Question 1

What fraction of the material arriving on Earth from outer space is in the form of stony meteorites?

Accepted Answer

A)  a few percent 
B)  10 to 20 percent 
C)  50 percent 
D)  95 percent 
A)  a few percent 
B)  10 to 20 percent 
C)  50 percent 
D)  95 percent

Question 2

What causes the dust tail of a comet to separate from the nucleus?

Accepted Answer

A)  radiation pressure 
B)  gravity 
C)  magnetic repulsion 
D)  collisions with the solar wind 
A)  radiation pressure 
B)  gravity 
C)  magnetic repulsion 
D)  collisions with the solar wind

Question 3

Earth's Moon subtends an angle of about 0.5° when viewed from Earth. Charon is about 1200 km in diameter and about 18,490 km away from the surface of Pluto. How large an angle does it subtend when viewed from Pluto?

Accepted Answer

A)  about the same size angle as Earth's Moon 
B)  about 7 times larger an angle than Earth's Moon 
C)  about 11 times larger an angle than Earth's Moon 
D)  over 100 times larger an angle than Earth's Moon 
A)  about the same size angle as Earth's Moon 
B)  about 7 times larger an angle than Earth's Moon 
C)  about 11 times larger an angle than Earth's Moon 
D)  over 100 times larger an angle than Earth's Moon

Question 4

A Kreutz comet is unusual because it

Accepted Answer

A)  has a small orbital inclination relative to the ecliptic. 
B)  has a gas tail that bends away from the Sun-comet line. 
C)  has a perihelion within about 0.01 au of the Sun. 
D)  has been captured by a giant planet. 
A)  has a small orbital inclination relative to the ecliptic. 
B)  has a gas tail that bends away from the Sun-comet line. 
C)  has a perihelion within about 0.01 au of the Sun. 
D)  has been captured by a giant planet.

Question 5

Often, an asteroid viewed from Earth appears to change its brightness periodically because the

Accepted Answer

A)  albedo is significantly different on one side than the other. 
B)  leading side is very dark and the trailing side is very bright like Iapetus, a satellite of Saturn. 
C)  asteroid is elongated, so it may present a larger or a smaller cross section to Earth as it rotates. 
D)  asteroid is simply passing through the shadow of another asteroid. 
A)  albedo is significantly different on one side than the other. 
B)  leading side is very dark and the trailing side is very bright like Iapetus, a satellite of Saturn. 
C)  asteroid is elongated, so it may present a larger or a smaller cross section to Earth as it rotates. 
D)  asteroid is simply passing through the shadow of another asteroid.

Question 6

Rocks laid down at around the time of the Permian/Triassic mass extinction 250 million years ago contain a surprising amount of fullerenes (football-shaped carbon molecules). What evidence is there that the fullerenes came from outer space?

Accepted Answer

A)  The isotope ratio of carbon13 to carbon12 is too great for the fullerenes to have originated on Earth. 
B)  The fullerenes show evidence of having been irradiated by the solar wind for millions of years. 
C)  Gases trapped inside the fullerenes could have come only from stars. 
D)  The rocks in which the fullerenes are found contain decay products of short-lived radioactive aluminum isotopes that are believed to be produced only in supernovae (explosions of stars). 
A)  The isotope ratio of carbon13 to carbon12 is too great for the fullerenes to have originated on Earth. 
B)  The fullerenes show evidence of having been irradiated by the solar wind for millions of years. 
C)  Gases trapped inside the fullerenes could have come only from stars. 
D)  The rocks in which the fullerenes are found contain decay products of short-lived radioactive aluminum isotopes that are believed to be produced only in supernovae (explosions of stars).

Question 7

What is Sedna?

Accepted Answer

A)  largest object discovered beyond the orbit of Pluto 
B)  bright comet to which scientists hope to send a rendezvous mission 
C)  largest object in the asteroid belt 
D)  largest of the Trojan asteroids 
A)  largest object discovered beyond the orbit of Pluto 
B)  bright comet to which scientists hope to send a rendezvous mission 
C)  largest object in the asteroid belt 
D)  largest of the Trojan asteroids

Question 8

A meteorite that recently fell to Earth was found to contain evidence of the existence earlier in its history of a short-lived radioactive isotope of aluminum, 26Al, which can be produced only under extremely energetic conditions and in nuclear reactions. What conclusion can be drawn from this observation?

