Question 1

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)  We have received on several occasions repeated signals that appear to be from some intelligent source, but we 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C)  Because of funding limitations, the entire program has been terminated and is no longer active.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)  We have occasionally detected particularly strong or unusual signals from space, but they have not been repeated, so we 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)  We have received on several occasions repeated signals that appear to be from some intelligent source, but we 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C)  Because of funding limitations, the entire program has been terminated and is no longer active.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)  We have occasionally detected particularly strong or unusual signals from space, but they have not been repeated, so we do not believe they are from an intelligent source.

Question 2

Is a planet with a moon thought 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 that 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 that 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 3

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)  We 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)  We cannot yet answer this question. 
D)  Less than one such star forms per thousand years.

Question 4

Which observation regarding the likelihood of life existing elsewhere in the universe has NOT yet been made?

Accepted Answer

A)  the discovery of assemblies of organic molecules into cell-like, self-replicating structures in the soils of Mars and the atmosphere of Venus 
B)  the discovery of long-chain carbon-based molecules in interstellar clouds by radio astronomers 
C)  the manufacture of organic compounds in laboratory simulations of primordial planetary atmospheres 
D)  the discovery of long-chain amino acid protein molecules in meteorites 
A)  the discovery of assemblies of organic molecules into cell-like, self-replicating structures in the soils of Mars and the atmosphere of Venus 
B)  the discovery of long-chain carbon-based molecules in interstellar clouds by radio astronomers 
C)  the manufacture of organic compounds in laboratory simulations of primordial planetary atmospheres 
D)  the discovery of long-chain amino acid protein molecules in meteorites

Question 5

Which type of meteorite was found to contain large organic molecules that make up the building blocks of life and provide strong evidence for their extraterrestrial production?

Accepted Answer

A)  iron 
B)  stony iron 
C)  carboneous chondrite 
D)  stony 
A)  iron 
B)  stony iron 
C)  carboneous chondrite 
D)  stony

Question 6

For which factor in the Drake equation do we 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 7

Why do we NOT consider stars with masses more than about 1.5 solar masses in the Drake equation when estimating the number of possible stars in the Milky Way Galaxy around which planets could form that would support our kind of intelligent life?

Accepted Answer

A)  More massive stars would produce massive planets on which life would not be possible. 
B)  More massive stars would never reach temperatures sufficient to maintain life-supporting conditions on the surfaces of its planets. 
C)  A more massive star would produce so much damaging UV radiation that it would sterilize its planets. 
D)  More massive stars would have evolved so rapidly that an advanced civilization would not have had time to evolve and develop. 
A)  More massive stars would produce massive planets on which life would not be possible. 
B)  More massive stars would never reach temperatures sufficient to maintain life-supporting conditions on the surfaces of its planets. 
C)  A more massive star would produce so much damaging UV radiation that it would sterilize its planets. 
D)  More massive stars would have evolved so rapidly that an advanced civilization would not have had time to evolve and develop.

Question 8

One of the "quiet" bands in the electromagnetic spectrum used for SETI is the so-called "water hole" between about 10³ and 10⁴ MHz.What is the principal source of the natural signals in this frequency band?

Accepted Answer

A)  emissions from the water molecule 
B)  emissions from oxygen molecules 
C)  cosmic microwave background radiation 
D)  radio emission from terrestrial sources 
A)  emissions from the water molecule 
B)  emissions from oxygen molecules 
C)  cosmic microwave background radiation 
D)  radio emission from terrestrial sources

Question 9

On which object in our planetary system is it NOT likely that life exists or existed at an earlier time?

Accepted Answer

A)  Mars 
B)  Callisto, a moon of Jupiter 
C)  Europa, a moon of Jupiter 
D)  Io, a moon of Jupiter 
A)  Mars 
B)  Callisto, a moon of Jupiter 
C)  Europa, a moon of Jupiter 
D)  Io, a moon of Jupiter

Question 10

The Drake equation attempts to predict the:

Accepted Answer

A)  number of inhabitable planets around stars in the Milky Way Galaxy. 
B)  number of intelligent civilizations that exist in the whole universe. 
C)  probability of primitive life existing elsewhere in the Milky Way Galaxy. 
D)  number of technically advanced civilizations in the Milky Way Galaxy. 
A)  number of inhabitable planets around stars in the Milky Way Galaxy. 
B)  number of intelligent civilizations that exist in the whole universe. 
C)  probability of primitive life existing elsewhere in the Milky Way Galaxy. 
D)  number of technically advanced civilizations in the Milky Way Galaxy.

Question 11

The Miller-Urey "experiment" 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 us, 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 us, 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 12

Why would intelligent alien beings wanting to communicate with us probably choose the 21-cm atomic hydrogen radio wavelength?

