Question 1

In the stratosphere of the Earth's atmosphere, how does the temperature vary with increasing altitude and what causes this variation?

Accepted Answer

Ozone in the stratosphere absorbs ultrav

Question 2

For the first 1 billion years of the Earth's evolution, the fraction of oxygen in its atmosphere was approximately:

Accepted Answer

A)  zero 
B)  1/2 of what it is today 
C)  2 times what it is today 
D)  10 times what it is today 
E)  the same as it is today 
A)  zero 
B)  1/2 of what it is today 
C)  2 times what it is today 
D)  10 times what it is today 
E)  the same as it is today

Question 3

_________ in our atmosphere is a direct consequence of the emergence of life.

Accepted Answer

A)  Carbon dioxide 
B)  Water vapor 
C)  Nitrogen 
D)  Oxygen 
E)  Helium 
A)  Carbon dioxide 
B)  Water vapor 
C)  Nitrogen 
D)  Oxygen 
E)  Helium

Question 4

Earth has roughly _________ times more atmospheric pressure than Mars and _________ times less than Venus.

Accepted Answer

A)  10; 10 
B)  200; 100 
C)  2,000; 2 
D)  2; 10 
E)  1,000; 200 
A)  10; 10 
B)  200; 100 
C)  2,000; 2 
D)  2; 10 
E)  1,000; 200

Question 5

If you found absorption rising from _________ in the spectrum of a planet, you could conclude that it might contain some form of life.

Accepted Answer

A)  oxygen 
B)  methane 
C)  water vapor 
D)  oxygen, methane, or water vapor 
A)  oxygen 
B)  methane 
C)  water vapor 
D)  oxygen, methane, or water vapor

Question 6

Earth's sky is blue because:

Accepted Answer

A)  blue light from the sun is more readily scattered by molecules in the atmosphere than red light 
B)  of reflected light from the oceans 
C)  red light from the sun is more readily scattered by molecules in the atmosphere than blue light 
D)  molecules that make up the Earth's atmosphere radiate preferentially at blue wavelengths 
E)  the Sun radiates more blue light than other wavelengths 
A)  blue light from the sun is more readily scattered by molecules in the atmosphere than red light 
B)  of reflected light from the oceans 
C)  red light from the sun is more readily scattered by molecules in the atmosphere than blue light 
D)  molecules that make up the Earth's atmosphere radiate preferentially at blue wavelengths 
E)  the Sun radiates more blue light than other wavelengths

Question 7

The best way to look for life on other planets is to search for absorption from nitrogen in their atmospheres in the infrared region of the spectrum.

Accepted Answer

A) True 
 B)False

Question 8

According to the figure shown below, approximately how many years ago did oxygen finally get to half its current abundance in Earth's atmosphere?

Accepted Answer

A)  3 billion years ago 
B)  1 billion years ago 
C)  0.6 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago 
A)  3 billion years ago 
B)  1 billion years ago 
C)  0.6 billion years ago 
D)  0.25 billion years ago 
E)  0.1 billion years ago

Question 9

Aurorae are produced only near the northern and southern magnetic poles of a planet because charged particles arriving in the solar wind cannot cross the magnetic field lines.

Accepted Answer

A) True 
 B)False

Question 10

The amount of carbon dioxide in the Earth's atmosphere has been increasing over the last 50 years because of:

Accepted Answer

A)  global warming 
B)  the growth of the ozone hole 
C)  the burning of fossil fuels 
D)  increased energy output from the Sun 
E)  increased magnetic activity in the Sun 
A)  global warming 
B)  the growth of the ozone hole 
C)  the burning of fossil fuels 
D)  increased energy output from the Sun 
E)  increased magnetic activity in the Sun

Question 11

Given the thickness and chemical composition of Venus's atmosphere, by how much would you expect its average surface temperature to change between day and night?

Accepted Answer

A)  There should be almost no change in temperature. 
B)  by tens of K (like Earth) 
C)  by hundreds of K (like Mercury) 
D)  The answer depends on where Venus is in its orbit around the Sun. 
A)  There should be almost no change in temperature. 
B)  by tens of K (like Earth) 
C)  by hundreds of K (like Mercury) 
D)  The answer depends on where Venus is in its orbit around the Sun.

Question 12

The shape of the Earth's magnetosphere is modified by:

Accepted Answer

A)  the Moon's tidal force 
B)  the solar wind 
C)  Earth's own gravity 
D)  asymmetries in the shape of Earth's core 
E)  Earth's elliptical orbit 
A)  the Moon's tidal force 
B)  the solar wind 
C)  Earth's own gravity 
D)  asymmetries in the shape of Earth's core 
E)  Earth's elliptical orbit

Question 13

Carbon dioxide levels in Earth's atmosphere have been rising by about 4 percent per decade due to the use of fossil fuels. If this trend continues, what could happen to Earth?

Accepted Answer

Increased concentration of carbon dioxid

Question 14

Why does the temperature decrease as you go higher up in altitude in the troposphere on Earth?

Accepted Answer

The temperature decreases as y

Question 15

The atmosphere of Mars is mostly composed of carbon dioxide; therefore the greenhouse effect makes the average temperature 35 degrees warmer than it would be without its atmosphere.

Accepted Answer

A) True 
 B)False

Question 16

What makes carbon dioxide a highly effective greenhouse gas?

