Question 1

Mars is a(n):

Accepted Answer

A) inner planet. 
B) terrestrial planet. 
C) jovian planet. 
D) dwarf planet. 
A) inner planet. 
B) terrestrial planet. 
C) jovian planet. 
D) dwarf planet.

Question 2

Which one of the following is more or less uniform across the planets of our solar system?

Accepted Answer

A) density 
B) magnetic field strength 
C) direction of orbital motion around the Sun 
D) extent of cratering 
A) density 
B) magnetic field strength 
C) direction of orbital motion around the Sun 
D) extent of cratering

Question 3

Pluto is now classified as a(n):

Accepted Answer

A) planet. 
B) minor planet. 
C) asteroid. 
D) trans-Neptunian object. 
A) planet. 
B) minor planet. 
C) asteroid. 
D) trans-Neptunian object.

Question 4

How can we determine the mass of a planet?

Accepted Answer

A) from the orbital parameters of one of its moons 
B) by observing its gravitational influence on a passing comet 
C) by observing its gravitational influence on the trajectory of a spacecraft 
D) All of the above are correct. 
A) from the orbital parameters of one of its moons 
B) by observing its gravitational influence on a passing comet 
C) by observing its gravitational influence on the trajectory of a spacecraft 
D) All of the above are correct.

Question 5

How does spectroscopy help determine the composition of a planet's atmosphere?

Accepted Answer

A) Radiation emitted by the planet passes through the atmosphere on its way to Earth, and analysis of the resulting absorption spectrum gives clues to the atmosphere's composition. 
B) Heat from the planet makes its atmosphere emit large amounts of radiation. Analysis of the resulting emission spectrum gives clues to the atmosphere's composition. 
C) Light from the Sun passes through the planet's atmosphere before and after reflecting from the planet's surface. Analysis of the resulting absorption spectrum gives clues to the atmosphere's composition. 
D) At present, the only way to determine the composition of a planet's atmosphere is to have a flyby spacecraft scoop up a sample and then analyze it with an on-board spectrometer. 
A) Radiation emitted by the planet passes through the atmosphere on its way to Earth, and analysis of the resulting absorption spectrum gives clues to the atmosphere's composition. 
B) Heat from the planet makes its atmosphere emit large amounts of radiation. Analysis of the resulting emission spectrum gives clues to the atmosphere's composition. 
C) Light from the Sun passes through the planet's atmosphere before and after reflecting from the planet's surface. Analysis of the resulting absorption spectrum gives clues to the atmosphere's composition. 
D) At present, the only way to determine the composition of a planet's atmosphere is to have a flyby spacecraft scoop up a sample and then analyze it with an on-board spectrometer.

Question 6

The low average densities of the jovian planets, which have high masses and hence high gravitational fields, is an indication that their interiors are:

Accepted Answer

A) gaseous and have not condensed to liquid or solid form. 
B) composed mainly of very light elements, such as H and He. 
C) composed of very porous rock (many small, empty cavities). 
D) composed of H2O, CH4 (methane), and NH3 (ammonia). 
A) gaseous and have not condensed to liquid or solid form. 
B) composed mainly of very light elements, such as H and He. 
C) composed of very porous rock (many small, empty cavities). 
D) composed of H2O, CH4 (methane), and NH3 (ammonia).

Question 7

Table 7-2 (in the text) describes the seven largest satellites in the solar system. From these data it can be seen that the presence of an atmosphere correlates with:

Accepted Answer

A) diameter. The largest satellites have atmospheres, the smaller ones do not. 
B) mass. The more massive the satellite, the more likely the satellite is to have an atmosphere. 
C) average density. The satellites with the larger average densities are more likely to have atmospheres. 
D) None of the above is correct. 
A) diameter. The largest satellites have atmospheres, the smaller ones do not. 
B) mass. The more massive the satellite, the more likely the satellite is to have an atmosphere. 
C) average density. The satellites with the larger average densities are more likely to have atmospheres. 
D) None of the above is correct.

Question 8

In our solar system, which of the following planets is not a member of the jovian group?

Accepted Answer

A) Mars 
B) Saturn 
C) Neptune 
D) Jupiter 
A) Mars 
B) Saturn 
C) Neptune 
D) Jupiter

Question 9

How big is Ceres, the largest asteroid?

Accepted Answer

A) It is larger than Mercury. 
B) Its diameter is about the length of California. 
C) It is about the size of Rhode Island. 
D) It is the size of two football fields. 
A) It is larger than Mercury. 
B) Its diameter is about the length of California. 
C) It is about the size of Rhode Island. 
D) It is the size of two football fields.

