Astronomy Exam 3 TXST
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
Using only pencil and paper calculations, Arrhenius concluded that a doubling of the carbon dioxide concentration would raise global temperatures by about _____.
5 degrees C
Which describes our understanding of flowing water on Mars?
It was important once, but no longer
Imagine that you visit an alien world that has an atmospheric composition similar to that of Earth (that is, mostly nitrogen and oxygen) and a surface atmospheric pressure of 1.2 bars. Which of the following statements best describes the effects of this pressure?
It will feel quite similar to the atmospheric pressure on Earth.
Why does the Moon have a layer of "powdery soil" on its surface?
It's the result of gradual erosion by micrometeorites striking the Moon
Earth has a relatively strong magnetic field, but Mars does not. Which of the following probably explains why Mars lacks a strong magnetic field today?
Its core is too cool for convection.
Which of the following most likely explains why Venus does not have a strong magnetic field?
Its rotation is too slow
Why is Mars red?
Its surface rocks were rusted by oxygen
A rover on Mars found small round rocks that look like blueberries. Why was this significant?
The blueberries were made of Hematite which only forms these in water confirming there was water on Mars in its past
Gas particles in Earth's atmosphere most easily escape from the ____.
exosphere
The "edge of space" occurs in the layer we call the ____.
exosphere.
The Moon has no detectable atmosphere.
false
The earthquakes that occur in Southern California generally occur above a
fault
What are greenhouse gases?
gases that absorb infrared light
The existence of a core-mantle-crust interior structure tells us that a world __________.
once had a molten interior
How many of the five terrestrial worlds have surfaces being constantly reshaped by plate tectonics?
one
Earth is the only planet on our solar system with a stratosphere. Why?
only earth has plants
Juno is a spacecraft that
orbited Jupiter and sent back stunning images.
How did the Moon, Mercury and Earth get their first atmospheres (their initial atmospheres)?
outgassing from volcanoes
Which process is the primary source of the atmospheric gases on Earth?
outgassing from volcanoes.
Which of the following is not a product of outgassing?
oxygen
Which of the following gases absorbs ultraviolet light best?
ozone
What causes the release of oxygen into Earth's atmosphere?
photosynthesis
From where did the molecular oxygen in Earth's atmosphere originate?
photosynthesis from single-celled organisms
What kind of light warms the stratosphere?
ultraviolet
About how large (on average) is an impact crater compared to the size of the impactor?
10 times larger.
How many more times is the atmospheric pressure in Jupiter's core greater than the atmospheric pressure at Earth's surface?
100 million
This diagram represents the conveyor-like action of plate tectonics on Earth. Which numbered position represents a place where new seafloor crust is being made?
2
How long, approximately, do geologists estimate it takes for the entire seafloor to be replaced due to plate tectonics?
200 million years
Suppose Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be
250 K, which is well below freezing.
On the graphs shown, you can identify an ice age by looking for __________.
a trough (bottom of a dip) on the temperature graph
A solar day on Jupiter is
about 9.8 hours
The temperature of the core of Jupiter is
about the same as earth's core temperature as it formed at the same time.
In order to be classified as a greenhouse gas the gas must
absorb infra-red wavelengths of light
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.
The thermosphere is warm because it
absorbs X rays.
Which source of internal heat is most responsible for heating planetary interoirs?
accretion
The three principal sources of internal heat of terrestrial planets are
accretion, differentiation, and radioactivity
The interior of earth is pretty hot real estate! Where did this heat primarily come from?
accretion: it is the trapped original heat of formation!
Scientists have confidence in the predictions of today's best climate models because they
agree well with actual data for recent decades.
Which of the following statements about the greenhouse effect is true?
all of the above is true
The belts and zones of Jupiter are
alternating bands of rising and falling air at different latitudes.
The geological feature in this photo is _________.
an impact crater
X rays from the Sun's corona
are absorbed in Earth's thermosphere.
Why is the sky blue?
atmospheric gases scatter blue light more than red
The Maria on the Moon are best described as
impact craters that filled with lava over time and then solidified
Scientists can estimate the age of a planetary surface by counting
impact craters.
Where is most of the water on Mars?
in its polar caps and subsurface ground ice
How does the carbon dioxide cycle keep the earth from warming up too much?
increased heat means increased participation which in turn removes CO2 from the atmosphere causing the earth to cool.
