Question 1

At about what fraction of the speed of light do today's spacecraft travel?

Accepted Answer

A)   1/2
B)   1/10
C)   1/100
D)   1/1,000
E)   1/10,000

Question 2

Which of the following statements about matter-antimatter engines is not true?

Accepted Answer

A)   Matter-antimatter engines would be great in theory, but to date we have no evidence that antimatter even exists.
B)   Matter-antimatter reactions represent the most efficient possible reactions in terms of energy release.
C)   Spacecraft powered by matter-antimatter engines could probably reach speeds of more than half the speed of light.
D)   One of the major challenges to developing matter-antimatter engines is finding a way to store antimatter after it is produced. A

Question 3

Relativistic time-dilation means that astronauts aboard a spaceship traveling close to the speed of light will actually age less than their families left behind on the Earth.

Accepted Answer

A) True 
 B)False

Question 4

Briefly explain the Fermi Paradox, namely the paradox of the question "Where are the aliens?"

Accepted Answer

If we survive and decide to become inter...

Question 5

The Pioneer and Voyager spacecraft carry a message from Earth, just in case an alien civilization ever runs across them.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following best describes what we mean by a habitable world?

Accepted Answer

A)   A planet or moon that could support life, if any life happened to be on it
B)   A planet or moon with life
C)   A planet or moon that lies within its star's habitable zone
D)   A planet or moon on which humans could survive if we happened to go there

Question 7

Why is Europa considered a good candidate for the possible existence of life?

Accepted Answer

A)   Strong evidence suggests that it has a deep, subsurface ocean of liquid water.
B)   The Galileo spacecraft found strange seasonal changes on its surface that look like they could be due to life.
C)   It is located within our Sun's habitable zone.
D)   It has a thick atmosphere with a surface pressure greater than that on Earth. A

Question 8

Which of the following describes a major challenge of interstellar travel at near light speed?

Accepted Answer

A)   Any interstellar journey will take much longer than the lives of the crew members.
B)   Time dilation will slow the heartbeats of the crew to a dangerously low rate.
C)   Atoms and ions in interstellar space will hit the spacecraft like a flood of dangerous cosmic rays.
D)   Asteroid fields floating in interstellar space will present a severe navigational challenge.
E)   Supernova explosions could destroy spaceships passing nearby.

Question 9

Which of the following best describes how the Drake equation is useful?

Accepted Answer

A)   It helps us understand what we need to know in order to determine the likelihood of finding other civilizations.
B)   It has allowed us to determine the number of civilizations in the Milky Way Galaxy.
C)   It allows us to calculate the masses of planets orbiting other stars.
D)   It tells us what wavelengths of light will be most useful to examine in the search for extraterrestrial intelligence.

Question 10

Briefly explain the purpose of the equation
Number of Civilizations = Np × $ f_{\mathrm{}} $life × $ f_{\mathrm{}} $civilization × $ f_{\mathrm{}} $ now.

Accepted Answer

This equation is used to estim...

Question 11

Which of the following statements about matter-antimatter engines is not true?

Accepted Answer

A)   Matter-antimatter reactions represent the most efficient reactions possible in terms of energy release.
B)   Matter-antimatter engines would be possible in theory, but to date, we have no evidence that antimatter exists.
C)   One of the major challenges to developing matter-antimatter engines is finding a way to produce enough antimatter.
D)   One of the major challenges to developing matter-antimatter engines is finding a way to store antimatter after it is produced.
E)   Spacecraft powered by matter-antimatter engines could probably reach speeds of 90 percent of the speed of light.

Question 12

Although antimatter is an interesting theoretical idea, there is no evidence that it actually exists.

Accepted Answer

A) True 
 B)False

Question 13

According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?

Accepted Answer

A)   Oxygen was removed from the atmosphere by chemical reactions with surface rocks as quickly as it was released by life.
B)   Early forms of animal life consumed the oxygen released by plants during the first billion years of life on Earth.
C)   Early life did not release oxygen, and oxygen releasing organisms didn't evolve for a billion years after the earliest life.
D)   Oxygen was removed from the atmosphere by dissolving in the ocean as quickly as it was released by life.

Question 14

Which of the following is not key evidence in support of the idea that all life today shares a common ancestor?

Accepted Answer

A)   We have identified fossils of the first life forms that ever existed on Earth.
B)   All life uses DNA and the same genetic code.
C)   Mapping of gene sequences shows how life is all related.
D)   All life builds proteins from the same amino acids and uses ATP to store energy in cells.

Question 15

Which of the following was the most important for maintaining the Earth's stable climate over the time it took for large organisms to evolve?

Accepted Answer

A)   sustained volcanic activity
B)   the cessation of the heavy bombardment phase
C)   plate tectonics
D)   the Moon
E)   underground sea vents

Question 16

When we analyze whether a world is a possible home to life, the key thing we look for is ________.

Accepted Answer

A)   the past or present existence of liquid water
B)   evidence of atmospheric oxygen
C)   the presence of organic molecules such as amino acids
D)   surface coloration changes that could indicate vegetative growth

Question 17

We have already launched spacecraft whose orbits will carry into interstellar space.

Accepted Answer

A) True 
 B)False  True

Question 18

Generalizing from a Single Example: Many would argue that our concept of life and intelligence is severely limited by the fact that we have only the "single example" of the Earth. Do you agree with this view (address the questions of life and intelligence separately)? To what extent do you feel that the search for extraterrestrial life is biased by the example of life on the Earth? Does the search for extraterrestrial intelligent life suffer more or less from the same bias?

Accepted Answer

I agree that our concept of life and int...