Question 10

Evidence of cratering by the impact of massive objects is found:

Accepted Answer

A) throughout the solar system. 
B) only in the inner part of the solar system. 
C) only in the outer part of the solar system. 
D) only on the satellites of the planets and not on the planets themselves. 
A) throughout the solar system. 
B) only in the inner part of the solar system. 
C) only in the outer part of the solar system. 
D) only on the satellites of the planets and not on the planets themselves.

Question 11

Suppose we discover a comet that is an elliptical orbital plane perpendicular to the ecliptic. What is the most likely place of origin of this comet?

Accepted Answer

A) the Oort cloud 
B) the Kuiper belt 
C) the asteroid belt 
D) outside the solar system 
A) the Oort cloud 
B) the Kuiper belt 
C) the asteroid belt 
D) outside the solar system

Question 12

The craters on the Moon are all nearly circular. Why is this?

Accepted Answer

A) Most of the craters on the Moon were formed by volcanoes, and this results in circular craters. 
B) It is believed that the objects that formed the impact craters on the Moon's surface all struck the Moon approximately perpendicular to its surface, and this would result in circular craters. 
C) The objects that produced the impact craters came in at a variety of angles, but the craters were actually made by the shock waves generated by impact-and this results in circular craters. 
D) The objects that produced the impact craters had been rounded by many previous collisions in space, and round objects produce circular craters regardless of their direction of impact. 
A) Most of the craters on the Moon were formed by volcanoes, and this results in circular craters. 
B) It is believed that the objects that formed the impact craters on the Moon's surface all struck the Moon approximately perpendicular to its surface, and this would result in circular craters. 
C) The objects that produced the impact craters came in at a variety of angles, but the craters were actually made by the shock waves generated by impact-and this results in circular craters. 
D) The objects that produced the impact craters had been rounded by many previous collisions in space, and round objects produce circular craters regardless of their direction of impact.

Question 13

The average speed of methane molecules (CH4, molecular mass = 2.66 × 10-26 kg) in the atmosphere of Neptune (temperature = 63 K = -210°C) is:

Accepted Answer

A) 313 m/s. 
B) 327,000 m/s. 
C) 572 m/s. 
D) 98,000 m/s. 
A) 313 m/s. 
B) 327,000 m/s. 
C) 572 m/s. 
D) 98,000 m/s.

Question 14

The discovery of nitrogen gas (N2) in the atmosphere of Titan was made by:

Accepted Answer

A) direct sampling of the atmosphere by a probe as it descended to Titan's surface. 
B) ultraviolet spectroscopy from Earth. 
C) measurement of microwave emission from N2 molecules by radio telescopes on Earth. 
D) infrared spectroscopy from the Cassini spacecraft. 
A) direct sampling of the atmosphere by a probe as it descended to Titan's surface. 
B) ultraviolet spectroscopy from Earth. 
C) measurement of microwave emission from N2 molecules by radio telescopes on Earth. 
D) infrared spectroscopy from the Cassini spacecraft.

Question 15

Most of the ammonia on Jupiter is in the form of a:

Accepted Answer

A) gas. 
B) liquid. 
C) solid. 
D) plasma. 
A) gas. 
B) liquid. 
C) solid. 
D) plasma.

Question 16

Our planetary system consists of:

Accepted Answer

A) one large planet, and many small planets of about the same size, all accompanied by small moons. 
B) large and small planets, all of them accompanied by small moons, none of which is as large as a planet.. 
C) large and small planets, some accompanied by moons as large as the smaller planets. 
D) a series of planets of about the same size, some of which are accompanied by moons, the largest of which are as big as the planets themselves. 
A) one large planet, and many small planets of about the same size, all accompanied by small moons. 
B) large and small planets, all of them accompanied by small moons, none of which is as large as a planet.. 
C) large and small planets, some accompanied by moons as large as the smaller planets. 
D) a series of planets of about the same size, some of which are accompanied by moons, the largest of which are as big as the planets themselves.

Question 17

A nitrogen molecule (N2) has a mass of 4.7 × 10-26 kg, and a carbon dioxide molecule (CO2) has a mass of 7.3 × 10-26 kg. On a day when the temperature is 18°C (64°F), the N2 molecules will have a:

Accepted Answer

A) greater average kinetic energy and greater average speed than the CO2 molecules. 
B) smaller average kinetic energy but greater average speed than the CO2 molecules. 
C) smaller average speed than the CO2 molecules but the same average kinetic energy. 
D) greater average speed than the CO2 molecules but the same average kinetic energy. 
A) greater average kinetic energy and greater average speed than the CO2 molecules. 
B) smaller average kinetic energy but greater average speed than the CO2 molecules. 
C) smaller average speed than the CO2 molecules but the same average kinetic energy. 
D) greater average speed than the CO2 molecules but the same average kinetic energy.