Heat escapes from a planet's surface into space by thermal radiation. Planets radiate almost entirely in the wavelength range of the
infrared
The greenhouse effect raises Earth's surface temperature (from what it would be otherwise) because the infrared light radiated by Earth's surface __________.
is absorbed by greenhouse gases, slowing the escape of this energy to space
What kind of gas is most affected by thermal escape?
light gases
Where is most of the CO2 that has outgassed from Earth's volcanoes?
locked up in rocks
Convection occurs in the troposphere but not in the stratosphere because
lower altitudes of the troposphere are warmer than higher altitudes, unlike in the stratosphere.
Most of the charged particles from the Sun are deflected around Earth by the ____.
magnetosphere.
The terrestrial planet cores contain mostly metal because
metals sank to the center during a time when the interiors were molten throughout.
The sky is blue because
molecules scatter blue light more effectively than red light
The polar caps on Mars are composed of
mostly solid carbon dioxide and some water ice
The greenhouse effect causes warming primarily in Earth's ____.
troposphere.
The greenhouse effect occurs in the
troposphere.
Earth outgassed as much carbon dioxide as Venus, but it is locked up in the oceans and rocks.
true
One bar of atmosphere is roughly equal to Earth's atmospheric pressure at sea level.
true
How is the interior of Earth cooling off? (More than one may be correct)
- Convection in the mantle - conduction through the lithosphere
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?
- Earth's global temperature has generally risen over the past century. - Rises in global average temperature tend to be closely associated with rises in atmospheric carbon dioxide concentration. - Atmospheric carbon dioxide levels have risen dramatically over the past century.
All of 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.
Percival Lowell's claims of a Martian civilization generated great public interest, but other scientists of his time were highly skeptical of these claims. Which two of the following statements (which are all true) explain why other scientists of the late 19th and early 20th centuries rejected Lowell's claims?
- Lowell's canals did not appear in photographs of Mars taken through telescopes. - Lowell's canals followed perfectly straight lines for thousand of kilometers.
Which of the following are significant finds for the rovers Spirit and Opportunity? (There may be more than one answer.)
- Mineral evidence that confirms long ago areas stayed wet for extended periods - Mineral evidence that confirms conditions could have been suitable for microbial life early in Mars's history. - Close up views of pebbles in dried river beds - Hematite "blueberries" a mineral that only forms in water
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. - 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.
Now go to the screen "Major Geological Features," and explore the main screen with labels on and off and elevation on and off. Then complete the sentences below.
- Tharsis Bulge is a high-elevation dotted by tall volcanoes. - The tallest mountain on Mars is called Olympus Mons. - The large, roundish, low-elevation region in the southern hemisphere is called Hellas Basin. - The long, deep canyon running along the equator is called Valles Marineris.
Go to the screen in the interactive figure called "Major Geological Features." Which of the following statements about the Tharsis Bulge, often simply called "Tharsis," are true?
- Tharsis has higher elevation than surrounding regions. - one end of Valles Marineris is connected to Tharsis. - Tharsis has several large volcanoes.
Which of the follow are true? Note both or neither may be true.
- The Sun reverses its magnetic poles every 11 years. - The earth also reverses its magnetic poles, but it is every 200,000 to 300,000 years.
Which of the following gases are greenhouse gases?
- Water vapor H2O - methane CH4 - CO2
Which of the following describe the core of our planet? There are several correct answers.
- The outer core is liquid metal. - The inner core is likely a single molecule of iron because there is an axis of easy passage for P-waves characteristic of single molecules. - The inner an outer core are very rich in iron.
Which of the following describes impact craters on Venus? (there may be more than one answer)
- There are an even number of craters over the entire surface indicating the entire surface is the same age - The entire surface is young, maybe only 750 million years old
Mars is a good place to observe which of the following?
- a global dust storm - a polar ice cap - the largest volcano in the solar system - a huge canyon - a dry river bed - impact craters
Based on Planet Z's size, orbital distance, and rotation rate, which of the following properties is it likely to have?
- active tectonics. - active volcanoes. - an atmosphere produced by outgassing.
Which of the following are true regarding air pressure? There are four correct answers.
