Question 1

The wide absorption features in the optical spectrum of Titan's atmosphere (See Figure 7-3 of Universe, 11th ed.) are produced by:
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Accepted Answer

A) water vapor, H2O. 
B) methane gas, CH4. 
C) hydrogen gas, H2. 
D) oxygen gas, O2. 
A) water vapor, H2O. 
B) methane gas, CH4. 
C) hydrogen gas, H2. 
D) oxygen gas, O2.

Question 2

The composition of the solid surfaces of planets and satellites (moons) that do not have substantial atmospheres can be found by:

Accepted Answer

A) measuring the thermal emission from the surface at several wavelengths in the microwave and infrared regions of the spectrum. 
B) comparing the spectrum of the sunlight reflected from the surface with the spectrum of direct sunlight from the Sun. 
C) comparing very broad absorption features in their spectra with spectra of known substances on Earth. 
D) measuring the wavelengths of narrow absorption lines in their spectra. 
A) measuring the thermal emission from the surface at several wavelengths in the microwave and infrared regions of the spectrum. 
B) comparing the spectrum of the sunlight reflected from the surface with the spectrum of direct sunlight from the Sun. 
C) comparing very broad absorption features in their spectra with spectra of known substances on Earth. 
D) measuring the wavelengths of narrow absorption lines in their spectra.

Question 3

Comparing Earth's Moon to the rest of the solar system, which contains about 130 known satellites, it is found that the Moon is:

Accepted Answer

A) a typical satellite of about average size. 
B) the largest satellite in the solar system. 
C) the largest satellite in the inner part of the solar system. 
D) larger than some planets, including Mercury and Mars. 
A) a typical satellite of about average size. 
B) the largest satellite in the solar system. 
C) the largest satellite in the inner part of the solar system. 
D) larger than some planets, including Mercury and Mars.

Question 4

The largest of the terrestrial planets in our solar system is:

Accepted Answer

A) Jupiter. 
B) Venus. 
C) Mars. 
D) Earth. 
A) Jupiter. 
B) Venus. 
C) Mars. 
D) Earth.

Question 5

Which one of the following planets shows the greatest amount of cratering on its surface?

Accepted Answer

A) Mercury 
B) Earth 
C) Mars 
D) Jupiter 
A) Mercury 
B) Earth 
C) Mars 
D) Jupiter

Question 6

In order to produce a planet-wide magnetic field, a planet must have in its interior some material capable of carrying the electric current in such a way as to produce a dynamo effect. All of the following substances appear to be able to fill this role, except one. Which is the exception?

Accepted Answer

A) molten iron 
B) solid iron 
C) liquid metallic hydrogen 
D) a liquid water-ammonia mixture under high pressure 
A) molten iron 
B) solid iron 
C) liquid metallic hydrogen 
D) a liquid water-ammonia mixture under high pressure

Question 7

The average density of the outer "giant" planets compared to that of liquid water is:

Accepted Answer

A) much less than that of water. 
B) about 1.2 times. 
C) about 5 times. 
D) greater than 10 times. 
A) much less than that of water. 
B) about 1.2 times. 
C) about 5 times. 
D) greater than 10 times.

Question 8

To an astronomer, the word "ice" can mean:

Accepted Answer

A) water (H2O), carbon dioxide (CO2), methane (CH4), or ammonia (NH3). 
B) hydrogen (H2), water (H2O), carbon dioxide (CO2), methane (CH4), or ammonia (NH3). 
C) only water (H2O). 
D) water (H2O) or carbon dioxide (CO2). 
A) water (H2O), carbon dioxide (CO2), methane (CH4), or ammonia (NH3). 
B) hydrogen (H2), water (H2O), carbon dioxide (CO2), methane (CH4), or ammonia (NH3). 
C) only water (H2O). 
D) water (H2O) or carbon dioxide (CO2).

Question 9

Planets and satellites with a large amount of surface cratering generally have insignificant atmospheres. Why are these two conditions correlated?

