chapter 7

Compared to the distance between Earth and Mars, the distance between Jupiter and Saturn is A) about the same. B) much larger. C) much smaller. D) just slightly less.

much larger.

Oceans cover more of Earth's surface than land.

TRUE

The jovian planets have no solid surface.

TRUE

Which jovian planet does not have rings? A) Jupiter B) Neptune C) Uranus D) Mars E) All the jovian planets have rings.

All the jovian planets have rings.

The more massive planets in the solar system tend to be less dense than the lower mass planets.

TRUE

How is Einstein's famous equation, E= mc2, important in understanding the Sun? A) It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each day. B) It explains why the Sun's surface temperature is about 6,000°C. C) It explains why the Sun is so massive. D) It explains why the Sun has a magnetic field strong enough influence the atmospheres of the planets.

It explains the fact that the Sun generates energy to shine by losing some 4 million tons of mass each day.

Which of the following best describes Pluto in terms of the general characteristics of terrestrial and jovian planets? A) size and density similar to terrestrial planets; distance and composition similar to jovian planets B) size and solid surface similar to terrestrial planets; distance similar to jovian planets C) size and distance similar to terrestrial planets; gaseous surface and composition similar to jovian planets D) solid surface and density similar to terrestrial planets; temperature and composition similar to jovian planets E) solid surface and temperature similar to terrestrial planets; distance and density similar to jovian planets

size and solid surface similar to terrestrial planets; distance similar to jovian planets

Mars has two moons that are most similar in character to A) small asteroids. B) comets. C) Earth's Moon. D) particles in the rings of Saturn.

small asteroids.

Astronomers have decided that, rather than being a planet, Pluto is really just a large member of A) the asteroid belt. B) the Kuiper belt. C) the Oort cloud. D) the moon system around Neptune. E) an extrasolar planetary system.

the Kuiper belt.

Which moons are sometimes called the Galilean moons? A) the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto B) the two largest moons in the solar system: Ganymede and Titan C) the moons that orbit their planet "backward" compared to their planet's rotation, such as Neptune's moon Triton D) the moons orbiting Uranus, which was once named "planet Galileo"

the four largest moons of Jupiter: Io, Europa, Ganymede, and Callisto

Which of the following is not an exception to the general patterns in the solar system? A) the counterclockwise rotation of Venus B) the large size of Earth's Moon C) the rings of Saturn D) the extreme axis tilt of Uranus E) the retrograde rotation of Triton around Neptune

the rings of Saturn

Suppose you view the solar system from high above Earth's North Pole. Which of the following statements about planetary orbits will be true? A) All the planets orbit counterclockwise around the Sun. B) The inner planets orbit the Sun counterclockwise while the outer planets orbit the Sun clockwise. C) All the planets except Uranus orbit the Sun counterclockwise; Uranus orbits in the opposite direction. D) The inner planets orbit the Sun clockwise while the outer planets orbit the Sun counterclockwise

All the planets orbit counterclockwise around the Sun.

How do asteroids differ from comets? A) Asteroids are rocky bodies and are denser than the comets, which are made of icy material. B) Asteroids are rocky bodies and are less dense than the comets, which are made of icy material. C) Asteroids are made of icy material and are denser than the comets, which are more rocky. D) Asteroids are made of icy material and are less dense than the comets, which are rockier. E) Asteroids and comets are both made of rocky and icy material, but asteroids are smaller in size than comets.

Asteroids are rocky bodies and are denser than the comets, which are made of icy material.

Which of the following is not a real difference between asteroids and comets? A) Asteroids orbit the Sun while comets just float randomly around in the Oort cloud. B) Most asteroids are located much nearer to the Sun than most comets. C) It is thought that comets are far more numerous than asteroids. D) Asteroids are made mostly of rock and comets are made mostly of ice.

Asteroids orbit the Sun while comets just float randomly around in the Oort cloud.

In what way is Venus most similar to Earth? A) Both planets are nearly the same size. B) Both planets have very similar atmospheres. C) Both planets have similar surface geology. D) Both planets have warm days and cool nights.

Both planets are nearly the same size

Which is the densest planet in the solar system? A) Mercury B) Venus C) Earth D) Mars E) Jupiter

Earth

Why was it advantageous for the Voyager mission to consist of flybys rather than orbiters? A) Spacecraft making flybys can return to Earth more quickly than orbiters. B) Each individual spacecraft was able to visit more than one planet. C) It was easier for data to be radioed back to Earth with flybys than orbiters. D) Flyby spacecraft can get closer to a planet than an orbiting spacecraft.

