Chapter 6-9
An icy leftover planetesimal orbiting the Sun is A) a comet. B) a meteor. C) an asteroid. D) a meteorite. E) possibly any of the above
A
From where did the oxygen in the Earth's atmosphere originate? A) photosynthesis from plant life and single-celled organisms B) chemical reactions between gas in the upper atmosphere and the solar wind C) outgassing from volcanoes D) atmospheric bombardment E) oxidation of surface rocks
A
How do asteroids differ from comets? A) Asteroids are made of rocky material. Comets are made of icy material. B) Asteroids are made of icy material. Comets are made of rocky material. C) Asteroids and comets are both made of rocky and icy material, but asteroids are larger in size than comets. D) Asteroids and comets are both made of rocky and icy material, but asteroids are smaller in size than comets.
A
How do the jovian planet interiors differ? A) All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium. B) The core mass decreases with the mass of the planet. C) The composition changes from mostly ammonia in Jupiter and Saturn to mostly methane in Uranus and Neptune. D) The composition changes from mostly hydrogen in Jupiter and Saturn to mostly helium in Uranus and Neptune. E) All have about the same amount of hydrogen and helium but the proportion of rocks is greater in those planets closer to the Sun.
A
If a major asteroid collision in the asteroid belt occurs, on average, 1 time in 100,000 years, then how many major collisions have occurred over the approximately 4 billion year history of the solar system? A) about 40,000 B) about 4 million C) about 4 billion D) about 4,000
A
If all the asteroids were gathered into a single object, it would make an object A) about half the diameter of Earth's moon. B) about the size of Earth's moon. C) about the size of the Earth. D) with enough mass to gather hydrogen and helium and become a gas giant.
A
Pluto is different from the other 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 only one moon. E) It doesn't have rings.
A
Primitive meteorites can be distinguished from other meteorites and terrestrial rocks because they A) contain a noticeable fraction of pure metallic flakes. B) resemble the composition of Earth's core. C) contain a lot of iron and were used by humans to make iron tools. D) resemble the composition of Earth's mantle. E) resemble the composition of rocks from lava flows that occurred on asteroids very shortly after the formation of the solar system.
A
Spacecraft have landed on all the terrestrial worlds except A) Mercury. B) Venus. C) Moon. D) Mars.
A
Suppose Earth's atmosphere had no greenhouse gases. Then Earth's average surface temperature would be A) -16°C, which is well below freezing. B) 0°C, or about the freezing point for water. C) 10°C or about 5°C cooler than it is now. D) 15°C, or about the same as it is now. E) 20°C, or about 5°C warmer than it is now.
A
The Galileo spacecraft dropped a probe into Jupiter's atmosphere that survived 200 km, or 0.3% of Jupiter's radius. Which is the deepest layer that this probe was able to directly sample? A) gaseous hydrogen layer B) liquid hydrogen layer C) metallic hydrogen layer D) rocky core
A
The greenhouse effect makes Earth warmer than it would be otherwise by about A) 30 K. B) 15 K. C) -16 K. D) There is no greenhouse effect.
A
Why does Mars have more extreme seasons than Earth? A) because it is farther from the Sun B) because it has a larger axis tilt C) because it has a more eccentric orbit D) because it has more carbon dioxide in its atmosphere E) all of the above
C
What do asteroids and comets have in common? A) Most are unchanged since their formation in the solar nebula. B) They have similar densities. C) They have similar orbital radii. D) They have a similar range of orbital inclinations. E) They have nothing in common with each other.
A
What drives the motion of the continental plates on Earth? A) convection cells in the mantle B) rotation of the liquid core C) lava flows in trenches along the sea floor D) Earth's magnetic field E) tidal forces
A
What evidence led astronomers to conclude that the Oort cloud is a spherical distribution of comets? A) the observation that comets enter the solar system from random directions B) direct observation of comets orbiting the sun in the Oort cloud C) Astronomers did not draw that conclusion; the Oort cloud is shaped like a flat ring in the same plane as the planets.
A
What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size? A) Ice has a lower melting point than rock. B) Ice is less rigid than rock. C) Ice contains more radioactive elements than rock. D) Ice is affected by tidal forces to a greater extent than rock. E) Ice is less dense than rock.
