Question 1

The primary constituents for the organic molecules needed for life do NOT include which of these compounds?

Accepted Answer

A)  oxygen 
B)  sulfur 
C)  carbon 
D)  silicon 
A)  oxygen 
B)  sulfur 
C)  carbon 
D)  silicon

Question 2

What is the status of the search for extraterrestrial intelligence?

Accepted Answer

A)  The search must rely upon only small, inexpensive TV satellite antennas, and thus most astronomers believe it cannot succeed. 
B)  Astronomers have received on several occasions repeated signals that appear to be from some intelligent source, but they are waiting to receive one from the vicinity of an Earthlike planet before declaring that SETI has made contact with an extraterrestrial race. 
C)  Because of funding limitations the entire program has been terminated and is no longer active. 
D)  Astronomers have occasionally detected particularly strong or unusual signals from space, but they have not been repeated so astronomers do not believe they are from an intelligent source. 
A)  The search must rely upon only small, inexpensive TV satellite antennas, and thus most astronomers believe it cannot succeed. 
B)  Astronomers have received on several occasions repeated signals that appear to be from some intelligent source, but they are waiting to receive one from the vicinity of an Earthlike planet before declaring that SETI has made contact with an extraterrestrial race. 
C)  Because of funding limitations the entire program has been terminated and is no longer active. 
D)  Astronomers have occasionally detected particularly strong or unusual signals from space, but they have not been repeated so astronomers do not believe they are from an intelligent source.

Question 3

Which of these ideas has been borne out by actual astronomical observations over the past few centuries?

Accepted Answer

A)  The probability of life existing elsewhere in the universe, even elsewhere in the solar system, is extremely great. 
B)  Earth appears to occupy a unique position in the universe, unrepeated anywhere, since the Sun is unique in properties and position in a remarkable galaxy. 
C)  All the observational evidence so far suggests that conditions for the evolution of life exist only on Earth in its position near the Sun. 
D)  The Sun is an unremarkable star in a commonplace galaxy, and many similar stars exist in the universe around which life might evolve on planets. 
A)  The probability of life existing elsewhere in the universe, even elsewhere in the solar system, is extremely great. 
B)  Earth appears to occupy a unique position in the universe, unrepeated anywhere, since the Sun is unique in properties and position in a remarkable galaxy. 
C)  All the observational evidence so far suggests that conditions for the evolution of life exist only on Earth in its position near the Sun. 
D)  The Sun is an unremarkable star in a commonplace galaxy, and many similar stars exist in the universe around which life might evolve on planets.

Question 4

Which of these characteristics is NOT usually taken to be sufficient to rule out the existence of life on an extrasolar planet?

Accepted Answer

A)  planet is too close to the star 
B)  star is 20 times more massive than the Sun 
C)  a planet in synchronous rotation around its star 
D)  star is older than the Sun 
A)  planet is too close to the star 
B)  star is 20 times more massive than the Sun 
C)  a planet in synchronous rotation around its star 
D)  star is older than the Sun

Question 5

Existing telescopes are capable of detecting radio signals similar to those generated by humans from

Accepted Answer

A)  about a dozen or so of the closest stars. 
B)  any star around which planets have been detected. 
C)  any star within a 100 pc or so of the solar system. 
D)  stars in giant elliptical galaxies since these stars, being oldest, are most likely to have advanced civilizations. 
A)  about a dozen or so of the closest stars. 
B)  any star around which planets have been detected. 
C)  any star within a 100 pc or so of the solar system. 
D)  stars in giant elliptical galaxies since these stars, being oldest, are most likely to have advanced civilizations.

Question 6

How often do Sunlike stars (of a type considered likely to be circled by an inhabitable planet) form in the Milky Way Galaxy, on average?

Accepted Answer

A)  Hundreds of such stars form per year. 
B)  About one such star forms per year. 
C)  Astronomers cannot yet answer this question. 
D)  Less than one such star forms per thousand years. 
A)  Hundreds of such stars form per year. 
B)  About one such star forms per year. 
C)  Astronomers cannot yet answer this question. 
D)  Less than one such star forms per thousand years.

