Question 1

There are now over 3700 known extrasolar planets. When astronomers consider them as possible homes for life, it is important to remember that MOST of them are

Accepted Answer

A)  Earthlike planets with water on their surfaces. 
B)  hydrogen-rich planets like Jupiter. 
C)  in extremely elliptical orbits, like comets. 
D)  still in the process of forming and thus not old enough to have evolved life. 
A)  Earthlike planets with water on their surfaces. 
B)  hydrogen-rich planets like Jupiter. 
C)  in extremely elliptical orbits, like comets. 
D)  still in the process of forming and thus not old enough to have evolved life.

Question 2

In which of these very harsh environments has life NOT been found on Earth?

Accepted Answer

A)  deep inside Earth's crust 
B)  in a lake locked far under the Antarctic ice pack 
C)  in the hot water within geothermal vents on the ocean floor 
D)  Life has been found in all of these environments. 
A)  deep inside Earth's crust 
B)  in a lake locked far under the Antarctic ice pack 
C)  in the hot water within geothermal vents on the ocean floor 
D)  Life has been found in all of these environments.

Question 3

What is the status of the search for life elsewhere in the universe?

Accepted Answer

A)  Life has been discovered elsewhere in the solar system. 
B)  Signs of life have been discovered on Earthlike planets circling other stars elsewhere in the Milky Way Galaxy. 
C)  Earthlike planets, with an abundance of liquid water, have been discovered around other stars, but signs of life have not yet been found on them. 
D)  Life has not yet been discovered elsewhere in the universe. 
A)  Life has been discovered elsewhere in the solar system. 
B)  Signs of life have been discovered on Earthlike planets circling other stars elsewhere in the Milky Way Galaxy. 
C)  Earthlike planets, with an abundance of liquid water, have been discovered around other stars, but signs of life have not yet been found on them. 
D)  Life has not yet been discovered elsewhere in the universe.

Question 4

It is unlikely that planets near stars much more massive than the Sun would develop life because

Accepted Answer

A)  planets would have to be too close to these cool stars in order to be sufficiently warm for life to evolve and they would become tidally linked, resulting in no night and day. 
B)  these stars would have evolved to red giant and even supernova stages before life could evolve sufficiently to produce a civilization. 
C)  no moon would form around a planet near such a star, and the Moon is considered to have been essential for the evolution of life because of tidal variations on Earth. 
D)  there would be no region around the star where ultraviolet, visible, and infrared light intensities would be suitable for the evolution of life. 
A)  planets would have to be too close to these cool stars in order to be sufficiently warm for life to evolve and they would become tidally linked, resulting in no night and day. 
B)  these stars would have evolved to red giant and even supernova stages before life could evolve sufficiently to produce a civilization. 
C)  no moon would form around a planet near such a star, and the Moon is considered to have been essential for the evolution of life because of tidal variations on Earth. 
D)  there would be no region around the star where ultraviolet, visible, and infrared light intensities would be suitable for the evolution of life.

Question 5

The Drake equation calculates the number of technologically advanced civilizations in the Galaxy as a product of seven factors: R* fp ne fl fi fc L. In the sample calculation in the text, these values are taken as 1 *1 * 0.2 * 1 * 1 * 1 * 500 = 100. Suppose this estimate is too conservative, in that all the factors that can in principle become larger are increased by a factor of ten. What would be the resulting number of technologically advanced civilizations in the Galaxy?

Accepted Answer

A)  100 
B)  105 
C)  107 
D)  109 
A)  100 
B)  105 
C)  107 
D)  109

Question 6

In the search for intelligent life, why do scientists tend to assume that its biochemistry is more likely to be based on the element carbon than on any other element?

Accepted Answer

A)  Carbon is the most versatile element, combining with the largest number of other elements in many different ways to produce long-chain molecules. 
B)  Carbon is the only element that can combine into ring-shaped molecules, which is the shape of life-form molecular structure. 
C)  Carbon releases far more energy than do other similar atoms when it combines with other elements, a process that is essential for the support of life. 
D)  Scientists expect that life will mimic that on the surface of Earth, which is carbon-based. 
A)  Carbon is the most versatile element, combining with the largest number of other elements in many different ways to produce long-chain molecules. 
B)  Carbon is the only element that can combine into ring-shaped molecules, which is the shape of life-form molecular structure. 
C)  Carbon releases far more energy than do other similar atoms when it combines with other elements, a process that is essential for the support of life. 
D)  Scientists expect that life will mimic that on the surface of Earth, which is carbon-based.

Question 7

Which of these phenomena was probably NOT a source of large organic molecules, the building blocks of life, on the early Earth?

