Astronomy Test #3

According to the graphs, the concentration of carbon dioxide in Earth's atmosphere in 2015 was about __________ parts per million. 350 400 450

400

Which of the following most likely explains why Venus does not have a global magnetic field like Earth? Its rotation is too slow.It does not have a metallic core.It has too thick of an atmosphere.Unlike Earth, Venus does not have a liquid outer core.

Its rotation is too slow. Rotation is required for a magnetic field.

In essence, the nebular theory holds that __________. 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 the planets formed as a result of a near-collision between our Sun and another star nebulae are clouds of gas and dust in space

our solar system formed from the collapse of an interstellar cloud of gas and dust This cloud of gas and dust that gave birth to our solar system is called the solar nebula.

By assuming 0% reflectivity, find the maximum possible "no greenhouse" temperature for a planet at 1 AU.

280K (On Earth basically)

On the graphs shown, you can identify an ice age by looking for __________. a peak on the temperature graph a trough (bottom of a dip) on the temperature graph a place on the temperature graph where the temperature curve falls steeply a trough (bottom of a dip) on the carbon dioxide graph

a trough (bottom of a dip) on the temperature graph For example, the graph shows that the most recent ice age ended only about 10,000 years ago, and there are numerous other ice ages shown on the graph.

Two atoms of carbon are isotopes if they have different numbers of _____. protons neutrons electrons

neutrons

Suppose you have a rock that, when it solidifies, contains 1 microgram of a radioactive isotope. How much of this isotope remains after five half-lives? 1/8 microgramnone1/32 microgram1/16 microgramCannot be determined without knowing the daughter isotope.

1/32 microgram The video showed you that 1/16 of the parent isotope remains after 4 half lives. So after a fifth half life, half of that 1/16 will remain, which is 1/32. Since the rock started with 1 microgram of the parent isotope, 1/32 microgram remains after 5 half lives.

Why is the Coriolis effect so weak on Venus? Because Venus has such a thick atmosphere. Because Venus has such a strong greenhouse effect. Because Venus is so hot. Because Venus rotates so slowly.

Because Venus rotates so slowly. Submit The strength of the Coriolis effect depends on a planet's size and rotation rate.

What is the importance of the carbon dioxide (CO2) cycle? It will prevent us from suffering any consequences from global warming. It makes the growth of continents possible. It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate. It allows for an ultraviolet-absorbing stratosphere.

But remember that this natural cycle operates over time scales of hundreds of thousands of years, and hence cannot help us with the problem of human-induced global warming.

What is the leading hypothesis for Venus's lack of water? Venus formed closer to the Sun and accreted very little water. Its water is locked away in the crust. Its water molecules were broken apart, and hydrogen was lost to space

Its water molecules were broken apart, and hydrogen was lost to space

Sort each of the planetary properties below based on whether they apply to some, all, or none of the four jovian planets in our solar system. Solid surface under a thick atmosphere Magnetic field stronger than Earth's blue color because of methane composed mostly hydrogen compounds interior is mostly liquid or metallic hydrogen

Jupiter and Saturn only: interior mostly liquid or metallic hydrogen composed mostly of hydrogen and helium Uranus and Neptune only: blue color because of methane composed mostly hydrogen compounds All four jovian planets: approximately 10 earth-mass core orbited by rings of ice and rock Magnetic field stronger than Earth's No jovian planets: solid surface under a thick atmosphere The jovian planets share many characteristics in common such as approximate core size, severe weather, rings and numerous moons, and strong magnetic fields. Jupiter and Saturn have similar compositions of hydrogen and helium, while Uranus and Neptune are composed primarily of hydrogen compounds. Unlike the terrestrial planets, the jovian planets do not have solid surfaces.

When were the heat-trapping effects of gases that cause the greenhouse effect first measured by scientists? More than 150 years ago.In the late 1950s.In the early 1990s.In ancient Greek times.

More than 150 years ago. As noted in the video, these measurements were first made by John Tyndall in 1859, and they have been repeated and refined ever since. In other words, concerns about the greenhouse effect and global warming are not new.

Which of the following is thought to explain why Venus has so much more atmospheric gas than Earth? Venus has gained much more gas through outgassing than has Earth.Because of its lack of magnetic field, Venus has been able to gain gas through the impacts of solar wind particles, while Earth has not gained gas in this way.Earth has lost much more gas to thermal escape than has Venus.Most of the gases that have been released from volcanoes on Earth later returned to the surface.

Most of the gases that have been released from volcanoes on Earth later returned to the surface. The water vapor rained down to form oceans the carbon dioxide dissolved and became incorporated into carbonate rock.

Why are there fewer large impact craters on Earth's seafloor than on the continents? Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts.Erosion erases impact craters must faster on the ocean bottom than on land.Most impacts occur on the land.The oceans slow large impactors and prevent them from making craters.

Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts. Seafloor crust is continually recycled, so that the seafloor is nearly everywhere younger than about 200 million years. Therefore, any evidence of earlier impacts has been erased as the seafloor crust was recycled.

All the following statements are true. Which one explains why convection can occur in the troposphere but not in the stratosphere? Atmospheric pressure is much greater in the troposphere than in the stratosphere. The stratosphere contains significant amounts of ozone but the troposphere does not. Temperature declines with altitude in the troposphere but increases with altitude in the stratosphere. Clouds tend to form in the troposphere but not the stratosphere.

Temperature declines with altitude in the troposphere but increases with altitude in the stratosphere. Convection can only occur when temperature declines with altitude, so that warm air rises and cool air falls.

Based on the evidence that atmospheric carbon dioxide is a cause of planetary warming, what aspect of the graphs should most concern us? The carbon dioxide concentration today is significantly higher than at any time in the past 800,000 years and is rapidly rising Earth's past carbon dioxide concentration rises and falls naturally .Earth's past temperature rises and falls naturally.

The carbon dioxide concentration today is significantly higher than at any time in the past 800,000 years and is rapidly rising Therefore, if past trends continue, we would expect Earth's temperature to rise substantially as a result of this increase in the carbon dioxide concentration.

Many scientists suspect that Venus has a stronger and thicker lithosphere than Earth. If this is true, which of the following could explain it? The high surface temperature that has "baked out" all the liquid water from Venus's crust and mantle.The slow rotation of Venus.The apparent lack of plate tectonics on Venus.The smaller size of Venus, which has allowed it to lose much more internal heat than Earth.

The high surface temperature that has "baked out" all the liquid water from Venus's crust and mantle. Without water, the rock would be stronger and the lithosphere could become thicker.

Look at the average densities of the jovian planets given in Figure 1. Can you identify a trend in jovian planet densities with mass or distance from the Sun? The more massive the planet, the higher the density. The more massive the planet, the lower the density. There is no clear trend in the densities with mass or distance. The densities decrease in order of distance from the Sun. The densities increase in order of distance from the Sun.

There is no clear trend in the densities with mass or distance.

Which of the following statements best explains why the densities of Uranus and Neptune are higher than that of Saturn, even though Saturn is much more massive? They are at greater distances from the Sun. They have stronger magnetic fields. They have a higher proportion of hydrogen compounds and rock. Their interiors are more compressed due to stronger gravity. They have higher masses.

They have a higher proportion of hydrogen compounds and rock. At similar temperature and pressure, hydrogen compounds and rock are much higher in density than hydrogen and helium. The internal conditions in the jovian planets are similar enough so that composition has a major effect on average density. Uranus and Neptune are higher in density than because they are made primarily of higher-density hydrogen compounds and rock.

If a world is subject to tidal heating, we'd expect it to have a __________. high internal temperature high surface temperature shape that is nonspherical

high internal temperature Tidal heating affects the interior of a world, making the interior much hotter than it would be otherwise. Tidal heating is a source of internal heat created by tidal friction, which is friction generated as a result of a varying tidal force.

what types of evidence for recent or ongoing geological activity have been observed on one or more jovian moons? ice crystals being sprayed out into space large, violent storms swirling in counterclockwise directions active volcanoes river valleys feeding into surface lakes of liquid water river valleys feeding into surface lakes of very cold liquids surfaces with very few impact craters

ice crystals being sprayed out into space active volcanoes river valleys feeding into surface lakes of very cold liquids surfaces with very few impact craters

According to Kepler's third law, what is the relationship between orbital period and orbital radius? Kepler's third law tells us that __________. all planets orbit the Sun at the same speed planets nearer to the Sun orbit at higher speed than planets farther from the Sun planets nearer to the Sun orbit at slower speed than planets farther from the Sun

planets nearer to the Sun orbit at higher speed than planets farther from the Sun Kepler's laws apply to all orbiting objects; that is, particles in the rings of Saturn must obey the same laws as planets orbiting the Sun.

Which region of Earth has warmed the most in recent decades? all regions have warmed about the same amountthe tropicsthe Antarcticthe mid-Atlanticthe Arctic

the Arctic As shown in the video, Arctic regions have warmed more than any other regions.

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 the law of conservation of energy the law of conservation of angular momentum Kepler's second law Newton's third law of motion

the law of conservation of energy The law of conservation of energy tells us that energy must always be conserved. Because the cloud has much more gravitational potential energy w

Which of the following is an example of convection? warm air expanding and rising, while cooler air contracts and fallsgas bubbling upward through a liquidrocks sinking in waterdifferent kinds of material separating by density, like oil and water

warm air expanding and rising, while cooler air contracts and falls Convection is any type of heat-driven circulation like this.

While we may never be able to prove that our Moon really formed in a giant impact, which of the following would give scientists greater confidence that the model is correct? Select all that apply. Smashing together two glass marbles in a laboratory and then gluing the remnants together to make marbles that have the same size ratio as the Earth and Moon.Finding evidence that other giant impacts occurred in our solar system, with a total number of impacts consistent with what models of solar system formation lead us to expect.Creating more sophisticated models of the giant impact that correctly predict many detailed characteristics of the Earth and Moon.Having the giant impact model endorsed by a dozen Nobel prize winners.Observing evidence of recent giant impacts in other solar systems that are currently in the process of formation.

