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now that you know that stars vary in

2
00:00:13,190 --> 00:00:11,360
abundance for every element we can look

3
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at how one element affects the chance of

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00:00:17,510 --> 00:00:15,679
life in a planetary system the habitable

5
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zone is the region around a star that

6
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can support liquid water we know that as

7
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stars age this region moves away from

8
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the star therefore any orbiting planets

9
00:00:27,910 --> 00:00:26,640
only have a certain time to remain

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habitable

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recent calculations have shown that

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variations in oxygen alone greatly

13
00:00:35,270 --> 00:00:33,840
affect the distance and lifetimes of

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habitable zones

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for example a star with half the oxygen

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00:00:41,590 --> 00:00:39,680
of our sun would have a habitable zone

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00:00:43,430 --> 00:00:41,600
at a greater distance and would last

18
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about three and a half billion years

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whereas if it had twice the oxygen it

20
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would be closer and last about nine

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billion years

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as well as determining the habitability