Astronomy 101 Chapter 10; Mastering Astronomy Assignment, Ch. 10 Practice Test Questions, ASTR 101 CH 10, Astronomy Final Study
The major processes that heat the interiors of the terrestrial worlds are:
(1) Heat deposited as the planets were built from planetesimals; (2) heat deposited as the planets underwent differentiation; (3) heat released by radioactive decay.
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.
460
How is it possible that the Moon might have some water ice today?
Ice brought by comet impacts may be frozen in craters near the Moon's poles.
You discover an impact crater that is 10 kilometers across. Which of the following can you conclude?
It was created by the impact of an object about 1 kilometer across.
How did molecular oxygen (O2) get into Earth's atmosphere?
It was released by life through the process of photosynthesis.
Which of the following most likely explains why Venus does not have a global magnetic field like Earth?
Its rotation is too slow.
What makes us think that Mars must once have had an atmosphere that was warmer and had higher surface pressure?
The atmosphere is too cold and thin for liquid water today, yet we see evidence of flowing water in the past.
Gas particles in Earth's atmosphere most easily escape from the __________
exosphere
The earthquakes that occur in Southern California generally occur above a _________
fault
Which of the following is not a greenhouse gas?
oxygen (O2)
On the graphs shown, you can identify an ice age by looking for __________.
a trough (bottom of a dip) on the temperature graph
Suppose we represent Earth with a basketball. On this scale, most of the air in Earth's atmosphere would fit in a layer that is _________.
about the thickness of a sheet of paper
Greenhouse gases in the atmosphere, such as carbon dioxide and water vapor, make Earth warmer than it would be otherwise because these gases __________.
absorb infrared light emitted by the surface
Scientists have confidence in the predictions of today's best climate models because they __________.
agree well with actual data for recent decades
Most of the charged particles from the Sun are deflected around Earth by the _______
magnetosphere
Which two factors are most important to the existence of plate tectonics on Earth?
mantle convection and a thin lithosphere
The cores of the terrestrial worlds are made mostly of metal because ______.
metals sunk to the centers a long time ago when the interiors were molten throughout
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?
not much - on human time scales, the mantle looks like solid rock
Shown below are the four terrestrial planets of our solar system. Assume that all the planets started out equally hot inside. Rank the planets based on their expected cooling rates, from fastest cooling to slowest cooling.
(FASTEST COOLING) Mercury, Mars, Venus, Earth (SLOWEST COOLING)
The following images represent four types (wavelength bands) of light. Rank these from left to right based on the amount of each that is emitted (as thermal radiation) by Earth's surface, from greatest to least. If you think that two (or more) types should be ranked as equal, drag one on top of the other(s) to show this equality.
(GREATEST AMOUNT) infrared. (visible, ultraviolet, & X-ray light EQUAL AT "LEAST AMOUNT")
In Part A, you found that Earth emits only infrared light. This infrared light can be absorbed by greenhouse gases, such as carbon dioxide and water vapor, in the atmosphere. In fact, all the terrestrial planets emit infrared light from their surfaces. The following images show the four terrestrial planets in our solar system. Rank these planets from left to right based on the total amount of infrared-absorbing greenhouse gases in their atmospheres, from greatest to least.
(GREATEST) Venus, Earth, Mars, Mercury (LEAST)
The following images show the four terrestrial planets in our solar system. Rank the planets from left to right based on the amount by which the greenhouse effect increases their surface temperatures, compared to what their temperatures would be without the greenhouse effect, from largest to smallest increase.
(LARGEST INCREASE) Venus, Earth, Mars, Mercury (SMALLEST INCREASE)
Shown following are three terrestrial planets of our solar system. Rank the planets based on the amount of time the surface of the planet has had a moderate to high level of volcanic/tectonic activity, from longest to shortest.
(LONGEST TIME) Earth, Mars, Mercury (SHORTEST TIME)
The following images show the four terrestrial planets in our solar system. Rank the planets from left to right based on the strength of the greenhouse effect occurring at their surfaces, from strongest to weakest.
(STRONGEST) Venus, Earth, Mars, Mercury (WEAKEST)
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. -Greenhouse gases make Earth warmer than it would be otherwise.
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? Check all that apply.
-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.
Start on the home screen of the interactive figure, with "Elevation is off." Then turn elevation on, and compare what you see. You may wish to switch back and forth between elevation on and off a few times. Then select the statements below that are true. Note: Features such as impact craters that are actually round in shape are distorted into oval shapes at mid- to high-latitudes by map projection effects. Select all that apply.