Accepted Answer

A)  It easily absorbs UV radiation. 
B)  It easily absorbs visible light. 
C)  It easily absorbs infrared radiation. 
D)  It easily reacts chemically with rock. 
E)  It easily photodissociates in the upper atmosphere. 
A)  It easily absorbs UV radiation. 
B)  It easily absorbs visible light. 
C)  It easily absorbs infrared radiation. 
D)  It easily reacts chemically with rock. 
E)  It easily photodissociates in the upper atmosphere.

Question 17

Would a nitrogen atom in Venus's atmosphere, whose temperature is 740 K, eventually escape into outer space? Note that a nitrogen atom has a mass that is 14 times that of a hydrogen atom. Recall that atoms eventually will escape if their average velocity is greater than 1/6 times the escape velocity of the planet. The escape velocity of Venus is 10 km/s. For comparison, a hydrogen atom has an average velocity of 2.5 km/s at a temperature of 300 K.

Accepted Answer

A)  The average velocity of nitrogen atoms is 0.4 km/s, and nitrogen does not escape. 
B)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen does not escape. 
C)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen escapes. 
D)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen does not escape. 
E)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen escapes. 
A)  The average velocity of nitrogen atoms is 0.4 km/s, and nitrogen does not escape. 
B)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen does not escape. 
C)  The average velocity of nitrogen atoms is 1.0 km/s, and nitrogen escapes. 
D)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen does not escape. 
E)  The average velocity of nitrogen atoms is 4.5 km/s, and nitrogen escapes.

Question 18

Like Mars and Venus, Earth originally had a significant amount of carbon dioxide in its atmosphere. Where is the majority of the carbon now?

Accepted Answer

A)  It has escaped into outer space. 
B)  It is bound up in the plant life on Earth. 
C)  It is bound up in rocks. 
D)  It is dissolved into the oceans. 
E)  It is still in the atmosphere in the form of complex molecules. 
A)  It has escaped into outer space. 
B)  It is bound up in the plant life on Earth. 
C)  It is bound up in rocks. 
D)  It is dissolved into the oceans. 
E)  It is still in the atmosphere in the form of complex molecules.

Question 19

If photosynthesis were to disappear on Earth:

Accepted Answer

A)  the atmosphere would become less dense 
B)  oxygen would disappear from the atmosphere 
C)  the atmosphere would become hotter 
D)  nitrogen would disappear from the atmosphere 
E)  the amount of water vapor in the atmosphere would decrease 
A)  the atmosphere would become less dense 
B)  oxygen would disappear from the atmosphere 
C)  the atmosphere would become hotter 
D)  nitrogen would disappear from the atmosphere 
E)  the amount of water vapor in the atmosphere would decrease

Question 20

If an average hydrogen atom in Earth's atmosphere has a velocity of 2.5 km/s, what would be the average velocity of an oxygen molecule in the Earth's atmosphere? Note that the atomic mass of an oxygen atom is 16 times that of a hydrogen atom.

Accepted Answer

A)  0.16 km/s 
B)  2.5 km/s 
C)  0.62 km/s 
D)  0.44 km/s 
E)  0.25 km/s 
A)  0.16 km/s 
B)  2.5 km/s 
C)  0.62 km/s 
D)  0.44 km/s 
E)  0.25 km/s

Exam 9: Atmospheres of the Terrestrial Planets

In the stratosphere of the Earth's atmosphere, how does the temperature vary with increasing altitude and what causes this variation?

For the first 1 billion years of the Earth's evolution, the fraction of oxygen in its atmosphere was approximately:

_________ in our atmosphere is a direct consequence of the emergence of life.

Earth has roughly _________ times more atmospheric pressure than Mars and _________ times less than Venus.

If you found absorption rising from _________ in the spectrum of a planet, you could conclude that it might contain some form of life.

Earth's sky is blue because:

The best way to look for life on other planets is to search for absorption from nitrogen in their atmospheres in the infrared region of the spectrum.

According to the figure shown below, approximately how many years ago did oxygen finally get to half its current abundance in Earth's atmosphere?

Aurorae are produced only near the northern and southern magnetic poles of a planet because charged particles arriving in the solar wind cannot cross the magnetic field lines.

The amount of carbon dioxide in the Earth's atmosphere has been increasing over the last 50 years because of:

Given the thickness and chemical composition of Venus's atmosphere, by how much would you expect its average surface temperature to change between day and night?

The shape of the Earth's magnetosphere is modified by:

Carbon dioxide levels in Earth's atmosphere have been rising by about 4 percent per decade due to the use of fossil fuels. If this trend continues, what could happen to Earth?

Why does the temperature decrease as you go higher up in altitude in the troposphere on Earth?

The atmosphere of Mars is mostly composed of carbon dioxide; therefore the greenhouse effect makes the average temperature 35 degrees warmer than it would be without its atmosphere.

What makes carbon dioxide a highly effective greenhouse gas?

Like Mars and Venus, Earth originally had a significant amount of carbon dioxide in its atmosphere. Where is the majority of the carbon now?

If photosynthesis were to disappear on Earth:

If an average hydrogen atom in Earth's atmosphere has a velocity of 2.5 km/s, what would be the average velocity of an oxygen molecule in the Earth's atmosphere? Note that the atomic mass of an oxygen atom is 16 times that of a hydrogen atom.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Large-Scale Structure in the Universe

Life

Filters

Earth has roughly _ times more atmospheric pressure than Mars and _ times less than Venus.