Accepted Answer

A)  comets 
B)  meteorites 
C)  lightning flashes in the early terrestrial atmosphere 
D)  volcanic eruptions 
A)  comets 
B)  meteorites 
C)  lightning flashes in the early terrestrial atmosphere 
D)  volcanic eruptions

Question 8

Around which types of stars are astronomers MOST likely to find planets supporting life similar to that of Earth?

Accepted Answer

A)  high-mass main-sequence stars 
B)  red giant stars 
C)  very low-mass stars 
D)  None of these answers are correct. 
A)  high-mass main-sequence stars 
B)  red giant stars 
C)  very low-mass stars 
D)  None of these answers are correct.

Question 9

One aspect of astrobiology is the attempt to replicate the steps in the process that led to the creation and evolution of life. An important step occurred in 2010 when

Accepted Answer

A)  living organisms were discovered on a carbonaceous chondrite meteorite. 
B)  a living virus was created in a laboratory. 
C)  a simple artificial cell was fabricated. 
D)  organic structures were discovered in the Martian meteorite ALH84001. 
A)  living organisms were discovered on a carbonaceous chondrite meteorite. 
B)  a living virus was created in a laboratory. 
C)  a simple artificial cell was fabricated. 
D)  organic structures were discovered in the Martian meteorite ALH84001.

Question 10

Which wavelength range in the electromagnetic spectrum has been the MOST fruitful in the search for complex organic molecules in space?

Accepted Answer

A)  gamma radiation 
B)  visible radiation 
C)  ultraviolet radiation 
D)  microwaves and short-wavelength radio waves 
A)  gamma radiation 
B)  visible radiation 
C)  ultraviolet radiation 
D)  microwaves and short-wavelength radio waves

Question 11

Several lines of evidence now suggest that large and complex organic molecules can exist or could evolve in outer space, from which the building blocks of life could be formed. Which of these is NOT one of these observational findings?

Accepted Answer

A)  radio astronomical observations of large organic molecules in giant molecular clouds 
B)  discovery of organic molecules inside some meteorites 
C)  discovery by the Viking landers of large organic molecules in the Martian regolith 
D)  laboratory experiments in which electrical sparks passing through a combination of simple gases such as H2O, H2, N2, and CO2 produced large organic molecules 
A)  radio astronomical observations of large organic molecules in giant molecular clouds 
B)  discovery of organic molecules inside some meteorites 
C)  discovery by the Viking landers of large organic molecules in the Martian regolith 
D)  laboratory experiments in which electrical sparks passing through a combination of simple gases such as H2O, H2, N2, and CO2 produced large organic molecules

There are now over 3700 known extrasolar planets. When astronomers consider them as possible homes for life, it is important to remember that MOST of them are

In which of these very harsh environments has life NOT been found on Earth?

What is the status of the search for life elsewhere in the universe?

It is unlikely that planets near stars much more massive than the Sun would develop life because

In the search for intelligent life, why do scientists tend to assume that its biochemistry is more likely to be based on the element carbon than on any other element?

Which of these phenomena was probably NOT a source of large organic molecules, the building blocks of life, on the early Earth?

Around which types of stars are astronomers MOST likely to find planets supporting life similar to that of Earth?

One aspect of astrobiology is the attempt to replicate the steps in the process that led to the creation and evolution of life. An important step occurred in 2010 when

Which wavelength range in the electromagnetic spectrum has been the MOST fruitful in the search for complex organic molecules in space?

Several lines of evidence now suggest that large and complex organic molecules can exist or could evolve in outer space, from which the building blocks of life could be formed. Which of these is NOT one of these observational findings?

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

There are now over 3700 known extrasolar planets. When astronomers consider them as possible homes for life, it is important to remember that MOST of them are

In which of these very harsh environments has life NOT been found on Earth?

What is the status of the search for life elsewhere in the universe?

It is unlikely that planets near stars much more massive than the Sun would develop life because

In the search for intelligent life, why do scientists tend to assume that its biochemistry is more likely to be based on the element carbon than on any other element?

Which of these phenomena was probably NOT a source of large organic molecules, the building blocks of life, on the early Earth?

Around which types of stars are astronomers MOST likely to find planets supporting life similar to that of Earth?

One aspect of astrobiology is the attempt to replicate the steps in the process that led to the creation and evolution of life. An important step occurred in 2010 when

Which wavelength range in the electromagnetic spectrum has been the MOST fruitful in the search for complex organic molecules in space?

Several lines of evidence now suggest that large and complex organic molecules can exist or could evolve in outer space, from which the building blocks of life could be formed. Which of these is NOT one of these observational findings?

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