton's third law The law of conservation of angular momentum The law of conservation of energy The two laws of thermal radiation
the law of conservsation of energy
What is the primary basis upon which we divide the ingredients of the solar nebula into four categories (hydrogen/helium; hydrogen compound; rock; metal)? The temperatures at which various materials will condense from gaseous form to solid form. The atomic mass numbers of various materials. The amounts of energy required to ionize various materials. The locations of various materials in the solar nebula.
the temperatures at which various materials will condense from gaseous form to solid form