A
What lucky factor prevented the Chelyabinsk object from causing much damage at ground level? A) It hit Earth at an oblique angle and thus exploded high in the air. B) It was made entirely of ices and thus exploded high in the air. C) A prototype asteroid defense system was being tested nearby.
A
What would be the approximate radius of a hydrogen/helium planet with a mass one-tenth that of Jupiter? A) about 0.7 times the radius of Jupiter B) about 0.5 times the radius of Jupiter C) about 1 time the radius of Jupiter D) about 0.9 times the radius of Jupiter
A
Where did comets that are now in the Oort cloud originally form? A) near the jovian planets B) outside Neptune's orbit C) inside Jupiter's orbit D) within the solar nebula, but far outside the orbit of Pluto E) all of the answers
A
Which of the following best describes the composition of the particles forming Saturn's rings? A) water ice B) metallic grains C) methane ice D) volcanic rock E) hydrogen and helium
A
Which of the following is not a characteristic of the outer planets? A) They have very few, if any, satellites. B) They all have large quantities 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.
A
Which of the following lists the ingredients of the solar nebula from highest to lowest percentage of mass of the nebula? A) light gases, H, He, hydrogen compounds, H2O, CH4, NH3, rocks, metals B) hydrogen compounds, H2O, CH4, NH3, light gases, H, He, rocks, metals C) light gases, H, He, hydrogen compounds, H2O, CH4, NH3, metals, rocks D) hydrogen compounds, H2O, CH4, NH3, light gases, H, He, metals, rocks E) hydrogen compounds, H2O, CH4, NH3, rocks, metals, light gases, H, He
A
Why aren't small asteroids spherical in shape? A) The strength of gravity on small asteroids is less than the strength of the rock. B) Small asteroids have odd shapes because they were all chipped off larger objects. C) Large asteroids were once molten and therefore became spherical, but small asteroids were never molten. D) Large asteroids became spherical because many small collisions chipped off pieces until only a sphere was left; this did not occur with small asteroids.
A
Why do asteroids and comets differ in composition? A) Asteroids formed inside the frost line, while comets formed outside. B) Asteroids and comets formed at different times. C) Comets formed from the jovian nebula, while asteroids did not. D) Comets are much larger than asteroids. E) Asteroids are much larger than comets.
A
Why do we sometimes observe asteroids at the distances of the gaps in the asteroid belt? A) A gap is located at an average orbital distance, and asteroid orbits often have large eccentricities. B) Jupiter's gravitational tugs keep them there. C) They are held in place by resonances with other asteroids. D) They are kept in place by shepherding asteroids. E) Actually, we never see asteroids in the gaps.
A
Why does the plasma tail of a comet always point away from the Sun? A) The solar wind blows the plasma ions directly away from the Sun. B) Radiation pressure from the Sun's light pushes the ions away. C) The conservation of the angular momentum of the tail keeps it always pointing away from the Sun. D) Gases from the comet, heated by the Sun, push the tail away from the Sun. E) It is allergic to sunlight.
A
Why was the Shoemaker-Levy 9 impact so important to astronomers? A) It dredged up material that gave us our first direct look at Jupiter's interior composition. B) It wiped out the dinosaurs. C) It was the first direct proof that impacts really occur. D) It confirmed our theory of solar system formation. E) It was the first event in modern history that was brighter than the full moon in the sky.
A
According to our theory of solar system formation, why do we find some exceptions to the general rules and patterns of the planets? A) Our theory is not quite correct because it cannot explain these exceptions. B) Most of the exceptions are the result of giant impacts or close gravitational encounters. C) The exceptions probably represent objects that formed recently, rather than early in the history of the solar system. D) The exceptions probably represent objects that were captured by our solar system from interstellar space. E) The exceptions exist because, even though our theory is as correct as possible, nature never follows rules precisely.
B
Astronomers now classify Pluto as 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.
B
Kirkwood gaps in the asteroid belt occur at distances where A) the density of asteroids is high enough for a large collision to pulverize a number of asteroids. B) the period of an orbiting asteroid would be a simple fraction (like 1/3 or 1/4) of Jupiter's orbital period. C) the period of an orbiting asteroid would be the same as Jupiter's orbital period. D) the period of an orbiting asteroid would be the same as Mars's orbital period. E) the orbit would take the asteroid beyond the "frost line" in the solar system.
