Question 1

How do the sizes of Pluto and its moon, Charon, compare to that of Earth's Moon?

Accepted Answer

A) Pluto is larger than Earth's Moon, but Charon is smaller than Earth's Moon. 
B) Pluto is almost the same size as Earth's Moon, but Charon is much smaller than Earth's Moon. 
C) Both Pluto and Charon are larger than Earth's Moon. 
D) They are both smaller than Earth's Moon. 
A) Pluto is larger than Earth's Moon, but Charon is smaller than Earth's Moon. 
B) Pluto is almost the same size as Earth's Moon, but Charon is much smaller than Earth's Moon. 
C) Both Pluto and Charon are larger than Earth's Moon. 
D) They are both smaller than Earth's Moon.

Question 2

The smallest angle in the sky that can be resolved from Earth's surface, using the best telescopes under the best observing conditions, is approximately 0.1 arcsec. (You may wish to review the small-angle formula in Box 1-1 of Universe, 11th ed.) Consequently, no feature can be resolved at the distance of Pluto if it is smaller than:

Accepted Answer

A) 7 times the diameter of Pluto. 
B) 2/3 of the diameter of Pluto. 
C) 1/15 of the diameter of Pluto. 
D) 1.2 times the diameter of Pluto. 
A) 7 times the diameter of Pluto. 
B) 2/3 of the diameter of Pluto. 
C) 1/15 of the diameter of Pluto. 
D) 1.2 times the diameter of Pluto.

Question 3

What is believed to be the basic structure of the interior of Uranus?

Accepted Answer

A) rocky core; thick layer of water and ammonia; thin gaseous atmosphere 
B) iron core; thick layer of rock; thin, gaseous atmosphere 
C) rocky core; thick layer of water and ammonia; thick layer of liquid hydrogen and liquid helium; thin, gaseous atmosphere 
D) rocky core; thick layer of liquid hydrogen and liquid helium; thin, gaseous atmosphere 
A) rocky core; thick layer of water and ammonia; thin gaseous atmosphere 
B) iron core; thick layer of rock; thin, gaseous atmosphere 
C) rocky core; thick layer of water and ammonia; thick layer of liquid hydrogen and liquid helium; thin, gaseous atmosphere 
D) rocky core; thick layer of liquid hydrogen and liquid helium; thin, gaseous atmosphere

Question 4

What name was given to the first moon of Pluto to be discovered?

Accepted Answer

A) Charon 
B) Chiron 
C) Callisto 
D) Triton 
A) Charon 
B) Chiron 
C) Callisto 
D) Triton

Question 5

How was an atmosphere detected on Triton?

Accepted Answer

A) Material ejected from geyserlike plumes was seen to form streaks against the surface, indicating high-altitude winds. 
B) Clouds of nitrogen crystals were seen to move at speeds different from the rotational speed of the surface. 
C) Infrared radiation was seen to be Doppler shifted off moving cloud layers. 
D) Dust layers were seen to blow onto and off portions of the surface, much like the situation on Mars. 
A) Material ejected from geyserlike plumes was seen to form streaks against the surface, indicating high-altitude winds. 
B) Clouds of nitrogen crystals were seen to move at speeds different from the rotational speed of the surface. 
C) Infrared radiation was seen to be Doppler shifted off moving cloud layers. 
D) Dust layers were seen to blow onto and off portions of the surface, much like the situation on Mars.

Question 6

In the sunlit southern hemisphere of Uranus, the observed variation of temperature with latitude is:

Accepted Answer

A) unknown, because Uranus is too far away for us to measure temperatures at different latitudes. 
B) much cooler at the equator than at the south pole because the south pole is tilted almost directly toward the Sun. 
C) much cooler at the south pole than at the equator because the Sun is always close to (or below) the horizon, as seen from the pole of any planet. 
D) almost nonexistent between the equator and the south pole, implying an efficient equator-to-pole circulation pattern. 
A) unknown, because Uranus is too far away for us to measure temperatures at different latitudes. 
B) much cooler at the equator than at the south pole because the south pole is tilted almost directly toward the Sun. 
C) much cooler at the south pole than at the equator because the Sun is always close to (or below) the horizon, as seen from the pole of any planet. 
D) almost nonexistent between the equator and the south pole, implying an efficient equator-to-pole circulation pattern.

Question 7

Which of the following statements describes correctly how the atmosphere of Neptune differs from that of Uranus?