- air is made of molecules and atoms so it has mass - air in a gravitational field has weight - on the atomic scale, air pressure is caused by atomic and molecular collisions of - the atmosphere of a planet is held to the planet by gravity
Planetary rings are
- composed of a large number of individual particles that orbit their planet in accord with Kepler's third law. - nearer to their planet than any of the planet's large moons. - known to exist for all of the jovian planets. - orbiting in the equatorial plane of their planet.
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?
- infrared light emitted by the surface and atmosphere. - visible light reflected by clouds. - visible light reflected by the surface.
Which of the following are true about the troposphere? (more than one is correct)
- it is where convection occurs - it is where the greenhouse effect dominate - it is where weather occurs
Which of the following are relevant to why Mercury has long scarps? (Three are correct)
- its core is relatively large compared to the size of the planet and made of metal - metal shrink when it cools - as the core shrunk the surface fell buckling to form cliffs
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?
- more infrared light is absorbed in the lower atmosphere. - the average surface temperature rises.
Which of the following are true about Ozone? (three are correct)
- ozone absorbs UV radiation - the ozone layer is the stratosphere - ozone processes warm the stratosphere
Which of the following factors play a role in determining the geological activity present on a planet?
- rate of rotation - distance from the Sun - size of the planet
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 are found among impact craters. - the recurring slope lineae look like narrow dark streaks. - the recurring slope lineae appear to grow in spring and summer.
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.
- 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. - most of the northern hemisphere has much lower elevation that the southern hemisphere.
Which of the following statements about our solar system's terrestrial worlds are true?
- they are all of nearly the same age. - they are all made primarily of rock and metal. - their interiors all have a core, mantle, and crust.
Which feature in this photo of the full moon is one of the lunar maria?
1
What is Jupiter's Great Red Spot?
A long-lived, high-pressure storm.
At what temperature and pressure does liquid metal form on Jupiter?
About 2,000,000 bar and 5000 degrees Kelvin.
Earth's stratosphere is heated primarily by which process?
Absorption of ultraviolet radiation by ozone.
Which internal energy source produces heat by converting gravitational potential energy into thermal energy?
Accretion and differentiation.
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?
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.
Which of the following is not an expected consequences of the rising carbon dioxide concentration or global warming?
Animal deaths due to carbon dioxide poisoning.
The image below shows a rock formation nicknamed "the face on Mars" that was taken by the Viking 1 orbiter in 1976. Given the clear resemblance to a face, what is an appropriate scientific reaction to this image?
Assume it is most likely a coincidental result of light and shadow, and plan higher resolution follow-up observations.
How do astronomers think Jupiter generates its internal heat?
By contracting, changing gravitational potential energy into thermal energy.
How have we been able to construct detailed maps of surface features on Venus?
By using radar from spacecraft that were sent to orbit Venus.
Of the four gases CO2, H2O, N2, and O2, which are greenhouse gases?
CO2 and H2O
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 successfully reproduce the major recent trend in temperature data only if both human and natural factors are included.
What drives the motion of the tectonic plates on Earth?
Convection cells in the mantle
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 helps generate a magnetic field, and the magnetic field creates the magnetosphere.
Which of the following best describes the internal layering of Jupiter, from the center outward?
Core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer.
Why does Jupiter have several distinct cloud layers?
Different layers represent clouds made of gases that condense at different temperatures.
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.
Early Mars: - strong greenhouse effect. - substantial volcanism and outgassing. - strong magnetosphere. - some craters held lakes of water. - core convection. Mars today: - solar wind strips atmospheric gas. - very weak greenhouse effect. - surface pressure too low for stable liquid water.
Which of the following planets has a stratosphere?
Earth
Which of the terrestrial worlds has the strongest magnetic field?
Earth
The most significant difference between the atmosphere of Earth and that of Venus comes from the fact
Earth has oceans
Choose the correct description of the conveyor-like action of plate tectonics on Earth.
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. This movement causes spreading in some places and subduction in others.
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.
Earth, Mars, Mercury
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?
Emissions of carbon dioxide rose much faster than Arrhenius had anticipated.
How does it explain the differences between seafloor and continental crust?
Every time a bit of rock is subducted and expelled, its chemistry changes, making it lighter. The lighter rock becomes the continental plates, while the relatively unprocessed rocks are the seafloor plates.
The magnetic and rotational north poles on Earth are the same
False
There is no erosion of surface features on the Moon.
False
How is the atmosphere of a planet affected by the rotation rate?
Faster rotation rates produce stronger winds
How does the greenhouse effect work?
Greenhouse gases transmit visible light, allowing it to heat the surface, but then absorb infrared light from Earth, trapping the heat near the surface.
What motivated Arrhenius to calculate how changes in carbon dioxide might affect the climate?
He was seeking to understand the causes of ice ages.
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?
Impact cratering and erosion.
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.
Impact cratering: - mostly occurred during heavy bombardment. - affected all solid worlds similarly. Volcanism: - created the smooth lunar maria. - erased virtually all craters on lo. - 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 key process underlies why Mars changed so much from its early conditions to its conditions today?
Interior cooling.
How does the amount of heat released in a planet's interior by radioactive decay change with time?
It drops off with time.
How much energy does Jupiter emit compared with how much it receives from the Sun?
It emits twice as much.
Why is Neptune denser than Saturn?
It has a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks.
Why does Venus have such a great difference in temperature between its "no atmosphere" temperature and its actual temperature?
It has a large amount of greenhouse gases in its atmosphere.
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 has measured rates of gas loss from the atmosphere today.
Which of the following best describes rain on Venus?
It has sulfuric acid rain in its atmosphere, but the drops evaporate before hitting the surface.
How does Jupiter's core compare to Earth?
It is about the same size but is 10 times more massive.
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 best describes convection?
It is the process in which warm material expands and rises while cool material contracts and falls.
Why doesn't Mars have a stratosphere?
It lacks a layer of ultraviolet absorbing gas.
Deuterium is more abundant on Venus than elsewhere in the solar system. What do we think this fact tells us about Venus?
It once had huge amounts of water in its atmosphere.
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.
What is the leading hypothesis for Venus's lack of water?
Its water molecules were broken apart, and hydrogen was lost to space.
Which of the following is true?
Jupiter is the most massive planet and yet a solar day on Jupiter is only 9.8 hours long.
How did the lunar maria form?
Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins.
Where is the largest (tallest and widest) volcano in the solar system?
Mars
Which of the following show evidence of ancient river beds?
Mars
This photo was taken from orbit around some planet. What planet is it, and how do you know?
Mars because we see dried up riverbeds
All of the following statements are true. Which one explains why Mars has lost so much more interior heat than Earth.
Mars is smaller than Earth.
Which of the following planets has the least substantial atmosphere?
Mercury
Which planet experiences the greatest change between its actual day temperature and actual night temperature?
Mercury
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.
Mercury, Mars, Venus, Earth
Why do Uranus and Neptune have blue methane clouds but Jupiter and Saturn do not?
Methane does not condense into ice in the warmer atmospheric temperatures of Jupiter and Saturn.
Why does Neptune appear blue and Jupiter red?
Methane in Neptune's atmosphere absorbs red light.
Rank the five terrestrial worlds in order of size from smallest to largest.
Moon, Mercury, Mars, Venus, Earth
When were the heat-trapping effects of gases that cause the greenhouse effect first measured by scientists?
More than 150 years ago.
How do we know global warming is real?
NASA has more than 25 current missions taking data and monitoring how our climate is changing and key indicators clearly determining we are causing climate change.
Which of the following planets cannot be seen with the naked eye?
Neptune.
Can the carbon dioxide cycle correct the effects of global warming?
No, it can only correct small changes over 10's of thousands of years--it cannot correct rapid changes like global warming
The arrow in this photo is pointing at a feature known as _____________________.
Olympus Mons
Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?
Olympus Mons
Each statement below represents a feature that has been claimed to exist on Mars. Sort the statements into the correct bin according to whether each is a feature that actually exists, that does not actually exist, or that might exist but about which we cannot yet draw a definitive conclusion.
Real Mars: - minerals of types known to form in liquid water. - abundant water ice. - dried-up river beds. Imaginary Mars: - a network of straight-line canals. - cities built by an ancient civilization. - frequent rainfall and snowfall. Unknown Mars: - microscopic life. - underground pockets of liquid water.
Which of a planets fundamental properties has the greatest effect on its level of volcanic and tectonic activity and why?
Size is most important as it determines if there is still trapped internal heat
Spacecraft have landed on all the terrestrial worlds except
Spacecraft have landed on all the terrestrial worlds.
Which of the following best describes the greenhouse effect?
Sunlight warms the ground and dense surface features which in turn radiate because of thermal emission which is absorbed by greenhouse gases converting this energy into kinetic energy and heating the atmosphere.