-Most of the northern hemisphere has much lower elevation than the southern hemisphere. -There is a long, deep canyon that stretches along a region close to Mars's equator. -Several large volcanoes are found near or somewhat north of Mars's equator. -There is a large, roundish region of low-elevation in the southern hemisphere.
Go to the screen "Key Evidence of Water," and and select the feature called "Recurring Slope Lineae." Study this feature at each of the four zoom levels offered, and be sure to view the animation called "recurring slope linaea (gif)" that you will see at the third zoom level. Which of the following statements are true?
-The recurring slope lineae look like narrow dark streaks. -The recurring slope lineae are found among impact craters. -The recurring slope lineae appear to grow in spring and summer.
Based on Planet Z's size, orbital distance, and rotation rate, which of the following properties is it likely to have? Check all that apply.
-an atmosphere produced by outgassing -active tectonics -active volcanoes
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 forms does Earth return most of this energy to space? Check all that apply.
-infrared light emitted by the surface and atmosphere -visible light reflected by clouds -visible light reflected by the surface
What are the basic requirements for a terrestrial world to have a global magnetic field?
A core layer of molten, convecting material and sufficiently rapid rotation.
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.
In the context of plate tectonics, what is a subduction zone?
A place where a seafloor plate is sliding under a continental plate.
Which of the following best describes how the greenhouse effect works?
A planet's surface absorbs visible sunlight and returns this absorbed energy to space as infrared light. Greenhouse gases slow the escape of this infrared radiation, which thereby heats the lower atmosphere.
In the context of a planetary atmosphere, what is a bar?
A unit of pressure roughly equal to the atmospheric pressure at sea level on Earth.
Which of the following is not an expected consequence of the rising carbon dioxide concentration or global warming?
Animal deaths due to carbon dioxide poisoning.
Which of the following is not a characteristic of the seasons on Mars?
As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect.
Why is the Coriolis effect so weak on Venus?
Because Venus rotates so slowly.
Why is the sky blue (on Earth)?
Because molecules scatter blue light more effectively than red light.
Why is thermal escape of atmospheric gas much easier from the Moon than from Earth?
Because the Moon's gravity is so much weaker than Earth's.
In general, which things below are affected by a magnetic field?
Charged particles or magnetized materials (such as iron).
Why is Mars red?
Chemical reactions between surface rock and atmospheric oxygen literally rusted the surface.
Why is Earth's continental crust lower in density than seafloor crust?
Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.
Suppose Earth were to cool down a little. How would the carbon dioxide cycle tend to restore temperatures to normal?
Cooler temperatures lead to slower formation of carbonate minerals in the ocean, so carbon dioxide released by volcanism builds up in the atmosphere and strengthens the greenhouse effect.
From center to surface, which of the following correctly lists the interior layers of a terrestrial world?
Core, mantle, crust.
Which of the following best describes the geological histories of the Moon and Mercury?
Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all.
Why does Earth have so little carbon dioxide in its atmosphere compared to Venus?
Earth has just as much carbon dioxide as Venus, but most of it is locked up in carbonate rocks rather than being free in the atmosphere.
What would happen to Earth if we somehow moved our planet to the orbit of Venus?
Earth would suffer a runaway greenhouse effect and become as hot or hotter than Venus.
Which of the following places is the result of volcanoes erupting over a hot spot in the mantle?
Hawaii
Which internal heat source still generates heat within the terrestrial worlds today?
Heat from radioactive decay.
The large, roundish, low-elevation region in the southern hemisphere is called _______
Hellas Basin
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 _____.
Human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere.
Observations indicate that the Moon has water ice in craters near the poles. Where do scientists suspect this water came from?
Ice brought by comet impacts long ago.
Each of the following statements is best associated with one of the four major geological processes. Drag each statement into the correct bin for its associated process. Drag the appropriate items to their respective bins.
Impact Cratering: -Mostly occurred during heavy bombardment. -Affected all solid worlds similarly. Volcanism: -Created the smooth lunar maria. -Erased virtually all craters on Io. -Responsible for the existence of Earth's atmosphere and oceans. Tectonics: -On Earth, involves motion of plates. -Includes surface compression that builds mountains. Erosion: -Includes features sculpted by wind.
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.
Which of the following statements about Earth's troposphere is not generally true?
It is the layer of the atmosphere in which ozone absorbs dangerous ultraviolet light from the Sun.
Why does the Moon have a layer of "powdery soil" on its surface?
It is the result of countless tiny impacts by small particles striking the Moon.
On a cloudless day, what happens to most of the visible light headed toward Earth?
It reaches Earth's surface, where some is reflected and some is absorbed.
In the context of Earth's climate history, what do we mean by snowball Earth?
