Question 1

Why is Earth a stronger radio emitter than the Sun?

Accepted Answer

Since many commercial FM radio stations have come on the air,we have been emitting a large amount of radio signals into space.

Question 2

Why does SETI concentrate on the water hole?

Accepted Answer

The interval between the H and hydroxyl molecules is a very quiet part of the radio spectrum.

Question 3

In terms of temperature alone,there are ________ terrestrial planets within the widest boundaries of the Sun's zone of habitability.

Accepted Answer

three

Question 4

Why is the hypothesis that life on Earth came from outer space considered plausible?

Accepted Answer

A)  because alien DNA is like human DNA 
B)  because organic molecules have been found in space 
C)  because many meteorites contain complex organic molecules 
D)  because Earth has had many collisions in its history 
E)  because Earth formed with the Sun from the solar nebula 
A)  because alien DNA is like human DNA 
B)  because organic molecules have been found in space 
C)  because many meteorites contain complex organic molecules 
D)  because Earth has had many collisions in its history 
E)  because Earth formed with the Sun from the solar nebula

Question 5

Conducted in 1953,the ________ experiments were designed to show what types of complex molecules might have formed in the Earth's primitive environment.

Accepted Answer

The answer of Conducted in 1953,the ________ experiments were designed...

Question 6

Comet impacts might have been a good mechanism for seeding the hot early Earth with the water and molecules of life.

Accepted Answer

A) True 
 B)False

Question 7

Which of these does Mars NOT have to help its case of past or present life?

Accepted Answer

A)  occasional water flows, and past records of much larger ones 
B)  a protective ozone layer 
C)  carbon dioxide to provide some greenhouse warming 
D)  a favorable distance from the Sun 
E)  rover discoveries of sedimentary rocks and carbonates on the surface of Mars 
A)  occasional water flows, and past records of much larger ones 
B)  a protective ozone layer 
C)  carbon dioxide to provide some greenhouse warming 
D)  a favorable distance from the Sun 
E)  rover discoveries of sedimentary rocks and carbonates on the surface of Mars

Question 8

Organic molecules are:

Accepted Answer

A)  living cells. 
B)  carbon-based. 
C)  silicon-based. 
D)  found only on Earth. 
E)  not found outside our solar system. 
A)  living cells. 
B)  carbon-based. 
C)  silicon-based. 
D)  found only on Earth. 
E)  not found outside our solar system.

Question 9

In terms of its thick and chemically active atmosphere of hydrocarbons,which jovian moon was visited by the Huygens probe in 2005?

Accepted Answer

A)  Europa 
B)  Triton 
C)  Titan 
D)  Titania 
E)  Enceladus 
A)  Europa 
B)  Triton 
C)  Titan 
D)  Titania 
E)  Enceladus

Question 10

Europa is the most promising of the bodies in the outer solar system for life in its salty seas.

Accepted Answer

A) True 
 B)False

Question 11

Why are type O,A,and M stars considered poor candidates to find a technological civilization?

Accepted Answer

Considering the time it took life on Ear

Question 12

Most SETI searches are done at:

Accepted Answer

A)  X-ray wavelengths. 
B)  infrared wavelengths. 
C)  visual wavelengths. 
D)  radio wavelengths. 
E)  gamma wavelengths. 
A)  X-ray wavelengths. 
B)  infrared wavelengths. 
C)  visual wavelengths. 
D)  radio wavelengths. 
E)  gamma wavelengths.

Question 13

Our earliest atmosphere,formed by outgassing,was much poorer in ________ than now.

Accepted Answer

The answer of Our earliest atmosphere,formed by outgassing,was much poorer...

Question 14

The ________ habitable zone is set by the activity of the nucleus on the inside,and the rate of star formation and proper chemistry on the outside.

Accepted Answer

The answer of The ________ habitable zone is set by...

Question 15

Of the terrestrial planets,Mars seems to most promising to exobiologists.