Accepted Answer

A)  An energetic nuclear event, a supernova, occurred near the formation site of the Sun, and it produced the 26Al at about the time the meteorite was formed. 
B)  The meteorite became so hot on its descent through Earth's atmosphere that it became radioactive, and the 26Al was formed at that time. 
C)  The meteorite had probably passed through radioactive clouds in space and collected the 26Al before hitting Earth. 
D)  Radioactivity occurs spontaneously in normal matter, so this finding is not surprising. 
A)  An energetic nuclear event, a supernova, occurred near the formation site of the Sun, and it produced the 26Al at about the time the meteorite was formed. 
B)  The meteorite became so hot on its descent through Earth's atmosphere that it became radioactive, and the 26Al was formed at that time. 
C)  The meteorite had probably passed through radioactive clouds in space and collected the 26Al before hitting Earth. 
D)  Radioactivity occurs spontaneously in normal matter, so this finding is not surprising.

Question 9

A comet is observed to have an orbit that is highly inclined relative to the orbits of the solar system planets. It MOST likely originated from

Accepted Answer

A)  the Oort cloud. 
B)  the Kuiper belt 
C)  another star. 
D)  the breakup of a body passing too close to a giant planet. 
A)  the Oort cloud. 
B)  the Kuiper belt 
C)  another star. 
D)  the breakup of a body passing too close to a giant planet.

Question 10

The two stable Lagrange points in the Jupiter-Sun planetary system are

Accepted Answer

A)  positions in space at Jupiter's orbital distance from the Sun where the combined gravitational forces from the Sun and Jupiter produce an equilibrium point at which asteroids can become trapped. 
B)  points at high latitudes on Jupiter where auroras (called Lagrange auroras on Jupiter) occur most frequently. 
C)  areas in the asteroid belt where gravitational interaction of Jupiter with asteroids disturbs their orbits and causes a Kirkwood gap. 
D)  an area between the Sun and Jupiter where the gravitational forces on an object from these massive bodies are equal and opposite. 
A)  positions in space at Jupiter's orbital distance from the Sun where the combined gravitational forces from the Sun and Jupiter produce an equilibrium point at which asteroids can become trapped. 
B)  points at high latitudes on Jupiter where auroras (called Lagrange auroras on Jupiter) occur most frequently. 
C)  areas in the asteroid belt where gravitational interaction of Jupiter with asteroids disturbs their orbits and causes a Kirkwood gap. 
D)  an area between the Sun and Jupiter where the gravitational forces on an object from these massive bodies are equal and opposite.

Question 11

In order of abundance, from most abundant to least abundant, the occurrence of meteorite impacts ("falls") is believed to be

Accepted Answer

A)  stony, iron, stony iron. 
B)  stony iron, iron, stony. 
C)  iron, stony iron, stony. 
D)  stony, stony iron, iron. 
A)  stony, iron, stony iron. 
B)  stony iron, iron, stony. 
C)  iron, stony iron, stony. 
D)  stony, stony iron, iron.

Question 12

A few of the largest asteroids appear to be spherical. How does this occur?

Accepted Answer

A)  The visible outer atmospheres of these large asteroids are spherical even though the underlying surfaces are irregular. 
B)  The largest asteroids solidified from spherical gas clouds in their early history and retained this shape. 
C)  Repeated collisions with other asteroids have worn the largest asteroids down to spheres. 
D)  Self-gravity was sufficient to pull the largest asteroids into a spherical shape during their early history. 
A)  The visible outer atmospheres of these large asteroids are spherical even though the underlying surfaces are irregular. 
B)  The largest asteroids solidified from spherical gas clouds in their early history and retained this shape. 
C)  Repeated collisions with other asteroids have worn the largest asteroids down to spheres. 
D)  Self-gravity was sufficient to pull the largest asteroids into a spherical shape during their early history.

Question 13

When compared with the diameter of Earth's Moon, the diameters of the biggest asteroids are

Accepted Answer

A)  very much smaller (less than 1/10). 
B)  about the same size. 
C)  very much larger, by a factor of at least 5. 
D)  between 1/10 and 1/3 as large. 
A)  very much smaller (less than 1/10). 
B)  about the same size. 
C)  very much larger, by a factor of at least 5. 
D)  between 1/10 and 1/3 as large.

Question 14

By 1891 only about 300 asteroids had been discovered. After 1891 hundreds more were discovered quickly. What caused this increased discovery rate for asteroids?

Accepted Answer

A)  invention of the telescope 
B)  invention of photography 
C)  advent of astrophotography 
D)  heightened interest in the solar system fueled by Percival Lowell and the Martian canals controversy 
A)  invention of the telescope 
B)  invention of photography 
C)  advent of astrophotography 
D)  heightened interest in the solar system fueled by Percival Lowell and the Martian canals controversy

Question 15

The nucleus of Comet Halley, as seen on close-up photographs taken by the Giotto spacecraft, is

Accepted Answer

A)  roughly spherical, moderately cratered, and covered with dark dust. 
B)  roughly spherical, light-colored, icy, and covered with many cracks and grooves. 
C)  potato-shaped and darker than coal. 
D)  oblong, with a bright ice surface. 
A)  roughly spherical, moderately cratered, and covered with dark dust. 
B)  roughly spherical, light-colored, icy, and covered with many cracks and grooves. 
C)  potato-shaped and darker than coal. 
D)  oblong, with a bright ice surface.

Question 16

How was the dwarf planet Pluto discovered?

Accepted Answer

A)  by prediction using Newton's laws to account for the deviations from uniform orbits of Uranus and Neptune 
B)  by the infrared cameras on the IRAS spacecraft 
C)  by Voyager spacecraft cameras, which were used between planetary encounters to survey the planetary system 
D)  by searching photographs of the sky for an object that moved against the background of distant stars 
A)  by prediction using Newton's laws to account for the deviations from uniform orbits of Uranus and Neptune 
B)  by the infrared cameras on the IRAS spacecraft 
C)  by Voyager spacecraft cameras, which were used between planetary encounters to survey the planetary system 
D)  by searching photographs of the sky for an object that moved against the background of distant stars

Question 17

The MOST likely origin of the "dirty snowballs" that become comets when they are deflected into orbits that bring them closer to the Sun is the

Accepted Answer

A)  icy surfaces of the moons of Jupiter and Saturn. 
B)  dust and gas clouds in the Milky Way Galaxy. 
C)  asteroid belt because most asteroids are actually comet nuclei. 
D)  Kuiper belt and Oort cloud surrounding the solar system. 
A)  icy surfaces of the moons of Jupiter and Saturn. 
B)  dust and gas clouds in the Milky Way Galaxy. 
C)  asteroid belt because most asteroids are actually comet nuclei. 
D)  Kuiper belt and Oort cloud surrounding the solar system.

Question 18

Pluto's mass was poorly known before 1978. What happened in that year to change this?

Accepted Answer

A)  The Hubble Space Telescope was launched. 
B)  The new Keck telescopes became operational. 
C)  Charon was discovered. 
D)  The return echo of a radar pulse, sent many years before, returned to Earth allowing a Doppler shift measurement of its rotation rate. 
A)  The Hubble Space Telescope was launched. 
B)  The new Keck telescopes became operational. 
C)  Charon was discovered. 
D)  The return echo of a radar pulse, sent many years before, returned to Earth allowing a Doppler shift measurement of its rotation rate.

Question 19

A small particle of rock (with a diameter smaller than 10 m) orbiting the Sun would be called a

Accepted Answer

A)  meteor. 
B)  micrometer. 
C)  meteorite. 
D)  meteoroid. 
A)  meteor. 
B)  micrometer. 
C)  meteorite. 
D)  meteoroid.

Question 20

What is the origin of iron meteorites?

Accepted Answer

A)  Because they are iron, they must have been produced within the nearby supernova that exploded 4.6 billion years ago and caused the collapse that resulted in Earth's solar nebula. 
B)  Because iron has a high condensation temperature, these must have been formed in orbits very close to the Sun. They were probably drawn outward by the pull of the Jovian planets when they were in the inner solar system (Nice model). 
C)  Iron is formed in various chemical reactions, but only at very low temperatures. So, these meteoroids must have been formed in the outer solar system and drifted toward the Sun along with the Jovian planets. 
D)  They came from the core of an asteroid that had differentiated due to the heat of radioactive materials within it. 
A)  Because they are iron, they must have been produced within the nearby supernova that exploded 4.6 billion years ago and caused the collapse that resulted in Earth's solar nebula. 
B)  Because iron has a high condensation temperature, these must have been formed in orbits very close to the Sun. They were probably drawn outward by the pull of the Jovian planets when they were in the inner solar system (Nice model). 
C)  Iron is formed in various chemical reactions, but only at very low temperatures. So, these meteoroids must have been formed in the outer solar system and drifted toward the Sun along with the Jovian planets. 
D)  They came from the core of an asteroid that had differentiated due to the heat of radioactive materials within it.

What fraction of the material arriving on Earth from outer space is in the form of stony meteorites?

What causes the dust tail of a comet to separate from the nucleus?

Earth's Moon subtends an angle of about 0.5° when viewed from Earth. Charon is about 1200 km in diameter and about 18,490 km away from the surface of Pluto. How large an angle does it subtend when viewed from Pluto?

A Kreutz comet is unusual because it

Often, an asteroid viewed from Earth appears to change its brightness periodically because the

Rocks laid down at around the time of the Permian/Triassic mass extinction 250 million years ago contain a surprising amount of fullerenes (football-shaped carbon molecules). What evidence is there that the fullerenes came from outer space?

What is Sedna?

A comet is observed to have an orbit that is highly inclined relative to the orbits of the solar system planets. It MOST likely originated from

The two stable Lagrange points in the Jupiter-Sun planetary system are

In order of abundance, from most abundant to least abundant, the occurrence of meteorite impacts ("falls") is believed to be

A few of the largest asteroids appear to be spherical. How does this occur?

When compared with the diameter of Earth's Moon, the diameters of the biggest asteroids are

By 1891 only about 300 asteroids had been discovered. After 1891 hundreds more were discovered quickly. What caused this increased discovery rate for asteroids?

The nucleus of Comet Halley, as seen on close-up photographs taken by the Giotto spacecraft, is

How was the dwarf planet Pluto discovered?

The MOST likely origin of the "dirty snowballs" that become comets when they are deflected into orbits that bring them closer to the Sun is the

Pluto's mass was poorly known before 1978. What happened in that year to change this?

A small particle of rock (with a diameter smaller than 10 m) orbiting the Sun would be called a

What is the origin of iron meteorites?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 10: Vagabonds of the Solar System

What fraction of the material arriving on Earth from outer space is in the form of stony meteorites?

What causes the dust tail of a comet to separate from the nucleus?

Earth's Moon subtends an angle of about 0.5° when viewed from Earth. Charon is about 1200 km in diameter and about 18,490 km away from the surface of Pluto. How large an angle does it subtend when viewed from Pluto?

A Kreutz comet is unusual because it

Often, an asteroid viewed from Earth appears to change its brightness periodically because the

Rocks laid down at around the time of the Permian/Triassic mass extinction 250 million years ago contain a surprising amount of fullerenes (football-shaped carbon molecules). What evidence is there that the fullerenes came from outer space?

What is Sedna?

A comet is observed to have an orbit that is highly inclined relative to the orbits of the solar system planets. It MOST likely originated from

The two stable Lagrange points in the Jupiter-Sun planetary system are

In order of abundance, from most abundant to least abundant, the occurrence of meteorite impacts ("falls") is believed to be

A few of the largest asteroids appear to be spherical. How does this occur?

When compared with the diameter of Earth's Moon, the diameters of the biggest asteroids are

By 1891 only about 300 asteroids had been discovered. After 1891 hundreds more were discovered quickly. What caused this increased discovery rate for asteroids?

The nucleus of Comet Halley, as seen on close-up photographs taken by the Giotto spacecraft, is

How was the dwarf planet Pluto discovered?

The MOST likely origin of the "dirty snowballs" that become comets when they are deflected into orbits that bring them closer to the Sun is the

Pluto's mass was poorly known before 1978. What happened in that year to change this?

A small particle of rock (with a diameter smaller than 10 m) orbiting the Sun would be called a

What is the origin of iron meteorites?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

The Sun: Our Extraordinary Star

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters