Question 1

About what percentage of the planets discovered outside our solar system are giant planets,orbiting close to their parent star?

Accepted Answer

A) 33 
B) 15 
C) 55 
D) 70 
A) 33 
B) 15 
C) 55 
D) 70 A

Question 2

Why is it easier to use Doppler shifts to discover binary stars than to discover planets orbiting other stars?

Accepted Answer

A) The orbital periods of binary stars are longer than those of planets 
B) The Doppler shifts are very small in the case of planets 
C) For planets the shifts are so large they shift the lines out of the visible 
D) Stars orbited by planets do not generally show spectral lines 
A) The orbital periods of binary stars are longer than those of planets 
B) The Doppler shifts are very small in the case of planets 
C) For planets the shifts are so large they shift the lines out of the visible 
D) Stars orbited by planets do not generally show spectral lines B

Question 3

Which of the following is one of the characteristics of water that make it crucial to terrestrial life?

Accepted Answer

A) It is tasteless 
B) It has a density less than that of mercury 
C) It is a very poor solvent 
D) It has a large heat capacity 
A) It is tasteless 
B) It has a density less than that of mercury 
C) It is a very poor solvent 
D) It has a large heat capacity D

Question 4

Billions of years from now,the habitable zone of the solar system will not include the
Earth but will include

Accepted Answer

A) Mars 
B) Mercury 
C) Venus 
D) The Moon 
A) Mars 
B) Mercury 
C) Venus 
D) The Moon

Question 5

How are pulsar planets detected?

Accepted Answer

A) By looking for variations in the light output of the planet. 
B) By observing the pulsar planet as tidal forces tear it apart. 
C) By looking for shifts in the period of the planets orbit. 
D) By observing variations between pulses. 
A) By looking for variations in the light output of the planet. 
B) By observing the pulsar planet as tidal forces tear it apart. 
C) By looking for shifts in the period of the planets orbit. 
D) By observing variations between pulses.

Question 6

Why is the frequency range between 1 and 10 GHz particularly favorable for interstellar communication?

Accepted Answer

A) The numbers 1 and 10 are nice round numbers 
B) Background noise is at a minimum in that range 
C) We have already received signals in that range 
D) It is easiest to build radio telescopes that operate in that range 
A) The numbers 1 and 10 are nice round numbers 
B) Background noise is at a minimum in that range 
C) We have already received signals in that range 
D) It is easiest to build radio telescopes that operate in that range

Question 7

An organism's characteristics are encoded in its

Accepted Answer

A) DNA 
B) Amino acids 
C) Proteins 
D) Carbon atoms 
A) DNA 
B) Amino acids 
C) Proteins 
D) Carbon atoms

Question 8

Which strategies have been used to look for interstellar signals?

Accepted Answer

A) Sweeping the sky alone 
B) Pointed observations alone 
C) Neither sweeping the sky nor pointed observations 
D) Both sweeping the sky and pointed observations 
A) Sweeping the sky alone 
B) Pointed observations alone 
C) Neither sweeping the sky nor pointed observations 
D) Both sweeping the sky and pointed observations

Question 9

The oldest fossils date from about how long after Earth formed?

Accepted Answer

A) 10 million years 
B) 100 million years 
C) 1 billion years 
D) 10 billion years 
A) 10 million years 
B) 100 million years 
C) 1 billion years 
D) 10 billion years

Question 10

About how long does it take radio signals to travel from the Earth to the nearest stars?

Accepted Answer

A) A few minutes 
B) A few weeks 
C) A few years 
D) A few centuries 
A) A few minutes 
B) A few weeks 
C) A few years 
D) A few centuries

Question 11

Why does the habitable zone shift outward as a star evolves?

Accepted Answer

A) The star produces more radiation as it ages on the main sequence. 
B) The star produces less radiation as it ages on the main sequence. 
C) The planets adaptive mechanisms shift toward producing a more habitable environment. 
D) The planets adaptive mechanisms shift toward producing a less habitable environment. 
A) The star produces more radiation as it ages on the main sequence. 
B) The star produces less radiation as it ages on the main sequence. 
C) The planets adaptive mechanisms shift toward producing a more habitable environment. 
D) The planets adaptive mechanisms shift toward producing a less habitable environment.

Question 12

The habitable zone is defined by what characteristic?