Question 7

One of the great lessons being learned from modern astronomy is that

Accepted Answer

A)  Earth occupies a unique position in the universe, and nowhere else are conditions equivalent to those in the solar system likely to be found. 
B)  Earth's position and circumstances in the universe are quite ordinary and certainly not unique. 
C)  the chemistry, geology, and physics on Earth are unique to it, and the behavior of matter anywhere else appears to be significantly different from that on Earth. 
D)  Earth is at the center of a very massive black hole, and all the observed cosmological effects such as redshift and cosmic background radiation and even the evolution of life are a consequence of the unique position Earth occupies. 
A)  Earth occupies a unique position in the universe, and nowhere else are conditions equivalent to those in the solar system likely to be found. 
B)  Earth's position and circumstances in the universe are quite ordinary and certainly not unique. 
C)  the chemistry, geology, and physics on Earth are unique to it, and the behavior of matter anywhere else appears to be significantly different from that on Earth. 
D)  Earth is at the center of a very massive black hole, and all the observed cosmological effects such as redshift and cosmic background radiation and even the evolution of life are a consequence of the unique position Earth occupies.

Question 8

Why is the strategy of searches for extraterrestrial life usually based on carbon chemistry?

Accepted Answer

A)  Carbon dioxide is the main ingredient of planetary atmospheres, both terrestrial and Jovian. 
B)  No other atom can combine easily with the abundant hydrogen and helium to form long molecules in interstellar gas. 
C)  Most meteorites that reach Earth are composed of carbon. 
D)  Carbon is abundant and is versatile in forming complex, long-chain molecules. 
A)  Carbon dioxide is the main ingredient of planetary atmospheres, both terrestrial and Jovian. 
B)  No other atom can combine easily with the abundant hydrogen and helium to form long molecules in interstellar gas. 
C)  Most meteorites that reach Earth are composed of carbon. 
D)  Carbon is abundant and is versatile in forming complex, long-chain molecules.

Question 9

Which of these characteristics of carbon is NOT considered essential to the chemistry of life?

Accepted Answer

A)  It can bond with three or more atoms. 
B)  The bonds it forms are covalent rather than ionic. 
C)  Its bonds are both strong and flexible. 
D)  Its bonds create gels and liquids. 
A)  It can bond with three or more atoms. 
B)  The bonds it forms are covalent rather than ionic. 
C)  Its bonds are both strong and flexible. 
D)  Its bonds create gels and liquids.

Question 10

At the present time, the search for extraterrestrial life in the solar system has been concentrated on a few bodies. These do NOT include

Accepted Answer

A)  Venus. 
B)  Mars. 
C)  Europa. 
D)  Callisto. 
A)  Venus. 
B)  Mars. 
C)  Europa. 
D)  Callisto.

Question 11

There have been many reports of aliens from other planets visiting Earth. Many of these reports include contacts with humans. How many of these reports have yielded scientific evidence that was analyzed to confirm the encounter?

Accepted Answer

A)  none 
B)  one 
C)  four 
D)  dozens 
A)  none 
B)  one 
C)  four 
D)  dozens

Question 12

The first successful detection of signals from extraterrestrial civilizations was accomplished in which year?

Accepted Answer

A)  1985 
B)  Never-no such signals have been detected yet. 
C)  1999 
D)  1960 
A)  1985 
B)  Never-no such signals have been detected yet. 
C)  1999 
D)  1960

Question 13

The so-called water hole is a range in the electromagnetic spectrum in which searches for transmissions of extraterrestrial origin are being conducted. In what region of the electromagnetic spectrum does the water hole occur?

Accepted Answer

A)  ultraviolet 
B)  visible 
C)  infrared 
D)  radio 
A)  ultraviolet 
B)  visible 
C)  infrared 
D)  radio

Question 14

For which of these factors in the Drake equation do astronomers actually have observational knowledge rather than just a speculative estimate?

Accepted Answer

A)  R*, the rate at which solar-type stars form in the Galaxy 
B)  fl, the fraction of Earthlike planets on which life actually arises 
C)  fi, the fraction of life-forms that evolve into intelligent species 
D)  fc, the fraction of intelligent species that develop adequate technology and then choose to send messages out into space 
A)  R*, the rate at which solar-type stars form in the Galaxy 
B)  fl, the fraction of Earthlike planets on which life actually arises 
C)  fi, the fraction of life-forms that evolve into intelligent species 
D)  fc, the fraction of intelligent species that develop adequate technology and then choose to send messages out into space

Question 15

Life has been found on Earth in a lake deep under the Antarctic ice pack. This resembles what other environment in the solar system that has been considered a possible location for life?

Accepted Answer

A)  the surface of ancient Mars 
B)  Venus 
C)  Europa 
D)  Miranda 
A)  the surface of ancient Mars 
B)  Venus 
C)  Europa 
D)  Miranda

Question 16

Is a planet with a large, nearby moon more likely to evolve life than a planet without a moon?