Finding evidence that other giant impacts occurred in our solar system, with a total number of impacts consistent with what models of solar system formation lead us to expect.Creating more sophisticated models of the giant impact that correctly predict many detailed characteristics of the Earth and Moon. Observing evidence of recent giant impacts in other solar systems that are currently in the process of formation. Submit In fact, we already have greater confidence for all three reasons. Models of solar system formation suggest that at least a few other giant impacts should have occurred in our solar system, and we do indeed see other solar system bodies that appear to have been involved in giant impacts (including Uranus and Pluto). Telescopic observations have revealed some evidence for giant impacts in other young solar systems. And scientists are continually refining models of the giant impact thought to have formed our Moon, and these models yield testable predictions that, at least so far, have proven valid.

On a cloudless day, what happens to most of the visible light headed toward Earth? It is reflected by Earth's atmosphere. It is absorbed and reemitted by gases in Earth's atmosphere. It is completely reflected by Earth's surface. It reaches Earth's surface, where some is reflected and some is absorbed.

It reaches Earth's surface, where some is reflected and some is absorbed. Most visible light passes through our atmosphere, and this light heats the surface as it is absorbed.

Which of the following statements was true beyond the frost line (but not interior to it)? It was cold enough for hydrogen compounds to condense into ices.It was so warm that only metal and rock could condense from the gas.No object as small as a terrestrial planet could form.This was the only region that flattened into a disk

It was cold enough for hydrogen compounds to condense into ices. The frost line defined the place beyond which temperatures were low enough for ices to condense from the gas.

Based on the nebular theory as it explains our own solar system, which of the following should we expect to be true for other star systems? Jovian planets always form farther from their star than terrestrial planets.Many extras olar planets should fall into the terrestrial or jovian categories .Planetary systems will always have four terrestrial planets and four jovian planets. Some planetary systems will have terrestrial planets that orbit their star in a direction opposite to the orbital direction of the jovian planets. Planetary systems should generally have all planets orbiting in nearly the same plane. Planetary systems should be common.

Jovian planets always form farther from their star than terrestrial planets.Many extrasolar planets should fall into the terrestrial or jovian categories. Planetary systems should generally have all planets orbiting in nearly the same plane. Planetary systems should be common. We expect all solar systems to form in similar ways from collapsing gas clouds and therefore to share basic features, such as the planets all orbiting in the same direction and nearly the same plane. We also expect planets to form similarly through accretion, with planets that form near a star tending to be terrestrial in nature and planets that form farther away tending to be jovian; however, as you'll learn in later chapters, the details of planetary formation allow for additional types of planets beyond just those two categories. We do not expect particulars that are probably coincidental, such as the precise numbers of planets, to be the same in different solar systems.

The tidal force that acts on Io is due primarily to the gravity of __________. Europa Jupiter both Europa and Ganymede

Jupiter As indicated by the force arrows in the video, the tidal force on Io is caused by the gravity of Jupiter. Keep in mind that, because gravity weakens with distance, tidal forces must also weaken with distance. In fact, the tidal force weakens more rapidly with distance than the gravitational force. Tidal heating is a source of internal heat created by tidal friction, which is friction generated as a result of a varying tidal force. A tidal force is a force arising from a difference in the strength of a gravitational attraction across an object, causing the object to stretch. For example, the Moon exerts a gravitational attraction on Earth, but this attraction is stronger on the side of Earth that is facing the Moon than on Earth's opposite side. Note that in the video, the tidal force is represented by the difference in the lengths of the two arrows (which represent the gravitational force between Jupiter and the two sides of Io).

What is the minimum number of moons that must be orbiting a planet for the moons to have an orbital resonance? 1 2 3

2 An orbital resonance occurs when one moon's orbital period is a simple fraction of the other's, such as 1/2 or 1/3 or 1/4. This means that at least two moons are required.

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? 1.25 billion years5.0 billion years2.5 billion years3.75 billion years

3.75 billion years The current 10 micrograms of potassium-40 is 1/8 of the original 80 grams, which means the amount of potassium-40 has declined by a factor of 8. Therefore, three half-lives have passed (23 = 8) and the rock is 3 &times1.25 = 3.75 billion years old.

Make a prediction: If the rise in carbon dioxide concentration continues at its current pace, the concentration in the year 2050 will be about _____ parts per million. 400 430 460 510

460 Note that this concentration would be more than 60% higher than the concentration of 280 parts per million at the beginning of the industrial age (around the year 1750). It is also far higher than the carbon dioxide concentration reached naturally during the prior 800,000 years. In fact, the situation could be even worse: Careful study of the graph shows an acceleration of the rate of increase in recent years, which would lead the carbon dioxide concentration to be even higher than 460 parts per million by 2050.

From 1980 to 2015, the carbon dioxide concentration increased by about _____ parts per million. 20 100 60

60

What reflectivity would be necessary to keep the average temperature exactly at the freezing point?

9.6%

According to modern science, what was the approximate chemical composition of the solar nebula? 98% hydrogen and helium, 2% everything else98% hydrogen, 2% helium50% hydrogen and helium, 50% everything elseroughly equal proportions of hydrogen, helium, water, and methane

98% hydrogen and helium, 2% everything else The Sun still has this basic composition today.

What change in the Sun during the solar system's history is thought to be important to understanding the climates of Venus, Earth, and Mars? A gradual brightening with time. A gradual weakening of the solar wind with time. A gradual dimming with time. A gradual reduction in the amount of ultraviolet and x-ray radiation coming from the Sun.

A gradual brightening with time. The Sun is thought to be about 30% brighter today than it was when it was born.

All of the following have occurred over long periods of time on Earth. Which one is not thought to have played a major role in long-term changes in Earth's climate? A gradual rise in the atmospheric content of oxygen. Changes in the Earth's overall reflectivity. Changes in the atmospheric concentration of greenhouse gases. Changes in the Earth's axis tilt.

A gradual rise in the atmospheric content of oxygen. Oxygen is not a greenhouse gas, so it does not play a direct role in climate change.

The verdict at the end of the Extraordinary Claims box says "Likely correct, though may never be possible to prove definitively." In the context of models, which of the following best explains this verdict? Models are not reality, and we can never trust their results to reflect what might happen in the real world (or universe).No model could ever be good enough to reproduce the major characteristics of the Moon.Models are very vague, and cannot be used to make mathematically precise predictions.A model that precisely reproduces major characteristics of the Moon would seem likely correct, but we can't go back in time to see that it actually happened that way.

A model that precisely reproduces major characteristics of the Moon would seem likely correct, but we can't go back in time to see that it actually happened that way. Today's models use computers to make precise predictions based on mathematical formulations of the known laws of nature. When these predictions match reality (such as the successfully reproducing the major characteristics of the Moon) we have great confidence that they are on the right track, but we can't completely rule out that some other scenario would also produce the same result.

When did the objects that we now see as asteroids and comets form in the solar system? Before the cloud flattened into a disk.After the cloud flattened into a disk but before solid particles condensed from the gas.After the planets finished forming.After solid particles condensed from the gas but before the planets finished forming.

After solid particles condensed from the gas but before the planets finished forming. Submit Asteroids and comets are leftover planetesimals, and as shown in the video, planetesimals formed through the accretion of the solid particles that condensed from the nebula.

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. There are two basic types of planets in our solar system: terrestrial and jovian. The four largest planets all have disk-shaped ring systems around them. All the planets orbit the Sun in the same direction and in nearly the same plane.

All the planets orbit the Sun in the same direction and in nearly the same plane. Submit The orbits of the planets reflect the rotation pattern of the flat, rotating disk in which they formed.

Since the time Arrhenius made his prediction, the carbon dioxide concentration has risen by about 30% and the global average temperature has risen by about 1°C. Which statement below best describes how scientists should evaluate Arrhenius's prediction? The actual change is so much lower than Arrhenius predicted that we must conclude he was wrong in his assumption that a rising carbon dioxide concentration would lead to global warming. The actual change is so much higher than Arrhenius predicted that we must conclude that he was incorrect in assuming that the carbon dioxide concentration affects the climate. Although Arrhenius's prediction was not exact, the actual change is similar enough to the predicted change to validate the general idea that a rising carbon dioxide concentration would lead to global warming .We cannot evaluate Arrhenius's prediction, because he made a prediction for a 50% rise in the carbon dioxide concentration and the actual rise since his time has been only about 30%.

Although Arrhenius's prediction was not exact, the actual change is similar enough to the predicted change to validate the general idea that a rising carbon dioxide concentration would lead to global warming The climate is very complex, so we would not expect simple paper and pencil calculations to give an exact prediction for future climate trends. However, if the basic ideas are correct, then these calculations should predict the correct trend and be at least moderately close to the actual values. The actual change is in the correct direction (warming) and not more than a few degrees less than predicted, which is quite good for such simple calculations.

As discussed in the Extraordinary Claims box, when the giant impact idea was first proposed, it was generally thought to be so unlikely that it wasn't seriously considered until decades later, after the Apollo missions to the Moon. What key piece of scientific understanding was missing that made it seem so unlikely when first proposed? A precise age for the solar system.An understanding of the difficulty of gravitationally capturing a body as large as our Moon.An understanding of how heavily cratered the Moon's surface is.An understanding of the number and size of leftover planetesimals in the early solar system.

An understanding of the number and size of leftover planetesimals in the early solar system. Models of solar system formation were not yet sophisticated enough to have made the idea of giant impacts seem plausible. The likelihood of a giant impact only began to seem reasonable after we understood that many large, leftover planetesimals would have been roaming the early solar system.

Which of the following is not an expected consequence of the rising carbon dioxide concentration or global warming? Increasing acidity of the oceans.Melting of polar ice.Animal deaths due to carbon dioxide poisoning.Rising sea level.An increase in extreme weather events, including severe winter weather.

Animal deaths due to carbon dioxide poisoning. The carbon dioxide level is nowhere near high enough to poison animals directly. All the other consequences are real; review the video or your textbook if you have questions about the reasons behind any of them.

Click the third tab (labeled "Global Warming"), then explore the graph and the expanded views you will find by clicking the "?" buttons. Which of the following statements are supported by the data shown? Human activity has caused the carbon dioxide concentration to swing up and down wildly over the past 800,000 years. Atmospheric carbon dioxide levels have risen dramatically over the past century. Rises in global average temperature tend to be closely associated with rises in atmospheric carbon dioxide concentration. Earth's global average temperature has generally risen over the past century. Earth's global temperature today is higher than it has ever been before.

