Chapter 6 home work 11 Telescopes Flashcards Preview

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Flashcards in Chapter 6 home work 11 Telescopes Deck (65)
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61

The "rare Earth hypothesis" holds that Earth-like planets will prove to be quite rare. Which of the following statements best sums up the current status of the debate over this hypothesis?

The debate raged for a while, but is now settled. We are now quite certain that Earth-like planets are common.
The debate raged for a while, but is now settled. We are now quite certain that Earth-like planets are rare.
It is no longer discussed, because as part of its broad cover-up of UFOs, the United States government has classified all the material relating to this debate as Top Secret.
We do not have enough data to settle the debate, because counterarguments can be made for each argument suggesting Earth-like planets may be rare.

We do not have enough data to settle the debate, because counterarguments can be made for each argument suggesting Earth-like planets may be rare

62

At present, what is the primary way that the search for extraterrestrial intelligence (SETI) is carried out?

by using X-ray telescopes to search for exhaust from interstellar spacecraft
by searching for planets around distant stars
by using radio telescopes to search for signals from extraterrestrial civilizations
by seeking access to the secret records and alien corpses kept at the military's Area 51 in Nevada
by analyzing high-resolution images of nearby stars in search of evidence for structures that could not have developed naturally

by using radio telescopes to search for signals from extraterrestrial civilizations

63

In the Drake equation (Number of Civilizations = NHP × flife × fciv × fnow), what do we mean by fnow?

the fraction of planets in the galaxy on which a civilization could theoretically develop right now
the fraction of all species ever to exist that we currently are aware of
the fraction of civilizations in the universe that currently are sending messages to us
the fraction of planets with civilizations at the present time (as opposed to only in the past or future).

the fraction of planets with civilizations at the present time (as opposed to only in the past or future).

64

If there are other civilizations at present in the Milky Way Galaxy, which statement is almost undoubtedly true?

They have social structures that are completely different from our own; for example, different types of "family" units, and so on.
They are anatomically much like us, with two arms, two legs, two eyes, and two ears.
They are far more technologically advanced than we are.
For fun, they enjoy "buzzing" to Earth and temporarily abducting people, showing a clear preference for people located in less-developed rural areas.

They are far more technologically advanced than we are.

65

In the Drake equation, suppose that the term flife=12. What would this mean?
Half the stars in the Milky Way Galaxy have a planet with life.
Half of all life-forms in the universe are intelligent.
Half of the habitable worlds in the galaxy actually have life, while the other half don't.

Half of the habitable worlds in the galaxy actually have life, while the other half don't.