chapter 7 - mastering astronomy · listed below are geographic features of the terrestrial worlds....

11/20/2016 Chapter 7 Homework

https://session.masteringastronomy.com/myct/assignmentPrintView?assignmentID=1646890 1/12

Chapter 7 HomeworkDue: 11:59pm on Sunday, September 25, 2016

To understand how points are awarded, read the Grading Policy for this assignment.

Question 1

Part A

Listed below are geographic features of the terrestrial worlds. In each case, identify the geological process: impact cratering, volcanism, erosion, ortectonics (where tectonics is any largescale processes affecting the structure of the planetary crust), most responsible for the feature described.Match the geographic feature to the appropriate geologic process.

Hint 1. Are tall volcanoes required for volcanism?

ANSWER:

Hint 2. How can you distinguish impact craters from volcanic craters?

Which of the following would tell you that craters you are observing were formed by impacts rather than volcanism?

ANSWER:

Hint 3. What is tectonics?

The geological process that we call tectonics refers to __________.

ANSWER:

Hint 4. What is required for erosion?

Which of the following is necessary for erosion to occur on a planet or moon?

ANSWER:

Hint 5. What is Valles Marineris?

ANSWER:

Volcanism refers to only the building of tall volcanoes. the building of tall volcanoes and any subsequent lava flows that come from them. any flow of molten lava across a surface.

The craters are circular. The craters have smooth bottoms indicating that lava flowed in them. The craters are not associated with any mountains or lava flows.

any surface disruption, such as stretching or crumpling, caused by stresses within the interior of the world only surface changes, such as the movement of continents, caused by the motion of plates around the world’s surface the surface features that we see when a world has been heavily bombarded by impacts

liquid water an atmosphere lava flows both liquid water and an atmosphere both liquid water and lava flows



Hint 6. What is Olympus Mons?

ANSWER:

Hint 7. How did Mercury’s cliffs form?

ANSWER:

Hint 8. What surface features do we see in the lunar highlands?

ANSWER:

ANSWER:

Valles Marineris is

a giant mountain on Mars. a system of driedup rivers on Mars. a long system of canyons stretching nearly a fifth of the way around Mars, looking much like a set of giant cracks in the surface.

Olympus Mons is

a giant mountain on Mars, with a crater at its top. a huge impact crater on Mars. a long system of canyons stretching nearly a fifth of the way around Mars, looking much like a set of giant cracks in the surface.

Mercury’s long, tall cliffs are thought to have formed when Mercury was bombarded by impacts. the entire planet shrank, causing the surface to crumple. water gushed through canyons and left great walls exposed as cliffs.

The major surface features of the lunar highlands are giant volcanoes. craters. smooth plateaus that must once have been flooded by lava.



Correct

Remember that the four processes are interrelated, so although one may be most important to a particular feature, others often also play a role.For example, some erosion has occurred on the volcanic island of Hawaii, there are impact craters on the slopes of Olympus Mons, andvolcanism and tectonics almost always go handinhand.

Question 2

Choose the best answer.

Part A

Which heat source continues to contribute to Earth’s internal heat?

ANSWER:

Correct

Question 3


Part A

Which of a planet's fundamental properties has the greatest effect on its level of volcanic and tectonic activity?

ANSWER:

Correct

Question 4


Part A

What do we conclude if a planet has few impact craters of any size?

ANSWER:

Correct

accretion radioactive decay sunlight

size distance from the Sun rotation rate

The planet was never bombarded by asteroids or comets. Its atmosphere stopped impactors of all sizes. Other geological processes have wiped out craters.



Question 5

Part A

The processes responsible for virtually all surface geology are _________.

ANSWER:

Correct

Question 6

Part A

Which of the following is the most basic definition of a greenhouse gas?

ANSWER:

Correct

Question 7

Part A

What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?

ANSWER:

Correct

Question 8

First, launch the animation below. Explore the interactive photo before beginning to answer the questions. Be sure you have clicked the “Show labels”button.

impact cratering, volcanisms, tectonics, and erosion accretion, differentiation, and radioactive decay convection, conduction, and radiation eruptions, lava flows, and outgassing

a gas that reflects a lot of sunlight a gas that makes a planet much hotter than it would be otherwise, even in small amounts a gas that absorbs infrared light a gas that keeps warms air from rising, and therefore warms the surface

Mercury's unusually high density the presence of many long, tall cliffs the presence of many impact craters the characteristics of the Caloris Basin



Part A

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 leadyou to suspect about water on Mars?

Hint 1. How many rivers, lakes, and seas are visible in the photo of Mars?

True or False? Many examples of presentday rivers, lakes, and seas are plainly visible in the photo of Mars.

ANSWER:

Hint 2. What features are visible at Mars’s north and south poles?

True or False? Polar caps are plainly visible at Mars’s poles, suggesting the presence of frozen water there.

ANSWER:

ANSWER:

CorrectThere is nothing on the brownish surface to suggest liquid water, and closeup 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. Infact, they contain both frozen carbon dioxide and frozen water.

Part B

Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?

Hint 1. What surface features are signs of past volcanic activity on terrestrial planets?

True or False? The presence of either volcanoes or large lava plains indicates past volcanic activity on a terrestrial planet.

ANSWER:

True False

True False

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.



Hint 2. Do craters always indicate past volcanic activity?

True or False? The presence of craters is always a sign of past volcanic activity.

ANSWER:

ANSWER:

Correct

Olympus Mons is a very large shield volcano. You can also see numerous other volcanoes on Mars, including three large ones on the Tharsisbulge.

Part C

When you zoom in on the section labeled “Southern Highlands,” which geologic processes are most clearly evident?

Hint 1. What surface features are prominent in the southern highlands?