Atmospheric carbon dioxide levels have risen dramatically over the past century. Rises in global average temperature tend to be closely associated with rises in atmospheric carbon dioxide concentration. Earth's global average temperature has generally risen over the past century. Rising carbon dioxide is closely associated with rising temperatures, and both the carbon dioxide concentration and temperature have been rising over the past century, which is why scientists are so concerned about global warming. Note that today's temperature is not the highest it has been in the past 800,000 years, though it is getting close to that level. (But Earth's temperature has been higher in the more distant past.)

Consider the three items from Part A that are not relevant to the giant impact hypothesis. As you'll learn in later chapters, the lack of volcanoes is a result of the Moon's relatively small size. But what explains the other two items — the Moon's synchronous rotation and gradually increasing distance from Earth? Synchronous rotation is simply a coincidence, and this coincidence in turn causes the Moon to move farther away with time.Both are results of the Moon's small size.The giant impact would have caused the Moon to rotate synchronously, and the outward fling from the impact would explain the increasing distance.Both are results of tidal interactions between the Moon and Earth.

Both are results of tidal interactions between the Moon and Earth. As discussed in the section of your textbook on tides, the Moon's synchronous rotation arose as tidal friction slowed the Moon's rotation until its period matched its orbital period. The Moon's gradually increasing distance is a result of the fact that tidal friction is still gradually slowing Earth's rotation, and this leads to forces that push the Moon outward in its orbit so that the total angular momentum of the Earth-Moon system remains conserved.

Why do we think that ring particles must be replenished over time? Where we think ring particles come from? Choose the correct statement. Because collisions are constantly occurring within the ring systems, ring particles are continually being ground down to dust. Dust in ring systems tends to aggregate and form larger particles as the time time. These larger particles tend to fall onto the planet due to gravity, so we think that ring systems cannot survive very long and thus that ring particles must be replenished, probably by impacts on small embedded moons and ring particles by micrometeorites and the occasional larger impacts. Because collisions are constantly occurring within the ring systems, ring particles are continually being ground down to dust. Dust in ring systems tends to aggregate and form larger particles as the time time. These larger particles tend to fall onto the planet due to gravity, so we think that ring systems cannot survive very long and thus that ring particles must be replenished, probably by capturing small particles from the asteroid belt or the Kuiper belt. Because collisions are constantly occurring within the ring systems, ring particles are continually being ground down to dust. Dust cannot survive long in ring systems because sunlight pressure makes the particles slowly fall onto the planet. So we think that ring systems cannot survive very long and thus that ring particles must be replenished, probably by impacts on small embedded moons and ring particles by micrometeorites and the occasional larger impacts. Because collisions are constantly occurring within the ring systems, ring particles are continually being ground down to dust. Dust cannot survive long in ring systems because sunlight pressure makes the particles slowly fall onto the planet. So we think that ring systems cannot survive very long and thus that ring particles must be replenished, probably by capturing small particles from the asteroid belt or the Kuiper belt.

Because collisions are constantly occurring within the ring systems, ring particles are continually being ground down to dust. Dust cannot survive long in ring systems because sunlight pressure makes the particles slowly fall onto the planet. So we think that ring systems cannot survive very long and thus that ring particles must be replenished, probably by impacts on small embedded moons and ring particles by micrometeorites and the occasional larger impacts.

Which position in the diagram represents the part of the cycle in which carbon dioxide is turned into carbonate minerals and rock? clouds ocean/river/lake mantle volcanoe

Carbon dioxide dissolves in the ocean and reacts with minerals to form carbonate rock. ocean/river

Why is Mars red? The red color of Mars is a result of the scattering of light in the Martian sky.Martian volcanoes released a much redder lava than volcanoes on Earth.Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface.The red color is caused by water ice chemically bound in surface rock.

Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface. That is why Mars has a rust-like color.

Click the fourth tab (labeled "Computer Models"), then explore how the graph changes as you click among the three buttons to its left. What is the primary message of the full graph (with all three curves shown)? Climate models are unable to account for the major recent trend in temperature data. Climate models successfully reproduce the major recent trend in temperature data only if both human and natural factors are included. Climate models can successfully reproduce the major recent trends in temperature data by considering natural factors alone.

Climate models successfully reproduce the major recent trend in temperature data only if both human and natural factors are included. The red curve represents models that include both natural factors and human contributions, and it provides a close match to actual temperature data (the black curve).

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? Colliding cloud particles exchange angular momentum and, on average, end up with the rotation pattern for the cloud as a whole. 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. All collapsing objects tend to flatten into a disk, regardless of their rotation. 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. Particles in the collapsing cloud inevitably collide with one another. These collisions allow particles to exchange angular momentum, but their total angular momentum must be conserved. Therefore, many collisions result in an averaging out of the angular momentums of individual cloud particles, a process that brings their orbits into approximately the same plane.

As you found in Part A, early Mars had both core convection and a strong magnetosphere. What is the connection between these two things? Core convection creates volcanism and outgassing, the gas creates the magnetosphere. Both core convection and a magnetosphere can exist only a very young planet. Core convection helps generate a magnetic field, and the magnetic field creates the magnetosphere. Both core convection and a magnetosphere are consequences of a strong greenhouse effect.

Core convection helps generate a magnetic field, and the magnetic field creates the magnetosphere. Early Mars had a strong magnetic field because of the combination of convection in its molten metal core and a relatively rapid rotation rate. The magnetic field created the magnetosphere that shielded the atmosphere from the solar wind.

How does it explain the differences between seafloor and continental crust? Denser oceanic crust is constantly recycled, sinking in mantle at subduction zones and forming anew from mantle matter at spreading zones. Continental crust is less dense than the oceanic crust, so it does not sink at subduction zones and is older than oceanic crust.Thin and flexible oceanic sinks into the mantle at subduction zones and then floats back at spreading zones. Thick and a rigid continental crust breaks in pieces at subduction zones and builds up mountain ranges. Therefore, the oceanic crust is older than the continental crust.Dense oceanic crust sink into the mantle and melts down at the subduction zones. Less dense continental crust is generated from the raising mantle matter at the spreading zones. Therefore, the oceanic crust is older than the continental crust.Less dense oceanic crust is constantly recycled, melting in mantle at subduction zones and forming anew from mantle matter at spreading zones. Continental crust is more dense than the oceanic crust, so it does not melt at subduction zones and is older than oceanic crust.

Denser oceanic crust is constantly recycled, sinking in mantle at subduction zones and forming anew from mantle matter at spreading zones. Continental crust is less dense than the oceanic crust, so it does not sink at subduction zones and is older than oceanic crust.

Each of the following statements was either true for Mars in the distant past (early Mars) or is true for Mars today. Sort the statements by dragging each into the correct bin. Some craters held lakes of water. Strong greenhouse effect. Substantial volcanism and outgassing. Core convection. Strong magnetosphere Surface pressure too low for stable liquid water. Solar wind strips atmospheric gas. Very weak greenhouse effect. Submit

Early Mars: Some craters held lakes of water. Strong greenhouse effect. Substantial volcanism and outgassing. Core convection. Strong magnetosphere. Mars Today: Surface pressure too low for stable liquid water. Solar wind strips atmospheric gas. Very weak greenhouse effect. Submit

Which of the following best describes the geological histories of the Moon and Mercury? All four geological processes were important in their early histories, but only tectonics still reshapes their surfaces today.Impact cratering is the only major geological process that has affected their surfaces.Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all.Impact cratering shaped these worlds early in their histories. Then, during the past few million years, they were reshaped by episodes of volcanism and tectonics. Submit

Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all. For most practical purposes, the Moon and Mercury are now geologically dead.

Compare your result in the previous part to the Earth's actual reflectivity, 29%, and choose the correct conclusion Earth would be frozen, if there were no greenhouse effect in the atmosphere. Because of the greenhouse effect, Earth's reflectivity does not influence of the surface temperature. Greenhouse effect would be significantly stronger, if the reflectivity of Earth were less. Reflectivity of Earth would be significantly less, if there were no greenhouse effect in the atmosphere

Earth would be frozen, if there were no greenhouse effect in the atmosphere.

Choose the correct description of the conveyor-like action of plate tectonics on Earth. Earth's mantle is broken up into plates that float beneath the overlying lithosphere. The bottoms of the mantle's convection cells drag the tops of the plates, making them move relatively to each other.Earth's lithosphere is broken up into plates that float beneath the overlying mantle. The bottoms of the mantle's convection cells drag the tops of the plates, making them move relatively to each other.Earth's lithosphere is broken up into plates that float on the underlying mantle. The tops of the mantle's convection cells drag the bottoms of the plates, making them move relatively to each other.Earth's mantle is broken up into plates that float on the underlying lithosphere. The tops of the mantle's convection cells drag the bottoms of the plates, making them move relatively to each other.

Earth's lithosphere is broken up into plates that float on the underlying mantle. The tops of the mantle's convection cells drag the bottoms of the plates, making them move relatively to each other.

Arrhenius was not particularly alarmed by his discovery at the time. What changed that made later scientists become much more concerned about the climate effects of carbon dioxide? Scientists discovered errors in Arrhenius's calculations that made the effects of carbon dioxide much greater than he had expected.Scientists discovered that there is much more natural carbon dioxide in the atmosphere than Arrhenius had thought.Emissions of carbon dioxide rose much faster than Arrhenius had anticipated.Scientists became concerned about carbon dioxide only after measurements showed the world was warming substantially

Emissions of carbon dioxide rose much faster than Arrhenius had anticipated. As discussed in the Extraordinary Claims box, concern about these rising emissions is what led Keeling and others to begin measuring the carbon dioxide concentration.

What motivated Arrhenius to calculate how changes in carbon dioxide might affect the climate? He was seeking to understand why the world was rapidly warming up.He was seeking to understand the causes of ice ages.He was seeking to understand the consequences of burning fossil fuels.He knew that the carbon dioxide concentration was increasing and sought to understand how that would affect the climate.

He was seeking to understand the causes of ice ages. This answer is stated directly in the Extraordinary Claims box.

All the following statements are true. Which two represent the two facts that lead us to expect Earth to be warming up as a result of human activity? Be sure to choose two of the statements below. Human activity is increasing the concentration of carbon dioxide and other greenhouse gases in the atmosphere.Water vapor is a greenhouse gas, but nitrogen and oxygen are not.Greenhouse gases make Earth warmer than it would be otherwise.Venus has a much stronger greenhouse effect than Earth.If the polar caps melted, sea level would be much higher than it is today.Temperatures are generally warmer in summer and cooler in winter.