Accepted Answer

A) Zone where planets of a suitable size to support advanced life are located. 
B) Zone where planets of a suitable internal composition to support advanced life are located. 
C) Zone where water can exist as a liquid. 
D) Zone where X-ray intensity from solar radiation drops below a critical value. 
A) Zone where planets of a suitable size to support advanced life are located. 
B) Zone where planets of a suitable internal composition to support advanced life are located. 
C) Zone where water can exist as a liquid. 
D) Zone where X-ray intensity from solar radiation drops below a critical value.

Question 13

The Drake Equation contains several terms that are known to a high degree of accuracy.

Accepted Answer

A) True 
 B)False

Question 14

Why have few planets with conditions considered habitable have been found so far?

Accepted Answer

A) Habitable planets are thought to be highly improbable. 
B) Terrestrial planets at 1 AU distance are hard to detect with current technologies. 
C) Giant planets usually create conditions that are unfavorable for terrestrial planets. 
D) Very few solar systems are thought to have had suitable angular momentum to create terrestrial planets. 
A) Habitable planets are thought to be highly improbable. 
B) Terrestrial planets at 1 AU distance are hard to detect with current technologies. 
C) Giant planets usually create conditions that are unfavorable for terrestrial planets. 
D) Very few solar systems are thought to have had suitable angular momentum to create terrestrial planets.

Question 15

SETI stands for

Accepted Answer

A) Signal Enhancement Through Interferometry 
B) Search for Extraterrestrial Intelligence 
C) Satellite Examination of Technological Images 
D) Studies of Europa's Tidal Icefields 
A) Signal Enhancement Through Interferometry 
B) Search for Extraterrestrial Intelligence 
C) Satellite Examination of Technological Images 
D) Studies of Europa's Tidal Icefields

Question 16

Why are interstellar signals likely to have narrow bandwidths?

Accepted Answer

A) The signals will be brighter than with a broader bandwidth 
B) It makes it harder to guess the correct frequency 
C) It produces more distinct spectral channels for communication 
D) Most transmitters only operate over a narrow frequency range 
A) The signals will be brighter than with a broader bandwidth 
B) It makes it harder to guess the correct frequency 
C) It produces more distinct spectral channels for communication 
D) Most transmitters only operate over a narrow frequency range

Question 17

About what percentage of planets discovered outside our solar system are farther away from their parent star than 1 AU?

Accepted Answer

A) 25 
B) 35 
C) 50 
D) 70 
A) 25 
B) 35 
C) 50 
D) 70

Question 18

Possible evidence that life once existed on Mars has been discovered.The evidence

Accepted Answer

A) Was discovered in a meteorite that originated on Mars 
B) Was discovered in samples of Mars returned to Earth by a spacecraft 
C) Was seen in images of the surface of Mars taken by Global Surveyor 
D) Consisted of chlorophyll lines found in spectra of Mars 
A) Was discovered in a meteorite that originated on Mars 
B) Was discovered in samples of Mars returned to Earth by a spacecraft 
C) Was seen in images of the surface of Mars taken by Global Surveyor 
D) Consisted of chlorophyll lines found in spectra of Mars

Question 19

Most of the planets discovered to be orbiting other solar-type stars have masses that are similar to that of

Accepted Answer

A) The Sun 
B) Jupiter 
C) Earth 
D) The Moon 
A) The Sun 
B) Jupiter 
C) Earth 
D) The Moon

Exam 27: Life in the Universe

About what percentage of the planets discovered outside our solar system are giant planets,orbiting close to their parent star?

Why is it easier to use Doppler shifts to discover binary stars than to discover planets orbiting other stars?

Which of the following is one of the characteristics of water that make it crucial to terrestrial life?

Billions of years from now,the habitable zone of the solar system will not include the Earth but will include

How are pulsar planets detected?

Why is the frequency range between 1 and 10 GHz particularly favorable for interstellar communication?

An organism's characteristics are encoded in its

Which strategies have been used to look for interstellar signals?

The oldest fossils date from about how long after Earth formed?

About how long does it take radio signals to travel from the Earth to the nearest stars?

Why does the habitable zone shift outward as a star evolves?

The habitable zone is defined by what characteristic?

The Drake Equation contains several terms that are known to a high degree of accuracy.

Why have few planets with conditions considered habitable have been found so far?

SETI stands for

Why are interstellar signals likely to have narrow bandwidths?

About what percentage of planets discovered outside our solar system are farther away from their parent star than 1 AU?

Possible evidence that life once existed on Mars has been discovered.The evidence

Most of the planets discovered to be orbiting other solar-type stars have masses that are similar to that of

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