Question 18

In general, planets with interiors that are assumed to be molten are also expected to possess planet-wide magnetic fields. Which planet below is believed to have a molten interior and no planet-wide magnetic field?

Accepted Answer

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

Question 19

On Mars, the temperature can reach 290 K and the escape speed is 5.0 km/sec. What is the average speed of a carbon dioxide molecule (mass = 7.31 × 10-26 kg) at this temperature, and what can you say about the retention of carbon dioxide on Mars?

Accepted Answer

A) The average speed is 0.4 km/sec, so Mars should retain its carbon dioxide. 
B) The average speed is 0.4 km/sec, so Mars should lose its carbon dioxide. 
C) The average speed is 1.9 km/sec, so Mars should retain its carbon dioxide. 
D) The average speed is 1.9 km/sec, so Mars should lose its carbon dioxide. 
A) The average speed is 0.4 km/sec, so Mars should retain its carbon dioxide. 
B) The average speed is 0.4 km/sec, so Mars should lose its carbon dioxide. 
C) The average speed is 1.9 km/sec, so Mars should retain its carbon dioxide. 
D) The average speed is 1.9 km/sec, so Mars should lose its carbon dioxide.

Question 20

Mercury is small enough to have lost most of its internal heat, but it still has enough to produce a magnetic field. What is thought to be the source of this heat?

Accepted Answer

A) proximity to the Sun 
B) tidal forces 
C) residual heat from formation 
D) volcanic activity 
A) proximity to the Sun 
B) tidal forces 
C) residual heat from formation 
D) volcanic activity

Exam 7: Comparative Planetology I: Our Solar System

Mars is a(n):

Which one of the following is more or less uniform across the planets of our solar system?

Pluto is now classified as a(n):

How can we determine the mass of a planet?

How does spectroscopy help determine the composition of a planet's atmosphere?

The low average densities of the jovian planets, which have high masses and hence high gravitational fields, is an indication that their interiors are:

Table 7-2 (in the text) describes the seven largest satellites in the solar system. From these data it can be seen that the presence of an atmosphere correlates with:

In our solar system, which of the following planets is not a member of the jovian group?

How big is Ceres, the largest asteroid?

Evidence of cratering by the impact of massive objects is found:

Suppose we discover a comet that is an elliptical orbital plane perpendicular to the ecliptic. What is the most likely place of origin of this comet?

The craters on the Moon are all nearly circular. Why is this?

The average speed of methane molecules (CH4, molecular mass = 2.66 × 10-26 kg) in the atmosphere of Neptune (temperature = 63 K = -210°C) is:

The discovery of nitrogen gas (N2) in the atmosphere of Titan was made by:

Most of the ammonia on Jupiter is in the form of a:

Our planetary system consists of:

A nitrogen molecule (N2) has a mass of 4.7 × 10-26 kg, and a carbon dioxide molecule (CO2) has a mass of 7.3 × 10-26 kg. On a day when the temperature is 18°C (64°F), the N2 molecules will have a:

In general, planets with interiors that are assumed to be molten are also expected to possess planet-wide magnetic fields. Which planet below is believed to have a molten interior and no planet-wide magnetic field?

On Mars, the temperature can reach 290 K and the escape speed is 5.0 km/sec. What is the average speed of a carbon dioxide molecule (mass = 7.31 × 10-26 kg) at this temperature, and what can you say about the retention of carbon dioxide on Mars?

Mercury is small enough to have lost most of its internal heat, but it still has enough to produce a magnetic field. What is thought to be the source of this heat?

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 average speed of methane molecules (CH₄, molecular mass = 2.66 × 10^-26 kg) in the atmosphere of Neptune (temperature = 63 K = -210°C) is:

The discovery of nitrogen gas (N₂) in the atmosphere of Titan was made by:

A nitrogen molecule (N₂) has a mass of 4.7 × 10^-26 kg, and a carbon dioxide molecule (CO₂) has a mass of 7.3 × 10^-26 kg. On a day when the temperature is 18°C (64°F), the N₂ molecules will have a:

On Mars, the temperature can reach 290 K and the escape speed is 5.0 km/sec. What is the average speed of a carbon dioxide molecule (mass = 7.31 × 10^-26 kg) at this temperature, and what can you say about the retention of carbon dioxide on Mars?