B
The greatest number of asteroids are found A) between 1 and 2 AU from the sun. B) between 2 and 3 AU from the sun. C) between 3 and 4 AU from the sun. D) between 4 and 5 AU from the sun.
B
The planet closest in size to Earth is A) Mercury. B) Venus. C) the Moon. D) Mars. E) Pluto.
B
The relatively few craters that we see within the lunar maria A) were formed by impacts that occurred before those that formed most of the craters in the lunar highlands. B) were formed by impacts that occurred after those that formed most of the craters in the lunar highlands. C) were created by the same large impactor that led to the formation of the maria. D) are volcanic in origin, rather than from impacts. E) are sinkholes that formed when sections of the maria collapsed.
B
The three principal sources of the internal heat of terrestrial planets are A) conduction, differentiation, and accretion. B) accretion, differentiation, and radioactivity. C) accretion, differentiation, and eruption. D) convection, differentiation, and eruption. E) conduction, convection, and eruption.
B
What happened to the "Impactor" of the Deep Impact mission? A) It landed safely on the surface of the comet and returned material to Earth. B) It created a small crater on the comet. C) It blasted straight through the comet leaving a small hole. D) It blasted the comet apart, thus preventing a potential Earth collision. E) It missed the comet altogether.
B
What is the Cassini division of Saturn's rings? A) a dark ring, visible from Earth, composed of dark, dusty particles B) a large gap, visible from Earth, produced by an orbital resonance with the moon Mimas C) the imaginary circle marking the halfway point of Saturn's rings D) the widest ring of Saturn, located between two large ring gaps E) the most opaque ring of Saturn, made of highly reflective ice particles
B
What is the most abundant gas in Titan's atmosphere? A) methane B) nitrogen C) hydrogen compounds D) oxygen E) argon
B
What kind of material in the solar nebula could remain solid at temperatures as high as 1,500 K, such as existed in the inner regions of the nebula? A) rocks B) metals C) silicon-based minerals D) hydrogen compounds E) molecules such as methane and ammonia
B
What was the Stardust mission? A) a mission to study the composition of an asteroid by hitting it with a massive object and observing the material thrown into space B) a mission to study the composition of a comet by collecting material from its tail and return that material to Earth C) a mission to study the outer planets of the solar system by sending a probe from one to the next with a wide variety of instruments D) a mission to study the surface structure of a comet by dropping a lander onto its surface
B
Where are the Trojan asteroids located? A) surrounding Jupiter B) along Jupiter's orbit, 60° ahead of and behind Jupiter C) in the center of the asteroid belt D) on orbits that cross Earth's orbit E) on orbits that cross Mars's orbit
B
Where is Jupiter's strong magnetic field generated? A) rocky core B) metallic hydrogen layer C) liquid hydrogen layer D) gaseous hydrogen layer E) cloud tops
B
Which of the following most likely explains why Venus does not have a strong magnetic field? A) It does not have a metallic core. B) Its rotation is too slow. C) It is too close to the Sun. D) It is too large. E) It has too thick an atmosphere.
B
Which of the following statements about comets and asteroids is true? A) Only asteroids collide with Earth. B) Comets are balls of ice and dust. C) Most of the trillions of comets in our solar system have tails. D) All asteroids lie in the asteroid belt between Mars and Jupiter. E) There are about 1 million known asteroids in the solar system.
B
Which of the following worlds has the most substantial atmosphere? A) Mercury B) Venus C) the Moon D) Mars E) Earth
B
Why did the solar nebula heat up as it collapsed? A) Nuclear fusion occurring in the core of the protosun produced energy that heated the nebula. B) As the cloud shrank, its gravitational potential energy was converted to thermal energy. C) Radiation from other nearby stars that had formed earlier heated the nebula. D) The shock wave from a nearby supernova heated the gas. E) Collisions among planetesimals generated friction and heat.
B
Why do we think Mercury has so many tremendous cliffs? A) They were probably carved in Mercury's early history by running water. B) They were probably formed by tectonic stresses when the entire planet shrank as its core cooled. C) They probably formed when a series of large impacts hit Mercury one after the other. D) They are almost certainly volcanic in origin, carved by flowing lava. E) They represent one of the greatest mysteries in the solar system, as no one has suggested a reasonable hypothesis for their formation.
B
Why is Jupiter denser than Saturn? A) It is made of a different composition than Saturn, including a higher proportion of hydrogen compounds and rocks. B) The extra mass of Jupiter compresses its interior to a greater extent than that of Saturn. C) Its core is much larger than Saturn's. D) It has a greater proportion of helium to hydrogen compared to Saturn. E) Scientists do not know why this is so.
B
The age of the solar system can be established by radioactive dating of A) the oldest rocks on Earth. B) the oldest rocks on the Moon. C) the oldest meteorites. D) the atmosphere of Mars. E) It hasn't been done yet, but the age of the solar system could be obtained from a sample of Io's surface.
C
A rocky leftover planetesimal orbiting the Sun is A) a comet. B) a meteor. C) an asteroid. D) a meteorite. E) possibly any of the above
C
How do asteroids appear in long exposure images? A) as points of light, like the stars B) as resolved disks, like the planets C) as straight lines across a background of stars D) as complex curving and looping lines
C
How frequently do objects that threaten widespread devastation hit the Earth? A) about once every year B) about once every thousand years C) about once every million years D) about once every hundred million years
C
Mars' atmosphere is mostly carbon-dioxide. Why does it not experience a runaway greenhouse effect like Venus? A) It is protected by its magnetic field. B) It does not have enough additional water to magnify the warming. C) Its atmosphere is too thin.
C
Processed meteorites with high metal content probably are A) leftover chunks of rock from the earliest period in the formation of the solar system. B) pieces of comets rather than of asteroids. C) chunks of the core of a larger asteroid that was shattered by a collision. D) chunks of rock chipped off the planet Mercury. E) chunks of rock chipped off the planet Mars.
C
The nebular theory of the formation of the solar system successfully predicts all but one of the following. Which one does the theory not predict? A) Planets orbit around the Sun in nearly circular orbits in a flattened disk. B) the compositional differences between the terrestrial and jovian planets C) the equal number of terrestrial and jovian planets D) the presence of asteroids and comets E) the craters on the Moon
C
The terrestrial planet cores contain mostly metal because A) the entire planets are made mostly of metal. B) metals condensed first in the solar nebula and the rocks then accreted around them. C) metals sank to the center during a time when the interiors were molten throughout. D) radioactivity created metals in the core from the decay of uranium. E) convection carried the metals to the core.
C
Volcanism is more likely on a planet that A) is closer to the Sun. B) is struck often by meteors and solar system debris. C) has high internal temperatures. D) doesn't have an atmosphere or oceans.
C
What do astronomers mean when they refer to "gaps" in the asteroid belt between Mars and Jupiter? A) There are very few asteroids with diameters between 1 and 100 kilometers, creating a "gap" in the size distribution. B) Asteroids typically cluster together and this creates "gaps" on the sky. C) Asteroids seem to avoid certain orbits around the Sun, creating "gaps" in the orbits that asteroids can have. D) There is a large population of asteroids too faint to see called the "gap" asteroids. E) There are either pure metal or pure rock asteroids, but no mixtures. Thus there is a "gap" in the composition of asteroids.
C
What is Tunguska? A) a postulated binary companion to the Sun thought to be responsible for mass extinctions B) a long period comet that struck Jupiter in 1994 C) the site of an asteroid impact that occurred in Siberia in 1908 D) the Gulf of Mexico basin that is the crater of the asteroid impact that caused the mass extinction of the dinosaurs 65 million years ago E) a newly discovered moon of Pluto
C
What is a meteorite? A) a streak of light caused by a star moving across the sky B) a streak of light caused by a small particle from space burning up in Earth's atmosphere C) a fragment of an asteroid from the solar system that has fallen to Earth's surface D) a small moon that orbits one of the giant planets E) a comet that burns up in Earth's atmosphere
C
Where did the elements heavier than hydrogen and helium come from? A) They were produced in the Big Bang. B) They evolved from hydrogen and helium shortly after the Big Bang. C) They were produced inside stars. D) They were produced inside dense interstellar gas. E) All of the above
C
What is the approximate diameter of the largest asteroid? A) 1 km B) 10 km C) 100 km D) 1,000 km E) 10,000 km
D
Which of the following describes tectonics? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
C
Which of the following is not a product of outgassing? A) water B) nitrogen C) oxygen D) carbon dioxide
C
Which of the following is not an exception to the general patterns of motion 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 "backward" orbit of Triton around Neptune
C
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.
C
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
C
Why do Uranus and Neptune appear blue? A) Gas molecules in their atmosphere preferentially scatter blue light. B) Methane snowflakes absorb all colors except blue, which they reflect. C) Methane gas absorbs all colors except blue. D) Small dust grains preferentially scatter blue light.
C
Why do the jovian planet interiors differ? A) The more distant planets formed in a cooler region of the solar nebula and therefore contain a greater proportion of ices than the closer jovian planets. B) They differ due to giant impacts at the late stages of planet formation. C) Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets. D) The more distant planets had longer to form than the closer planets, since the solar nebula lasted longer at greater distances from the Sun.
C
Meteorites can come from A) the cores of asteroids. B) the crusts and mantles of asteroids. C) the Moon. D) Mars. E) all of the answers
E
A typical shooting star in a meteor shower is caused by a ________ entering Earth's atmosphere. A) boulder-size particle from an asteroid B) boulder-size particle from a comet C) pea-size particle from an asteroid D) pea-size particle from a comet E) microscopic particle of interstellar dust
D
According to the nebular theory, how did the asteroid belt form? A) It is material left over from the interstellar cloud that never contracted with the rest of the gases to form the solar nebula. B) It is made of planetesimals that formed beyond Neptune's orbit and never accreted to form a planet. C) It consists of objects that fragmented from the protosun during a catastrophic collision early in the formation of the solar system. D) It is made of planetesimals between the orbits of Mars and Jupiter that never formed into a planet. E) It is made of planetesimals formed in the outer solar system that were flung into distant orbits by encounters with the jovian planets.
D
How do the size and mass of Jupiter's core compare to the size and mass of Earth? A) It is the same size and mass. B) It is about 10 times larger both in size and mass. C) It is about 10 times larger in size and the same mass. D) It is about the same size but is 10 times more massive. E) Jupiter doesn't have a core—it is made entirely from hydrogen and helium.
D
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.
D
On average, how often do impacts large enough to produce mass extinction on the Earth occur? A) once every century B) once every thousand years C) once every million years D) once every hundred million years E) once in Earth's history
D
Planetary rings are A) orbiting in the equatorial plane of their planet. B) composed of a large number of individual particles that orbit their planet in accord with Kepler's third law. C) known to exist for all of the jovian planets. D) all of the answers
D
The large Jovian satellites have sizes comparable to Mercury. Why do they have an icy composition compared to Mercury's rocky composition? A) They are captured comets. B) They formed from hydrogen compounds expelled by the Jovian planets. C) They experienced many more cometary impacts during the Late Heavy Bombardment. D) They formed beyond the frost line, where ices were three to four times more abundant than metals and rock.
D
What are the conditions necessary for a terrestrial planet to have a strong magnetic field? A) a molten metallic core only B) fast rotation only C) a rocky mantle only D) both a molten metallic core and reasonably fast rotation E) both a metal core and a rocky mantle1
D
What do meteorites reveal about the solar system? A) They reveal that meteorites are much older than the comets and planets. B) Nothing, because they come from other star systems. C) They reveal that the solar system once contained 10 planets. D) They reveal that the age of the solar system is approximately 4.6 billion years. E) They reveal that the early solar system consisted mostly of hydrogen and helium gas.