Human activity is increasing the concentration of carbon dioxide and other greenhouse gases in the atmosphere. Greenhouse gases make Earth warmer than it would be otherwise. As explained in the video, these two facts lead us to expect Earth to be warming up as we add more greenhouse gas to the atmosphere, and global temperature data verify that temperatures are indeed rising.

According to 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? Hydrogen and helium are the most common elements throughout the universe.Gravity only acted on hydrogen and helium.All elements besides hydrogen and helium were swept out of the solar system by the solar wind.All the elements besides hydrogen and helium escaped from the solar nebula before the Sun and planets formed.

Hydrogen and helium are the most common elements throughout the universe. In other words, the chemical composition of the solar system is fairly close to that of the universe as a whole.

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? 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 .Denser particles of rock and metal sank into the inner solar system, leaving only gases 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.

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 Only metal and rock could condense at the high temperature of the inner solar system, so the inner planets were built by the accretion of metal and rock. Farther out, ices could also condense, leading to the accretion of ice-rich planetesimals. Some of these grew large enough for their gravity to attract gas from the solar nebula and become jovian planets.

What key process underlies why Mars changed so much from its early conditions to its conditions today? Evaporation of its ocean. Interior cooling. Slowing of its rotation rate. Outgassing.

Interior cooling. Cooling of the interior explains both why core convection stopped, leading to weakening of the magnetic field and magnetosphere, and why volcanism and outgassing became so much weaker.

As you saw in Part A, Io's elliptical orbit is necessary to its tidal heating. This elliptical orbit, in turn, is a result of the orbital resonance among Io, Europa, and Ganymede. This orbital resonance causes Io to have a more elliptical orbit than it would otherwise, because __________. Europa and Ganymede are unusually large moons Io, Europa and Ganymede periodically return to the same orbital positions, creating the same gravitational tugs Europa and Ganymede always pull on Io from the same direction as Jupiter pulls on Io all three moons orbit with the same period, staying aligned at all times

Io, Europa and Ganymede periodically return to the same orbital positions, creating the same gravitational tugs The repeated passes at the same orbital position mean that Io experiences repeated gravitational tugs at the same place in each orbit, and these tugs make its orbit more elliptical than it would be otherwise.

As discussed in the video, the leading hypothesis for why Mars changed holds that interior cooling led to loss of its magnetosphere, allowing the solar wind to strip atmospheric gas away. How has the MAVEN mission provided evidence for this hypothesis? It measured the amount of atmospheric gas that Mars had long ago.It has measured the strength of the magnetic field that Mars had long ago.It has measured the rate at which Mars's interior has lost heat.It has measured rates of gas loss from the atmosphere today.

It has measured rates of gas loss from the atmosphere today. These measurements confirm that Mars is still losing gas to solar wind stripping, and also allow scientists to estimate how much gas loss has occurred over time.

Based on the leading scientific theory of solar system formation, which of the following statements best explains why Uranus and Neptune have a significantly different composition than Jupiter and Saturn? The lower masses of Uranus and Neptune allowed more of their hydrogen and helium gas to escape into space. Jupiter and Saturn formed closer to the Sun, where there was more hydrogen and helium gas and less hydrogen compounds and rock. Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune. The lower temperatures at the locations of Uranus and Neptune allowed more material to condense into solid form into solid form.

Jupiter and Saturn captured more gas from the solar nebula than Uranus and Neptune. Accretion is thought to have occurred more rapidly in the denser regions of the solar nebula that were closer to the Sun. Therefore, although all four jovian planets captured hydrogen and helium gas from the solar nebula around similar-mass planetesimals (made of hydrogen compounds and rock), Jupiter and Saturn had more time to capture this gas. As a result, Jupiter and Saturn accreted so much hydrogen and helium gas that these ingredients ended up dominating their composition. In contrast, Uranus and Neptune were left with compositions dominated by hydrogen compounds and rock.

All of the following statements are true. Which one explains why Mars has lost so much more interior heat than Earth. Mars lacks a large moon. Mars has lost much more atmospheric gas than Earth. Mars is farther from the Sun than Earth. Mars has a much weaker greenhouse effect than Earth. Mars is smaller than Earth.

Mars is smaller than Earth. Submit Smaller objects cool more rapidly than large ones, so Mars's smaller size explains why it has lost much more interior heat than Earth.

Scientists suspect 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? The Martian core is made of rock, while Earth's core is made of metal.Mars rotates much slower than the Earth.Mars is too far from the Sun to have a global magnetic field.Mars's interior has cooled so much that its molten core layer no longer undergoes convection.

Mars's interior has cooled so much that its molten core layer no longer undergoes convection. Convection of the molten core is required for a global magnetic field.

Although the data show only a correlation between the carbon dioxide concentration and the global average temperature, scientists have other reasons to think that a rise in the carbon dioxide concentration actually causes a rise in the global average temperature. All of the following statements are true. Which statements lend support to the idea that carbon dioxide is a cause of planetary warming? Models of the greenhouse effect successfully predict the temperatures of Venus and Mars from their atmospheric carbon dioxide amounts .We understand the physical mechanism of the greenhouse effect, through which carbon dioxide can increase a planet's temperature. Isotope ratios in atmospheric carbon dioxide show that much of the carbon dioxide in Earth's atmosphere today comes from the burning of fossil fuels. Models of Earth's climate that include recent increases in the carbon dioxide concentration match observed temperature increases better than those that do not include it.

Models of the greenhouse effect successfully predict the temperatures of Venus and Mars from their atmospheric carbon dioxide amounts .We understand the physical mechanism of the greenhouse effect, through which carbon dioxide can increase a planet's temperature. Models of Earth's climate that include recent increases in the carbon dioxide concentration match observed temperature increases better than those that do not include it. Together, the success of the models and our clear understanding of the mechanism of the greenhouse effect leave little room for doubt that carbon dioxide is indeed a cause of higher temperatures on a planet.

Suppose we had a device that allowed us to see Earth's interior. If we looked at a typical region of the mantle, what would we see happening? Hot molten rock rising upward throughout the mantle and cool, solid rock falling downward.A rapid, up and down churning of the material in the mantle.Dense metals falling downward and low-density rock rising upward.Not much: on human time scales, the mantle looks like solid rock.

Not much: on human time scales, the mantle looks like solid rock. Most of the mantle is solid. Mantle convection is the slow flow of this solid rock, but it occurs too slowly to notice on human time scales. (The cycling time for rock from the bottom to the top of the mantle is about 100 million years.)

Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars? the polar capsthe southern highlandsValles MarinerisOlympus Mons

Olympus Mons Olympus Mons is a very large, shallow-sloped volcano (or "shield volcano"). You can also see numerous other volcanoes on Mars, including three large ones on the Tharsis bulge.

What are the 3 ways that a terrestrial world transfers energy away from the interior?

One of these is convection, which we see a bunch in other chapters Another is radiation, which is related to the thermal spectrum we talked about earlier this semester

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 science, the primary purpose of a model is to __________. show a miniature representation of some object make predictions that can be tested observationally record the exact way in which some physical process actually works

make predictions that can be tested observationally

Which of the following statements correctly describes the motion of the particles in Saturn's rings? Particles in all the rings hover motionlessly high above Saturn. Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings. Particles in the inner rings orbit Saturn at a slower speed than particles in the outer rings. All the particles in the rings orbit Saturn with the same orbital period.

Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings. In accord with Kepler's third law, particles closer to Saturn orbit at a faster speed than more distant particles.

According to current models of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn? Ices were able to condense at the distance of Jupiter and Saturn, but only rock and metal could condense at the distances of Uranus and Neptune. The solar nebula had different chemical composition at different distances from the Sun, leading to the differences in mass. Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula. The size differences are thought to be a random coincidence.

Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula.

Based on what the nebular theory tells us about the formation of our own solar system, what does the theory predict for the possibility of other planetary systems? Most stars should have one or two planets, but not more.Planetary systems should be very rare.Planetary systems should be common.Other planetary systems should be identical to our own.

Planetary systems should be common. The same basic processes should accompany the births of most or all stars as they form from the gravitational collapse of interstellar clouds, so we should expect planetary systems to be common. This prediction of the nebular theory has been verified by discoveries of extrasolar planets.

The choices describe four hypothetical planets. Which one would you expect to have the most features of erosion? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) Size: same as Venus.Distance from Sun: same as Mars.Rotation rate: once every 25 hours.Size: same as Mars.Distance from Sun: same as Earth.Rotation rate: once every 18 hours.Size: twice as big as Earth.Distance from Sun: same as Mercury.Rotation rate: once every 6 months.Size: same as the Moon.Distance from Sun: same as Mars.Rotation rate: once every 10 days.

Size: same as Venus.Distance from Sun: same as Mars.Rotation rate: once every 25 hours. This planet is large enough to have had outgassing make an atmosphere, and rotates fast enough to drive winds.

The choices describe four hypothetical planets. Which one's surface would you expect to be most crowded with impact craters? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) Size: twice as big as Earth.Distance from Sun: same as Mercury.Rotation rate: once every 6 months.Size: same as Venus.Distance from Sun: same as Mars.Rotation rate: once every 25 hours.Size: same as Mars.Distance from Sun: same as Earth.Rotation rate: once every 18 hours.Size: same as the Moon.Distance from Sun: same as Mars.Rotation rate: once every 10 days.

Size: same as the Moon.Distance from Sun: same as Mars.Rotation rate: once every 10 days. The smallest size means the least geological activity to have erased past impact craters, so lots of craters would still be present.

The choices describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) Size: twice as big as Earth.Distance from Sun: same as Mercury.Rotation rate: once every 6 months.Size: same as Venus.Distance from Sun: same as Mars.Rotation rate: once every 25 hours.Size: same as the Moon.Distance from Sun: same as Mars.Rotation rate: once every 10 days.Size: same as Mars.Distance from Sun: same as Earth.Rotation rate: once every 18 hours.

Size: twice as big as Earth.Distance from Sun: same as Mercury.Rotation rate: once every 6 months. Largest size means the highest interior temperature.

Which of the following best explains why we can rule out the idea that planets are usually formed by near collisions between stars? 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. A near collision should have left a trail of gas extending out behind the Sun, and we see no evidence of such a trail. 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 stars. The near collisions (close encounter) idea seemed unlikely even before we knew of extrasolar planets, but the existence of many other planetary systems makes it completely implausible.

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. There is nothing on the brownish surface to suggest liquid water, and close-up photos confirm that there is no liquid water on Mars today. However, the prominent polar caps look much like Earth's polar caps, and would therefore make you suspect that they are made of water ice. In fact, they contain both frozen carbon dioxide and frozen water.

Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why? Jupiter and Saturn do not contain any methane gas. The rapid rotation of Jupiter and Saturn prevents methane clouds from forming. Temperatures on Jupiter and Saturn are too high for methane to condense. The stronger gravity on Jupiter and Saturn pulls methane downward so that it can't form clouds.

Temperatures on Jupiter and Saturn are too high for methane to condense. But methane can condense on Uranus and Neptune because they are farther from the Sun and hence colder.

Deuterium is much more abundant on Venus than Earth. What do scientists think this fact tells us about Venus? That Venus once had a much stronger magnetic field than it does today.That the greenhouse effect on Venus must have been much weaker in the distant past.That volcanoes on Venus did not outgas as much water as volcanoes on Earth.That Venus has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space

That Venus has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space. Deuterium is less likely to escape than ordinary hydrogen, which would explain the high deuterium abundance.

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'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 large crater, probably the one made by the giant impact.Computer simulations show that the Moon could really have formed through a giant impact.The Moon has a much smaller proportion of easily vaporized materials than Earth.

The Pacific Ocean appears to be a large crater, probably the one made by the giant impact. The Pacific Ocean is not an impact crater. Moreover, because the continents are rearranged with time, we can be sure that the giant impact occurred long, long before there was a Pacific Ocean.

Many meteorites appear to have formed very early in the solar system's history. How do these meteorites support the nebular theory's scenario for the formation of the terrestrial planets? The overall composition of these meteorites is just what we believe the composition of the solar nebula to have been: mostly hydrogen and helium.The sizes of these meteorites are just what we'd expect if metal and rock condensed and accreted as the nebular theory suggests.The appearance and composition of these meteorites is just what we'd expect if metal and rock condensed and accreted as the nebular theory suggests.The appearance and composition of these meteorites matches what we observe in comets today, suggesting that they were once pieces of icy planetesimals.

The appearance and composition of these meteorites is just what we'd expect if metal and rock condensed and accreted as the nebular theory suggests. In other words, meteorites support our models of how accretion should have occurred.

What do we mean by the period of heavy bombardment in the context of the history of our solar system? The first few hundred million years after the planets formed, which is when most impact craters were formed.The period about 65 million years ago when an impact is thought to have led to the extinction of the dinosaurs.The time during which heavy elements condensed into rock and metal in the solar nebula.The time before planetesimals finished accreting into planets, during which time many growing planetesimals must have shattered in collisions.

The first few hundred million years after the planets formed, which is when most impact craters were formed. The heavy bombardment ended once most of the objects that could create impacts had either crashed into a planet or attained a stable orbit around the Sun.

According to the nebular 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? The two laws of thermal radiation The law of conservation of angular momentum The law of conservation of energy Newton's third law

The law of conservation of energy As it shrank in size, gas particles lost gravitational potential energy. Because energy must be conserved, this energy became thermal energy.

Which of the following is not generally true of all the terrestrial world lithospheres? Rock in the lithosphere is stronger than rock beneath it.The thickness of the lithosphere depends on interior temperature, with cooler interiors leading to thicker lithospheres.The lithosphere is broken into a set of large plates that float on 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 on the softer rock below. This is true of Earth, but not of the other terrestrial lithospheres.

Most of the Moon's surface is densely covered with craters, but we find relatively few craters within the lunar maria. What can we conclude? The regions of the maria were hit by fewer impacts than the densely cratered regions.The maria formed within the past 1 billion years.The maria formed after the heavy bombardment ended.Erosion affects the maria more than it affects other regions of the Moon.

The maria formed after the heavy bombardment ended. They contain few craters because they formed after most impacts had occurred.

What do we mean when we say that a nucleus undergoes radioactive decay? The mass of the nucleus is converted into high-energy X rays and gamma rays.The nucleus splits into two equal size pieces.The nucleus emits radio waves.The number of protons or neutrons (or both) in the nucleus changes.

The number of protons or neutrons (or both) in the nucleus changes. Radioactive decay can happen in many different ways, but in all cases involves a change in the number of protons or the number of neutrons, or both, in the nucleus.

Which statement about Saturn's rings is not true? The rings must look much the same today as they did shortly after Saturn formed. The rings are so thin that they essentially disappear from view when seen edge-on. The large gap known as the Cassini Division is shaped by an orbital resonance with the moon Mimas, which orbits well outside the rings. Some features of the rings are shaped by small moons that actually orbit within the ring system. Submit

The rings must look much the same today as they did shortly after Saturn formed. Ring particles cannot last long compared to the age of the solar system, so the rings much change their appearance with time.

Suppose that Earth's ice caps melted, but everything else about the Earth;s surface and atmosphere stayed the same. What would happen to Earth's average surface temperature? The surface temperature would decrease. The surface temperature would increase. The temperature would not be affected at all. The surface temperature would change radically, until it was equal to the melting temperature of ice.

The surface temperature would increase. Ice has a high reflectivity, so melting the ice caps would decrease Earth's overall reflectivity, which means more sunlight being absorbed, which tends to increase temperature.

What is the primary basis on which we divide the ingredients of the solar nebula into the four categories hydrogen/helium, hydrogen compounds, rock, and metal? The amounts of energy required to ionize various materials.The locations of various materials in the solar nebula.The atomic mass numbers of various materials.The temperatures at which various materials can condense from gaseous form to solid form.

The temperatures at which various materials can condense from gaseous form to solid form. Condensation determined the materials available in solid form in different regions of the nebula.

According to the nebular theory of solar system formation, what key difference in their early formation explains why the jovian planets ended up so different from the terrestrial planets? According to the nebular theory of solar system formation, what key difference in their early formation explains why the jovian planets ended up so different from the terrestrial planets?

The terrestrial planets formed inside the frost line of the solar nebula and the jovian planets formed beyond it. This meant that there was a lot more material that could solidify in the region where the jovian planets formed (because ices could condense along with metal and rock). This led to the accretion of much larger solid planetesimals, and for the four jovian planets, these planetesimals became so massive that their gravity could then pull in hydrogen and helium gas, adding further to their masses.

Why does Jupiter have three distinct layers of clouds? The three layers represent clouds made of gases that condense at different temperatures. Jupiter has three different types of wind, each of which makes a different type of cloud. The three layers reflect regions of Jupiter's atmosphere with different chemical compositions. Clouds form randomly, so on average there are always three layers.

The three layers represent clouds made of gases that condense at different temperatures. The three cloud layers are ammonia, ammonium hydrosulfide, and water. Each of these gases condenses at a different temperature and hence at a different altitude in Jupiter's atmosphere.

Notice that the peaks and troughs on the temperature graph occur at the about the same times as peaks and troughs on the carbon dioxide graph. What can we infer from this fact alone? Higher carbon dioxide concentrations cause higher global average temperatures. The carbon dioxide concentration is inversely related to the global average temperature. There is a correlation between the carbon dioxide concentration and the global average temperature. Higher global average temperatures cause higher carbon dioxide concentrations.

There is a correlation between the carbon dioxide concentration and the global average temperature. A correlation means that two things go up and down together. In this case, there is a correlation between the temperature and the carbon dioxide concentration because both were generally high at the same times in the past and low at the same times in the past.

Which of the following statements comparing the jovian interiors is not thought to be true? They all have cores of roughly the same mass. They all have cores that contain at least some rock and metal. Deep inside them, they all have pressures far higher than that found on the bottom of the ocean on Earth. They all have the same exact set of internal layers, though these layers differ in size.

They all have the same exact set of internal layers, though these layers differ in size. Submit The layers on Uranus and Neptune are significantly different from those on Jupiter and Saturn.

Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury? They have only small amounts of gas, all of which is left over from outgassing long ago. They have thin atmospheres produced by outgassing, but still have the layers of a troposphere, thermosphere, and exosphere. They have thin exospheres only, with gas coming from impacts of subatomic particles and photons. They have thin tropospheres only, with gas coming from vaporization.

They have thin exospheres only, with gas coming from impacts of subatomic particles and photons. In essence, the Moon and Mercury lack an atmosphere in the way we think of atmospheres on other planets; their small amounts of gas are essentially just atoms blasted from the surface, which bounce around until they settle back to the surface.

This diagram shows Earth's atmospheric carbon dioxide concentration over the past few decades. What is the significance of the up and down wiggles? They show seasonal variations in the concentration. They show that the rise in carbon dioxide concentration is caused by human activity. They show that the carbon dioxide concentration can vary randomly and by large amounts. They show that there is a lot of noise in data that attempt to measure the carbon dioxide concentration.

They show seasonal variations in the concentration. But even with these seasonal variations, the trend is still clearly upward with time.

Using only pencil and paper calculations, Arrhenius concluded that a doubling of the carbon dioxide concentration would raise global temperatures by about _____. 1° C 2° C 5° C 15° C

This answer is stated directly in the Extraordinary Claims box.

Choose the correct explanation of whether the discovery should be considered reasonable or surprising: Drilling into the slopes of a Martian volcano, a robotic spacecraft discovers liquid water beneath the surface This would be exciting, but not surprising. Geothermal heat from Martian volcanoes may well be enough to melt water under the Mars surface.This would be exciting and surprising. Because of the weak gravity of Mars, all hydrogen should be leaked from the planet long ago, so there is no any water in any phase on Mars.This would be exciting, but not surprising. The active atmosphere of Mars and traces of recent erosion on its surface both imply that liquid water present sometimes on the Martian surface.This would be exciting and surprising. Mars is certainly geologically inactive planets, so the temperature in its interior should not be increasing with depth

This would be exciting, but not surprising. Geothermal heat from Martian volcanoes may well be enough to melt water under the Mars surface.

Choose the correct explanation, whether the discovery below should be considered reasonable or surprising: A planet orbiting another star is made primarily of hydrogen and helium and has approximately the same mass as Jupiter but is the same size as Neptune. This would be reasonable. If that orbits closer to the star than our jovian planets, it could be compressed additionally by the gravitation and solar wind of its star, and contracted to Neptune-like size. This would be reasonable. The jovian planets tends to generate enormous pressure inside, so one of them could reach the pressure enough to make most of its hydrogen metallic and to contract to Neptune's size. This would be surprising and possibly implausible. Planets made of hydrogen and helium all have the same density because of metallic hydrogen's properties, as Saturn and Jupiter in our Solar system. This would be surprising and possibly implausible. The mass and composition defines the size and density, so Jupiter-mass hydrogen planet should have sizes similar to Jupiter too.