Accepted Answer

A) The impacts that create the craters also tend to vaporize the atmosphere. 
B) A large amount of cratering implies a small size, and this, in turn, implies a low escape speed. 
C) A large amount of cratering implies a small size, and this, in turn, implies a high escape speed. 
D) Most of the solar system debris that caused cratering was near the Sun. Thus, heavily cratered planets and satellites are near the Sun where high temperatures result in high average molecular speeds. 
A) The impacts that create the craters also tend to vaporize the atmosphere. 
B) A large amount of cratering implies a small size, and this, in turn, implies a low escape speed. 
C) A large amount of cratering implies a small size, and this, in turn, implies a high escape speed. 
D) Most of the solar system debris that caused cratering was near the Sun. Thus, heavily cratered planets and satellites are near the Sun where high temperatures result in high average molecular speeds.

Question 10

How many orbits of the Sun (sidereal periods) has Neptune completed since its discovery? (See Table 7-1, Universe, 11th ed. (in the text).)

Accepted Answer

A) just more than 1 
B) fewer than 1 
C) about 147 
D) more than 2 
A) just more than 1 
B) fewer than 1 
C) about 147 
D) more than 2

Question 11

An oxygen (O2) molecule has twice the mass of a methane (CH4) molecule. In a planet's atmosphere at some particular temperature, the average kinetic energy of an oxygen molecule is:

Accepted Answer

A) the same as that of a methane molecule (that is, all molecules have the same average kinetic energy at the same temperature). 
B) 1.4 times greater than that of a methane molecule (that is, the average kinetic energy increases in proportion to the square root of the mass). 
C) 4 times greater than that of a methane molecule (that is, the average kinetic energy increases in proportion to the square of the mass). 
D) twice that of a methane molecule (that is, the average kinetic energy increases in the same proportion as the mass). 
A) the same as that of a methane molecule (that is, all molecules have the same average kinetic energy at the same temperature). 
B) 1.4 times greater than that of a methane molecule (that is, the average kinetic energy increases in proportion to the square root of the mass). 
C) 4 times greater than that of a methane molecule (that is, the average kinetic energy increases in proportion to the square of the mass). 
D) twice that of a methane molecule (that is, the average kinetic energy increases in the same proportion as the mass).

Question 12

The natural satellites (moons) of the planets in our solar system:

Accepted Answer

A) fall into three main classes: three larger than Mercury, five others larger than our Moon, and the rest less than 300 km in diameter. 
B) fall into two main classes: seven larger than 2000 km in diameter, the rest much smaller. 
C) are all small, less than 2000 km in diameter. 
D) are all approximately the size of our Moon or larger. 
A) fall into three main classes: three larger than Mercury, five others larger than our Moon, and the rest less than 300 km in diameter. 
B) fall into two main classes: seven larger than 2000 km in diameter, the rest much smaller. 
C) are all small, less than 2000 km in diameter. 
D) are all approximately the size of our Moon or larger.

Question 13

In general, large bodies in the solar system show less evidence of cratering than do small bodies. Why should we expect this correlation?

Accepted Answer

A) The gravity of large bodies deflects incoming projectiles and thus there are fewer collisions. 
B) Large bodies are more likely to retain an atmosphere, and thus most large projectiles burn up before striking the ground. 
C) Large bodies actually receive more hits because of their larger size, but later craters obliterate earlier ones, and we only see evidence of the most recent. 
D) Large bodies cool more slowly and are more likely to retain internal heat and be geologically active, capable of resurfacing the planet and obliterating craters. 
A) The gravity of large bodies deflects incoming projectiles and thus there are fewer collisions. 
B) Large bodies are more likely to retain an atmosphere, and thus most large projectiles burn up before striking the ground. 
C) Large bodies actually receive more hits because of their larger size, but later craters obliterate earlier ones, and we only see evidence of the most recent. 
D) Large bodies cool more slowly and are more likely to retain internal heat and be geologically active, capable of resurfacing the planet and obliterating craters.

