Chapter 12

What is the largest dwarf planet discovered to date? a) Pluto b) Triton c) Ceres d) Eris e) Sedna

d) Eris

Orbits of asteroids in the asteroid belt a) often intersect the orbits of the planets. b) are mostly between Mars and Jupiter. c) are grouped into patterns by resonances with Jupiter. d) are mostly inside the frost line. e) all except A

e) all except A

Meteorites can come from a) the cores of asteroids. b) Mars. c) comets. d) the Moon. e) all of the above

e) all of the above

What are the most common type of meteorite? a) carbon-rich primitive meteorites b) stony primitive meteorites c) metal-rich processed meteorites d) rocky processed meteorites e) meteorites from the Moon and Mars

b) stony primitive meteorites

When you see the bright flash of a meteor, what are you actually seeing? a) emission of visible light from a particle that has not yet entered Earth's atmosphere b) the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere c) a star that has suddenly shot across the sky d) the flash that occurs when a speeding rock from space hits the ground

b) the glow from a pea-size particle and the surrounding air as the particle burns up in our atmosphere

Comet nuclei are often described as a) "icy asteroids." b) "icy impactors." c) "dirty snowballs." d) "giant snowballs." e) "dirty ice cubes."

c) "dirty snowballs."

What is a dwarf planet? a) A dwarf planet is any object orbiting the Sun that is not one of the 9 planets. b) A dwarf planet is any object orbiting the Sun that is not one of the 8 planets. c) A dwarf planet is any object orbiting the Sun that is large enough to be round but not one of the 8 planets. d) A dwarf planet is any object orbiting the Sun that is large enough to be round but not one of the 4 jovian planets. e) A dwarf planet is any object orbiting the Sun that is not one of the 4 jovian planets.

c) A dwarf planet is any object orbiting the Sun that is large enough to be round but not one of the 8 planets.

Why do asteroids and comets differ in composition? a) Asteroids are much larger than comets. b) Asteroids and comets formed at different times. c) Asteroids formed inside the frost line, while comets formed outside. d) Comets formed from the jovian nebula, while asteroids did not. e) Comets are much larger than asteroids.

c) Asteroids formed inside the frost line, while comets formed outside.

Why is there a meteor shower every year on Aug. 10, 11, and 12? a) Meteorites only enter the solar system on certain dates. b) Meteorites often have 1 year orbital periods. c) Earth passes through the orbit of a comet and hits the remaining debris at the same time each year. d) none of the above

c) Earth passes through the orbit of a comet and hits the remaining debris at the same time each year

What is the best way to find the density of an asteroid? a) Look at its spectrum. b) Study a sample of its matter. c) Find an asteroid with a moon and use Kepler's 3rd law. d) none of the above

c) Find an asteroid with a moon and use Kepler's 3rd law.

In order to have a comet named after you, you have to a) publish a picture of it in an astronomical journal. b) be a well-known astronomer. c) calculate its orbit and predict when it will return. d) be one of the first three discoverers who report it to the International Astronomical Union (IAU). e) be and do all of the above

d) be one of the first three discoverers who report it to the International Astronomical Union (IAU).

How can we determine an asteroid's reflectivity? a) by determining how far from the Sun it is b) by seeing how dark or light it looks in telescopic images c) by determining its mass d) by comparing its infrared thermal emission to its visible-light reflection e) by determining its size

d) by comparing its infrared thermal emission to its visible-light reflection

Processed meteorites with low metal content probably are a) pieces of comets rather than of asteroids. b) chunks of rock chipped off the planet Mercury. c) chunks of rock chipped off the planet Mars. d) chunks of a larger asteroid that was shattered by a collision. e) leftover chunks of rock from the earliest period in the formation of the solar system.

d) chunks of a larger asteroid that was shattered by a collision.

