Astronomy 1010 Exam #2 Chapter 9

The total mass of Mars 's atmosphere is 2.79×1016 kg and carbon dioxide makes up about 98.1 percent of its atmospheric mass. What is the mass of carbon dioxide in Mars's atmosphere?

2.74x 10^16kg

A bar is a measure of atmospheric pressure, where one bar is equivalent to Earth's atmospheric pressure at sea level. Venus's atmosphere has a pressure of 92 bars. Water pressure in Earth's oceans increases by one bar for every 10 m of depth. How deep would you have to go to experience pressure equal to the atmospheric surface pressure on Venus?

920 m deep

Based on the relation shown here between rising carbon dioxide (CO2) concentrations and average global temperatures, what is a logical prediction about what would happen if CO2 levels were to continue to rise? Choose one: A. Average global temperatures would increase. B. Average global temperatures would decrease. C. There is no way to make this prediction based on the information shown. D. Average global temperatures would stay constant.

A. Average global temperatures would increase.

Earth is special among the planets because it has an ozone layer to protect it from ultraviolet light that can destroy water vapor molecules and a strong magnetic field to protect it from the solar wind stripping off its atmosphere. It has just the right air pressure, and it is at just the right distance from the Sun for liquid water to exist on its surface. Because carbon dioxide is removed from the atmosphere by liquid water, this is key in keeping Earth's atmospheric carbon dioxide level in check. The upper graph shows the carbon dioxide content in Earth's atmosphere as a function of time, and the lower graph shows the average yearly temperature in Antarctica, where the carbon dioxide levels were measured. Note that the units of time are in thousands of years. Study the above figure, then select all the statements below that are correct. Choose one or more: A. There are cyclical temperature variations seen on this graph (a periodic increase, then decrease) every few 10,000 to 100,000 years or so. B. The temperature is directly related to the amount of carbon dioxide in the atmosphere—an increase in one coincides with an increase in the other. C. There is no correlation between the carbon dioxide content in the atmosphere and temperature. D. There are cyclical temperature variations seen on this graph (a periodic increase, then decrease) each year due to the passage of the seasons. E. The temperature is inversely related to the amount of carbon dioxide in the atmosphere—a decrease in one results in an increase in the other.

A. There are cyclical temperature variations seen on this graph (a periodic increase, then decrease) every few 10,000 to 100,000 years or so. B. The temperature is directly related to the amount of carbon dioxide in the atmosphere—an increase in one coincides with an increase in the other.

The following graph shows the concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years along with global temperatures. What is the correlation between concentrations of these two chemicals and global temperature? Choose one: A. When concentrations are high global temperatures are high. B. Global temperatures only follow changing CO2 concentrations C. Global temperatures are not correlated with concentration changes. D. When concentrations are low global temperatures are high

A. When concentrations are high global temperatures are high.

The words weather and climate Choose one or more: A. refer to very different time scales. B. refer to very different size scales. C. mean essentially the same thing.

A. refer to very different time scales. B. refer to very different size scales.

The greenhouse effect plays a major role in the climate of a planet. Visit the Greenhouse Effect AstroTour, and use what you learn there to choose all the statements below that are correct. Note that 273 K = 0°C = 32°F. Choose one or more: A. The Earth absorbs sunlight and reemits it in the ultraviolet. B. If there were no greenhouse effect, liquid water would not exist on the surface of the Earth. C. It would be beneficial to humanity to develop technology that would eliminate the greenhouse effect on Earth. D. The Earth has reached thermal equilibrium, emitting the same amount of energy into space as it absorbs from the Sun. E. The more carbon dioxide there is in an atmosphere, the stronger the greenhouse effect will be.

B. If there were no greenhouse effect, liquid water would not exist on the surface of the Earth. D. The Earth has reached thermal equilibrium, emitting the same amount of energy into space as it absorbs from the Sun. E. The more carbon dioxide there is in an atmosphere, the stronger the greenhouse effect will be.