Question 14

The average speed of hydrogen molecules (H2) in Earth's atmosphere is below the calculated escape speed from Earth (11.2 km/s). So, is hydrogen gas retained in Earth's atmosphere?

Accepted Answer

A) Yes. Under these conditions H2 must be retained. 
B) No. Escape speed depends on the mass of the escaping object. Hydrogen is the lightest molecule, thus its escape speed is well below 11.2 km/s. 
C) No. Escape speed depends on the mass of the escaping object. Hydrogen is the lightest molecule, thus its escape speed is well above 11.2 km/s. 
D) No. While the average speed of H2 is below the escape speed, there will be some H2 molecules with speeds above escape speed-and these will escape. 
A) Yes. Under these conditions H2 must be retained. 
B) No. Escape speed depends on the mass of the escaping object. Hydrogen is the lightest molecule, thus its escape speed is well below 11.2 km/s. 
C) No. Escape speed depends on the mass of the escaping object. Hydrogen is the lightest molecule, thus its escape speed is well above 11.2 km/s. 
D) No. While the average speed of H2 is below the escape speed, there will be some H2 molecules with speeds above escape speed-and these will escape.

Question 15

A laboratory on the surface of Earth makes a spectrum of radiation that originates at the Sun and reflects off a celestial body with an atmosphere such as Saturn's large satellite Titan. Which one of the following statements about the resulting spectrum is correct?

Accepted Answer

A) The reflection from the solid surface produces sharp spectral lines. 
B) Earth's atmosphere contributes only very broad spectral features, not sharp lines, to the spectrum. 
C) The atmosphere of the body can contribute sharp absorption lines to the spectrum. 
D) There is no evidence in the spectrum of the solar origin of the radiation. 
A) The reflection from the solid surface produces sharp spectral lines. 
B) Earth's atmosphere contributes only very broad spectral features, not sharp lines, to the spectrum. 
C) The atmosphere of the body can contribute sharp absorption lines to the spectrum. 
D) There is no evidence in the spectrum of the solar origin of the radiation.

Question 16

In general, a heavily cratered surface should imply a solid interior. Lack of a planet-wide magnetic field should also imply a solid interior. Which one of the following bodies actually possesses both a heavily cratered surface and no planet-wide magnetic field?

Accepted Answer

A) Mercury 
B) Venus 
C) the Moon 
D) Mars 
A) Mercury 
B) Venus 
C) the Moon 
D) Mars

Question 17

Which of the large trans-Neptunian objects has the longest orbital period about the Sun?

Accepted Answer

A) Quaoar 
B) Sedna 
C) Pluto 
D) Eris 
A) Quaoar 
B) Sedna 
C) Pluto 
D) Eris

Question 18

The next planet beyond Saturn is Uranus. The distance from the orbit of Saturn to the orbit of Uranus is about the same as:

Accepted Answer

A) the distance from Saturn to the Sun. 
B) the distance from Earth to the Sun. 
C) the distance from the orbit of Earth to the orbit of Mars. 
D) the distance from the orbit of Saturn to the orbit of Jupiter. 
A) the distance from Saturn to the Sun. 
B) the distance from Earth to the Sun. 
C) the distance from the orbit of Earth to the orbit of Mars. 
D) the distance from the orbit of Saturn to the orbit of Jupiter.

Question 19

A molecule moves within the atmosphere of a planet. It would be less likely that this molecule would be retained in the atmosphere of this planet if the:

Accepted Answer

A) molecule were more massive. 
B) planet were more massive. 
C) planet's atmosphere were hotter. 
D) planet's magnetic field were stronger. 
A) molecule were more massive. 
B) planet were more massive. 
C) planet's atmosphere were hotter. 
D) planet's magnetic field were stronger.

Question 20

Which of the following planets shows the least amount of cratering on its surface?

