Question 1

The cause of the meteor showers seen at regular times each year on Earth is MOST likely

Accepted Answer

A)  Earth running into material within the spiral arm structure of the Milky Way. 
B)  unstable weather conditions on Earth. 
C)  Earth moving through the remnant dust and rock fragments of an old comet that are orbiting the Sun in the comet's old orbit. 
D)  sunspot activity and the resultant geomagnetic disturbances. 
A)  Earth running into material within the spiral arm structure of the Milky Way. 
B)  unstable weather conditions on Earth. 
C)  Earth moving through the remnant dust and rock fragments of an old comet that are orbiting the Sun in the comet's old orbit. 
D)  sunspot activity and the resultant geomagnetic disturbances.

Question 2

A few thousand comets with perihelia very close to the Sun have been observed. These originate from

Accepted Answer

A)  the breakup of a single comet, so these comets all have very nearly the same orbit. 
B)  gravitational disturbances of the Oort cloud by a nearby star. 
C)  gravitational disturbances of the Kuiper belt by Jupiter. 
D)  gravitational disturbances of the Kuiper belt caused by resonances between Neptune and Kuiper belt objects. 
A)  the breakup of a single comet, so these comets all have very nearly the same orbit. 
B)  gravitational disturbances of the Oort cloud by a nearby star. 
C)  gravitational disturbances of the Kuiper belt by Jupiter. 
D)  gravitational disturbances of the Kuiper belt caused by resonances between Neptune and Kuiper belt objects.

Question 3

The size of the largest asteroid, Ceres, compared with the largest mare or impact basin on the Moon, which covers about one-quarter of the Moon's face, is

Accepted Answer

A)  not comparable because all asteroids are very small objects (1 km diameter), whereas most maria are large (100-1000 km diameter). 
B)  much smaller, only about 1/3 the size. 
C)  very similar, about 1000 km across. 
D)  much larger, by a factor of more than 2. 
A)  not comparable because all asteroids are very small objects (1 km diameter), whereas most maria are large (100-1000 km diameter). 
B)  much smaller, only about 1/3 the size. 
C)  very similar, about 1000 km across. 
D)  much larger, by a factor of more than 2.

Question 4

What was the purpose of the Stardust space probe?

Accepted Answer

A)  to plunge into the nucleus of a comet, throwing dust and icy grains out from under the comet's surface into space, where they can be seen and analyzed from Earth 
B)  to analyze dust samples from other stars and transmit the results back to Earth 
C)  to fly through the tail of a comet and transmit images back to Earth 
D)  to collect samples of comet material and bring them back to Earth 
A)  to plunge into the nucleus of a comet, throwing dust and icy grains out from under the comet's surface into space, where they can be seen and analyzed from Earth 
B)  to analyze dust samples from other stars and transmit the results back to Earth 
C)  to fly through the tail of a comet and transmit images back to Earth 
D)  to collect samples of comet material and bring them back to Earth

Question 5

The nucleus of a typical comet is

Accepted Answer

A)  irregular in shape, with a bright and very reflective, icy surface. 
B)  spherical, with a very smooth, dark surface. 
C)  irregular in shape, with a very dark and cratered surface. 
D)  spherical, smooth, and very light-colored, being composed mostly of ice. 
A)  irregular in shape, with a bright and very reflective, icy surface. 
B)  spherical, with a very smooth, dark surface. 
C)  irregular in shape, with a very dark and cratered surface. 
D)  spherical, smooth, and very light-colored, being composed mostly of ice.

Question 6

What is the approximate orbital period of a comet nucleus that orbits the Sun on the outer fringes of the Oort cloud?

Accepted Answer

A)  10 million years 
B)  10,000 years 
C)  100,000 years 
D)  1000 years 
A)  10 million years 
B)  10,000 years 
C)  100,000 years 
D)  1000 years

Question 7

On the basis of the recent interpretation of geological evidence, the impact of a 10-km-diameter asteroid on the surface of Earth would be very likely to

Accepted Answer

A)  disrupt the global ecology and cause the extinction of a large percentage of all species living on Earth. 
B)  create significant damage near the impact site but have relatively little lasting worldwide effect. 
C)  shatter Earth into fragments. 
D)  completely destroy life on Earth. 
A)  disrupt the global ecology and cause the extinction of a large percentage of all species living on Earth. 
B)  create significant damage near the impact site but have relatively little lasting worldwide effect. 
C)  shatter Earth into fragments. 
D)  completely destroy life on Earth.