Where did comets that are now in the Oort cloud originally form? a) within the solar nebula, but far outside the orbit of Pluto b) inside Jupiter's orbit c) outside Neptune's orbit d) near the jovian planets e) all of the above

d) near the jovian planets

Gaps in the asteroid belt (often called Kirkwood gaps) are caused by a) tidal forces from the Sun. b) tidal forces from Jupiter. c) the competing gravitational tugs of Mars and Jupiter. d) orbital resonances with Jupiter.

d) orbital resonances with Jupiter.

If you keep pushing a person on a swing with little pushes, at just the right frequency, they will swing very high. This is an example of a) Newton's second law. b) Newton's first law. c) energy conservation. d) resonance. e) conservation of angular momentum.

d) resonance.

Most meteorites are a) carbon-rich and primitive. b) rocky and processed. c) carbon-rich and processed. d) rocky and primitive. e) iron-rich and processed.

d) rocky and primitive.

A meteor a) is a flash of light made by a falling meteorite. b) is usually seen at night. c) is a fragment of asteroid or comet that reaches Earth's surface. d) all of the above e) A and B

e) A and B

Primitive meteorites a) are approximately 4.6 billion years old. b) give us clues to what the early solar system was like. c) represent samples of shattered worlds. d) all of the above e) A and B

e) A and B

What is the size of the largest asteroid? a) 10 km b) 1,000 km c) 10,000 km d) 1 km e) 100 km

b) 1,000 km

How many moons have been discovered around Pluto? a) 1 b) 2 c) 3 d) 4 e) 5

e) 5

Suppose there were no solar wind. How would the appearance of a comet in our inner solar system be different? a) It would have only one tail instead of two. b) It would not have a coma. c) It would not have a nucleus. d) It would be much brighter in appearance.

a) It would have only one tail instead of two.

Which of the following is not a piece of evidence supporting the idea that an impact caused the mass extinction that occurred 65 million years ago? a) Fossilized dinosaur bones contain fragments of rock from the impact. b) Unusually large abundances of iridium and other rare metals are found in a layer of clay that dates to 65 million years ago. c) A large impact crater along the coast of Mexico dates to 65 million years ago. d) Grains of quartz formed under high pressure are found in a layer of clay that dates to 65 million years ago.

a) Fossilized dinosaur bones contain fragments of rock from the impact.

Why isn't there a planet where the asteroid belt is located? a) Gravitational tugs from Jupiter prevented material from collecting together to form a planet. b) A planet once formed here, but it was broken apart by a catastrophic collision. c) There was too much rocky material to form a terrestrial planet, but not enough gaseous material to form a jovian planet. d) There was not enough material in this part of the solar nebula to form a planet. e) The temperature in this portion of the solar nebula was just right to prevent rock from sticking together.

a) Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

What is Pluto's moon Charon thought to have in common with our own Moon? a) It probably formed as a result of a giant impact. b) It has the same basic composition. c) It has the same approximate mass. d) It has the same average density.

a) It probably formed as a result of a giant impact.

What produces meteor showers? a) Meteor showers are caused by the passage of Earth through the debris left by a comet in its orbit. b) Meteor showers are caused by the passage of Earth through the dust tail of a comet. c) Meteor showers are caused by the passage of Earth through a debris cloud from an asteroid collision. d) Meteor showers are produced by a large meteoroid breaking up as it enters the atmosphere.

a) Meteor showers are caused by the passage of Earth through the debris left by a comet in its orbit.

Why are most meteorites found in Antarctica? a) Meteorites are dark and easy to spot against the ice in Antarctica. b) Meteorites melt coming through the atmosphere and usually only survive if quickly refrozen by the cold temperatures of Antarctica. c) Because of the slower rotational speed of Earth near the poles, meteorites are more likely to survive atmospheric entry near the poles. d) The orbits of meteoroids and the tilt Earth's axis make them more likely to impact near the poles. e) Penguins confuse meteorites with their eggs and rescue them, making them easy to collect from Antarctica.

a) Meteorites are dark and easy to spot against the ice in Antarctica.

What do asteroids and comets have in common? a) Most are unchanged since their formation in the solar nebula. b) They have nothing in common with each other. c) They have a similar range of orbital inclinations. d) They have similar orbital radii. e) They have similar densities.

a) Most are unchanged since their formation in the solar nebula.