Each individual spacecraft was able to visit more than one planet.

All comets orbit the Sun in the same direction as the planets.

FALSE

All the planets in the solar system have at least one moon.

FALSE

The planet Uranus held a special place in the mythology of the ancient Romans.

FALSE

In what way is Pluto more like a comet than a planet? A) It sometimes enters the inner solar system. B) It has a long tail. C) It is made mostly of rock and ice. D) It has a moon.

It is made mostly of rock and ice.

Imagine that an alien spaceship crashed onto Earth. Which statement would most likely be true? A) The aliens' home world is another planet in our own solar system. B) The crash would create a noticeable crater. C) All the evidence of the crash would be quickly whisked off by the U.S. military to Area 51 in Nevada. D) It would crash in the ocean.

It would crash in the ocean.

Which planet (besides Earth) has been visited by the largest number of robotic spacecraft? A) Jupiter B) Venus C) Mars D) Saturn

Mars

Which planet listed below has the most extreme seasons? A) Uranus B) Mars C) Earth D) Jupiter

Uranus

The planet in our solar system with the highest average surface temperature is A) Venus. B) Mercury. C) Earth. D) Neptune.

Venus.

Which planet has a ring system? A) Jupiter B) Saturn C) Uranus D) Neptune E) all of the above

all of the above

The Cassini mission to Saturn consists of A) an orbiter that orbits Saturn and a probe that descended to the surface of Titan. B) a large spacecraft that flew by Saturn on its way to other planets. C) an orbiter that orbits Saturn and a probe that descended into Saturn's atmosphere. D) a spacecraft that orbits Saturn and a sample return mission that landed on Titan, scooped up a surface sample, and will return it to Earth.

an orbiter that orbits Saturn and a probe that descended to the surface of Titan.

Based on the frequency with which we see comets from Earth, astronomers estimate the total number of comets in the solar system to be A) 100 million. B) 1 billion. C) 10 billion. D) 100 billion. E) 1 trillion.

1 trillion.

Which of the following is not true of Mercury? A) It has been studied closely by several NASA spacecraft. B) At any given time, about half the planet is colder than Antarctica. C) Its surface is heavily cratered. D) Mercury has essentially no atmosphere.

It has been studied closely by several NASA spacecraft

How does the Sun's mass compare with that of the planets? A) It is a hundred times more massive than Earth. B) It is a thousand times more massive than Earth. C) It is a hundred times more massive than all the planets combined. D) It is a thousand times more massive than all the planets combined. E) It is about as massive as all the planets combined.

It is a thousand times more massive than all the planets combined.

What is the Oort cloud? A) It is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances. B) It is another name for the cloud of gas from which our solar system was born. C) It is a great cloud of gas that resides far beyond the orbit of Pluto. D) It is a giant storm in the atmosphere of Saturn.

It is not really a cloud at all, but rather refers to the trillion or so comets thought to orbit the Sun at great distances.

Which of the following statements about Pluto is not true? A) It has more in common with comets in the Kuiper belt than it does with the jovian planets. B) It is orbited by at least three moons. C) Its mass is less than 1% of Earth's mass. D) It is the largest known object that is considered to be a dwarf planet.

It is the largest known object that is considered to be a dwarf planet.

Which of the following statements about the recently-discovered object Eris is not true? A) It is slightly larger than Pluto. B) It lies well beyond Pluto and Neptune. C) It is thought to be the first example of a new class of object. D) It orbits the Sun in the same direction as the other planets.

It is thought to be the first example of a new class of object.

Why has NASA sent recent orbiters to Mars on trajectories that required them to skim through Mars's atmosphere ("aerobraking") before settling into their final orbits? A) It saved money because the spacecraft used atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines. B) It allowed the orbiters to get higher resolution pictures of the surface as it came close when skimming through the atmosphere. C) It allowed the spacecraft to collect samples of the atmospheric gas for return to Earth. D) Each spacecraft also carried a lander, and the lander could only be dropped to the Martian surface when the spacecraft passed through the atmosphere.

It saved money because the spacecraft used atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines.

luto is different from the outer planets in all of the following ways except which one? A) Its surface temperature is very cold. B) It is made mostly of ices. C) Its orbit is not very close to being circular. D) It has few moons. E) It doesn't have rings.

Its surface temperature is very cold.

The jovian planets in our solar system are A) Mercury, Venus, Earth, and Mars. B) Jupiter, Saturn, Uranus, Neptune, Pluto, and Eris. C) Jupiter, Saturn, Uranus, and Neptune. D) Io, Europa, Ganymede, and Callisto.

Jupiter, Saturn, Uranus, and Neptune.

Which planet, other than Earth, has visible water ice on it? A) Mercury B) Venus C) the Moon D) Mars E) Jupiter

Mars

The terrestrial planets in our solar system are A) Mercury, Venus, Earth, and Mars. B) Jupiter, Saturn, Uranus, and Neptune. C) Mercury, Venus, Earth, Mars, and Pluto. D) Jupiter, Saturn, Uranus, Neptune, Pluto, and Eris.

Mercury, Venus, Earth, and Mars.

The most metal-rich terrestrial planet is A) Mercury. B) Venus. C) Earth. D) the Moon. E) Mars.

Mercury.

Which of the following statements is not an observed pattern of motion in our solar system? A) Most planets orbit at the same speed. B) All planets orbit the Sun in the same direction. C) Most planetary orbits lie nearly in the same plane. D) Most planets rotate in the same direction in which they orbit. E) Almost all moons orbit their planet in the same direction as the planet's rotation.

Most planets orbit at the same speed.

Which of the following is not a major pattern of motion in the solar system? A) Nearly all comets orbit the Sun in same direction and roughly the same plane. B) Most of the solar system's large moons orbit in their planet's equatorial plane. C) The Sun and most of the planets rotate in the same direction in which the planets orbit the Sun. D) All of the planets orbit the Sun in the same direction—counterclockwise as viewed from above Earth's north pole.

Nearly all comets orbit the Sun in same direction and roughly the same plane.

Which of the following is not a pattern of motion in our solar system? A) Planets all orbit in the same direction. B) Planets all rotate in the same direction. C) Planets all orbit the same direction as the Sun's spin. D) Large planets all have many moons orbiting them.

Planets all rotate in the same direction.

Which of the following is not an advantage of spacecraft flybys over ground-based telescope observations? A) Spacecraft can sample the gravitational field of a planet. B) Spacecraft can view "backlit" views of planetary rings. C) Spacecraft can measure local magnetic fields. D) Spacecraft can monitor changes in a planet's atmosphere over long times. E) Spacecraft can make highly detailed images of the planet and its moons.

Spacecraft can monitor changes in a planet's atmosphere over long times.

All four of the giant outer planets-Jupiter, Saturn, Uranus, and Neptune-have rings.

TRUE

All planets orbit the Sun in the same direction (counterclockwise as viewed from above Earth's North Pole).

TRUE

Which of the following is not a major difference between the terrestrial and jovian planets in our solar system? A) Terrestrial planets contain large quantities of ice and jovian planets do not. B) Terrestrial planets orbit much closer to the Sun than jovian planets. C) Terrestrial planets are higher in average density than jovian planets. D) Jovian planets have rings and terrestrial planets do not.

Terrestrial planets contain large quantities of ice and jovian planets do not.

Consider the following statement: "Rocky asteroids are found primarily in the asteroid belt and Kuiper belt while icy comets are found primarily in the Oort cloud." What's wrong with this statement? A) Asteroids are not made of rock. B) Comets are not icy. C) The Kuiper belt contains icy comets, not rocky asteroids. D) The Oort cloud has nothing to do with comets. E) The statement is accurate as written.

The Kuiper belt contains icy comets, not rocky asteroids.

Which of the following statements about our Sun is not true? A) The Sun is a star. B) The Sun's diameter is about 5 times that of Earth. C) The Sun contains more than 99% of all the mass in our solar system. D) The Sun is made mostly of hydrogen and helium.

The Sun's diameter is about 5 times that of Earth.

Which of the following statements about the asteroid belt is not true? A) The combined mass of all the asteroids is roughly the same as the mass of Earth. B) It is located between the orbits of Mars and Jupiter. C) Asteroids in the asteroid belt orbit the Sun in the same direction that planets orbit the Sun. D) Asteroids in the asteroid belt are made mostly of rock.

The combined mass of all the asteroids is roughly the same as the mass of Earth.

The following statements are all true. Which one counts as an "exception to the rule" in being unusual for our solar system? A) Venus does not have a moon. B) Jupiter has a very small axis tilt. C) Saturn has no solid surface. D) The diameter of Earth's Moon is about 1/4 that of Earth.

The diameter of Earth's Moon is about 1/4 that of Earth.

What is the primary reason why a Pluto flyby mission would be cheaper than a Pluto orbiter? A) The flyby can use less expensive cameras than the orbiter. B) The flyby is easier to design than the orbiter. C) The fuel needed for an orbiter to slow down when it reaches Pluto is very expensive in and of itself. D) The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft. E) The question is incorrect; in general, orbiters are cheaper than flybys.

The fuel needed for an orbiter to slow down when it reaches Pluto adds a lot of weight to the spacecraft.

Which of the following observations indicates that conditions on Mars may have been suitable for life in the past? A) There are very large extinct volcanoes on Mars. B) There is a very deep and long canyon that extends across Mars. C) There are dried-up riverbeds on Mars. D) Mars has polar caps made of "dry ice." E) Mars has two small moons.

There are dried-up riverbeds on Mars.

Which of the following is not a characteristic of the inner planets? A) They are relatively smaller than the outer planets. B) They all have solid, rocky surfaces. C) Their orbits are relatively closely spaced. D) They all have substantial atmospheres. E) They have very few, if any, satellites.

They all have substantial atmospheres.

Which of the following is not a characteristic of the outer planets? A) They have very few, if any, satellites. B) They are all large balls of gas. C) They are primarily made of hydrogen and helium. D) Their orbits are separated by relatively large distances. E) They all have rings.

They have very few, if any, satellites.

The planet closest in size to Earth is A) Mercury. B) Venus. C) the Moon. D) Mars. E) Pluto.

Venus

Which planet has the highest average surface temperature, and why? A) Mercury, because it is closest to the Sun B) Mercury, because of its dense carbon dioxide atmosphere C) Venus, because of its dense carbon dioxide atmosphere D) Mars, because of its red color E) Jupiter, because it is so big

Venus, because of its dense carbon dioxide atmosphere

Which of the following statements about Mars is not true? A) We have landed spacecraft on its surface. B) It is considered part of our inner solar system. C) We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks. D) It is frozen today, but once had flowing water.

We could survive on Mars without spacesuits, as long as we brought oxygen in scuba tanks.

Which of the following is farthest from the Sun? A) Pluto B) Neptune C) an asteroid in the asteroid belt D) a comet in the Kuiper belt E) a comet in the Oort cloud

a comet in the Oort cloud

What is the Kuiper belt? A) a region of the solar system that extends almost a fourth of the way to the nearest stars and contains a trillion comets with orbits going in all directions around the Sun B) a technical name for the asteroid belt C) the most prominent ring of Saturn that is visible in photographs D) a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets

a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets

Venus has a higher average surface temperature than Mercury. Why? A) because it is closer to the Sun B) because its surface is heated by an extreme greenhouse effect C) because its surface is covered with hot lava from numerous active volcanoes D) because its slow rotation gives it more time to heat up in sunlight

because its surface is heated by an extreme greenhouse effect

Where are most of the known asteroids found? A) between the orbits of Mars and Jupiter B) in the Kuiper belt C) in the Oort cloud D) between the orbits of the jovian planets E) between the orbits of the terrestrial planets

between the orbits of Mars and Jupiter

When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals except A) water. B) carbon dioxide. C) ammonia. D) methane.

carbon dioxide.

What are the main constituents of the jovian planets? A) rocky minerals and water, as on Earth B) hydrogen and helium C) ammonia and methane D) ammonia and water E) nitrogen and methane

hydrogen and helium

Where does nuclear fusion occur in the Sun? A) on the surface B) anywhere below the surface C) in its core D) just above the visible surface E) all of the above

in its core

What is aerobraking? A) the technique of using a planetary atmosphere to change the orbit of a spacecraft B) the use of a planetary atmosphere to redirect a spacecraft to another planet C) the controlled landing of a spacecraft on a planetary surface D) the gradual decrease of speed as a spacecraft leaves the solar system E) the destruction of a spacecraft by the intense pressure as it descends into the atmosphere

the technique of using a planetary atmosphere to change the orbit of a spacecraft