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?
Surface water only exists as frozen ice.
Planets form by accretion. This means small planetesimals coalesce to form a larger ball that is uniform in composition. How is it then that planets end up differentiated? What has to happen?
The accretion process is so enegertic that the planet essentially melts allowing the heavy stuff to sink to the center and the lighter material to float to the top thus forming a high density core and a low-density crust.
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 is in many ways the twin of Venus. So why does the earth not have a thick CO2 atmosphere like Venus?
The earth is cool enough for oceans and rain and they trap CO2 from the atmosphere turning it into carbonate rock.
Why is Jupiter denser than Saturn?
The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn.
Which of the following is NOT true regarding Jupiter's Magnetic field.
The field emanates from Jupiter's solid iron core.
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.
What is the exosphere?
The highest layer in the atmosphere
This figure summarizes the geological histories of the terrestrial worlds. Based on this figure, what can you conclude?
The most important factor in a planet's geological history is its size.
Under what circumstances can differentiation occur in a planet?
The planet must have a molten interior.
Why are there fewer large craters on the seafloor than on the continents?
The seafloor crust is younger than the continental crust.
This image shows two tall volcanoes on Venus. Why is it yellow?
The yellow color is arbitrary because this image was created with radar data rather than visible light.
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 degrees 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.
This photo from the Curiosity rover shows what appears to be layered sedimentary rock on Mars. What does this photo seem to be telling us?
This region of Mars once held a body of water such as a lake.
In Part A, you found that Planet Z should not have strong winds and violent storms. What single change to Planet Z's characteristics would cause it to have strong winds and violent storms?
a faster rotation rate
Which of the following best describes why the smaller terrestrial worlds have cooler interiors than the larger ones?
They have relatively more surface area compared to their volumes.
What is the significance of the yellow lines on this map of Earth?
They represent boundaries between the plates that make up Earth's lithosphere.
Why do we think Mercury has so many tremendous cliffs?
They were probably formed by tectonic stresses when the entire planet shrank as its core cooled
What is the primary mission of geology?
To learn the history of the celestial body as told by rocks.
Earth is the only planet in the solar system known to have plate tectonics.
True
Jupiter is slowly shrinking through gravitational contraction today.
True
Mars has virtually no magnetic field
True
Spacecraft have landed on all of the terrestrial worlds.
True
We have a probe on Mars right now monitoring Marsquakes!
True
What is the most likely reason that the surface of Uranus is featureless?
Uranus lacks the internal heat that seeds convection cells.
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?
Venus
Which of the following worlds has the greatest difference in temperature between its "no atmosphere" temperature and its actual temperature?
Venus
Which of the following worlds has the most substantial atmosphere?
Venus
Which terrestrial world has the most atmosphere?
Venus
Which planet(s) have an atmosphere that consists mostly of carbon dioxide?
Venus and Mars
Which planet has the greatest greenhouse effect and why?
Venus because its atmosphere is a very dense CO2 atmosphere
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.
How fast do plates move on Earth?
a few centimeters per year
The following images show the four terrestrial planets in our solar system (not to scale). Rank these planets from left to right based on the total amount of gas in their atmospheres, from most to least.
Venus, Earth, Mars, Mercury
The following images show the four terrestrial planets in our solar system (not to scale). Rank these planets from left to right based on the atmospheric pressure at the surface, from highest to lowest.
Venus, Earth, Mars, Mercury.
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
Listed following are characteristics of the atmospheres of Venus, Earth, and Mars. Match each atmospheric characteristic to the appropriate planet.
Venus: - sulfuric acid clouds. - almost no surface winds. - runaway greenhouse effect. Earth: - atmosphere composed primarily of nitrogen. - ultraviolet-absorbing stratosphere. Mars: - extremely low density atmosphere. - global dust storms.
Listed below are geographic features of the terrestrial worlds. In each case, identify the geological process: impact cratering, volcanism, erosion, or tectonics (where tectonics is any large-scale processes affecting the structure of the planetary crust), most responsible for the feature described. Match the geographic feature to the appropriate geologic process.
Volcanism: - Big Island of Hawaii. - smooth surfaces of the lunar maria. - Mars's Olympus Mons. Impact cratering: - old surface features of the lunar highlands. Erosion: - Earth's Grand Canyon. Tectonics: - current locations of Earth's continents. - Mercury's many long, tall cliffs. - Mars's Valles Marineris.
