[extropy-chat] Our Solar System Planets
amara at amara.com
Wed Aug 16 11:10:11 UTC 2006
The planets in our Solar System are now 12:
To make the most sense, read the docs in order.
1. Press Release 2. Resolution text 3. Questions & Answers
Question and Answers:
Forwarded in an email from Mark Sykes, (PSI), who forwarded
it from Richard Binzel at the IAU meeting in Prague:
BRIEF SUMMARY (TWO PARTS)
A. Planet = Hydrostatic Equilibrium Shape.
-Pluto status as planet remains unchanged.
-There are currently 12 planets, and counting.
-Ceres now a planet.
-Charon now a planet (not a satellite; barycenter is in free space)
-2003 UB313 now a planet; will be named after IAU Meeting.
B. New IAU Category of planets created: "Plutons"
-Pluto is the prototype.
-Many new planets to be added, these will be the largest TNOs
that satisfy the "planet" definition. (IAU may create a
separate "pluton catalog". This is a separate discussion.)
-Currently three objects recognized as "plutons":
Pluto, Charon, UB313.
-New discoveries of large objects (and currently known large TNOs)
to be evaluated for "planet" status on a case by case basis.
"Planets" among the TNOs are also known as "Plutons".
NOTE: "Pluton" is an official IAU word.
Terrestrial planet, classical planet, dwarf planet, etc.
are all descriptive words, not IAU terms. We want to work
hard to NOT have "classical planet", "dwarf planet" be mis-
interpreted as official IAU categories. They are not.
Amara Graps, PhD www.amara.com
Istituto di Fisica dello Spazio Interplanetario (IFSI), Roma, ITALIA
Associate Research Scientist, Planetary Science Institute (PSI), Tucson
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