Question 19

According to fossil evidence, how far back in time did life on Earth exist?

Accepted Answer

A)   About 3.5 billion years or more
B)   About 2.0 billion years
C)   About 545 million years
D)   About 65 million years

Question 20

What is the evidence that suggests planetary systems are common in the universe?

Accepted Answer

We know that stars form surrounded by di...

Exam 18: Life in the Universe

At about what fraction of the speed of light do today's spacecraft travel?

Correct Answer
verified

Which of the following statements about matter-antimatter engines is not true?

Correct Answer
verified
A

Relativistic time-dilation means that astronauts aboard a spaceship traveling close to the speed of light will actually age less than their families left behind on the Earth.

Correct Answer
verified

Briefly explain the Fermi Paradox, namely the paradox of the question "Where are the aliens?"

Correct Answer
verified
If we survive and decide to become inter...
View Answer

The Pioneer and Voyager spacecraft carry a message from Earth, just in case an alien civilization ever runs across them.

Correct Answer
verified

Which of the following best describes what we mean by a habitable world?

Correct Answer
verified

Why is Europa considered a good candidate for the possible existence of life?

Correct Answer
verified
A

Which of the following describes a major challenge of interstellar travel at near light speed?

Correct Answer
verified

Which of the following best describes how the Drake equation is useful?

Correct Answer
verified

Briefly explain the purpose of the equation Number of Civilizations = Np × $f_{\mathrm{}}$ life × $f_{\mathrm{}}$ civilization × $f_{\mathrm{}}$ now.

Correct Answer
verified
This equation is used to estim...
View Answer

Which of the following statements about matter-antimatter engines is not true?

Correct Answer
verified

Although antimatter is an interesting theoretical idea, there is no evidence that it actually exists.

Correct Answer
verified

According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?

Correct Answer
verified

Which of the following is not key evidence in support of the idea that all life today shares a common ancestor?

Correct Answer
verified

Which of the following was the most important for maintaining the Earth's stable climate over the time it took for large organisms to evolve?

Correct Answer
verified

When we analyze whether a world is a possible home to life, the key thing we look for is ________.

Correct Answer
verified

We have already launched spacecraft whose orbits will carry into interstellar space.

Correct Answer
verified
True

Correct Answer
Answered by ExamLex AI
I agree that our concept of life and int...
View Answer

According to fossil evidence, how far back in time did life on Earth exist?

Correct Answer
verified

What is the evidence that suggests planetary systems are common in the universe?

Correct Answer
verified
We know that stars form surrounded by di...
View Answer

Exam 18: Life in the Universe

At about what fraction of the speed of light do today's spacecraft travel?

Correct AnswerverifiedShow Answer

Which of the following statements about matter-antimatter engines is not true?

Correct AnswerverifiedA

Relativistic time-dilation means that astronauts aboard a spaceship traveling close to the speed of light will actually age less than their families left behind on the Earth.

Correct AnswerverifiedShow Answer

Briefly explain the Fermi Paradox, namely the paradox of the question "Where are the aliens?"

Correct AnswerverifiedIf we survive and decide to become inter...View AnswerShow Answer

The Pioneer and Voyager spacecraft carry a message from Earth, just in case an alien civilization ever runs across them.

Correct AnswerverifiedShow Answer

Which of the following best describes what we mean by a habitable world?

Correct AnswerverifiedShow Answer

Why is Europa considered a good candidate for the possible existence of life?

Correct AnswerverifiedA

Which of the following describes a major challenge of interstellar travel at near light speed?

Correct AnswerverifiedShow Answer

Which of the following best describes how the Drake equation is useful?

Correct AnswerverifiedShow Answer

Briefly explain the purpose of the equation Number of Civilizations = Np × f f_{\mathrm{}} f​ life × f f_{\mathrm{}} f​ civilization × f f_{\mathrm{}} f​ now.

Correct AnswerverifiedThis equation is used to estim...View AnswerShow Answer

Which of the following statements about matter-antimatter engines is not true?

Correct AnswerverifiedShow Answer

Although antimatter is an interesting theoretical idea, there is no evidence that it actually exists.

Correct AnswerverifiedShow Answer

According to current science, why didn't oxygen begin to accumulate in the atmosphere for more than a billion years after life appeared on the Earth?

Correct AnswerverifiedShow Answer

Which of the following is not key evidence in support of the idea that all life today shares a common ancestor?

Correct AnswerverifiedShow Answer

Which of the following was the most important for maintaining the Earth's stable climate over the time it took for large organisms to evolve?

Correct AnswerverifiedShow Answer

When we analyze whether a world is a possible home to life, the key thing we look for is ________.

Correct AnswerverifiedShow Answer

We have already launched spacecraft whose orbits will carry into interstellar space.

Correct AnswerverifiedTrue

Correct AnswerAnswered by ExamLex AII agree that our concept of life and int...View AnswerShow Answer

According to fossil evidence, how far back in time did life on Earth exist?

Correct AnswerverifiedShow Answer

What is the evidence that suggests planetary systems are common in the universe?

Correct AnswerverifiedWe know that stars form surrounded by di...View AnswerShow Answer

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified
If we survive and decide to become inter...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

Briefly explain the purpose of the equation Number of Civilizations = Np × $f_{\mathrm{}}$ life × $f_{\mathrm{}}$ civilization × $f_{\mathrm{}}$ now.

Correct Answer
verified
This equation is used to estim...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
True

Correct Answer
Answered by ExamLex AI
I agree that our concept of life and int...
View Answer

Correct Answer
verified

Correct Answer
verified
We know that stars form surrounded by di...
View Answer