1. Is Pluto a Planet? Dr John K. Davies & Dr Suzie Ramsay Howat UK Astronomy Technology Centre, Royal Observatory, Edinburgh, Scotland

2. The classical solar system

3. Planet Uranus imaged from Voyager 2.

4. Planet Neptune from Voyager 2.

5. Percival Lowell

6. Lowell’s Tomb, shaped like Planet Saturn

7. Clyde Tombaugh and the Pluto Telescope.

8. Discovery of Pluto, 1930

9. Orbits of Pluto and Neptune.

10. Nucleus of Halley’s Comet

11. Pluto is Shrinking

12. Pluto is covered with ice.

13. Pluto and Charon (Gemini Observatory)

14. Pluto should have vanished by now !

15. Mercury and Venus: Planets without Moons

16. 9064 Johndavies. A minor planet Discovered 1993 Status: Main belt asteroid Diameter: about 6km Brightness: V=17-18 Composition: Rocky Dist from Sun 2.1-2.7 AU

17. 243 Ida and Dactyl Ida: Size about 56 km long. Dactyl: Size about 1.5 km.

18. 45 Eugenia and its moon. Eugenia size ~215km Satellite size ~13 km Period ~4.7 days

19. Eugenia, The Movie

20. Pluto has an atmosphere

21. Pluto Express Mission. 2020?

22. Comets in the Oort Cloud

23. Comet Hale-Bopp

24. Comet Orbits Long Period Comet, like Hale-Bopp Short Period Comet. Interstellar comet (never seen)

25. Gerard Kuiper 1905-1973

26. Kenneth Edgeworth. 1880-1973

27. Jane Luu and Dave Jewitt

28. University of Hawaii 2.2m Telescope

29. Discovery of 1992 QB 1

30. The Classical Kuiper Belt

31. The Plutinos

32. 1998 WW31 a Kuiper Belt Object with a satellite

33. Some of the the largest known Kuiper Belt Objects

34. Stop Press – ‘Sedna’

35. Sedna: EKO or Oort Cloud Object?

36. Sedna. Planet10?

37. Orbital Elements and Stable Regions

38. Comet Ring as predicted by Fred Whipple in 1964, virtually what we today call the Kuiper Belt

39. But 4 of these are no longer in lists of planets published today Ceres Vesta Pallas Juno Sun Venus Earth Mars According to ‘First Steps to Astronomy and Geography’, Hatchard & Son, London, 1828 there are 11 planets. Mercury, Venus, Earth, Mars, Vesta, Juno, Ceres, Pallas, Jupiter, Saturn and Herschel (Uranus)

40. Tradition in Astronomy Constellations Lunar Sea!

41. What makes a planet? It goes around a star.

42. Io and the Moon are not planets because they don’t go around a star.

43. What makes a planet? It goes around a star. It does not generate heat internally.

44. Jupiter is a planet. since it is not heated by nuclear reactions.

45. What makes a planet? It goes around a star. It does not make heat by nuclear reactions. It is spherical.

46. So MOST asteroids are not planets since they have not collapsed to spherical shapes.

47. What makes a planet? It goes around a star. It does not make heat by nuclear reactions It is (more-or-less) spherical. It is bigger than 1000km in diameter

48. Is Pluto a Planet? Please raise hands for yes

49. Or not ? Please raise hands for NO

50. Pluto is a small icy planet Like Neptune’s moon Triton

51. ..and a member of the Kuiper Belt Pluto

52. Pluto could have dual status. 1000 Piazzi 2000 Herschel 3000 Leonardo 4000 Hipparcus 5000 IAU 6000 United Nations 7000 Curie 8000 Isaac Newton 9000 HAL 10000 Pluto?

53. ATC Clapometer Clap Cheer Standby Mode: Quiet Please

54. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

55. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

56. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

57. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

58. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

59. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

60. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

61. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

62. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

63. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

64. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

65. Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No

66. Thanks very much!

67. Bye for now, Drive safely.

68. Is Pluto a Planet? Presented by: John Davies and Suzie Ramsay Howat. Written by: John Davies Thanks to: Jason Cowan, Chad Trujillo, Lowell Observatory archives, NASA, Yerkes Observatory, Dave Jewitt, Jane Luu, Martin Duncan and John Spencer

69. For more information. Published by CUP, get it from Amazon.

70. Mutual Eclipses of Pluto and Charon