This would be surprising and possibly implausible. The mass and composition defines the size and density, so Jupiter-mass hydrogen planet should have sizes similar to Jupiter too.

Which of the following best explains what scientists think happened to outgassed water vapor on Venus? It turned into carbon dioxide by reacting with nitrogen in Venus's atmosphere.Ultraviolet light split the water molecules, and the hydrogen then escaped to space.Water was removed from the atmosphere by chemical reactions with surface rock.It is frozen as water ice in craters near the poles.

Ultraviolet light split the water molecules, and the hydrogen then escaped to space. This did not occur on Earth because the temperatures allowed the water vapor to condense into liquid water and rain down to the surface.

Which of the following statements best describes the general pattern of composition among the four jovian planets? All four planets have essentially the same composition. Jupiter is made mostly of hydrogen, Saturn is made mostly of helium, Uranus is made mostly of hydrogen compounds, and Neptune is made mostly of rock. Uranus and Neptune contain relatively more rock and hydrogen compounds than Jupiter and Saturn. Jupiter is made mostly of hydrogen and helium, while the other three jovian planets are made mostly of hydrogen compounds. Submit

Uranus and Neptune contain relatively more rock and hydrogen compounds than Jupiter and Saturn.

All of the following statements are true. Which one provides strong observational support for the claim that greenhouse gases make a planet warmer than it would be otherwise? Earth has a higher average temperature than Mars. Earth is the only planet with an ozone layer in its atmosphere. Mercury is much hotter than the Moon. Venus has a higher average temperature than Mercury.

Venus has a higher average temperature than Mercury. Submit The fact that Venus is hotter than Mercury despite being nearly twice as far from the Sun tells us that its thick carbon dioxide atmosphere must warm it significantly—just as we expect from the theory of the greenhouse effect.

All the following statements about Venus are true. Which one offers evidence of a global repaving about a billion years ago? Venus has relatively few impact craters and these craters are distributed fairly evenly over the entire planet.Venus appears to lack any water that could lubricate the flow of rock in its crust and mantle.Venus has many circular features, called coronae, which appear to be tectonic in origin.Venus's largest features are three elevated regions that look somewhat like continents

Venus has relatively few impact craters and these craters are distributed fairly evenly over the entire planet. This suggests that older impact craters were covered over everywhere on the planet.

Which of the following general statements about light and Earth's atmosphere is not true? Ultraviolet from the Sun is absorbed primarily in the stratosphere. Infrared light emitted by Earth itself is absorbed primarily in the troposphere. X-rays from the Sun are absorbed in the thermosphere. Visible light from the Sun is absorbed in the exosphere.

Visible light from the Sun is absorbed in the exosphere. If that were true, then we'd have no visible light here on the ground. More generally, atmospheric gases are essentially transparent to visible light.

Which of the following is not caused by the Coriolis effect on Earth? Earth's global circulation cells are split into three separate cells in each hemisphere. Hurricanes swirl in opposite directions in the Northern and Southern hemispheres. Air or objects moving northward in the Northern Hemisphere are deflected to the east. Water going down a drain swirls in opposite directions in the Northern and Southern hemispheres.

Water going down a drain swirls in opposite directions in the Northern and Southern hemispheres. This doesn't really happen. (For further discussion, see the Common Misconceptions box titled "Toilets in the Southern Hemisphere" in Section 10.2 of The Cosmic Perspective.)

What do we mean when we say that the terrestrial worlds underwent differentiation? 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.Their surfaces show a variety of different geological features resulting from different geological processes.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.

The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that ________. gas bubbles form and rise upward in boiling waterEarth contains more metal than the Moonthunderstorms tend to form on hot summer daysa large baked potato takes longer to cool than a small baked potato

a large baked potato takes longer to cool than a small baked potato A smaller object has proportionally more surface area through which to lose its interior heat.

What is tidal heating? a source of surface heating caused by active volcanoes like those on Io a source of surface heating caused by the sloshing of water or other liquids a source of internal heat caused by varying tidal forces acting on a moon or other object a source of internal heat that occurs on all moons that are large enough to be spherical

a source of internal heat caused by varying tidal forces acting on a moon or other object Tidal heating is very important on numerous jovian moons, including Jupiter's moons Io, Europa, and Ganymede.

Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases __________. form clouds that emit thermal radiation absorb infrared light emitted by the surface reflect visible light coming from the Sun absorb visible light coming from the Sun

absorb infrared light emitted by the surface Although the absorbed infrared light is quickly reemitted, it is reemitted in a random direction. As a result, greenhouse gases tend to slow the escape of infrared light from Earth to space, so that there is more heat (which means more energy) in the atmosphere than there would be if the infrared light escaped directly to space.

We cannot see tidal forces or tidal heating; rather, we predict that they must occur based on the orbital characteristics of the moons. What observational evidence confirms that tidal heating is important on Io? Io's surprisingly elliptical orbit Io's unusual, egg-like shape the orbital resonance between Io, Europa, and Ganymede active volcanoes on Io

active volcanoes on Io Io is barely larger than our Moon, and the Moon long ago cooled enough so that it no longer has volcanic activity. Without some ongoing source of internal heating, Io would be similarly inactive. Therefore, the fact that Io is the most volcanically active world in the solar system indicates that it must have an ongoing internal heat source, which we identify as tidal heating.

Scientists have confidence in the predictions of today's best climate models because they __________. represent the work of a great many dedicated scientistsare very complex and include many equations of physicshave been developed over a period of many yearsagree well with actual data for recent decades

agree well with actual data for recent decades As shown in the video, the models are very successful at reproducing recent temperature data, and this is why we have confidence that the models are on the right track.

Consider the hypothetical discovery from Part A reading: "A star's 5 terrestrial planets orbit in the opposite direction of its 3 jovian planets." This discovery would be inconsistent with the nebular theory because the theory holds that __________. terrestrial planets should orbit in a different plane from the plane of the jovian planetsall the planets formed in a rotating, disk-shaped nebulastar systems should have equal numbers of terrestrial and jovian planets

all the planets formed in a rotating, disk-shaped nebula The nebular theory predicts that all planets should be born on orbits going in the same direction and in nearly the same plane.

Where would you expect terrestrial planets to form in the solar nebula? within the innermost regions (within about the inner 0.3 AU) anywhere between the innermost regions (within about the inner 0.3 AU) and the frost line anywhere outside the innermost regions (within about the inner 0.3 AU) anywhere outside the frost line

anywhere between the innermost regions (within about the inner 0.3 AU) and the frost line Terrestrial planets are made mostly of metal and rock and therefore formed in the region in which it was cool enough for metal and rock to condense but still too warm for hydrogen compounds to condense into ices. This means the region between the innermost regions (within about the inner 0.3

Suppose you could float in space just a few meters above Saturn's rings. What would you see as you looked down on the rings? a solid, shiny surface, looking much like a piece of a Blu-ray disk or DVD (or vinyl record album) but a lot bigger countless icy particles, ranging in size from dust grains to large boulders long, solid strings of matter, each distinct from the next dozens of large "moonlets" made of metal and rock, each a few kilometers across

countless icy particles, ranging in size from dust grains to large boulders And each particle orbits Saturn independently.

Which of the following is thought to explain many of the "exceptions to the rules" of our solar system? giant impacts the solar nebula the heavy bombardment the frost line conservation of angular momentum

giant impacts Giant impacts probably explain most of the exceptions, including the existence of our surprisingly large Moon and the axis tilt of Uranus.

Go to the screen in the interactive figure called "Key Evidence of Water," then zoom in on the "Southern Highlands." Which geologic processes are most clearly evident in the southern highlands? volcanism and erosionimpact cratering and erosionimpact cratering and volcanismtectonics and erosionvolcanism and tectonics

impact cratering and erosion The most obvious features of the southern highlands are the many impact craters, but a close examination shows that many of them have been "smoothed out," indicating erosion that has occurred over time.

The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________. travels directly out to space becomes permanently trapped by greenhouse gases is absorbed by greenhouse gases, slowing the escape of this energy to space

is absorbed by greenhouse gases, slowing the escape of this energy to space As shown in the interactive figure and discussed in your textbook, the infrared light ultimately escapes to space, but its absorption and re-emission along the way has the overall effect of increasing molecular motions that raise the air temperature from what it would be otherwise.

Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny? whether or not it has liquid waterits distance from the Sunits compositionits size

its size Size determines how long the planet can retain internal heat, which drives geological activity.

What's the fundamental reason that Mars has so little geological activity compared to Earth? its rapid rotation compared to the Earthits small size compared to Earthits farther distance than Earth to the Sunits slow rotation compared to the Earthits closer distance than Earth to the Sunits large size compared to the Earth

its small size compared to Earth Small size leads to more rapid loss of internal heat, and internal heat is necessary to drive geological activity.

What does the Sun's color tell us about the light it emits?opened hint The Sun is yellowish-white in color, which tells us that __________. its thermal emission spectrum peaks in the visible portion of the spectrum it emits only yellow and green light its spectrum has strong emission lines in the yellow and white portions of the spectrum

its thermal emission spectrum peaks in the visible portion of the spectrum

According to our theory of solar system formation, what are asteroids and comets? chunks of rock or ice that were expelled from planets by volcanoeschunks of rock or ice that condensed after the planets and moons finished formingleftover planetesimals that never accreted into planetsthe shattered remains of collisions between planets

leftover planetesimals that never accreted into planets Asteroids are the rocky leftovers of the inner solar system and comets are the icy leftovers of the outer solar system.

What kind of gas is most affected by thermal escape? greenhouse gases light gases all gases equally

light gases

Where is most of the CO2 that has outgassed from Earth's volcanoes? in the atmosphere escaped into space locked up in rocks

locked up in rocks

Which two factors are most important to the existence of plate tectonics on Earth? Earth's liquid outer core and solid inner corethe existence of life and oxygen in the atmospheremantle convection and a thin lithosphereoxygen in the atmosphere and mantle convection

mantle convection and a thin lithosphere Mantle convection helps move the plates, and the plates probably exist because the lithosphere was thin enough to break into these plates.