D
What mechanism is most responsible for generating the internal heat of Io that drives its volcanic activity? A) accretion B) radioactive decay C) differentiation D) tidal heating E) bombardment
D
What part of a comet always points most directly away from the Sun? A) the nucleus B) the coma C) the jets of gas D) the plasma tail E) the dust tail
D
Which internal energy source produces heat by converting gravitational potential energy into thermal energy? A) accretion B) differentiation C)radioactivity D) both a and b. E) all of the above
D
Which of the following are evidence for an asteroid impact being the cause of the extinction of the dinosaurs 65 million years ago (as well as 75% of all species alive at the time)? A) a worldwide layer of the element iridium in 65 million year old rocks B) a buried crater more than 100 km across in the Gulf of Mexico C) no dinosaur fossils being present in rocks younger than 65 million years old D) all of the answer
D
Which of the following are relatively unchanged fragments from the early period of planet building in the solar system? A) asteroids B) Kuiper belt comets C) Oort cloud comets D) all of the above
D
Which of the following can act like a long-term "thermostat" for the Earth's average temperature? A) radioactive elements trapped in the Earth's mantle B) heat stored in the Earth's magnetosphere C) heat stored in the Earth's liquid core D) the carbon dioxide cycle
D
Which of the following describes erosion? A) the excavation of bowl-shaped depressions by asteroids or comets striking a planet's surface B) the eruption of molten rock from a planet's interior to its surface C) the disruption of a planet's surface by internal stresses D) the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather
D
Why did the solar nebula flatten into a disk? A) The interstellar cloud from which the solar nebula formed was originally somewhat flat. B) The force of gravity pulled the material downward into a flat disk. C) As the nebula cooled, the gas and dust settled onto a disk. D) It flattened as a natural consequence of collisions between particles in the nebula, changing random motions into more orderly ones.
D
How do astronomers think Jupiter generates its internal heat? A) radioactive decay B) internal friction due to its high rotation rate C) chemical processes D) nuclear fusion in the core E) by contracting, changing gravitational potential energy into thermal energy
E
How thick are Saturn's rings from top to bottom? A) a few million kilometers B) a few tens of thousands of kilometers C) a few hundred kilometers D) a few kilometers E) a few tens of meters
E
In what ways has Pluto long been known to be different from the planets? A) It has a highly eccentric orbit. B) Its orbit is more inclined to the ecliptic plane. C) It is far smaller than the terrestrial planets. D) It is composed primarily of ices. E) All of the answers
E
Under what circumstances can differentiation occur in a planet? A) The planet must have a rocky surface. B) The planet must be made of both metal and rock. C) The planet must have an atmosphere. D) The planet must be geologically active, that is, have volcanoes, planetquakes, and erosion from weather. E) The planet must have a molten interior.
E
What are the circumstances under which convection can occur in a substance? A) when the substance is subjected to a strong magnetic field B) when dense material is being added to the substance C) when the substance is strongly shaken or disturbed by a strong wind D) when the substance is strongly cooled from underneath E) when the substance is strongly heated from underneath
E
What characteristic distinguishes a meteorite from a terrestrial rock? A) A meteorite is usually covered with a dark crust from burning in Earth's atmosphere. B) A meteorite usually has a high metal content. C) Meteorites have different isotope ratios of particular elements when compared to terrestrial rocks. D) Meteorites contain rare elements, such as iridium, that terrestrial rocks do not. E) All of the answers are true.
E
What kind of observations can astronomers use to study Io's volcanoes? A) visible-light images to study the distribution of sulfur compounds on its surface B) visible-light images to study plumes using reflected sunlight C) infrared images to study warm plumes on Io's night-side D) spectroscopy to determine the composition of the plumes E) all of the above
E
What would be the consequence(s) of more frequent collisions between planets and asteroids? A) We would find more Martian meteorites on Earth. B) We would observe more meteor showers. C) Earth and other planets would have more large craters. D) a and b E) a and c
E
When we see a region of a planet that is not as heavily cratered as other regions, we conclude that A) there is little volcanic activity to create craters. B) the planet is rotating very slowly and only one side was hit by impactors. C) the planet formed after the age of bombardment and missed out on getting hit by leftover planetesimals. D) the surface in the region is older than the surface in more heavily cratered regions. E) the surface in the region is younger than the surface in more heavily cratered regions.
E
Which of the following is furthest 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
E
Which of the following statements about Titan is not true? A) It may have an ocean of liquid ethane. B) Its atmosphere is mostly nitrogen. C) Its temperature is too cold for liquid water to exist. D) Its surface is hidden from view by its thick atmosphere. E) It is the coldest moon in the solar system.
E
Which of the jovian planets has/have rings? A) Jupiter B) Saturn C) Uranus D) Neptune E) all of the above
E
Which planet has a ring system? A) Jupiter B) Saturn C) Uranus D) Neptune E) All of the above
E