Accepted Answer

A)  This wavelength shows a very strong Doppler effect when its source is moving, and intelligent alien beings would know that we would be able to detect the orbital motion of their home planet around their star by this method. 
B)  Intelligent alien beings would expect that many of our telescopes would already be tuned to this precise wavelength for scientific work. 
C)  This radiation at this particular wavelength is very weak from natural sources in space, and messages would be easily distinguished from other sources. 
D)  Intelligent alien beings would have detected this particular wavelength from our transmitters on Earth since it is used extensively for satellite communications, and they would know that we could detect them easily. 
A)  This wavelength shows a very strong Doppler effect when its source is moving, and intelligent alien beings would know that we would be able to detect the orbital motion of their home planet around their star by this method. 
B)  Intelligent alien beings would expect that many of our telescopes would already be tuned to this precise wavelength for scientific work. 
C)  This radiation at this particular wavelength is very weak from natural sources in space, and messages would be easily distinguished from other sources. 
D)  Intelligent alien beings would have detected this particular wavelength from our transmitters on Earth since it is used extensively for satellite communications, and they would know that we could detect them easily.

Question 13

In a few decades,a new generation of powerful telescopes especially designed to find extrasolar planets may be operational and sending us data.What might these results mean for our use of the Drake equation?

Accepted Answer

A)  With these results in hand, the Drake equation will become irrelevant. 
B)  The structure of the Drake equation itself will undoubtedly have to be drastically revised. 
C)  We will have much better values for the factors fp (the fraction of stars that have planets) and nₑ (the number of planets per solar system that are Earthlike). 
D)  We will have much better values for the factors fl (the fraction of Earthlike planets on which life actually arises), fᵢ (the fraction of life-forms that evolve into intelligent species), and fc (the fraction of intelligent species that develop adequate technology and then choose to send messages out into space). 
A)  With these results in hand, the Drake equation will become irrelevant. 
B)  The structure of the Drake equation itself will undoubtedly have to be drastically revised. 
C)  We will have much better values for the factors fp (the fraction of stars that have planets) and nₑ (the number of planets per solar system that are Earthlike). 
D)  We will have much better values for the factors fl (the fraction of Earthlike planets on which life actually arises), fᵢ (the fraction of life-forms that evolve into intelligent species), and fc (the fraction of intelligent species that develop adequate technology and then choose to send messages out into space).

What is the status of the search for extraterrestrial intelligence?

Is a planet with a moon thought more likely to evolve life than a planet without a moon?

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?

Which observation regarding the likelihood of life existing elsewhere in the universe has NOT yet been made?

Which type of meteorite was found to contain large organic molecules that make up the building blocks of life and provide strong evidence for their extraterrestrial production?

For which factor in the Drake equation do we actually have observational knowledge rather than just a speculative estimate?

Why do we NOT consider stars with masses more than about 1.5 solar masses in the Drake equation when estimating the number of possible stars in the Milky Way Galaxy around which planets could form that would support our kind of intelligent life?

One of the "quiet" bands in the electromagnetic spectrum used for SETI is the so-called "water hole" between about 10³ and 10⁴ MHz.What is the principal source of the natural signals in this frequency band?

On which object in our planetary system is it NOT likely that life exists or existed at an earlier time?

The Drake equation attempts to predict the:

The Miller-Urey "experiment" consisted of:

Why would intelligent alien beings wanting to communicate with us probably choose the 21-cm atomic hydrogen radio wavelength?

In a few decades,a new generation of powerful telescopes especially designed to find extrasolar planets may be operational and sending us data.What might these results mean for our use of the Drake equation?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Filters

Exam 15: Astrobiology

What is the status of the search for extraterrestrial intelligence?

Is a planet with a moon thought more likely to evolve life than a planet without a moon?

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?

Which observation regarding the likelihood of life existing elsewhere in the universe has NOT yet been made?

Which type of meteorite was found to contain large organic molecules that make up the building blocks of life and provide strong evidence for their extraterrestrial production?

For which factor in the Drake equation do we actually have observational knowledge rather than just a speculative estimate?

Why do we NOT consider stars with masses more than about 1.5 solar masses in the Drake equation when estimating the number of possible stars in the Milky Way Galaxy around which planets could form that would support our kind of intelligent life?

One of the "quiet" bands in the electromagnetic spectrum used for SETI is the so-called "water hole" between about 10³ and 10⁴ MHz.What is the principal source of the natural signals in this frequency band?

On which object in our planetary system is it NOT likely that life exists or existed at an earlier time?

The Drake equation attempts to predict the:

The Miller-Urey "experiment" consisted of:

Why would intelligent alien beings wanting to communicate with us probably choose the 21-cm atomic hydrogen radio wavelength?

In a few decades,a new generation of powerful telescopes especially designed to find extrasolar planets may be operational and sending us data.What might these results mean for our use of the Drake equation?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

The Galaxies

Cosmology

Filters