Comet nuclei can be darker than charcoal. a) True b) False

a) True

The total mass of the Kuiper belt is greater than that of the asteroid belt. a) True b) False

a) True

According to current evidence, Pluto is best explained as ______. a) a large member of the Kuiper belt b) a very small jovian planet c) a terrestrial planet that is surprisingly far from the Sun d) an escaped moon of Jupiter or Saturn

a) a large member of the Kuiper belt

A rock found on Earth that crashed down from space is called _________. a) a meteorite b) a meteor c) an impact d) an asteroid

a) a meteorite

How large was the object that caused the Tunguska event? a) about 40 meters across b) about 100 meters across c) about 400 meters across d) about 1 km across e) about 4 km across

a) about 40 meters across

Which direction do a comet's dust and plasma tails point? a) generally away from the Sun b) perpendicular to the ecliptic plane c) always almost due north d) straight behind the comet in its orbit

a) generally away from the Sun

The combined mass of all the asteroids in the asteroid belt is a) less than that of any terrestrial planet. b) about the same as that of Jupiter. c) about twice that of Earth. d) more than that of all the planets combined. e) about the same as that of Earth.

a) less than that of any terrestrial planet.

If we could put all the asteroids together, their total mass would be a) much less than the mass of any terrestrial planet. b) about the mass of Mercury. c) about the mass of Earth. d) greater than the mass of Earth but less than the mass of Jupiter.

a) much less than the mass of any terrestrial planet.

In science fiction movies, spaceships are often shown dodging through large numbers of closely spaced, boulder-size objects. Which of the following real things in our solar system would look most like such science fiction dangers? a) the rings of Saturn b) the asteroid belt c) the atmosphere of Jupiter d) the Oort cloud

a) the rings of Saturn

All meteorites collected on Earth come from asteroids or comets. a) True b) False

b) False

No spacecraft has ever visited an asteroid or comet. a) True b) False

b) False

Pluto is the largest Kuiper Belt Object. a) True b) False

b) False

Why didn't a planet form where the asteroid belt is now located? a) There was not enough material in this part of the solar nebula to form a planet. b) Gravitational tugs from Jupiter prevented material from collecting together to form a planet. c) There was too much rocky material to form a terrestrial planet, but not enough gaseous material to form a jovian planet. d) The temperature in this portion of the solar nebula was just right to prevent rock from sticking together.

b) Gravitational tugs from Jupiter prevented material from collecting together to form a planet.

The asteroid belt lies between the orbits of a) Earth and Mars. b) Mars and Jupiter. c) Jupiter and Saturn

b) Mars and Jupiter.

Suppose that large jovian planets had never formed in our solar system. Which of the following would most likely be true? a) Earth would have suffered far fewer impacts. b) Neither the asteroid belt nor Oort cloud would exist. c) There would be a large empty region in our solar system between the orbit of Mars and the Kuiper belt. d) Earth would orbit much closer to the Sun.

b) Neither the asteroid belt nor Oort cloud would exist.

Did a large terrestrial planet ever form in the region of the asteroid belt? a) No, because there was never enough mass there. b) No, because Jupiter prevented one from accreting. c) Yes, but it was shattered by a giant impact.

b) No, because Jupiter prevented one from accreting.

Which of the following statements about asteroids, Kuiper belt objects, and Oort cloud objects is true? a) Objects in the Oort cloud are made mostly of rock and metal. b) Objects in the asteroid belt and Kuiper belt orbit the Sun in nearly the same plane as the planets, but objects in the Oort cloud do not. c) Objects in the asteroid belt are made mostly of ice. d) Objects in the Kuiper belt are made mostly of rock and metal.

b) Objects in the asteroid belt and Kuiper belt orbit the Sun in nearly the same plane as the planets, but objects in the Oort cloud do not.

Which of the following objects are probably not located in the same region of the solar system in which they originally formed? a) Kuiper belt comets b) Oort cloud comets c) asteroids of the asteroid belt d) Pluto

b) Oort cloud comets

Why won't Pluto collide with Neptune? a) Pluto is always much farther from the Sun than Neptune. b) Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits, which ensures they never come close together. c) Pluto's orbit never comes anywhere close to Neptune's orbit. d) Actually, a collision of the two is inevitable within the next billion years.

b) Pluto orbits the Sun exactly 2 times for every 3 Neptune orbits, which ensures they never come close together.

Which of the following is a real piece of evidence pointing to geological activity on Pluto? a) Surface regions that show evidence of flooding by liquid water. b) Surface regions that suggest glacial movement of frozen ices of nitrogen and methane. c) Several towering volcanoes discovered on its surface. d) Crater rims showing evidence of erosion by rainfall

b) Surface regions that suggest glacial movement of frozen ices of nitrogen and methane.

What is the orientation of a comet's plasma tail? a) The plasma tail extends from the nucleus in the opposite direction of the comet's motion. b) The plasma tail extends from the nucleus in the opposite direction of the Sun. c) The plasma tail extends from the nucleus both away from the Sun and away from the orbital motion of the comet. d) The plasma tail extends from the nucleus toward the Sun. e) The plasma tail "wags" between various different orientations behind the direction of the comet's motion.

b) The plasma tail extends from the nucleus in the opposite direction of the Sun.

What are the Trojan asteroids? a) They are particularly large asteroids in the main asteroid belt. b) They are asteroids in the 1:1 resonance with Jupiter in Jupiter's orbit. c) They are asteroids whose orbits cross the orbits or Earth and Mars. d) They are asteroids in any resonance with Jupiter. e) They are hollow asteroids.

b) They are asteroids in the 1:1 resonance with Jupiter in Jupiter's orbit.

Where do the Kuiper belt comets come from? a) They formed in the asteroid belt and were scattered out by Jupiter. b) They formed in the Kuiper belt. c) They formed among the jovian planets and were scattered out by Jupiter. d) They formed among the jovian planets and were pushed out by the solar wind. e) They formed around another star and were captured by the Sun when it passed near that star.

b) They formed in the Kuiper belt.

Which of the following best describes why scientists seek to identify even small asteroids that could potentially hit Earth? a) To allow us to capture the asteroids and use them for their resources. b) To try to prevent an impact that might destroy a town or city. c) To try to prevent an impact that might cause the extinction of the human race. d) To help us understand the origin of the solar system.

b) To try to prevent an impact that might destroy a town or city.

What do astronomers think Pluto is? a) a major planet b) a large Kuiper belt comet c) an escaped moon of Neptune d) an asteroid

b) a large Kuiper belt comet

How often does an impactor large enough to cause a tsunamis and widespread devastation strike Earth? a) about once in 1000 years b) about once in a million years c) about once in a hundred million years d) about once in a billion years

b) about once in a million years

Asteroids a) are rocky and small-typically the size of a grain of rice or a marble. b) are rocky, with a wide range of sizes, up to hundreds of miles in diameter. c) have only thin atmospheres. d) are made mostly of metals. e) are mostly found in the inner solar system.

b) are rocky, with a wide range of sizes, up to hundreds of miles in diameter.

In the asteroid impact theory of the extinction of the dinosaurs some 65 million years ago, the dinosaurs (and over half of all the other species on Earth at that time) died off largely because a) radiation from iridium in the asteroid caused the dinosaurs to die of cancer. b) dust injected into the stratosphere from the impact absorbed visible light from the Sun, causing global temperatures to plummet. c) the impact caused massive earthquakes and volcanic activity worldwide. d) of injuries suffered from direct hits of pieces of the asteroid or comet. e) dust settled on the leaves of plants, making them inedible, so the animals died of starvation.

b) dust injected into the stratosphere from the impact absorbed visible light from the Sun, causing global temperatures to plummet.

Comets a) formed from planetesimals in the inner part of the early solar system. b) formed from planetesimals in the outer part of the early solar system. c) orbit the Sun and return time after time, for billions of years. d) have a single tail that streams out straight behind them.

b) formed from planetesimals in the outer part of the early solar system.

Every time a comet gets near the Sun, some of its material streams away in the tail. Shouldn't all comets be gone? a) yes b) no, not that much material vaporizes c) yes, but there are more comets stored in "deep freeze" beyond Pluto d) not yet, but they will all be gone sometime in the near future

b) no, not that much material vaporizes

Surprising discovery? - A mission to Pluto finds that it has lakes of liquid water on its surface. a) Plausible. Other icy bodies at great distances from the Sun may also have liquid water on their surfaces. b) Plausible. Studies of Pluto's surface show a long, narrow feature that looks like a lake. c) Implausible. Water would be frozen at Pluto's temperature, and we know of no heating sources that would cause the water to melt. d) Implausible. Pluto is mostly made of rock and metals, not water.

c) Implausible. Water would be frozen at Pluto's temperature, and we know of no heating sources that would cause the water to melt.

Suppose we discover a new comet on an orbit that brings it closer to the Sun than Mercury every 125 years. What can we conclude? a) It came from the Oort cloud. b) It came from the Kuiper belt. c) It has been on its current orbit for only a very short time compared to the age of our solar system. d) It has a coma and tail during most of each orbit.

c) It has been on its current orbit for only a very short time compared to the age of our solar system.

What is comet SL9? a) It is the largest comet in the Oort cloud. b) It is the comet that was studied by the Deep Impact spacecraft, which sent an impactor into its nucleus. c) It is a comet that was seen crashing into Jupiter. d) It is the comet that hit Earth 65 million years ago leading to a mass extinction.

c) It is a comet that was seen crashing into Jupiter.

Which of the following statements best describes the size of the largest asteroid, Ceres? a) It is about the size of a terrestrial planet. b) It is smaller than the jovian planets but larger than the terrestrial planets. c) It is a little less than half the diameter of our Moon. d) It is no larger than a typical mountain on one of the terrestrial planets.

c) It is a little less than half the diameter of our Moon.

Which of the following is not a piece of evidence supporting the idea that Pluto is a large comet of the Kuiper belt? a) Pluto's composition appears to match that of other known Kuiper belt comets. b) Triton, which must once have orbited the Sun before being captured by Neptune, is significantly larger than Pluto. c) Pluto grows a coma and a long tail when it is at the point in its orbit closest to the Sun. d) Pluto's orbit is very similar to the orbits of other known Kuiper belt comets. e) Pluto is not the largest object orbiting in the region of the Kuiper belt.

c) Pluto grows a coma and a long tail when it is at the point in its orbit closest to the Sun.

Why do comet tails always point away from the Sun? a) They are left behind as the comet moves. b) Newton's third law: If the comet goes one way, the tail must go the other way. c) The solar wind blows them away from the Sun. d) They don't; this is just a perspective effect of how we view them.

c) The solar wind blows them away from the Sun.

Why won't Pluto collide with Neptune? a) Pluto's orbit never comes anywhere close to Neptune's orbit. b) Pluto's orbit is completely inside Neptune's orbit. c) The two planets have an orbital resonance that prevents them from colliding. d) Pluto's orbit is completely outside Neptune's orbit. e) It could!

c) The two planets have an orbital resonance that prevents them from colliding.

Why do some comets come from far out in space and from all different directions (i.e., not in the plane of the solar system)? a) They come from other solar systems. b) They come from nebulae in interstellar space. c) They come from a giant spherical cloud called the Oort cloud. d) They come from the Kuiper belt when a comet is flung out by Neptune's gravity.

c) They come from a giant spherical cloud called the Oort cloud

Can an asteroid be pure metal? a) No, all asteroids contain rock. b) Yes, it must have formed where only metal could condense in the solar nebula. c) Yes, it must have been the core of a shattered asteroid.

c) Yes, it must have been the core of a shattered asteroid.

How big is the largest asteroid? a) about 100 km in diameter b) about 300 km in diameter c) about 1000 km in diameter d) about 3000 km in diameter e) about 10,000 km in diameter

c) about 1000 km in diameter

A typical meteorite is a) about the size of a house, and makes a crater when it impacts Earth's surface. b) about the size of a pea or grain of rice, and is invisible when it lands. c) about the size of a pea or grain of rice, and makes a bright streak in the sky as it burns up. d) about the size of a large city, and causes widespread destruction when it impacts Earth's surface.

c) about the size of a pea or grain of rice, and makes a bright streak in the sky as it burns up.

What is plasma (in astronomy)? a) an element commonly found in space b) a constituent of blood c) an ionized or charged gas made when atoms lose one or more electrons d) another name for the solar wind

c) an ionized or charged gas made when atoms lose one or more electrons

Most meteorites come from a) stars. b) destroyed planets. c) asteroids. d) the Moon and Mars. e) material ejected from volcanoes.

c) asteroids.

How can we determine the reflectivity of an asteroid? a) by taking a photograph of it b) by measuring its mass and radius c) by comparing its brightness in visible light to its brightness in infrared light d) by where it is located in the asteroid belt

c) by comparing its brightness in visible light to its brightness in infrared light

About how often is it estimated that an asteroid or comet impacts Earth with sufficient energy to cause mass extinction? a) once a millennium b) once every million years c) once every hundred million years d) once in Earth's history

c) once every hundred million years

What is the "reservoir" of cold comets beyond Pluto called? a) the comet reservoir b) The extrasolar system source c) the Kuiper belt d) the Oort cloud

c) the Kuiper belt

If Earth passed through the tail of a comet, what would happen? a) People would die from the gasses such as methane and ammonia. b) Earth would be bombarded by large impactors. c) Earth might be knocked out of its orbit or its axis might get tilted. d) A meteor shower would occur.

d) A meteor shower would occur.

When we see a meteor shower, it means that a) the solar wind is unusually strong. b) an Earth-approaching asteroid has recently come very close to our planet. c) you should duck and run for cover to avoid being blasted on the head by a rock from space. d) Earth is crossing the orbit of a comet.

d) Earth is crossing the orbit of a comet

Surprising discovery? - A small asteroid that orbits within the asteroid belt has an active volcano. a) Plausible. Several small objects in the solar system have active volcanoes. b) Plausible. Several asteroids are known to be composed of basaltic material (lava). c) Implausible. Only planets, not moons or asteroids, have volcanoes. d) Implausible. Asteroids are too small to be geologically active now.

d) Implausible. Asteroids are too small to be geologically active now.

How do orbital resonances with Jupiter affect the asteroid belt? a) In that region of the solar system, Jupiter's resonances shrinks the eccentricities of objects, making them to collide at low speed. This keeps them from clumping together and forming a planet. In fact, it tends to make the asteroids break apart when they collide. b) In that region of the solar system, Jupiter's resonances shrinks the eccentricities of objects, making them to collide at low speed. This keeps them from breaking apart. In fact, it tends to make the asteroids clump together when they collide. c) In that region of the solar system, Jupiter's resonances pump up the eccentricities of objects, making them to collide at high speed. This keeps them from breaking apart. In fact, it tends to make the asteroids clump together when they collide. d) In that region of the solar system, Jupiter's resonances pump up the eccentricities of objects, making them to collide at high speed. This keeps them from clumping together and forming a planet. In fact, it tends to make the asteroids break apart when they collide.

d) In that region of the solar system, Jupiter's resonances pump up the eccentricities of objects, making them to collide at high speed. This keeps them from clumping together and forming a planet. In fact, it tends to make the asteroids break apart when they collide.

Why didn't the material in the asteroid belt form a planet? a) There was not enough material there to gravitationally accrete into a planet. b) The asteroids were too far apart to run into each other frequently enough to form a planet. c) A planet formed early in the solar system and was broken apart by a giant impact. d) Orbital resonances with Jupiter disrupted the orbits of the asteroids and prevented them from forming a planet. e) Tidal forces from Jupiter prevented the asteroids from accreting into a planet.

d) Orbital resonances with Jupiter disrupted the orbits of the asteroids and prevented them from forming a planet.

Choose the correct explanation, where is the asteroid belt located, and why. a) The asteroid belt lies between the orbits of Jupiter and Saturn. It exists because of orbital resonances with Saturn. b) The asteroid belt lies between the orbits of Jupiter and Saturn. It exists because of orbital resonances with Jupiter. c) The asteroid belt lies between the orbits of Mars and Jupiter. It exists because of orbital resonances with Mars. d) The asteroid belt lies between the orbits of Mars and Jupiter. It exists because of orbital resonances with Jupiter.

d) The asteroid belt lies between the orbits of Mars and Jupiter. It exists because of orbital resonances with Jupiter.

How would the impact history on Earth have been different if Jupiter did not exist? a) There would be no significant difference. b) There would be more impacts from comets and asteroids. c) There would be fewer impacts from comets and asteroids. d) There would be more impacts from comets and fewer from asteroids. e) There would be more impacts from asteroids and fewer from comets.

d) There would be more impacts from comets and fewer from asteroids.

Suppose you find a meteorite made almost entirely of metal. According to current science, which of the following statements must be true? a) Radiometric dating will show the age of your meteorite to date to the formation of our solar system. b) Your meteorite was blasted off the surface of Mars by an impact. c) Your meteorite is a fragment of an object from the Kuiper belt. d) Your meteorite is a fragment from the core of a large asteroid that shattered in a collision.

d) Your meteorite is a fragment from the core of a large asteroid that shattered in a collision.

An icy leftover planetesimal orbiting the Sun is a) a meteorite. b) an asteroid. c) a meteor. d) a comet. e) possibly any of the above

d) a comet.

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 small moon that orbits one of the giant planets d) a fragment of an asteroid from the solar system that has fallen to Earth's surface e) a comet that burns up in Earth's atmosphere

d) a fragment of an asteroid from the solar system that has fallen to Earth's surface

What characteristic distinguishes a meteorite from a terrestrial rock? a) Meteorites contain rare elements, such as iridium, that terrestrial rocks do not. b) A meteorite is usually covered with a dark crust from burning in Earth's atmosphere. c) A meteorite usually has a high metal content. d) Meteorites have different isotope ratios of particular elements when compared to terrestrial rocks. e) All of the above are true.

e) All of the above are true.

Processed meteorites a) are meteorites that have been altered in a lab for study. b) come from a parent body that was large enough to develop a core and mantle. c) may be metallic or rocky. d) all of the above e) B and C

e) B and C

The nucleus of a comet a) is made of rock. b) is made of dust and ice, like a dirty snowball. c) turns to gas when the comet nears the Sun. d) All of the above e) B and C

e) B and C

What is Charon? a) the largest known asteroid b) one of the Galilean moons of Jupiter c) a moon of Neptune d) the largest known comet e) Pluto's largest moon

e) Pluto's largest moon

What is the average distance between asteroids in the asteroid belt? a) about 100 km b) about 1000 km c) about 10,000 km d) about 100,000 km e) about 1,000,000 km

e) about 1,000,000 km

Which of the following is not evidence for a large impact on Earth 65 million years ago? a) enhanced levels of elements common in meteorites in 65 million year old sediment layers b) soot in sediment layers indicating global fires c) traces of a crater scar underground d) solidified rock droplets in the sediment layers e) globally distributed meteorites with a radiometric age of 65 million years

e) globally distributed meteorites with a radiometric age of 65 million years

How is Pluto different than the other objects in the Kuiper belt? a) Its orbit is unlike the orbits of other Kuiper belt objects. b) It has moons, unlike other Kuiper belt objects. c) It is larger than all the other Kuiper belt objects. d) It is the only Kuiper belt object in resonance with Neptune. e) none of the above

e) none of the above