Accepted Answer

A)  No. There is no reason to believe the existence of a moon has any effect on the evolution of life. 
B)  Yes. A planet almost certainly must have liquid water to evolve life. A moon will raise tides, which can help to wash minerals into the water where it can provide a rich mixture conducive to the evolution of life. 
C)  Yes. A moon can help shield a planet from impacts which could destroy life in its early, formative stages. 
D)  The gravitational pull of a moon can help a planet establish a rhythmic day/night cycle which is important for the evolution of life. 
A)  No. There is no reason to believe the existence of a moon has any effect on the evolution of life. 
B)  Yes. A planet almost certainly must have liquid water to evolve life. A moon will raise tides, which can help to wash minerals into the water where it can provide a rich mixture conducive to the evolution of life. 
C)  Yes. A moon can help shield a planet from impacts which could destroy life in its early, formative stages. 
D)  The gravitational pull of a moon can help a planet establish a rhythmic day/night cycle which is important for the evolution of life.

Question 17

If humans do eventually make contact with other civilizations in the Milky Way, which of these conditions will inevitably hold?

Accepted Answer

A)  Humans will not be able to understand the messages. 
B)  The civilization is likely to be very much more technologically primitive than ours. 
C)  Conversations will take a very long time. 
D)  The chemistry and biology of the life-forms are likely to be very different from ours-for example, silicon-based rather than carbon-based. 
A)  Humans will not be able to understand the messages. 
B)  The civilization is likely to be very much more technologically primitive than ours. 
C)  Conversations will take a very long time. 
D)  The chemistry and biology of the life-forms are likely to be very different from ours-for example, silicon-based rather than carbon-based.

Question 18

What conditions restrict the suitable wavelength range for communication with extraterrestrial intelligence to the "water hole" in the high-frequency radio range of the electromagnetic spectrum?

Accepted Answer

A)  cosmic background radio noise at low frequencies and radio noise from the Sun and Jupiter at high frequencies 
B)  local radio noise from television, radio, and aircraft across the band, except a narrow range in which transmission is prohibited by international agreement to permit such extraterrestrial communication 
C)  atmospheric absorption by the ionosphere at low frequencies and by CO2 at high frequencies in the long infrared range 
D)  high galactic radio background noise at low frequencies and high atmospheric absorption by H2O and O2 at high frequencies, with a suitable region in between 
A)  cosmic background radio noise at low frequencies and radio noise from the Sun and Jupiter at high frequencies 
B)  local radio noise from television, radio, and aircraft across the band, except a narrow range in which transmission is prohibited by international agreement to permit such extraterrestrial communication 
C)  atmospheric absorption by the ionosphere at low frequencies and by CO2 at high frequencies in the long infrared range 
D)  high galactic radio background noise at low frequencies and high atmospheric absorption by H2O and O2 at high frequencies, with a suitable region in between

Question 19

The Miller-Urey experiments consisted of

Accepted Answer

A)  sending a coded message via radio toward nearby stars that are similar to the Sun and may have planets. 
B)  attaching a metal plaque to the Voyager spacecraft to tell extraterrestrial beings about Earth, should the spacecraft ever be recovered. 
C)  monitoring tens of millions of radio frequencies at once in an effort to detect extraterrestrial radio communications. 
D)  passing an electrical arc through a mixture of hydrogen, ammonia, methane, and water and looking for resulting organic compounds. 
A)  sending a coded message via radio toward nearby stars that are similar to the Sun and may have planets. 
B)  attaching a metal plaque to the Voyager spacecraft to tell extraterrestrial beings about Earth, should the spacecraft ever be recovered. 
C)  monitoring tens of millions of radio frequencies at once in an effort to detect extraterrestrial radio communications. 
D)  passing an electrical arc through a mixture of hydrogen, ammonia, methane, and water and looking for resulting organic compounds.

Question 20

The basic chemical molecules thought to have been present in abundance in the early planetary system, which were used in the classical Miller-Urey laboratory experiments in which complex compounds essential to life were formed by electric discharges, were

Accepted Answer

A)  CO2 (carbon dioxide), H2O (water), and H2 (hydrogen). 
B)  H2 (hydrogen), O2 (oxygen), and CO2 (carbon dioxide). 
C)  CH4 (methane), NH3 (ammonia), H2O (water), and H2 (hydrogen). 
D)  H2 (hydrogen), He (helium), Ar (argon), and Ne (neon). 
A)  CO2 (carbon dioxide), H2O (water), and H2 (hydrogen). 
B)  H2 (hydrogen), O2 (oxygen), and CO2 (carbon dioxide). 
C)  CH4 (methane), NH3 (ammonia), H2O (water), and H2 (hydrogen). 
D)  H2 (hydrogen), He (helium), Ar (argon), and Ne (neon).