What substances existed as solid flakes within the innermost regions (within about 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 Although all the materials were present in gaseous form, the innermost regions (within about the inner 0.3 AU) of the newly forming solar system was too warm for even rocks or metals to condense into solid flakes.

Which two factors are critical to the existence of the carbon dioxide (CO2) cycle on Earth? active volcanism and active tectonicslife and atmospheric oxygenlife and active volcanismplate tectonics and liquid water oceans

plate tectonics and liquid water oceans Carbon dioxide dissolves in the oceans and becomes incorporated into carbonate rock; plate tectonics recycles the carbonate rock into the mantle, where it melts and releases its gas back to the atmosphere.

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, and ices Because ices could condense only beyond the frost line, we expect jovian planets to form only beyond the frost line. Note that many extrasolar planets appear to be jovian but are located close to their stars, leading scientists to suspect that these planets migrated inward after originally forming beyond the frost lines of their star systems.

What substances were found in the innermost regions (within about the inner 0.3 AU) of the solar system before planets began to form? nothing at allonly rocks and metalsonly hydrogen compoundsonly hydrogen and helium gasesrocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form

rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form Submit As described in the video and your textbook, all the materials of the solar nebula were present in the inner region, but it was too hot for any of them to condense. As a result, they were all in gaseous form.

Click on the first tab at the top of the interactive figure (labeled "The Greenhouse Effect"), then explore what happens as you click among the buttons (labeled "none," "low," "medium," and "high") that adjust the greenhouse gas concentration. Which of the following occur as the greenhouse gas concentration increase? the average surface temperature rises less visible light reaches the ground more infrared light is absorbed in the lower atmosphere more infrared light comes to Earth from the Sun more visible light reaches the ground the average surface temperature falls more visible light is absorbed in the lower atmosphere

the average surface temperature rises more infrared light is absorbed in the lower atmosphere Greenhouse gases absorb (and re-emit) infrared light, so a higher greenhouse gas concentration leads to more infrared scattering and higher average surface temperature.

Which of the following is not a key line of evidence supporting the hypothesis that Mars once had abundant liquid water on its surface? small, rounded pebbles found in places that look like dry riverbedsthe canals of Mars mapped by Percival Lowellthe eroded rims of ancient craterschemical analysis of minerals found in what appear to be ancient lakebeds

the canals of Mars mapped by Percival Lowell These don't really exist.

Which characteristic of Earth explains why Earth has the ozone necessary for an ultraviolet-absorbing stratosphere? the existence of photosynthetic lifethe existence of plate tectonicsthe existence of oceansthe moderate surface temperature

the existence of photosynthetic life Photosynthesis released the oxygen in our atmosphere, and oxygen allows ozone (a form of oxygen) to be made in the stratosphere.

An ice age is a period in Earth's history in which __________. the carbon dioxide concentration is unusually low the global average temperature is unusually low the global average temperature is below freezing

the global average temperature is unusually low

What do we mean by accretion in the context of planet formation? the growth of planetesimals from smaller solid particles that collided and stuck togetherthe solidification of ices, rocks, and metal from the gas of the solar nebulathe growth of the Sun as the density of gas increased in the center of the solar nebulathe formation of moons around planets

the growth of planetesimals from smaller solid particles that collided and stuck together At first, accretion probably arose from electrostatic attractions, but as planetesimals grew larger their gravity allowed them to accrete more efficiently (as long as they didn't suffer collisions with similar-size planetesimals).

Observations show that interstellar clouds can have almost any shape and, if they are rotating at all, their rotation is not perceptible. However, the nebular theory predicts that a cloud will rotate rapidly once it shrinks to a relatively small size. What physical law explains why a collapsed cloud will rotate rapidly? the law of conservation of energy Kepler's second law the law of conservation of angular momentum Newton's third law of motion the universal law of gravitation

the law of conservation of angular momentum The law of conservation of angular momentum holds that the cloud's total angular momentum should stay unchanged as it shrinks in size. Like a spinning ice skater bringing in her arms, the cloud's rotation speed therefore increases as it shrinks. More technically, recall that angular momentum is proportional to velocity times radius; therefore, as the radius shrinks, the velocity of rotation must increase in order to keep the product of velocity times radius unchanged.

What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius? the characteristics of the Caloris BasinMercury's unusually high densitythe presence of many impact cratersthe presence of many long, tall cliffs

the presence of many long, tall cliffs These cliffs formed as the crust shrank and buckled.

In the context of planetary geology, what do we mean byoutgassing? the loss of atmospheric gas to outer spacethe evaporation of water that adds water vapor (a gas) to an atmospherethe release by volcanism of gases that had been trapped in a planetary interioranother name for a volcanic eruption

the release by volcanism of gases that had been trapped in a planetary interior Outgassing therefore released all the gases from Earth's interior that ultimately became our atmosphere or condensed to form the oceans.

a planet with 10 times the mass of Jupiter would have a radius about __________ as that of Jupiter the same 60% as large 10 times as large 100 times as large

the same Notice that the curve turns back downward at masses just a couple times that of Jupiter, and the radius of a 10 Jupiter-mass object is about the same as the radius of Jupiter.

The average temperature over the past 1000 years has been about 15∘C. From the graphs, you can conclude that Earth's average temperature during the past 800,000 years has __________. varied between about 7∘C and 19∘C varied between about −10∘C and +4∘C stayed remarkable steady, never varying by more than about 2∘C never been as high as it is today

varied between about 7∘C and 19∘C The zero level on the graph represents the 15∘C average temperature over the past millennium, so the peaks near +4 on the graph represent a temperature of about 15∘C+4∘C=19∘C and the troughs near −8 represent 15∘C−8∘C=7∘C.

Earth's temperature remains fairly steady, which means that Earth must return nearly the same amount of energy to space that it receives from the Sun. In what form(s) does Earth return most of this energy to space? visible light emitted by the surface and atmosphere visible light reflected by clouds visible light reflected by the surface ultraviolet light reflected by the surface infrared light emitted by the surface and atmosphere

visible light reflected by clouds visible light reflected by the surface The total amount of energy returned to space in these three forms of radiation is nearly equal to the amount of energy that reaches Earth in the form of sunlight, which is why Earth's average temperature stays fairly steady. (Note: global warming is occurring, but the change is taking place over time scales of years, which means the incoming and outgoing energy at any moment are quite closely balanced.)

By assuming 100% reflectivity, find the minimum possible "no greenhouse" temperature for a planet at 1 AU.

0 K

Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. Use each word only once. magnetosphere, stratosphere, thermosphere, exosphere, troposphere. 1. Most of the charged particles from the Sun are deflected around Earth by the __________ 2. Earth's ____________absorbs most of the ultraviolet light arriving here from the Sun. 3. Most of the X-rays coming from the Sun are absorbed in the ________________. 4. Gas particles in Earth's atmosphere most easily escape from the _________________. 5. The densest layer of the atmospheres of Venus, Earth, and Mars is the _________________.

1. Most of the charged particles from the Sun are deflected around Earth by the magnetosphere 2. Earth's stratosphere absorbs most of the ultraviolet light arriving here from the Sun. 3. Most of the X-rays coming from the Sun are absorbed in the thermosphere. 4. Gas particles in Earth's atmosphere most easily escape from the exosphere. 5. The densest layer of the atmospheres of Venus, Earth, and Mars is the troposphere.

What is the orbital resonance among Io, Europa, and Ganymede? Ganymede's orbit is exactly twice as far from Jupiter as Europa, and exactly four times as far from Jupiter as Io. Io, Europa, and Ganymede all orbit Jupiter in the same direction and in nearly the same plane. Io completes exactly 4 orbits for every 2 orbits of Europa and every 1 orbit of Ganymede.

Io completes exactly 4 orbits for every 2 orbits of Europa and every 1 orbit of Ganymede. As shown in the video, this means that these moons periodically line up in ways that contribute the same gravitational tugs as they move in their orbits. An orbital resonance means that one object's orbital period is a simple fraction of another's, such as 1/2 or 1/3 or 1/4. In such cases, the objects periodically line up in a way that allows their mutual gravity to affect their orbits.

All the following statements are true. Which one is most important in explaining the tremendous tidal heating that occurs on Io? Io orbits Jupiter on an elliptical orbit as a result of orbital resonances with other moons. Io orbits Jupiter in the Io torus, and therefore has a surface that is bombarded by many charged particles. Io is the closest to Jupiter of Jupiter's large moons. Io exhibits synchronous rotation, meaning that its rotation period and orbital period are the same.

Io orbits Jupiter on an elliptical orbit as a result of orbital resonances with other moons. On an elliptical orbit, tides vary and flex Io's shape.

What happens to the energy that the ground absorbs in the form of visible sunlight? It is returned upward in the form of infrared light. It is returned upward in the form of visible light. It makes the ground continually get hotter and hotter.

It is returned upward in the form of infrared light. It is returned upward in the form of infrared light. Remember that objects emit thermal radiation characteristic of their temperatures. Earth's surface has a temperature for which its thermal radiation peaks in the infrared. In other words, Earth absorbs energy from space in the form of visible light, and returns this energy to space in the form of infrared light.

What would happen to Jupiter if we could somehow double its mass? Its density would decrease and its diameter would double. Its density would increase, but its diameter would barely change. Its density would stay about the same and its volume would double. It would become a star, with nuclear fusion in its core.

Its density would increase, but its diameter would barely change. think about the pillow stack analogy

Which of the following best explains why Jupiter's density is higher than Saturn's? Jupiter is more massive than Saturn. Jupiter is closer to the Sun than Saturn. Jupiter has a higher proportion of hydrogen compounds and rock than Saturn. Jupiter has a stronger magnetic field than Saturn.

Jupiter is more massive than Saturn. Because Jupiter and Saturn have nearly identical composition, Jupiter's higher density indicates that its interior is more compressed than Saturn's. This greater compression is due to gravity, which is stronger for Jupiter because of its greater mass.

According to the leading model, which of the following best summarizes how the jovian planets formed? The process was different for each jovian planet, with the smaller jovian planets forming from smaller planetesimals. Large planetesimals of ice and rock accreted; the gravity of these planetesimals then drew in surrounding gas from the solar nebula. Accretion gradually pulled a mixture of hydrogen and helium gas into large balls that became the jovian planets.

Large planetesimals of ice and rock accreted; the gravity of these planetesimals then drew in surrounding gas from the solar nebula. All four jovian planets are thought to have formed around planetesimals of about 10 Earth masses, composed of a mixture of hydrogen compounds (ices) and rock. These planetesimals became the cores of the jovian planets. The planets have different atmospheric compositions today because each one captured different amounts of hydrogen and helium gas from the solar nebula.

Listed following are some of the distinguishing characteristics of the four Galilean moons of Jupiter. Match each characteristic to the appropriate moon. hot, glowing lava visible in some photos ice covered surface with few impact craters most distant from Jupiter of these four moons entire surface appears heavily cratered and ancient volcanoes currently erupting double-ridged surface features strongly suggest a subsurface ocean below source of ionized gas in the donut-shaped charged particle belt around Jupiter largest moon in the solar system heavily cratered terrain adjacent to fairly smooth terrain

Lo: source of ionized gas in the donut-shaped charged particle belt around Jupiter volcanoes currently erupting hot, glowing lava visible in some photos Europa: ice covered surface with few impact craters double-ridged surface features strongly suggest a subsurface ocean below Ganymede: largest moon in the solar system heavily cratered terrain adjacent to fairly smooth terrain Callisto: entire surface appears heavily cratered and ancient most distant from Jupiter of these four moons Remember that these differences are consequences of the different levels of tidal heating these moons experience. Io is very hot because it is the nearest of the Galielean moons to Jupiter and has the most tidal heating; Europa is farther and has more moderate tidal heating, and tidal heating is even weaker on Ganymede. Callisto is the most distant of the Galilean moons and does not partipate in the orbital resonance that leads to tidal heating on the other three moons, and therefore does not have any significant tidal heating.

The Frost Line Explain the difference between terrestrial and Jovian worlds based on the difference of their initial planetesimals where can metal condense? where can rock condense? where can hydrogen compounds condense? where can hydrogen and helium condense? Can they condense?

Location is key. The frost line is the point in which gasses can't condense. Jovian Planets: cool enough for rocks and metal ices to condense. planetesimals were much more massive. more mass = more gravity; strong enough gravity to capture hydrogen and helium, adding substantially more mass.

What are the 4 features of the Solar System caused by the Nebular Theory?

Planets all orbit and mostly rotate in the same way 2 types of planets 2 types of small objects (comets, asteroids) Exceptions to the Rules - and how does the nebular theory explain the exceptions

Understand the Nebular Theory : What is it? What does it predict? How does it explain the 4 features of the Solar System?

Planets formed from a collapsing cloud of interstellar gas and dust.

Jupiter and the other jovian planets are sometimes called "gas giants." In what sense is this term misleading? They are not in any sense "giants." The materials they are made of are not the kinds of thing we usually think of as gases. They actually contain relatively little material in a gaseous state. Actually, it's a great description because these worlds are big and gaseous throughout.

They actually contain relatively little material in a gaseous state. Much more of their mass is liquid, metallic, or in strange high-pressure states that we don't naturally find on Earth.

Now click the second tab (labeled "Terrestrial Planet Temperatures"), then explore what happens as you click the button that allows you to add or remove greenhouse gases. Which terrestrial planet would have its surface temperature the most dramatically changed if its greenhouse gases were removed from its atmosphere? Earth Mercury Mars Venus

Venus The change is by far the largest for Venus, because it has a thick atmosphere consisting primarily of carbon dioxide, a greenhouse gas.

According to scientists, the naturally occurring greenhouse effect makes Earth about 31∘C warmer than it would be if there were no greenhouse gases in our atmosphere. How do scientists "know" what Earth's temperature would be without greenhouse gases? They estimate it by averaging guesses made by many individual scientists .They assume that this temperature would be about the same as the temperature of Mars, which has much less of an atmosphere than Earth .Ancient fossils allow them to infer Earth's temperature at a time before our atmosphere contained greenhouse gases. They calculate this temperature from Earth's reflectivity and distance from the Sun.

They calculate this temperature from Earth's reflectivity and distance from the Sun. Aside from the greenhouse effect, the only factors that affect a planet's average temperature are its reflectivity and distance from the Sun. Since both distance and reflectivity have been measured, the expected temperature can be calculated easily and precisely. (Note that this assumes that the Sun's total emission of energy remains steady; measurements and theory both indicate that it varies very little over time scales less than a few million years.)

Match the moons listed to the left with the characteristics described in the sentences to the right. Drag words from the left to the blanks on the right. Each moon should be used only once. Triton TItan Lo Enceladus Ganymede Europa The only moon in the solar system with a thick atmosphere, it also has lakes of liquid methane and ethane : The largest moon in the solar system, this moon has some regions that are heavily cratered other regions that have very few craters. : This moon of Jupiter has an icy surface with very few impact craters, suggesting that craters have been covered by upwelling water. : The most volcanically active world in the solar system. : Orbits Saturn and has been observed to be spraying fountains of ice crystals into space. : This moon of Neptune orbits "backward" compared to Neptune's rotation.

Titan: The only moon in the solar system with a thick atmosphere, it also has lakes of liquid methane and ethane. Ganymede: The largest moon in the solar system, this moon has some regions that are heavily cratered other regions that have very few craters. Europa: This moon of Jupiter has an icy surface with very few impact craters, suggesting that craters have been covered by upwelling water. Io: The most volcanically active world in the solar system Enceladus: Orbits Saturn and has been observed to be spraying fountains of ice crystals into space. Triton: This moon of Neptune orbits "backward" compared to Neptune's rotation

Which jovian planet has the most extreme seasonal changes, and why? Jupiter, because of its large mass Neptune, because of its varying distance from the Sun Uranus, because of its extreme axis tilt Saturn, because it has an axis tilt similar to Earth

Uranus, because of its extreme axis tilt Its large axis tilt gives it seasons that each last about 1/4 of its 84-year orbit.

We now know of many Jupiter-size planets around other stars. Suppose that future observations show that one of these planets has two orbiting moons. What additional information, if any, would we need to decide whether these moons experience tidal heating? We need to know their orbital periods. We need to know whether the planet also has a third moon. We need to know whether either moon is volcanically active. No other information is needed: With two moons, there is sure to be tidal heating. No other information is needed: With two moons, there is no chance of any tidal heating.

We need to know their orbital periods. We expect tidal heating to be possible only if there is an orbital resonance that helps maintain an elliptical orbit. An orbital resonance occurs when one moon's orbital period is a simple fraction of the other's, such as 1/2 or 1/3 or 1/4. Therefore, by measuring their orbital periods, we can determine if there is a resonance. Having an orbital resonance doesn't automatically mean that there is tidal heating, but it makes it a good possibility.

Based solely on an understanding of the greenhouse effect (as displayed in the figure), which one of the following statements is true? We do not yet understand the greenhouse effect well enough to make predictions about how it affects our planet. Humans are causing global warming.Global warming poses a grave threat to our future. We should expect an increase in the greenhouse gas concentration to lead to global warming.

We should expect an increase in the greenhouse gas concentration to lead to global warming. Submit The evidence discussed in this tutorial makes it clear that greenhouse gases make a planet's surface warmer than it would otherwise be, so we should expect a rise in the greenhouse gas concentration to make Earth warmer. It is possible that there can be mitigating factors through feedbacks, but the basic link between greenhouse gas concentration and global warming is very strong.

What is the difference between weather and climate? Weather is something that we can control, and climate is not. Weather refers to atmospheric conditions in the troposphere; climate refers to atmospheric conditions in the stratosphere. Weather refers to short-term changes in wind, rain, and temperature; climate refers to the long-term average of weather. Weather refers to small storms; climate refers to large storms.

Weather refers to short-term changes in wind, rain, and temperature; climate refers to the long-term average of weather. In other words, the weather can change almost moment by moment, but climate changes more slowly.

Orbital resonance also gives Europa an elliptical orbit, so it experiences tidal heating, too. However, Europa experiences less tidal heating than Io, because Europa __________ than Io. is much smaller is farther from Jupiter is more perfectly spherical in shape contains much more ice

is farther from Jupiter It is Jupiter's gravity that exerts the primary tidal force on the Galilean moons, and both this force and the difference in this force across a moon (the source of tidal heating) weaken with distance from Jupiter. Io is closest to Jupiter and therefore experiences the most tidal heating; Europa experiences less tidal heating, and Ganymede experiences the least tidal heating. (Callisto is not expected to have any tidal heating since it does not participate in the orbital resonance that makes the other moons' orbits more elliptical.)

Io experiences tidal heating primarily because __________. it has an elongated shape that makes it look more like an egg than a sphere. it is located very close to Jupiter. its elliptical orbit causes the tidal force to vary as Io orbits Jupiter. it is made of relatively soft materials that deform quite easily.

its elliptical orbit causes the tidal force to vary as Io orbits Jupiter. The strength of the tidal force depends on Io's distance from Jupiter, so the tidal force varies as Io moves around its elliptical orbit. The tidal bulge even changes direction slightly because the orbital speed varies. These tidal effects essentially stretch and compress Io's interior, and this tidal friction causes the tidal heating.

Saturn's rings look bright because __________. light from the Sun reflects off the material in the rings the material in the rings is hot and creates its own light light from Saturn reflects off the material in the rings

light from the Sun reflects off the material in the rings Saturn's rings look bright because icy particles in the rings reflect (scatter) sunlight.

Saturn's rings are composed of __________. gas from the early solar system a series of solid concentric circles lots of individual particles of ice and rock parts of Saturn's upper atmosphere being vented into space

lots of individual particles of ice and rock Although Saturn's rings appear solid when viewed from Earth, they are actually made of countless icy particles ranging in size from dust grains to small boulders.

which of the following general statements about Earth's atmosphere is not true? the nitrogen and oxygen in Earth's atmosphere keep the surface pleasantly warm. Atmospheric pressure decreases with altitude. Even in low-Earth orbit, some atmospheric gas is still present. Atmospheric scattering of light explains why our daytime sky is bright and blue

the nitrogen and oxygen in Earth's atmosphere keep the surface pleasantly warm. Only greenhouse gases influence surface temperature, and neither oxygen nor nitrogen is a greenhouse gas.

The energy that warms Earth's surface comes primarily in the form of __________. infrared light from the Sun visible light from the Sun heat from Earth's interior heat from the Sun ultraviolet light from the Sun

visible light from the Sun In the figure, this fact is illustrated by the yellow squiggly line at the far left. https://session.masteringastronomy.com/problemAsset/1100265/14/TCP5e10_06.jpg