True or False? A great many craters are present in the southern highlands.

ANSWER:

Hint 2. Are all of the surface features in the southern highlands equally distinct?

True or False? Of the craters seen in the southern highlands, some have features that are more crisp and distinct than others.

ANSWER:

ANSWER:

True False

True False

the polar caps the southern highlands Valles Marineris Olympus Mons

True False

True False

volcanism and erosion impact cratering and erosion impact cratering and volcanism tectonics and erosion volcanism and tectonics



Correct

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.

Question 9

Part A

What do we mean by a runaway greenhouse effect?

ANSWER:

Correct

Question 10

Learning Goal:

To use your understanding of the terrestrial planets in our solar system to predict properties of terrestrial planets in other solar systems.

Introduction. The diagram shows the size, orbital distance, androtation rate of a hypothetical planet around another star, whichwe'll call Planet Z. Assume that Planet Z is a terrestrial planetshaped by the same basic processes that shape the terrestrialplanets of our solar system and that it orbits a star of the sametype and age as the Sun.

Part A

Based on Planet Z's size, orbital distance, and rotation rate, which of the following properties is it likely to have?

a greenhouse effect that starts on a planet but later disappears as gases are lost to space a greenhouse effect that heats a planet so much that its surface rock melts a process that heats a planet like a greenhouse effect, but that involves a completely different mechanism of heating that doesn't actually

involve greenhouse gases a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere



Check all that apply.

Hint 1. How does size affect the characteristics of a terrestrial world?

Large terrestrial worlds __________ than smaller terrestrial worlds.

ANSWER:

Hint 2. How does orbital distance affect the characteristics of a terrestrial world?

Terrestrial worlds that are close to their star tend to have __________ than terrestrial worlds that are farther away.

ANSWER:

Hint 3. How does rotation rate affect the characteristics of a terrestrial world?

Relatively rapid rotation is required for a world to have __________.

ANSWER:

ANSWER:

Correct

Continue on to explore why the planet has these characteristics.

Part B

You have found that Planet Z should have active tectonics and volcanism and an atmosphere produced by volcanic outgassing. What single factorexplains why the planet should have these characteristics?



ANSWER:

have higher surface temperatures retain internal heat longer have more erosion

more erosion higher surface temperatures thicker atmospheres

an atmosphere active volcanoes strong winds and violent storms

erosion due to liquid water strong winds and violent storms an atmosphere produced by outgassing seasons active volcanoes a surface crowded with impact craters polar ice caps active tectonics





ANSWER:



ANSWER:

ANSWER:

Correct

Large size means more internal heat. This internal heat drives active tectonics and volcanism, which is the source of outgassing.

Part C

In Part A, you found that Planet Z should not have polar ice caps or liquid water. What single change to Planet Z's characteristics would allow it tohave these things?



ANSWER:



ANSWER:

retain internal heat longer have more erosion have higher surface temperatures

higher surface temperatures thicker atmospheres more erosion

active volcanoes an atmosphere violent weather and storms

Planet Z

has a slow rotation rate. closely orbits its star. lacks axis tilt. has a large size for a terrestrial planet.

have higher surface temperatures have more erosion retain internal heat longer





ANSWER:

ANSWER:

Correct

The planet is too hot for liquid water or ice, so moving it farther from its star would allow it to cool down. If it cooled enough—but not too much—itcould have surface liquid water and ice caps.

Part D

In Part A, you found that Planet Z should not have strong winds and violent storms. What single change to Planet Z's characteristics would cause it tohave strong winds and violent storms?

Hint 1. What are the general requirements for strong winds and violent storms?

If a planet has an atmosphere, the most important factor determining the strength of its surface winds is its __________.

ANSWER:

ANSWER:

Correct

The basic requirements for strong winds and violent storms are an atmosphere and relatively rapid rotation. An atmosphere is necessary to havewind of any type, while rotation is necessary to create the forces (in particular, the Coriolis force) that tend to drive winds on a planet's surface.Storms will be even stronger if there is also evaporation of surface water.

higher surface temperatures thicker atmospheres more erosion

active volcanoes an atmosphere violent weather and storms

a smaller size a larger size a greater distance from its star a larger axis tilt

rotation rate distance from its star axis tilt

a faster rotation rate a larger axis tilt a smaller size a greater distance from its star



Part E

In Part A, you found that Planet Z should not have seasons. What single change to Planet Z's characteristics would cause it to have seasons?

Hint 1. What causes seasons on Earth?

The most important factor in the existence of seasons on Earth is Earth's __________.

ANSWER:

ANSWER:

Correct

Seasons are caused primarily by axis tilt, so a planet without axis tilt is not expected to have seasons (unless it has a highly elliptical orbit).

Question 11


Part A

The oxygen in Earth’s atmosphere was released by

ANSWER:

Correct

Question 12

Part A

What is the importance of the carbon dioxide (CO2) cycle?

ANSWER:

rotation rate distance from the Sun axis tilt

a greater distance from its star a faster rotation rate a smaller size a larger axis tilt

volcanic outgassing. the cycle. life.

CO2

It will prevent us from suffering any consequences from global warming. It allows for an ultravioletabsorbing stratosphere. It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate. It makes the growth of continents possible.



Correct

Question 13

Part A

Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by_____.

ANSWER:

Correct

Question 14

Part A

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?

ANSWER:

Correct

Score Summary:Your score on this assignment is 48.9%.You received 18.09 out of a possible total of 37 points.

human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere the increase in forest fires during recent years the human release of chemicals called CFCs into the stratosphere the fact that our politicians spout a lot of hot air

its distance from the Sun whether or not it has liquid water its size its composition

chapter 7 - mastering astronomy · listed below are geographic features of the terrestrial worlds....

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