The primary constituents for the organic molecules needed for life do NOT include which of these compounds?

What is the status of the search for extraterrestrial intelligence?

Which of these ideas has been borne out by actual astronomical observations over the past few centuries?

Which of these characteristics is NOT usually taken to be sufficient to rule out the existence of life on an extrasolar planet?

Existing telescopes are capable of detecting radio signals similar to those generated by humans from

How often do Sunlike stars (of a type considered likely to be circled by an inhabitable planet) form in the Milky Way Galaxy, on average?

One of the great lessons being learned from modern astronomy is that

Why is the strategy of searches for extraterrestrial life usually based on carbon chemistry?

Which of these characteristics of carbon is NOT considered essential to the chemistry of life?

At the present time, the search for extraterrestrial life in the solar system has been concentrated on a few bodies. These do NOT include

There have been many reports of aliens from other planets visiting Earth. Many of these reports include contacts with humans. How many of these reports have yielded scientific evidence that was analyzed to confirm the encounter?

The first successful detection of signals from extraterrestrial civilizations was accomplished in which year?

The so-called water hole is a range in the electromagnetic spectrum in which searches for transmissions of extraterrestrial origin are being conducted. In what region of the electromagnetic spectrum does the water hole occur?

For which of these factors in the Drake equation do astronomers actually have observational knowledge rather than just a speculative estimate?

Life has been found on Earth in a lake deep under the Antarctic ice pack. This resembles what other environment in the solar system that has been considered a possible location for life?

Is a planet with a large, nearby moon more likely to evolve life than a planet without a moon?

If humans do eventually make contact with other civilizations in the Milky Way, which of these conditions will inevitably hold?

What conditions restrict the suitable wavelength range for communication with extraterrestrial intelligence to the "water hole" in the high-frequency radio range of the electromagnetic spectrum?

The Miller-Urey experiments consisted of

The basic chemical molecules thought to have been present in abundance in the early planetary system, which were used in the classical Miller-Urey laboratory experiments in which complex compounds essential to life were formed by electric discharges, were

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

Vagabonds of the Solar System

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

Filters

Exam 20: Astrobiology

The primary constituents for the organic molecules needed for life do NOT include which of these compounds?

What is the status of the search for extraterrestrial intelligence?

Which of these ideas has been borne out by actual astronomical observations over the past few centuries?

Which of these characteristics is NOT usually taken to be sufficient to rule out the existence of life on an extrasolar planet?

Existing telescopes are capable of detecting radio signals similar to those generated by humans from

How often do Sunlike stars (of a type considered likely to be circled by an inhabitable planet) form in the Milky Way Galaxy, on average?

One of the great lessons being learned from modern astronomy is that

Why is the strategy of searches for extraterrestrial life usually based on carbon chemistry?

Which of these characteristics of carbon is NOT considered essential to the chemistry of life?

At the present time, the search for extraterrestrial life in the solar system has been concentrated on a few bodies. These do NOT include

There have been many reports of aliens from other planets visiting Earth. Many of these reports include contacts with humans. How many of these reports have yielded scientific evidence that was analyzed to confirm the encounter?

The first successful detection of signals from extraterrestrial civilizations was accomplished in which year?

The so-called water hole is a range in the electromagnetic spectrum in which searches for transmissions of extraterrestrial origin are being conducted. In what region of the electromagnetic spectrum does the water hole occur?

For which of these factors in the Drake equation do astronomers actually have observational knowledge rather than just a speculative estimate?

Life has been found on Earth in a lake deep under the Antarctic ice pack. This resembles what other environment in the solar system that has been considered a possible location for life?

Is a planet with a large, nearby moon more likely to evolve life than a planet without a moon?

If humans do eventually make contact with other civilizations in the Milky Way, which of these conditions will inevitably hold?

What conditions restrict the suitable wavelength range for communication with extraterrestrial intelligence to the "water hole" in the high-frequency radio range of the electromagnetic spectrum?

The Miller-Urey experiments consisted of

The basic chemical molecules thought to have been present in abundance in the early planetary system, which were used in the classical Miller-Urey laboratory experiments in which complex compounds essential to life were formed by electric discharges, were

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

Vagabonds of the Solar System

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

Filters