Geological evidence points to a history of extended ice ages in Earth's history. How did Earth recover from this snowball phase?
Volcanoes continued to inject CO2 into Earth's atmosphere, increasing the greenhouse effect to the point where ice melted.
We have only drilled about 8 miles deep. The radius of the earth is nearly 4,000 miles. How do we know what is deep inside our planet?
We know that there are layers in our planet from the study of how seismic waves propagate through these layers once an earthquake happens.
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 is the difference in meaning between the terms weather and climate?
Weather refers to short-term variations in conditions, and climate refers to long-term variations in conditions.
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.
On Jupiter what happens as you descend about 20% down from the surface clouds reaching 2,000,000 bar and 5,000 degrees Kelvin?
Your each a layer of liquid metallic hydrogen
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.
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.
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
In Part A, you found that Planet Z should not have seasons. What single change to Planet Z's characteristics would cause it to have seasons?
a larger axis tilt
A terrestrial world's lithosphere is
a layer of relatively strong, rigid rock, encompassing the crust and part of the mantle
In the context of plate tectonics, what is a subduction zone?
a place where a seafloor plate is sliding under a continental plate.
The strength of the Coriolis effect depends on
a planet's size and rotation rate.
Neil Armstrong's footprint on the Moon will likely
be ground away by micro-meteor bombardment but it will take millions of years
Why do we have different layers in our atmosphere?
because each layer has its own unique interactions between electromagnetic radiation and the atmospheric gases
Why are Zones white?
because of ammonia snow
The atmosphere on Mercury is due to
bombardment
What are the conditions necessary for a terrestrial planet to have a strong magnetic field?
both molten metallic core and reasonably fast rotation.
Why does the burning of fossil fuels increase the greenhouse effect on Earth?
burning releases carbon dioxide into the atmosphere.
Why do we have ice ages?
changes in the tilt of our spin axis and orbital shape
What kind of surface features may result from tectonics?
cliffs, valleys, mountains, volcanos (all of the above)
In which direction do hurricanes in the Southern Hemisphere rotate?
clockwise
The core, mantle, and crust of a planet are defined by differences in their
composition.
At the heart of the reason why cyclonic storms rotate counter clock wise in the northern hemisphere on earth and why we have zonal wind flow from the west at our latitude is
conservation of angular momentum
Australia is composed of relatively old and thick
continental crust
What is the driving force behind plate tectonics?
convection in the mantle
As a general rule, smaller planets __________ than larger planets.
cool more rapidly
From center to surface, which of the following correctly lists the interior layers of a terrestrial world?
core, mantle, crust
Which two properties are most important in determining the surface temperature of a planet?
distance from the Sun and atmosphere
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.
Volcanism is more likely on a planet that
has high internal temperatures.
A planet is most likely to have tectonic activity if it has
high internal temperature.
Old Faithful Geyser at Yellowstone National Park in the U.S. acquires its energy from a
hot spot.
The interiors of Uranus and Neptune are mostly
hydrogen ices like water, methane, and ammonia ices.
The processes responsible for virtually all surface geology are
impact cratering, volcanisms, tectonics, and erosion
Venus has 880 degrees Fahrenheit surface temperatures because
it has a thick CO2 atmosphere
The surface of Uranus is featureless. Why?
it has no internal heat
Three billion years ago Mars had a thick atmosphere and rivers and oceans. What happened?
it is because Mars is low mass allowing thermal escape and solar stripping after it lost its magnetic field
Why does Earth have the strongest magnetic field among the terrestrial worlds?
it is the only one that has bother a partially molten metallic core and reasonably rapid rotation
There are no aurora on Venus because it
lacks a strong magnetic field.
Valles Marineris is a
large canyon on Mars.
What powers plate tectonic on Earth? That is, what causes the plates to move?
large scale convection in the mantle
What process has shaped Earth's surface more than any other?
plate tectonics.
