1
00:00:01,266 --> 00:00:06,066
(MUSIC)

2
00:00:06,066 --> 00:00:07,366
JOAN CARTAN-HANSEN, HOST:

3
00:00:07,366 --> 00:00:08,700
The first astronomers observed

4
00:00:08,700 --> 00:00:09,966
comets by watching the night

5
00:00:09,966 --> 00:00:10,900
sky.

6
00:00:10,900 --> 00:00:12,233
From the ground, they identified

7
00:00:12,233 --> 00:00:14,166
about 900 comets from 1761 to

8
00:00:14,166 --> 00:00:16,233
1995.

9
00:00:16,233 --> 00:00:17,633
But as it turns out, human

10
00:00:17,633 --> 00:00:19,133
scientists are no match for the

11
00:00:19,133 --> 00:00:21,000
best comet hunter in space.

12
00:00:21,000 --> 00:00:22,233
That's the Solar and

13
00:00:22,233 --> 00:00:24,600
Heliospheric Observatory, better

14
00:00:24,600 --> 00:00:25,633
known as "SOHO."

15
00:00:25,633 --> 00:00:26,933
It was originally designed to

16
00:00:26,933 --> 00:00:28,300
study the sun, but scientists

17
00:00:28,300 --> 00:00:29,800
soon realized it was really good

18
00:00:29,800 --> 00:00:31,066
at finding comets.

19
00:00:31,066 --> 00:00:32,400
So far, it's found more than

20
00:00:32,400 --> 00:00:33,500
3000.

21
00:00:33,500 --> 00:00:35,000
But most of the comets its finds

22
00:00:35,000 --> 00:00:36,300
disintegrate.

23
00:00:36,300 --> 00:00:37,666
SOHO finds comets that pass very

24
00:00:37,666 --> 00:00:38,866
close to the sun.

25
00:00:38,866 --> 00:00:40,366
And those comets just can't

26
00:00:40,366 --> 00:00:41,833
handle the intense sunlight.

27
00:00:41,833 --> 00:00:42,866
So, they're destroyed.

28
00:00:42,866 --> 00:00:44,400
Astronomers think most of these

29
00:00:44,400 --> 00:00:45,833
comets are fragments of a much

30
00:00:45,833 --> 00:00:47,366
bigger comet that broke apart

31
00:00:47,366 --> 00:00:48,733
thousands of years ago.

32
00:00:48,733 --> 00:00:50,000
Scientists can learn a lot from

33
00:00:50,000 --> 00:00:51,200
these dying comets.

34
00:00:51,200 --> 00:00:52,566
Their tails are pushed around by

35
00:00:52,566 --> 00:00:54,233
the sun's magnetic fields.

36
00:00:54,233 --> 00:00:55,666
So, watching these tails move

37
00:00:55,666 --> 00:00:57,066
can tell researchers more about

38
00:00:57,066 --> 00:00:58,933
how the sun works.

39
00:00:58,933 --> 00:01:00,466
For more information about

40
00:01:00,466 --> 00:01:01,800
asteroids and comets, check out

41
00:01:01,800 --> 00:01:02,833
the Science Trek website.

42
00:01:02,833 --> 00:01:03,766
You'll find it at

43
00:01:03,766 --> 00:01:04,866
ScienceTrek.org