Chapter 10 Reading Quiz

In the context of a planetary atmosphere, what is a bar? A. A place where lawyers can get sodas and other drinks. B. A description of the atmospheric composition on Earth. C. The surface pressure on any planet. D. A unit of pressure roughly equal to the atmospheric pressure at sea level on Earth.

A unit of pressure roughly equal to the atmospheric pressure at sea level on Earth. -In other words, the atmospheric pressure at sea level is 1 bar.

Which of the following is not a characteristic of the seasons on Mars? A. The seasons last almost twice as long on Mars as on Earth. B. Global winds tend to blow from the summer pole toward the winter pole, sometimes initiating global sand storms. C. As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect. D. The polar caps shrink in summer and grow in winter.

As on Earth, the seasons are caused primarily by axis tilt and orbital distance has virtually no effect. -Orbital distance does influence the seasons on Mars, because Mars has a more highly elliptical orbit than Earth.

Why is the sky blue (on Earth)? A. Because deep space is blue in color. B. Because molecules scatter blue light more effectively than red light. C. Because the Sun emits mostly blue light. D. No one knows - this is one of the great mysteries of science. E. Because molecules scatter red light more effectively than blue light.

Because molecules scatter blue light more effectively than red light -Therefore blue light from the Sun is scattered all over the sky. At sunset or sunrise, when we see the Sun through more atmosphere (because it is on the horizon), so much blue light is scattered away that we are left with a red sunset (or sunrise).

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

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

In the context of Earth's climate history, what do we mean by snowball Earth? A. This term is used to describe all the ice ages that have occurred in the past few million years. B. It refers to a very deep ice age that occurred hundreds of millions of years ago. C. It is what we expect to see happen on Earth in about a billion years. D. It refers to a time when polar regions had much more snowfall than normal.

It refers to a very deep ice age that occurred hundreds of millions of years ago. -There may have been several snowball Earth periods in which it became so cold that most of the oceans froze. The most recent snowball Earth period is thought to have been some 580 million years ago.

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

It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate. -But remember that this natural cycle operates over time scales of hundreds of thousands of years, and hence cannot help us with the problem of human-induced global warming.

How did molecular oxygen (O2) get into Earth's atmosphere? A. It was released by life through the process of photosynthesis. B. It was captured from the solar nebula. C. It was outgassed from volcanoes. D. It came from chemical reactions with surface rocks.

It was released by life through the process of photosynthesis. -Earth's early atmosphere contained essentially no molecular oxygen; all the oxygen was made by living organisms that convert CO2 into oxygen (and use the carbon).

Which of the following is not an expected consequence of global warming? A. An increase in the severity of winter blizzards. B. An increase in the number and intensity of hurricanes. C. The entire Earth will warm up by the same amount. D. Melting of polar ice and glaciers.

The entire Earth will warm up by the same amount. -Global warming will change weather patterns, so some places may get cooler even as the Earth as a whole warms up.

Based on everything we have learned about Venus and Mars, what is the most surprising aspect of Earth's climate history? A. The fact that Earth apparently got a lot of atmospheric gas from outgassing by volcanoes. B. The fact that Earth had enough water to form oceans. C. The fact that Earth's climate can be affected by changes in its axis tilt. D. The fact that the temperature of our planet has remained relatively steady throughout our planet's history.

The fact that the temperature of our planet has remained relatively steady throughout our planet's history. -In contrast, both Venus and Mars underwent dramatic and permanent climate change.

Which of the following statements about ozone (in Earth's stratosphere) is not true: A. Ozone is a form of oxygen. B. The presence of ozone was crucial to the origin of life some 4 billion years ago. C. Ozone absorbs harmful ultraviolet light from the Sun. D. Without this ozone, Earth would not have a stratosphere.

The presence of ozone was crucial to the origin of life some 4 billion years ago. -There was no ozone layer 4 billion years ago.

Why does atmospheric pressure decrease as you go higher in altitude on Earth? A. There are fewer greenhouse gases at higher altitude. B. The weight of the atmosphere above you decreases with altitude. C. Gravity gets much weaker with altitude. D. Temperature decreases with altitude and lower temperature tends to mean lower pressure.