Question 8

Interplanetary material

Accepted Answer

A)  falls on Earth at the rate of several hundred tons per day, mostly as micrometeoroids. 
B)  occasionally hits Earth in the form of fairly large objects that form craters, but there is no continuous stream of incoming matter. 
C)  hits Earth at specific times of the year in the form of small particles that produce meteor showers, but interplanetary material does not fall on Earth at other times. 
D)  falls on Earth only very rarely in the form of single large objects, but these individual impacts can devastate parts of Earth and threaten life. 
A)  falls on Earth at the rate of several hundred tons per day, mostly as micrometeoroids. 
B)  occasionally hits Earth in the form of fairly large objects that form craters, but there is no continuous stream of incoming matter. 
C)  hits Earth at specific times of the year in the form of small particles that produce meteor showers, but interplanetary material does not fall on Earth at other times. 
D)  falls on Earth only very rarely in the form of single large objects, but these individual impacts can devastate parts of Earth and threaten life.

Question 9

Which two spacecraft have taken detailed photographs of the surface of an asteroid?

Accepted Answer

A)  NEAR Shoemaker and Cassini 
B)  Hyabusa and NEAR Shoemaker 
C)  Magellan and Cassini 
D)  Voyager 1 and Galileo 
A)  NEAR Shoemaker and Cassini 
B)  Hyabusa and NEAR Shoemaker 
C)  Magellan and Cassini 
D)  Voyager 1 and Galileo

Question 10

The asteroid belt exists between the orbits of the planets

Accepted Answer

A)  Earth and Mars. 
B)  Jupiter and Saturn. 
C)  Venus and Earth. 
D)  Mars and Jupiter. 
A)  Earth and Mars. 
B)  Jupiter and Saturn. 
C)  Venus and Earth. 
D)  Mars and Jupiter.

Question 11

Which meteorites are believed to be samples of primordial solar nebula material?

Accepted Answer

A)  carbonaceous chondrites 
B)  stony irons 
C)  meteorites showing Widmanstätten patterns when etched with acid 
D)  irons 
A)  carbonaceous chondrites 
B)  stony irons 
C)  meteorites showing Widmanstätten patterns when etched with acid 
D)  irons

Question 12

The particular feature of a comet that points away from the Sun and can vary significantly over the course of a few days is its

Accepted Answer

A)  hydrogen envelope. 
B)  ion or gas tail. 
C)  coma, or gas cloud. 
D)  dust tail. 
A)  hydrogen envelope. 
B)  ion or gas tail. 
C)  coma, or gas cloud. 
D)  dust tail.

Question 13

The Allende meteorite contained an abundance of 26Mg, an isotope of magnesium. 26Mg is the stable product of the decay of radioactive 26Al. What is the significance?

Accepted Answer

A)  Magnesium has a high melting point, so the asteroid of which Allende was originally a part must have formed in the inner part of the solar system. 
B)  ( The decay of 26Al would have produced enough radioactivity to cause the melting and differentiation of the Allende meteoroid.) 
C)  The 26Al from which the 26Mg formed was probably produced in a nearby supernova explosion about the time the solar system was formed. 
D)  This discovery suggests that heavy elements such as magnesium were more abundant in the early Kuiper belt than originally thought. 
A)  Magnesium has a high melting point, so the asteroid of which Allende was originally a part must have formed in the inner part of the solar system. 
B)  ( The decay of 26Al would have produced enough radioactivity to cause the melting and differentiation of the Allende meteoroid.) 
C)  The 26Al from which the 26Mg formed was probably produced in a nearby supernova explosion about the time the solar system was formed. 
D)  This discovery suggests that heavy elements such as magnesium were more abundant in the early Kuiper belt than originally thought.

Question 14

A meteor shower, or the appearance of many more "shooting stars" at a particular time in the year from a specific sky direction, is related to which astronomical phenomenon?

Accepted Answer

A)  passage of Earth through the remnants of an old comet 
B)  passage of Earth through intense streams of solar wind 
C)  Earth's passage through part of the asteroid belt 
D)  Earth's passage through different parts of the spiral arms of the Galaxy 
A)  passage of Earth through the remnants of an old comet 
B)  passage of Earth through intense streams of solar wind 
C)  Earth's passage through part of the asteroid belt 
D)  Earth's passage through different parts of the spiral arms of the Galaxy

Question 15

At the end of the Permian era 250 million years ago, 80% of all species living on land and 90% of all species living in the oceans disappeared. Which of these is among the MOST plausible explanations for this massive extinction?

Accepted Answer

A)  global warming from volcanic gases released during the breakup of the Gondwanaland supercontinent 
B)  nearby supernova (the explosion and total destruction of a star) 
C)  devastating impact by an asteroid 
D)  "snowball Earth" episode in which global cooling caused Earth's ocean surfaces to freeze and glaciers to cover the continents 
A)  global warming from volcanic gases released during the breakup of the Gondwanaland supercontinent 
B)  nearby supernova (the explosion and total destruction of a star) 
C)  devastating impact by an asteroid 
D)  "snowball Earth" episode in which global cooling caused Earth's ocean surfaces to freeze and glaciers to cover the continents

Question 16

Which of these characteristics of carbonaceous chondrites is unusual compared with other meteorites?

Accepted Answer

A)  Carbonaceous chondrites never show Widmanstätten patterns. 
B)  Carbonaceous chondrites contain water-a sure sign that they have never melted. 
C)  Carbonaceous chondrites show a fusion crust-a sure sign of short-lived, rapid heating. 
D)  Carbonaceous chondrites contain rocky material-a sure sign that they come from a differentiated asteroid. 
A)  Carbonaceous chondrites never show Widmanstätten patterns. 
B)  Carbonaceous chondrites contain water-a sure sign that they have never melted. 
C)  Carbonaceous chondrites show a fusion crust-a sure sign of short-lived, rapid heating. 
D)  Carbonaceous chondrites contain rocky material-a sure sign that they come from a differentiated asteroid.

Question 17

How large does the coma, or gas cloud surrounding a comet nucleus, become when it reaches its closest point to the Sun?

Accepted Answer

A)  only 10 km, but it glows brightly in sunlight 
B)  about 106 km, as big as the Sun 
C)  about 108 km, close to the size of Mercury's orbit 
D)  about 107 km, close to 1/10 of Mercury's orbit 
A)  only 10 km, but it glows brightly in sunlight 
B)  about 106 km, as big as the Sun 
C)  about 108 km, close to the size of Mercury's orbit 
D)  about 107 km, close to 1/10 of Mercury's orbit

Question 18

What is unusual about the surface of Haumea's moons?

Accepted Answer

A)  It is solid rock. 
B)  It appears to be a mixture of rock and ice. 
C)  It is almost pure water ice. 
D)  It is almost perfectly round. 
A)  It is solid rock. 
B)  It appears to be a mixture of rock and ice. 
C)  It is almost pure water ice. 
D)  It is almost perfectly round.

Question 19

Why do astronomers believe that Earth's water could NOT have come from comets similar to Comet Churyumov-Gerasimenko?

Accepted Answer

A)  Comets do not come close enough to Earth's orbit. 
B)  There is not nearly enough water stored in the comet population to provide Earth's water. 
C)  That comet's water has a very different isotope ratio than Earth's water. 
D)  Comets were not formed until after Earth already had most of its water. 
A)  Comets do not come close enough to Earth's orbit. 
B)  There is not nearly enough water stored in the comet population to provide Earth's water. 
C)  That comet's water has a very different isotope ratio than Earth's water. 
D)  Comets were not formed until after Earth already had most of its water.