Accepted Answer

A) True 
 B)False

Question 16

The simplest life forms appeared on Earth when it was how old?

Accepted Answer

A)  five million years 
B)  one billion years 
C)  2.5 billion years 
D)  3.5 billion years 
E)  4.5 billion years 
A)  five million years 
B)  one billion years 
C)  2.5 billion years 
D)  3.5 billion years 
E)  4.5 billion years

Question 17

Why do jovian planets with highly eccentric orbits indicate that it is unlikely that a star has a habitable terrestrial planet?

Accepted Answer

The large jovian planets with eccentric

Question 18

We have found Titan's surface to be perfect living condition for earthlike life.

Accepted Answer

A) True 
 B)False

Question 19

As the average estimated lifetime of a technical civilization increases,then the distances between neighboring civilizations would ________.

Accepted Answer

The answer of As the average estimated lifetime of a...

Question 20

What is the most important consideration in the "habitable zone" of a planetary system?

Accepted Answer

The distance from its star and

Exam 28: Life in the Universe: Are We Alone?

Why is Earth a stronger radio emitter than the Sun?

Why does SETI concentrate on the water hole?

In terms of temperature alone,there are ________ terrestrial planets within the widest boundaries of the Sun's zone of habitability.

Why is the hypothesis that life on Earth came from outer space considered plausible?

Conducted in 1953,the ________ experiments were designed to show what types of complex molecules might have formed in the Earth's primitive environment.

Comet impacts might have been a good mechanism for seeding the hot early Earth with the water and molecules of life.

Which of these does Mars NOT have to help its case of past or present life?

Organic molecules are:

In terms of its thick and chemically active atmosphere of hydrocarbons,which jovian moon was visited by the Huygens probe in 2005?

Europa is the most promising of the bodies in the outer solar system for life in its salty seas.

Why are type O,A,and M stars considered poor candidates to find a technological civilization?

Most SETI searches are done at:

Our earliest atmosphere,formed by outgassing,was much poorer in ________ than now.

The ________ habitable zone is set by the activity of the nucleus on the inside,and the rate of star formation and proper chemistry on the outside.

Of the terrestrial planets,Mars seems to most promising to exobiologists.

The simplest life forms appeared on Earth when it was how old?

Why do jovian planets with highly eccentric orbits indicate that it is unlikely that a star has a habitable terrestrial planet?

We have found Titan's surface to be perfect living condition for earthlike life.

As the average estimated lifetime of a technical civilization increases,then the distances between neighboring civilizations would ________.

What is the most important consideration in the "habitable zone" of a planetary system?

Charting the Heavens: The Foundations of Astronomy

The Copernican Revolution: The Birth of Modern Science

Radiation: Information from the Cosmos

Spectroscopy: The Inner Workings of Atoms

Telescopes: The Tools of Astronomy

The Solar System: Comparative Planetology and Formation Models

Earth: Our Home in Space

The Moon and Mercury: Scorched and Battered Worlds

Venus: Earth's Sister Planet

Mars: A Near Miss for Life?

Jupiter: Giant of the Solar System

Saturn: Spectacular Rings and Mysterious Moons

Uranus and Neptune: The Outer Worlds of the Solar System

Solar System Debris: Keys to Our Origin

Exoplanets: Planetary Systems Beyond Our Own

The Sun: Our Parent Star

The Stars: Giants,Dwarfs,and the Main Sequence

The Interstellar Medium: Gas and Dust among the Stars

Star Formation: A Traumatic Birth

Stellar Evolution: The Life and Death of a Star

Stellar Explosions: Novae,Supernovae,and the Formation of the Elements

Neutron Stars and Black Holes: Strange States of Matter

The Milky Way Galaxy: A Spiral in Space

Galaxies: Building Blocks of the Universe

Galaxies and Dark Matter: The Large-Scale Structure of the Cosmos

Cosmology: The Big Bang and the Fate of the Universe

The Early Universe: Toward the Beginning of Time

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