Accepted Answer

A) Neptune's atmosphere is almost featureless, whereas the atmosphere of Uranus shows wispy clouds and whirlpool-like vortices. 
B) Methane clouds form in Neptune's atmosphere, but not in that of Uranus, because of Neptune's much greater distance from the Sun. 
C) All parts of Neptune's visible atmosphere rotate at the same speed, whereas different parts of the atmosphere of Uranus rotate differently. 
D) Neptune's atmosphere shows considerable vertical convective motion in addition to east-west circulation, whereas Uranus's atmosphere has very little up-and-down motion. 
A) Neptune's atmosphere is almost featureless, whereas the atmosphere of Uranus shows wispy clouds and whirlpool-like vortices. 
B) Methane clouds form in Neptune's atmosphere, but not in that of Uranus, because of Neptune's much greater distance from the Sun. 
C) All parts of Neptune's visible atmosphere rotate at the same speed, whereas different parts of the atmosphere of Uranus rotate differently. 
D) Neptune's atmosphere shows considerable vertical convective motion in addition to east-west circulation, whereas Uranus's atmosphere has very little up-and-down motion.

Question 8

What does Neptune look like from space?

Accepted Answer

A) blue-green with white, high-altitude clouds and dark storms 
B) perpetually covered with yellowish, sulfur-rich clouds 
C) blue-green and featureless 
D) reddish belts and light zones parallel to the equator 
A) blue-green with white, high-altitude clouds and dark storms 
B) perpetually covered with yellowish, sulfur-rich clouds 
C) blue-green and featureless 
D) reddish belts and light zones parallel to the equator

Question 9

About 100 trans-Neptunian objects are called plutinos because they have what characteristic in common with Pluto?

Accepted Answer

A) They are about the same size as Pluto. 
B) They have nearly the same semimajor axis as Pluto. 
C) They have a large moon like Charon. 
D) They share Pluto's orbit around the Sun. 
A) They are about the same size as Pluto. 
B) They have nearly the same semimajor axis as Pluto. 
C) They have a large moon like Charon. 
D) They share Pluto's orbit around the Sun.

Question 10

How much closer than Neptune was Pluto to the Sun during Pluto's 1989 perihelion passage?

Accepted Answer

A) 1.82 au 
B) Pluto never gets closer to the Sun than Neptune. 
C) 0.23 au 
D) 0.67 au 
A) 1.82 au 
B) Pluto never gets closer to the Sun than Neptune. 
C) 0.23 au 
D) 0.67 au

Question 11

Which trans-Neptunian object has an unusually high albedo of 0.96?

Accepted Answer

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

Question 12

The distance between the orbits of Uranus and Neptune is roughly the same as the distance between:

Accepted Answer

A) the orbits of Jupiter and Saturn. 
B) the orbits of Earth and Uranus. 
C) Jupiter and the Sun. 
D) Saturn and the Sun. 
A) the orbits of Jupiter and Saturn. 
B) the orbits of Earth and Uranus. 
C) Jupiter and the Sun. 
D) Saturn and the Sun.

Question 13

If the orbital period of Uranus is 84 years, its axis tilt is 98°, and its rotational period is about 17 hours, how often will the Sun be at the zenith at the north pole?

Accepted Answer

A) never, because of the extreme tilt of the spin axis to the ecliptic plane 
B) once every 42 years 
C) once every 17 hours 
D) once every 84 years 
A) never, because of the extreme tilt of the spin axis to the ecliptic plane 
B) once every 42 years 
C) once every 17 hours 
D) once every 84 years

Question 14

The idea that Uranus and Neptune formed at their present orbital radii by the accretion of planetesimals has some serious difficulties. One of these is that:

Accepted Answer

A) these planets contain abnormally large amounts of hydrogen and helium, suggesting they were formed further out in the solar system. 
B) we do not expect planetesimals to exist that far out in the early solar system. 
C) evidence from other stars suggests that solar nebulae do not last long enough to form a massive planet at that distance by the accretion of planetesimals. 
D) planetesimals at this distance would be expected to have far more iron than we have postulated for the composition of Uranus and Neptune. 
A) these planets contain abnormally large amounts of hydrogen and helium, suggesting they were formed further out in the solar system. 
B) we do not expect planetesimals to exist that far out in the early solar system. 
C) evidence from other stars suggests that solar nebulae do not last long enough to form a massive planet at that distance by the accretion of planetesimals. 
D) planetesimals at this distance would be expected to have far more iron than we have postulated for the composition of Uranus and Neptune.

Question 15

Neptune was discovered:

Accepted Answer

A) totally by accident. 
B) because of deviations observed in the predicted orbit of Uranus. 
C) when it collided with a bright comet. 
D) by the Hubble Space Telescope (HST). 
A) totally by accident. 
B) because of deviations observed in the predicted orbit of Uranus. 
C) when it collided with a bright comet. 
D) by the Hubble Space Telescope (HST).

Question 16

The densities of the five largest moons of Uranus-about 1500 kg/m3 compared with the value of 3340 kg/m3 for Earth's Moon and 1000 kg/m3 for water ice-suggest a composition of:

Accepted Answer

A) primarily hydrogen and helium, with a slushy core of ice-forming compounds, such as water, methane, and ammonia. 
B) 50% rock and 50% ice-forming compounds, such as water, methane, and ammonia. 
C) 50% rock and 50% pure water ice. 
D) almost entirely water ice, with small amounts of other ice-forming compounds, such as methane and ammonia. 
A) primarily hydrogen and helium, with a slushy core of ice-forming compounds, such as water, methane, and ammonia. 
B) 50% rock and 50% ice-forming compounds, such as water, methane, and ammonia. 
C) 50% rock and 50% pure water ice. 
D) almost entirely water ice, with small amounts of other ice-forming compounds, such as methane and ammonia.

Question 17

If Uranus and Neptune had the same abundance of the elements as Jupiter and Saturn, they would have:

Accepted Answer

A) the same densities as Jupiter and Saturn even though they have smaller masses. 
B) smaller densities than Jupiter and Saturn because density is proportional to mass, implying that smaller masses always have smaller densities. 
C) larger densities than Jupiter and Saturn because density is inversely proportional to volume, implying that smaller volumes always have larger densities. 
D) smaller densities than Jupiter and Saturn because their smaller masses would produce less gravity, and the materials would be compressed less. 
A) the same densities as Jupiter and Saturn even though they have smaller masses. 
B) smaller densities than Jupiter and Saturn because density is proportional to mass, implying that smaller masses always have smaller densities. 
C) larger densities than Jupiter and Saturn because density is inversely proportional to volume, implying that smaller volumes always have larger densities. 
D) smaller densities than Jupiter and Saturn because their smaller masses would produce less gravity, and the materials would be compressed less.

Question 18

Using the best telescopes under the best observing conditions, the smallest angle in the sky that can be resolved from Earth's surface is approximately 0.1 arcsec. (You may wish to review the small-angle formula in Box 1-1 of Universe, 11th ed.) Consequently, the smallest feature that can be resolved at the distance of Uranus is about:

Accepted Answer

A) 1/400 of the diameter of Uranus. 
B) 1/4 of the diameter of Uranus. 
C) 4 times the diameter of Uranus. 
D) 1/40 of the diameter of Uranus. 
A) 1/400 of the diameter of Uranus. 
B) 1/4 of the diameter of Uranus. 
C) 4 times the diameter of Uranus. 
D) 1/40 of the diameter of Uranus.

Question 19

Which object was discovered as a result of the detailed prediction of its position using Newton's gravitational theory to explain deviations in the motions of known planets?

Accepted Answer

A) Pluto 
B) Neptune 
C) Mercury 
D) Saturn 
A) Pluto 
B) Neptune 
C) Mercury 
D) Saturn

Question 20

Uranus lacks an internal source of heat. One consequence of this is that:

Accepted Answer

A) Uranus lacks dynamic atmospheric activity. 
B) it is much colder than Neptune, even though it is closer to the Sun. 
C) the atmosphere is very thin because most of the atmospheric materials lie frozen on the surface. 
D) frozen material on the surface results in a much higher albedo than, say, Neptune. 
A) Uranus lacks dynamic atmospheric activity. 
B) it is much colder than Neptune, even though it is closer to the Sun. 
C) the atmosphere is very thin because most of the atmospheric materials lie frozen on the surface. 
D) frozen material on the surface results in a much higher albedo than, say, Neptune.

Exam 14: Uranus, Neptune, Pluto, and the Kuiper Belt: Remote Worlds

How do the sizes of Pluto and its moon, Charon, compare to that of Earth's Moon?

What is believed to be the basic structure of the interior of Uranus?

What name was given to the first moon of Pluto to be discovered?

How was an atmosphere detected on Triton?

In the sunlit southern hemisphere of Uranus, the observed variation of temperature with latitude is:

Which of the following statements describes correctly how the atmosphere of Neptune differs from that of Uranus?

What does Neptune look like from space?

About 100 trans-Neptunian objects are called plutinos because they have what characteristic in common with Pluto?

How much closer than Neptune was Pluto to the Sun during Pluto's 1989 perihelion passage?

Which trans-Neptunian object has an unusually high albedo of 0.96?

The distance between the orbits of Uranus and Neptune is roughly the same as the distance between:

If the orbital period of Uranus is 84 years, its axis tilt is 98°, and its rotational period is about 17 hours, how often will the Sun be at the zenith at the north pole?

The idea that Uranus and Neptune formed at their present orbital radii by the accretion of planetesimals has some serious difficulties. One of these is that:

Neptune was discovered:

The densities of the five largest moons of Uranus-about 1500 kg/m3 compared with the value of 3340 kg/m3 for Earth's Moon and 1000 kg/m3 for water ice-suggest a composition of:

If Uranus and Neptune had the same abundance of the elements as Jupiter and Saturn, they would have:

Which object was discovered as a result of the detailed prediction of its position using Newton's gravitational theory to explain deviations in the motions of known planets?

Uranus lacks an internal source of heat. One consequence of this is that:

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 I: Our Solar System

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

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

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The densities of the five largest moons of Uranus-about 1500 kg/m³ compared with the value of 3340 kg/m³ for Earth's Moon and 1000 kg/m³ for water ice-suggest a composition of: