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The "Rare Earth" hypothesis states that if other intelligent life is out there, where are they?
Examines the possibility that we could be the only planet with intelligent life, at least in the galaxy. |
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A small star composed mainly of
-They are thought to be the final evolutionary state of all stars whose mass is not high enough to become a supernova. (over 97% of stars in the galaxy)
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The fusion of helium in the core of low-mass stars |
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What do scientist mean by a "habitable zone" around a star? |
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-It must be of a temperature range suitable for liquid water.
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What is the approximate range of our Sun's habitable zone? |
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M-class dwarf- why a good canidate for habitability? |
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Stays in the main sequence for 50 billion years*, allowing so much time for life to develop. |
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M-class dwarf- bad candidate? |
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Too dim- habitable zone would be too close to the star, and narrow. Life and any atmosphere would be affected by solar flares and radioactivity (unless it was big enough to have a strong magnetic field). |
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| O & B stars spend less time on the main sequence than G and K stars- why? |
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Because they are too bright to maintain a stable habitable zone for more than a few million* years. |
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Which star type is...
the brightest
smallest mass
hottest
most similiar to our sun |
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Definition
O star
M star
O star
G star |
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Term
Why might the formation of Jovian planets be important to the Earth's formation? |
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Jovian planets with their large masses and gravitational pulls can suck up space junk that would potentially collide into the still-forming Earth. |
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The Drake equation:
(all 7 terms) |
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Definition
| 1.number of stars in the galaxy |
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Definition
A self-replicating machine, designed to investigate the target system and send information back to our solar system. |
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