This document summarizes the history of comet exploration. It describes how comets were initially seen as omens of disaster by ancient cultures but were later determined to follow predictable orbits by Halley. The 20th century saw significant advances in comet observation including spacecraft missions like Giotto, Stardust, Deep Impact and Rosetta that provided insights into comet composition and origins. Current theories suggest comets may have delivered water and organic molecules to early Earth. The most observed comet ever was ISON, intensely studied by spacecraft and ground telescopes in 2013 before disintegrating near the Sun.

1. Comets
History and Exploration

2. Imagine…
You are living on the plains 5000 years ago
Each evening as it gets dark, you go out and watch the
sky…

3. The Sun Sets…
And the same stars appear…

4. Night after night…

5. They shift just a little

6. A wanderer appears…

7. The Moon…

8. Year after year…

9. Every year, the same stars
mean Spring…

10. … the river will flood…

11. …get the harvest in before
the locusts come

12. The skies are a guide…

13. A calendar,

14. Until something new
appears

15. Something out of place

16. What could it Mean??

17. Disaster!

18. “destruction, storm and frost”

19. War

20. Bayeux Tapestry
http://www.bayeuxtapestry.org.uk/ Long Live The King - Scene 1

21. A disaster for every
comet…
http://www.nasa.gov/mission_pages/deepimpact/medi
a/f_ancient.html

22. But then…
Edmund Halley
convinced Issac Newton
to work out the orbits of
several comets, and
realized the comets of
1531, 1607 and 1682
were actually the same
comet!

23. Comets are solar system
objects!
Predictable, and
understandable!
Exciting, and NOT
a disaster!
Punch, 1909

24. Comet hunting in the 18th
century

25. Comet observing in the
Donati’s
comet, 1858
“Most beautiful
comet”
th
19
Century

26. Detailed orbital elements

27. Comet
Anatomy
Parts visible only
when close to the
Sun.

28. Ions
Atoms & molecules missing electrons
Often emit light -> Spectroscopy!

29. th
20
century observations
Comet 1913 f, Delavan
Publications of the Astronomical Observatory of the University of
Michigan ; v. 3, Ann Arbor : The University, 1923

30. Disaster!
Cyanogen gas found in Halley’s comet
Earth would pass through the comet’s
tail!!
http://www.wondersandmarvels.com/2010/12/con-men-and-comets.html

31. Questions only comets could
answer
How do planets / the solar system form?
What materials were available to build planets?
Where did Earth’s water come from?

32. ICE
International Sun-Earth
Explorer was designed
to study the Sun-earth
environment, but had
the chance to fly
through GiacobiniZinner’s tail!
Pelted by dust grains
Confirmed
spectroscopic
measurements

33. Giotto
April 1986

34. Stardust
Flew through
coma of Wild 2
Returned a
sample

35. Stardust
Returned a
sample

36. Life from comets?
Comets may
have brought the
water, carbon,
nitrogen, and
organic
molecules in to
the inner solar
system!
Stardust samples
included glycerin!
Matthew Genge / Imperial College London

37. Deep
Impact
Impacted
Temple 1
Comet was
softer than
expected!

38. “sungrazer”
ISON
Most observed comet ever
In addition to ground based observers, including amateurs,
many spacecraft watched the comet
Mike Hankey, Nov. 15, 2013, Auberry, California.

39. End of ISON
Nov 28, 2013
http://sohowww.nascom.nasa.gov/hotshots/index.html/

40. Rosetta
Rendezvous on January 20,
2014 with comet
67P/Churyumov–
Gerasimenko
Obit until November, then
send a lander

41. Disosaurs
Spaceplace.nasa.gov

42. Hakutake
http://www.twanight.org/newTWAN/photos.asp?ID=3002020

43. Waiting for the next Hale Bopp
http://www.twanight.org/newTWAN/guests_photos.asp?ID=5001238