Accepted Answer

A) Mercury 
B) Earth 
C) Mars 
D) Jupiter 
A) Mercury 
B) Earth 
C) Mars 
D) Jupiter

Exam 7: Comparative Planetology I: Our Solar System

The wide absorption features in the optical spectrum of Titan's atmosphere (See Figure 7-3 of Universe, 11th ed.) are produced by: ​ ​

The composition of the solid surfaces of planets and satellites (moons) that do not have substantial atmospheres can be found by:

Comparing Earth's Moon to the rest of the solar system, which contains about 130 known satellites, it is found that the Moon is:

The largest of the terrestrial planets in our solar system is:

Which one of the following planets shows the greatest amount of cratering on its surface?

In order to produce a planet-wide magnetic field, a planet must have in its interior some material capable of carrying the electric current in such a way as to produce a dynamo effect. All of the following substances appear to be able to fill this role, except one. Which is the exception?

The average density of the outer "giant" planets compared to that of liquid water is:

To an astronomer, the word "ice" can mean:

Planets and satellites with a large amount of surface cratering generally have insignificant atmospheres. Why are these two conditions correlated?

How many orbits of the Sun (sidereal periods) has Neptune completed since its discovery? (See Table 7-1, Universe, 11th ed. (in the text).)

An oxygen (O2) molecule has twice the mass of a methane (CH4) molecule. In a planet's atmosphere at some particular temperature, the average kinetic energy of an oxygen molecule is:

The natural satellites (moons) of the planets in our solar system:

In general, large bodies in the solar system show less evidence of cratering than do small bodies. Why should we expect this correlation?

The average speed of hydrogen molecules (H2) in Earth's atmosphere is below the calculated escape speed from Earth (11.2 km/s). So, is hydrogen gas retained in Earth's atmosphere?

A laboratory on the surface of Earth makes a spectrum of radiation that originates at the Sun and reflects off a celestial body with an atmosphere such as Saturn's large satellite Titan. Which one of the following statements about the resulting spectrum is correct?

In general, a heavily cratered surface should imply a solid interior. Lack of a planet-wide magnetic field should also imply a solid interior. Which one of the following bodies actually possesses both a heavily cratered surface and no planet-wide magnetic field?

Which of the large trans-Neptunian objects has the longest orbital period about the Sun?

The next planet beyond Saturn is Uranus. The distance from the orbit of Saturn to the orbit of Uranus is about the same as:

A molecule moves within the atmosphere of a planet. It would be less likely that this molecule would be retained in the atmosphere of this planet if the:

Which of the following planets shows the least amount of cratering on its surface?

Astronomy and the Universe

Knowing the Heavens

Eclipses and the Motion of the Moon

Gravitation and the Waltz of the Planets

The Nature of Light

Optics and Telescopes

Comparative Planetology II: the Origin of Our Solar System

The Living Earth

Our Barren Moon

Mercury, Venus, and Mars: Terrestrial, yet Unique

Jupiter and Saturn: Lords of the Planets

Jupiter and Saturns Satellites of Fire and Ice

Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

Asteroids, Comets, and Impacts

Our Star, the Sun

The Nature of the Stars

The Birth of Stars

Stellar Evolution: on and After the Main Sequence

Stellar Evolution: The Death of Stars

Stellar Remnants: Neutron Stars and Black Holes

Our Galaxy

Galaxies

Quasars and Active Galaxies

Cosmology: The Origin and Evolution of the Universe

Exploring the Early Universe

The Search for Extraterrestrial Life

Filters

The wide absorption features in the optical spectrum of Titan's atmosphere (See Figure 7-3 of Universe, 11th ed.) are produced by:

An oxygen (O₂) molecule has twice the mass of a methane (CH₄) molecule. In a planet's atmosphere at some particular temperature, the average kinetic energy of an oxygen molecule is:

The average speed of hydrogen molecules (H₂) in Earth's atmosphere is below the calculated escape speed from Earth (11.2 km/s). So, is hydrogen gas retained in Earth's atmosphere?