The weight of the atmosphere above you decreases with altitude. -You can notice the pressure change in your ears if you ascend or descend rapidly enough.

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

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

Which of the following describes a primary role of global circulation cells in a planet's atmosphere? A. They cause air to be diverted into hurricane-like swirls. B. They keep the poles cold enough to have polar caps. C. They transport heat from the equator toward the poles. D. They create severe weather such as thunderstorms.

They transport heat from the equator toward the poles. -For a slowly rotating planet, warm air rises near the equator and moves at high altitude toward the poles, while cool air descends at the poles and moves along the surface toward the equator. The same idea holds on a more rapidly rotating planet, but the Coriolis force can split the cells; on Earth, for example, each equator-to-pole circulation cell splits into three cells.

Which planet(s) have an atmosphere that consists mostly of carbon dioxide? A. Mars only B. Venus only C. Venus, Earth, and Mars D. Venus and Mars

Venus and Mars -Both Venus and Mars have atmospheres that are about 95% carbon dioxide, though Venus contains far moer atmospheric gas, making its total amount of carbon dioxide far greater than that on Mars. (That is why the greenhouse effect is so much stronger on Venus.)

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.) A. Earth, Venus, Mars, Moon/Mercury B. Venus, Mars, Moon/Mercury, Earth C. Mars, Venus, Earth, Moon/Mercury D. Venus, Earth, Mars, Moon/Mercury

Venus, Earth, Mars, Moon/Mercury -Venus has a very thick atmosphere, while the Moon and Mercury have virtually no atmosphere at all.

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

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

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

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

Which of the following is the most basic definition of a greenhouse gas? A. a gas that makes a planet much hotter than it would be otherwise, even in small amounts B. a gas that keeps warms air from rising, and therefore warms the surface C. a gas that absorbs infrared light D. a gas that reflects a lot of sunlight

a gas that absorbs infrared light -Greenhouse gases can therefore slow the escape of heat from a planet, because planets radiate infrared light.

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. a gradual reduction in the amount of ultraviolet and X-ray radiation coming from the Sun B. a gradual weakening of the solar wind with time C. a gradual brightening with time D. a gradual dimming with time

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

What do we mean by a runaway greenhouse effect? A. a greenhouse effect that starts on a planet but later disappears as gases are lost to space B. 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 C. a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere D. a greenhouse effect that heats a planet so much that its surface rock melts

a greenhouse effect that keeps getting stronger until all of a planet's greenhouse gases are in its atmosphere -This is presumably what happened on Venus.

What is a magnetosphere? A. the uppermost layer of any planetary atmosphere B. the layer of a planet in which its magnetic field is generated C. the region in a planet's atmosphere in which auroras occur D. a region of space around a planet in which the planet's magnetic field can trap charged particles

a region of space around a planet in which the planet's magnetic field can trap charged particles -That says it all.

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 _________. A. about the thickness of a sheet of paper B. about 6 inches thick C. about an inch thick D. About a half-inch thick

about the thickness of a sheet of paper -The atmosphere is remarkably thin compared to our entire planet.

Which of the following is not a greenhouse gas? A. water vapor (H2O) B. methane (CH4) C. carbon dioxide (CO2) D. oxygen (O2)

oxygen (O2) -Molecules with two atoms, such as molecular oxygen, nitrogen, and hydrogen, generally are not greenhouse gases.

Which of the following correctly lists the layers of Earth's atmosphere from the ground upward? A. exosphere, stratosphere, thermosphere, troposphere B. troposphere, stratosphere, thermosphere, exosphere C. troposphere, thermosphere, stratosphere, exosphere D. thermosphere, stratosphere, troposphere , exosphere

troposphere, stratosphere, thermosphere, exosphere -The lowest layer, the troposphere, is where we live and where weather occurs.

Suppose that Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be _______. A. slightly cooler, but still above freezing B. well below the freezing point of water C. slightly warmer, but still well below the boiling point of water D. about the same as it is now

well below the freezing point of water -Without the greenhouse effect, Earth's average temperature would be about -16°C, which is well below freezing (0°C). Thanks to the greenhouse effect, the actual global average temperature is about 15°C.