Is Pluto a Planet? Dr John K. Davies UK Astronomy Technology
Centre, Royal Observatory, Edinburgh, Scotland Slide 2 Executive
Summary Slide 3 The classical solar system Slide 4 Planet Uranus
imaged from Voyager 2. Slide 5 Planet Neptune from Voyager 2. Slide
6 Percival Lowell Slide 7 Lowells Tomb, shaped like Planet Saturn
Slide 8 Clyde Tombaugh and the Pluto Telescope. Slide 9 Discovery
of Pluto, 1930 Slide 10 Orbits of Pluto and Neptune. Slide 11
Nucleus of Halleys Comet Slide 12 Pluto is Shrinking Slide 13 Pluto
is covered with ice. Slide 14 Pluto and Charon (Gemini Observatory)
Slide 15 Pluto should have vanished by now ! Slide 16 Mercury and
Venus: Planets without Moons Slide 17 243 Ida and Dactyl Ida: Size
about 56 km long. Dactyl: Size about 1.5 km. Slide 18 45 Eugenia
and its moon. Eugenia size ~215km Satellite size ~13 km Period ~4.7
days Slide 19 Pluto has an atmosphere Slide 20 New Horizons
Mission-Pluto Flyby, July 2015. Slide 21 Comet Hale-Bopp Slide 22
Comet Orbits Long Period Comet, like Hale-Bopp Short Period Comet.
Interstellar comet (never seen) Slide 23 Gerard Kuiper 1905-1973
Slide 24 Kenneth Edgeworth. 1880-1973 Slide 25 Jane Luu and Dave
Jewitt Slide 26 University of Hawaii 2.2m Telescope Slide 27
Discovery of 1992 QB 1 Slide 28 The Classical Kuiper Belt Slide 29
The Plutinos Slide 30 1998 WW31 a Kuiper Belt Object with a
satellite Slide 31 Orbital Elements and Stable Regions Slide 32
Some of the the largest known Kuiper Belt Objects Late 2000 Varuna
Discovered Slide 33 November 2003 Sedna Announced Slide 34 Sedna:
EKO or Oort Cloud Object? Slide 35 Sedna. Planet10? Slide 36 The
Discoveries Continue June 2002. Quaour discovered. Late 2004. Orcus
(2004 DW 4 ) announced July 2005. Ortiz et al announce discovery of
2003 EL 61 July 2005. Brown et al announce, via press release,
existence of 2003 UB 313 amidst allegations of hacking by Ortiz et
al Slide 37 2003 EL 61 Irregular, rocky object with a glazing of
ice. Rotates every 4 hours. Has two satellites. Slide 38 2003 UB
313 aka Xena Slide 39 2003 UB 313 aka Xena Slide 40 2003 UB 313 aka
Xena Slide 41 What makes a planet? It goes around a star. Slide 42
Io and the Moon are not planets because they dont go around a star.
Slide 43 What makes a planet? It goes around a star. It does not
generate heat internally. Slide 44 Jupiter is a planet. since it is
not heated by nuclear reactions. Slide 45 What makes a planet? It
goes around a star. It does not make heat by nuclear reactions. It
is spherical. Slide 46 So MOST asteroids are not planets since they
have not collapsed to spherical shapes. Slide 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 Slide 48 IAU Committees 2003-5: First attempts at
planet definition split community almost equally so new panel
formed. 2006: Committee Meets in Paris to draft proposal for Prague
IAU meeting in August Slide 49 Sunday 13th: Draft IAU resolution
sent to press. Allows 12 planets and potential for many more. Slide
50 3 New Planets Slide 51 Lots of Potential New Planets Slide 52
Thursday 17th: Draft proposal slammed by Div III dynamicists Slide
53 Tuesday 22 nd lunchtime: Further Modified Draft Presented Slide
54 New proposal slammed even harder! Slide 55 Tuesday 22 nd 1800hr:
Further modifications seem to be getting closer to consensus Slide
56 Wednesday 23 rd More modifications and coffee break debates over
whether a dwarf-planet is the same thing as a dwarf planet. Slide
57 Wednesday 23 rd More modifications and coffee break debates over
whether a dwarf-planet is the same thing as a dwarf planet. and. If
a dwarf planet is a kind of planet or a whole different thing.