Question 20

Most meteor showers occur when Earth moves through the

Accepted Answer

A)  orbit of a comet (or of a former comet). 
B)  Kuiper belt. 
C)  asteroid belt. 
D)  Oort comet cloud. 
A)  orbit of a comet (or of a former comet). 
B)  Kuiper belt. 
C)  asteroid belt. 
D)  Oort comet cloud.

The cause of the meteor showers seen at regular times each year on Earth is MOST likely

A few thousand comets with perihelia very close to the Sun have been observed. These originate from

The size of the largest asteroid, Ceres, compared with the largest mare or impact basin on the Moon, which covers about one-quarter of the Moon's face, is

What was the purpose of the Stardust space probe?

The nucleus of a typical comet is

What is the approximate orbital period of a comet nucleus that orbits the Sun on the outer fringes of the Oort cloud?

On the basis of the recent interpretation of geological evidence, the impact of a 10-km-diameter asteroid on the surface of Earth would be very likely to

Interplanetary material

Which two spacecraft have taken detailed photographs of the surface of an asteroid?

The asteroid belt exists between the orbits of the planets

Which meteorites are believed to be samples of primordial solar nebula material?

The particular feature of a comet that points away from the Sun and can vary significantly over the course of a few days is its

The Allende meteorite contained an abundance of ²⁶Mg, an isotope of magnesium. ²⁶Mg is the stable product of the decay of radioactive ²⁶Al. What is the significance?

A meteor shower, or the appearance of many more "shooting stars" at a particular time in the year from a specific sky direction, is related to which astronomical phenomenon?

At the end of the Permian era 250 million years ago, 80% of all species living on land and 90% of all species living in the oceans disappeared. Which of these is among the MOST plausible explanations for this massive extinction?

Which of these characteristics of carbonaceous chondrites is unusual compared with other meteorites?

How large does the coma, or gas cloud surrounding a comet nucleus, become when it reaches its closest point to the Sun?

What is unusual about the surface of Haumea's moons?

Why do astronomers believe that Earth's water could NOT have come from comets similar to Comet Churyumov-Gerasimenko?

Most meteor showers occur when Earth moves through the

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

The cause of the meteor showers seen at regular times each year on Earth is MOST likely

A few thousand comets with perihelia very close to the Sun have been observed. These originate from

The size of the largest asteroid, Ceres, compared with the largest mare or impact basin on the Moon, which covers about one-quarter of the Moon's face, is

What was the purpose of the Stardust space probe?

The nucleus of a typical comet is

What is the approximate orbital period of a comet nucleus that orbits the Sun on the outer fringes of the Oort cloud?

On the basis of the recent interpretation of geological evidence, the impact of a 10-km-diameter asteroid on the surface of Earth would be very likely to

Interplanetary material

Which two spacecraft have taken detailed photographs of the surface of an asteroid?

The asteroid belt exists between the orbits of the planets

Which meteorites are believed to be samples of primordial solar nebula material?

The particular feature of a comet that points away from the Sun and can vary significantly over the course of a few days is its

The Allende meteorite contained an abundance of 26Mg, an isotope of magnesium. 26Mg is the stable product of the decay of radioactive 26Al. What is the significance?

A meteor shower, or the appearance of many more "shooting stars" at a particular time in the year from a specific sky direction, is related to which astronomical phenomenon?

At the end of the Permian era 250 million years ago, 80% of all species living on land and 90% of all species living in the oceans disappeared. Which of these is among the MOST plausible explanations for this massive extinction?

Which of these characteristics of carbonaceous chondrites is unusual compared with other meteorites?

How large does the coma, or gas cloud surrounding a comet nucleus, become when it reaches its closest point to the Sun?

What is unusual about the surface of Haumea's moons?

Why do astronomers believe that Earth's water could NOT have come from comets similar to Comet Churyumov-Gerasimenko?

Most meteor showers occur when Earth moves through the

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

The Allende meteorite contained an abundance of ²⁶Mg, an isotope of magnesium. ²⁶Mg is the stable product of the decay of radioactive ²⁶Al. What is the significance?