Weather is quite different from climate. Weather describes short-term variations in temperature in a localized place on Earth, while climate refers to the overall average temperature in a large region over a long period of time. To get an accurate indication of where Earth's temperature is heading in the long term, we must look back over a long period of time at the average behavior of the climate as a whole, ignoring short-term changes in weather. With this in mind, study the plot below. How has the global climate been changing over the past 100+ years? Choose one: A. The climate is changing completely at random, with no noticeable general trend. B. The climate is getting warmer with time. C. The climate is getting colder with time.

B. The climate is getting warmer with time.

Venus is hot and Mars is cold primarily because Choose one: A. the atmosphere of Venus is dominated by CO2, but the atmosphere of Mars is not. B. Venus has a much thicker atmosphere. C. Venus is closer to the Sun. D. Venus has stronger winds.

B. Venus has a much thicker atmosphere.

Venus and Earth are similar in size, so they should have had similar amounts of volcanic outgassing adding to the atmosphere, and similar gravities resulting in a similar loss of atmospheric gas to space. Why, then, are their atmospheres so different? This table shows the composition of the planets' atmospheres if all the carbon dioxide that exists anywhere on the planet were included. Carbon dioxide is added to the atmosphere through volcanic outgassing, and it is removed as it is absorbed by liquid water and then chemically combined with rock. Based on the text above and what you see in the table, what is the most likely reason Venus has a stronger greenhouse effect than Earth? Choose one: A. Venus had more carbon dioxide added to the air through volcanic outgassing. B. Venus is closer to the Sun, so any liquid water that might have existed on the surface in the distant past would have evaporated away faster than on the Earth. C. Venus is covered in clouds that reflect most of the sunlight away. D. Venus has a higher percentage of nitrogen than the Earth.

B. Venus is closer to the Sun, so any liquid water that might have existed on the surface in the distant past would have evaporated away faster than on the Earth.

The following graph shows the relative concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years. Approximately how often is there an especially high peak in concentrations of both chemicals? Choose one: A. every 200,000 years B. every 100,000 years C. every 50,000 years D. every 1,000,000 years

B. every 100,000 years

Auroras are the result of Choose one: A. upper-atmosphere lightning strikes. B. the interaction of particles from the Sun and Earth's atmosphere and magnetic field. C. the interaction of Earth's magnetic field with Earth's atmosphere. D. destruction of stratospheric ozone, which leaves a hole.

B. the interaction of particles from the Sun and Earth's atmosphere and magnetic field.

If we experience a year that is much hotter than the previous year, this means that Earth is going through a global warming trend, where the temperature will now continually increase each year. Choose one: A. true B. false C. It is impossible to tell with one year of data.

C. It is impossible to tell with one year of data.

The following graph shows the concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years along with global temperatures. How do the current levels of carbon dioxide and methane in the atmosphere compare with the values seen over the last 800,000 years? Choose one: A. The current concentrations of both are well within the historical range of variation B. Current CH4 concentrations are higher than average, but CO2 concentrations are lower. C. The current concentrations of both are far higher than the rest of the graph. D. The current concentrations of both are far lower than the rest of the graph.

C. The current concentrations of both are far higher than the rest of the graph.

The oxygen molecules in Earth's atmosphere Choose one: A. were part of the primary atmosphere. B. are being rapidly depleted by the burning of fossil fuels. C. are the result of life. D. arose when the secondary atmosphere formed.

C. are the result of life.

The periodic rise and fall of Earth's average temperature over 10,000s to 100,000s of years is due to the Milankovitch cycle, which is caused by periodic variations in the Earth's axis tilt and the eccentricity of its orbit. Ice ages occur when the axis tilt is low, and periods of relative warmth occur when it is high. As the amount of liquid water on Earth changes due to evaporation, precipitation, and freezing, the level of carbon dioxide removed from the air also changes, such that the greenhouse effect is strengthened during periods of intense cold and weakened during periods of intense warmth. This helps the Earth regulate its temperature and move out of periods of extreme climate without becoming like Mars or Venus. Based on the trends seen in this graph, what would you expect Earth's temperature to do over the next few thousand years? Choose one: A. It is impossible to tell because the temperature of the Earth is highly unpredictable. B. level out and stay at the current temperature C. decrease toward the next ice age D. increase toward the next warm period

C. decrease toward the next ice age

The following graph shows the relative concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years. What, if any, correlation is there between the concentrations of carbon dioxide and methane? Choose one: A. A rise in carbon dioxide concentration is always followed later by a rise in methane. B. There is no correlation between their concentrations. C. When the concentration of one is high the other tends to be low. D. Their concentrations appear to rise and fall together.

D. Their concentrations appear to rise and fall together.

According to the data, the global average temperature of the Earth is increasing. Based on the two plots below, what is likely causing this? Choose one: A. a sudden decrease in the strength of the greenhouse effect over the past 100-200 years B. a gradual decrease in the strength of the greenhouse effect over the past 2,000 years C. a gradual increase in the strength of the greenhouse effect over the past 2,000 years D. a sudden increase in the strength of the greenhouse effect over the past 100-200 years

D. a sudden increase in the strength of the greenhouse effect over the past 100-200 years

Rank, from greatest (at top) to smallest (at bottom), the seasonal variations of the terrestrial planets.

Greatest Mars Earth Venus Mercury Smallest

The AstroTour illustrates what the surface temperatures of Venus, Earth, and Mars would be without atmospheres, and it also shows the current value for each planet, with their actual atmospheres. Place the planets in order based on the discrepancy between their surface temperatures with and without their atmospheres.

Least difference Mars Earth Venus Most difference

The distinct layers of Earth's atmosphere vary in temperature in a somewhat surprising way. Arrange these four layers in ascending order, based on the temperature at the upper boundary of each.

Lowest temperature Mesosphere Troposphere Stratosphere Thermosphere Highest temperature

Why does Mars have such a low surface pressure? Visit the AstroTour "Atmospheres: Formation and Escape" on how planets gain and lose atmospheres. Choose the statement that corresponds to the biggest factor that resulted in Mars having a thinner atmosphere than Earth and Venus. Choose one: Mars is farther away from the Sun than Earth and Venus. Mars is less massive than Earth and Venus. Mars had fewer comet impacts than Earth and Venus. Mars has a longer year than Earth and Venus.

Mars is less massive than Earth and Venus.

Whether a planet has an atmosphere or not depends on a number of factors: mass, temperature, composition of the crust, volcanic activity, and complex evolutionary processes. Rank the planets according to how well they retain their atmospheres, using the following criteria: • The planet that still maintains its primary atmosphere, ranks first. • The planet that lost its primary atmosphere but retains a dense secondary atmosphere, ranks second. • The planet that lost its primary atmosphere and retains a tenuous secondary atmosphere, ranks third. • The planet that retained neither its primary nor secondary atmospheres, ranks last.

Most successful Jupiter Venus Mars Mercury Least successful

A planet's temperature depends on its distance from the Sun as well as the strength of its greenhouse effect. Let's remove the effect of distance from the Sun by just considering how the temperature of a planet changes due to the presence of its atmosphere. From the numbers given in the animation, calculate the difference in temperature for each planet with and without its atmosphere, and then rank the planets in order of increasing greenhouse effect.

Smallest Effect Mars Earth Venus Largest Effect

Place in chronological order the following steps in the formation and evolution of Earth's atmosphere:

Start Hydrogen and helium are captured from the protoplanetary disk. Hydrogen and helium are lost from the atmosphere. Volcanoes, comets, and asteroids increase the inventory of volatile matter. Life releases CO2 from the subsurface into the atmosphere. Plant life converts CO2 to oxygen. Oxygen enables the growth of new life-forms. End