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comets are the most spectacular thing in

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comets are important because they

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represent the leftover bits and pieces

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from the outer solar system formation

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process which took place four-and-a-half

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billion years ago as the planets formed

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the first thing you got was tiny clumps

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of dust in the inner solar system and in

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the outer solar system dust and ice the

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Comets are what made the cores of

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Jupiter Saturn Uranus and Neptune but

12
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the planets are so hot that the

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chemistry changes completely whereas the

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Comets have remained frozen the entire

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time so the chemistry is preserved

16
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comets are basically made up of a number

17
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of different regions a dirty ice ball

18
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relatively small and black when I guess

19
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near the Sun these ices start vaporizing

20
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which forms a atmosphere and then when

21
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some of these dust particles are blown

22
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back away from the Sun because of the

23
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pressure of sunlight you form a dust

24
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tail and often a gas or ion tail comets

25
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and asteroids have always gotten bad

26
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press the dinosaur is checked out 65

27
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million years ago because of an asteroid

28
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impact but what we don't hear about is

29
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how important these objects are in terms

30
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of bringing the building blocks of life

31
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to the early planet comets almost

32
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certainly brought most of the organic

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material and much of the water to earth

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in a sense we wouldn't even be here

35
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without comets and asteroids scientists

36
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like to put objects in boxes

37
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comets should look this way asteroids

38
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should look this way but mother nature

39
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keeps on knocking the boxes over and

40
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said no it doesn't look that way the few

41
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comments that we've seen they all are

42
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very different from one another so the

43
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question is are all these objects

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different from one another

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the EPOXI mission is an extended mission

46
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for the deep impact flyby spacecraft

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after we went past comet Tempel 1 and

48
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drove an impactor into it

49
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we spent a year or more observing

50
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extrasolar planets and we are now on

51
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target for a flyby of comet Hartley 2

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which is interesting in the sense that

53
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it's one of the smallest objects we've

54
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seen and it's thought to be active over

55
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a hundred percent of its surface if we

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understand the Comets really well it

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will tell us how all the planets got