It refers to a very deep ice age that occurred hundreds of millions of years ago.
What is the importance of the carbon dioxide (CO2) cycle?
It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
All the following statements about Mars are true. Which one might have led to a significant loss of atmospheric gas to space?
Mars lost any global magnetic field that it may once have had.
Recent evidence suggests that Mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic field like that of Earth?
Mars's interior has cooled so much that its molten core layer no longer undergoes convection.
When were the heat-trapping effects of gases that cause the greenhouse effect first measured by scientists?
More than 150 years ago.
Why do we think that Venus has so much more atmospheric gas than Earth?
Most of the gases that have been released from volcanoes on Earth later returned to the surface
Why do we think that Venus has so much more atmospheric gas than Earth?
Most of the gases that have been released from volcanoes on Earth later returned to the surface.
Does Venus have auroras around its poles, like Earth? Why or why not?
No, because it lacks a global magnetic field.
Does Venus have auroras around its poles, like the Earth? Why or why not?
No, because it lacks a global magnetic field.
The tallest mountain on Mars is called ___________
Olympus Mons
According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?
Oxygen released by life was removed from the atmosphere by chemical reactions with surface rocks until the surface rock could absorb no more.
________ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.
Seafloor crust
How does seafloor crust differ from continental crust?
Seafloor crust is thinner, younger, and higher in density.
Why are there fewer large impact craters on the 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.
The choices below 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.
The choices below 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: same as the Moon. Distance from Sun: same as Mars. Rotation rate: once every 10 days.
All the following statements are true. Which one explains why convection can occur in the troposphere but not in the stratosphere?
Temperature declines with altitude in the troposphere but increases with altitude in the stratosphere.
The choices below 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.
_______ is a high-elevation region dotted by tall volcanoes.
Tharsis Bulge
Deuterium is much more abundant on Venus than Earth. What do we think this fact tells us about Venus?
That it has lost a tremendous amount of water as a result of molecules being split by ultraviolet light and the hydrogen escaping to space.
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.
On a day with complete cloud cover, what happens to the visible light headed toward Earth?
The clouds reflect much of it back to space, though some still reaches the surface.
Which of the following is not an expected consequence of global warming?
The entire Earth will warm up by the same amount.
Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history?
The fact that the temperature of our planet has remained relatively steady throughout our planet's history.
Which of the following is not an example of tectonics?
The gradual disappearance of a crater rim as a result of wind and rain.
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.
Which of the following is not generally true of all the terrestrial world lithospheres?
The lithosphere is broken into a set of large plates that float upon the softer rock below.
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 maria formed after the heavy bombardment ended.
Which of the following statements about ozone (in Earth's stratosphere) is not true:
The presence of ozone was crucial to the origin of life some 4 billion years ago.
Go to the screen "Mars Mission Landing Sites," and and select Opportunity landing site (2004). Explore all five zoom levels offered, making sure to read the captions at the tops of the screens. Based on the information provided, why was the landing site,called Meridiani Planum, chosen for the Opportunity mission?
The region was already known to have minerals likely to have formed in liquid water.
Which of the following general statements about Earth's atmosphere is not true?
The sea level temperature depends primarily on the total amount of gas in our atmosphere
Which of the following general statements about Earth's atmosphere is not true?
The sea level temperature depends primarily on the total amount of gas in our atmosphere.
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 increase.
Why does atmospheric pressure decrease as you go higher in altitude on Earth?
The weight of the atmosphere above you decreases with altitude.
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?
There is a correlation between the carbon dioxide concentration and the global average temperature.
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 calculate this temperature from Earth's reflectivity and distance from the Sun.
Which of the following best describes the nature and origin of the atmospheres of the Moon and Mercury?
They have thin exospheres only, with gas coming from impacts of subatomic particles and photons.
In very general terms, how do the temperature structures of the atmospheres of Venus and Mars differ from that of Earth?
They lack ultraviolet-absorbing stratospheres.
Which of the following describes a primary role of global circulation cells in a planet's atmosphere?
They transport heat from the equator toward the poles.
Which of the following best explain what we think happened to outgassed water vapor on Venus?
Ultraviolet light split the water molecules, and the hydrogen then escaped to space.
The long, deep canyon running along the equator is called _______
Valles Marineris
Which planet(s) have an atmosphere that consists mostly of carbon dioxide?
Venus and Mars
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?
Venus has a higher average temperature than Mercury.
What is the difference between weather and climate?
Weather refers to short-term changes in wind, rain, and temperature, while climate refers to the long-term average of weather.
All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450 C hotter than the surface of Earth?
Venus has a much stronger greenhouse effect than Earth.