Slide 58 Thursday 24 th : The final Countdown 5A. A Planet is
round, goes around the Sun and dominates its local space. A dwarf
planet is round, goes around the Sun, has not cleared its local
space and is not a satellite. Everything else is a small solar-
system body 5B Change Planet to Classical Planet Slide 59 Thursday
24th: The final Countdown 6A Pluto is a dwarf planet by the above
definition and is recognised as the prototype of a new class of
trans-Neptunian Objects. 6B This class of dwarf planets will be
called Plutonids Slide 60 Thursday 24th: History is Made 5A. A
Planet is round, goes around the Sun and dominates its local space.
Slide 61 Thursday 24th: History is Made 5A. A Planet is round, goes
around the Sun and dominates its local space. 5B Change Planet to
Classical Planet Slide 62 Thursday 24th: History is Made 5A. A
Planet is round, goes around the Sun and dominates its local space.
5B Change Planet to Classical Planet 6A Pluto is a dwarf planet and
the prototype of a new class of TNOs Slide 63 Thursday 24th:
History is Made 5A. A Planet is round, goes around the Sun and
dominates its local space. 5B Change Planet to Classical Planet 6A
Pluto is a dwarf planet and the prototype of a new class of TNOs 6B
This class of dwarf planets will be called Plutonoids Slide 64 Mike
Browns Reaction Slide 65 Some Other Astronomer Reactions Slide 66
The Peoples Reaction Slide 67 The Astrologer Reaction. Scorpios can
be extremely explosive, and very direct, and this may be the
trigger that makes them explode Milton Black, Australian Astrologer
This is a moment Ive been waiting for, people are finally talking
about Charon Eric Francis, Minor Planet Astrologer Slide 68 Pluto
is a small icy dwarf planet Like Neptunes moon Triton Slide 69
..and a member of the Kuiper Belt Pluto Slide 70 Is Pluto a Planet?
What do you think? Slide 71 Clap for Yes, Pluto is a Planet Cheer
for No, Pluto is NOT a planet Yes No Slide 72 ATC Clapometer Clap
Cheer Standby Mode: Quiet Please Slide 73 Clap for Yes, Pluto is a
Planet Cheer for No, Pluto is NOT a planet Yes No Slide 74 Clap for
Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No
Slide 75 Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT
a planet Yes No Slide 76 Clap for Yes, Pluto is a Planet Cheer for
No, Pluto is NOT a planet Yes No Slide 77 Clap for Yes, Pluto is a
Planet Cheer for No, Pluto is NOT a planet Yes No Slide 78 Clap for
Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No
Slide 79 Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT
a planet Yes No Slide 80 Clap for Yes, Pluto is a Planet Cheer for
No, Pluto is NOT a planet Yes No Slide 81 Clap for Yes, Pluto is a
Planet Cheer for No, Pluto is NOT a planet Yes No Slide 82 Clap for
Yes, Pluto is a Planet Cheer for No, Pluto is NOT a planet Yes No
Slide 83 Clap for Yes, Pluto is a Planet Cheer for No, Pluto is NOT
a planet Yes No Slide 84 Thanks very much! Slide 85 Bye for now,
Drive safely. Slide 86 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
Slide 87 For more information. Published by CUP, get it from
Amazon. Slide 88 Mutual Eclipses of Pluto and Charon Slide 89 Comet
Ring as predicted by Fred Whipple in 1964, virtually what we today
call the Kuiper Belt Slide 90 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) Slide 91 Tradition in Astronomy Constellations
Lunar Sea!