How does Earth ultimately cool off?
radiation
Which internal energy source is the most important in continuing to heat the terrestrial planets today?
radioactivity
Which of the following best describes the lunar maria?
relatively smooth, flat plains on the Moon
Venus has a thicker atmosphere than Earth.
true
______ found in the Atlantic Ocean between North America and Europe is composed of dense and relatively young rock.
seafloor crust
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
Olympus Mons is a
shield volcano on Mars
Which of a planet's fundamental properties has the greatest effect on its level of volcanic and tectonic activity?
size
Earth's ______ absorbs most of the ultraviolet light arriving here from the Sun.
stratosphere
Ultraviolet light from the Sun is absorbed primarily in Earth's ______.
stratosphere.
Ultraviolet light is absorbed in the
stratosphere.
The extremely deep ocean Marianas Trench is a result of
subduction
Sunsets are red because
sunlight must pass through more atmosphere then, and the atmosphere scatters even more light at bluer wavelengths, transmitting mostly red light.
A distinguishing trait of the interior of Jupiter and Saturn is that
temperatures and pressures are high enough for a large layer of liquid metallic hydrogen to form.
Which region of Earth has warmed the most in recent decades?
the Arctic
The Caloris Basin on mercury covers a large region of the planet, but few smaller craters have formed on top of it. From this we conclude that
the Caloris Basin formed toward the end of the solar system's period of heavy bombardment
Which of the following is NOT true about the atmosphere of the Moon and Mercury?
the atmosphere is too hot for there to be any ice on these celestial objects
If there were no greenhouse gases in earth's atmosphere
the average surface temperature would be below freezing
What are fossil fuels?
the carbon-rich remains of planets that died millions of years ago.
What type of stresses broke Earth's lithosphere into plates?
the circulation of convection cells in the mantle, which dragged against the lithosphere.
Which of the following describes tectonics?
the disruption of a planet's surface by internal stresses
Which of the following describes impact cratering?
the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface
Which of the following NOT an example of tectonics?
the gradual disappearance of a crater rim as a result of wind and rain.
The origin of the magnetic field of our planet is
the liquid outer core as it acts as an electromagnet with charges in motion in the molten liquid causing the field.
What is the troposphere?
the lowest layer in the atmosphere
What is the thermosphere?
the part of the atmosphere that absorbs X rays
What is the stratosphere?
the part of the atmosphere that absorbs ultraviolet
Pretend you land on an unknown celestial object that is about half the mass of earth and orbits at 2.0 AU. You notice that the polar regions are heavily cratered while the equatorial region has few craters. Based only on this fact, you conclude in comparing these two regions that
the polar region has an older geologically speaking surface
Which of the following does not provide evidence that Mars once had large amounts of flowing water?
the presence of cast canals discovered in the later 1800s by Giovanni Schiaparelli and mapped by Percival Lowell
What is differentiation in planetary geology?
the process by which gravity separates materials according to density
When we see a region of a planet that is not as heavily cratered as other regions, we conclude that
the surface in the region is younger than the surface in more heavily cratered regions.
These four photos show features of Earth that change with time, some fast and some slow. Which one of these features is being shaped primarily by the process we call tectonics?
the third one
Venus may have started with an ocean's worth of water. Where is its water now?
the water was lost when ultraviolet light broke apart water molecules and the hydrogen escaped to space.
Which of the following describes erosion?
the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
WE cannot see through the clouds of Venus. And yet we have detected a volcanic eruption! How did we do that?
thermal emission spectrum detection from orbit
Most of the X-rays coming from the Sun are absorbed in the _____.
thermosphere
X-rays from the Sun are absorbed primarily in Earth's ____.
thermosphere.
Zones and belts give Jupiter its stripped appearance. What causes these?
they are the result of convection cells and the coriolis effect
The densest layer of the atmosphere of Venus, Earth, and Mars is the _____.
troposphere
Put the major layers of Earth's atmosphere in to the correct order from the ground upward. Lowest to Highest
troposphere, stratosphere, thermosphere, exosphere.
The proper order of the layers of a generic atmosphere from lowest altitude to highest is
troposphere, stratosphere, thermosphere, exosphere.
Convection and weather occur primarily in Earth's _____.
troposphere.
The average temperature over the past 1000 years has been about 15 degrees C. From the graphs, you can conclude that Earth's average temperature during the past 800,000 years has __________.
varied between about 7 degrees C.
The energy that warms Earth's surface comes primarily in the form of __________.
visible light from the Sun
The relatively few craters that we see within the lunar maria
were formed by impacts that occurred after those that formed most of the craters in the lunar highlands.
The ionosphere is a layer of ionized gas that is
within the thermosphere.