Chapter 7

If the Earth where half its size (making it a medium sized planet) which planet's surface would it resemble most?

Mars

Can a large planet have lots of impact craters long after it has formed?

No

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

In general, what kind of terrestrial planet would you expect to have the thickest lithosphere?

a small planet

On the graphs shown, you can identify an ice age by looking for __________.

a trough (bottom of a dip) on the temperature graph

Mercury is considered a small planet. How long after the formation of the solar system do you think volcanic and tectonic activity stopped on Mercury.

about 2 billion years

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

Venus is considered a large sized planet. How much of venus surface do you think is covered by volcanic and tectonic features?

all

As a general rule, smaller planets __________ than larger planets.

cool more rapidly

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

radioactive decay

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

- active volcanoes - active tectonics - an atmosphere produced by outgassing

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

Which planets will be significantly cratered after 4.5 Gyr, with very few features due to other geological processes?

Any small planet, regardless of its temperature

Which of the following would cause Venus's surface geology to look the most different from the way it looks today?

Make Venus half its current size (radius)

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

Olympus Mons

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

Other geological processes have wiped out craters.

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.

If we found an earth sized planets orbiting very close to another star, which planet would it surface resemble?

Venus

Which terrestrial world has the most atmospheric gas?

Venus

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.

Venus is a large hot planet and Earth is a large warm planet. What is the main difference in the surface of the two?

Venus has fewer erosion features than Earth.

Why does Mercury have more craters than Venus?

Venus is more massive than Mercury

If a planet is found to have lots of tectonic activity, which other geologic process is most likely to be very active as well?

Volcanism

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 planet have the most erosion features?

large, warm planets

How many of the five terrestrial worlds are considered "geologically dead"?

two

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

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 reflected by the surface, visible light reflected by clouds, and infrared light emitted by the surface and atmosphere

Which of the following is a strong greenhouse gas?

water vapor

Can small planets have lots of erosion features?

No

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.

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.

Why does Earth have more erosion features than Venus?

Earth is colder than Venus.

How does the amount of heat released in a planet's interior by radioactive decay change with time?

It drops off with time.

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.

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.

Which describes our understanding of flowing water on Mars?

It was important once, but no longer.

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.

If Mars were the same size as Mercury, which surface features would it have?

Lots of crater, but few valleys, mountains, and volcanoes

Why doesn't Mars have as many erosion features as Earth?

Mars is smaller than Earth.

Which planet will have a significant number of surface features due to all 4 geological processes after 4.5 billion years?

Medium warm planets

Which of the following represent the sequence in which the listed planets become geologically dead?

Mercury, Mars, Venus, Earth

Why doesn't Venus have many impact craters?

Most craters have been erased by tectonic and volcanic features.

Why doesn't the Earth have as many craters as the Moon?

Most of earths craters have been erased by volcanism, tectonic activity, and erosion

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.

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.

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.

Which of the following statements about our solar system's terrestrial worlds are true?

They are all made primarily of rock and metal. They are all of nearly the same age. Their interiors all have a core, mantle, and crust.

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.

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.

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

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

The oxygen in Earth's atmosphere was released by

life

Where is the most CO2 that has outgassed from Earth's volcanoes?

locked up in rocks

Mars is considered a medium sized planet. How much of Mars surface do you think is covered by volcanic and tectonic features?

most

The existence of a core-mantle-crust interior structure tells us that a world __________.

once had a molten interior

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

size