All the statements below are true. Which one gives the primary reason why the surface of Venus today is some 450°C hotter than the surface of Earth?
Venus has a much stronger greenhouse effect than Earth.
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.
Which of the following correctly lists the terrestrial worlds in order from the thickest atmosphere to the thinnest atmosphere? (Note: Mercury and the Moon are considered together in this question.)
Venus, Earth, Mars, Moon/Mercury
Which of the following general statements about light and Earth's atmosphere is not true?
Visible light from the Sun is absorbed in the exosphere.
On average, how fast do the plates move on the Earth?
a few centimeters per year
Which of the following is an example of convection?
Warm air expanding and rising while cooler air contracts and fall.
Which of the following is not caused by the Coriolis effect on Earth?
Water going down a drain swirls in opposite directions in the northern and southern hemispheres.
Based solely on an understanding of the greenhouse effect (as displayed in the figure), which one of the following statements is true?
We should expect an increase in the greenhouse gas concentration to lead to global warming.
What do we mean when we say that the terrestrial worlds underwent differentiation?
When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces.
Which of the following is the most basic definition of a greenhouse gas?
a gas that absorbs infrared light
Based on its surface features, the most important event on Venus in the past billion years or so was _______.
a global "repaving" that erased essentially all the surface features that had existed earlier.
Suppose we use a baseball to represent Earth. On this scale, the other terrestrial worlds (Mercury, Venus, the Moon, and Mars) would range in size approximately from that of ______.
a golf ball to a baseball
What important change in the Sun over the past four billion years is thought to be very important to understanding the climates of Venus, Earth, and Mars?
a gradual brightening with time
In Part A, you found that Planet Z should not have polar ice caps or liquid water. What single change to Planet Z's characteristics would allow it to have these things?
a greater distance from its star
What do we mean by a runaway greenhouse effect?
a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere
Olympus Mons is ______.
a huge shield volcano on Mars
The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that ________.
a large baked potato takes longer to cool than a small baked potato
A terrestrial world's lithosphere is ________.
a layer of relatively strong, rigid rock, encompassing the crust and part of the mantle
What is a magnetosphere?
a region of space around a planet in which the planet's magnetic field can trap charged particles
Australia is composed of relatively old and thick ______
continental crust
You have found that Planet Z should have active tectonics and volcanism and an atmosphere produced by volcanic outgassing. What single factor explains why the planet should have these characteristics?
has a large size for a terrestrial planet.
Old Faithful Geyser at Yellowstone National Park in the United States acquires its energy from a _______
hot spot
Scientists can estimate the age of a planetary surface by counting __________.
impact craters
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 _____.
human activities that are increasing the concentration of greenhouse gases in Earth's atmosphere
The processes responsible for virtually all surface geology are _________.
impact cratering, volcanisms, tectonics, and erosion
The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________.
is temporarily absorbed by greenhouse gases and then reemitted in random directions
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?
its size
Which of the following is the underlying reason why Venus has so little wind erosion?
its slow rotation
What's the fundamental reason that Mars, unlike the Earth, has become virtually geologically dead?
its small size compared to Earth
Which two factors are critical to the existence of the carbon dioxide (CO2) cycle on Earth?
plate tectonics and liquid water oceans
What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?
plate tectonics and widespread erosion
Which of the following best describes the lunar maria?
relatively smooth, flat plains on the Moon
The slowly increasing distance between South America and Africa is due to ______
seafloor spreading
Layered ________ exposed by erosion can be seen when looking at the Grand Canyon in the United States.
sedimentary rock
Earth's ______ absorbs most of the ultraviolet light arriving here from the Sun.
stratosphere
The extremely deep ocean Marianas Trench is a result of _______
subduction
Which region of Earth has warmed the most in recent decades?
the Arctic
Which characteristic of Earth explains why we have an ultraviolet-absorbing stratosphere?
the existence of photosynthetic life
Which of the following does not provide evidence that Mars once had abundant liquid water on its surface?
the presence of canali, discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell.
What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?
the presence of many long, tall cliffs
In the context of planetary geology, what do we mean by outgassing?
the release by volcanism of gases that had been trapped in a planetary interior
Most of the X-rays coming from the Sun are absorbed in the _______
thermosphere
The densest layer of the atmospheres of Venus, Earth, and Mars is the _______
troposphere
Which of the following correctly lists the layers of Earth's atmosphere from the ground upward?
troposphere, stratosphere, thermosphere, exosphere
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
The energy that warms Earth's surface comes primarily in the form of __________.
visible light from the Sun
Suppose that Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be _______.
well below the freezing point of water
