View Single Post
  #71  
Old September 11th 06, 11:42 AM posted to sci.astro.amateur,uk.sci.astronomy,alt.astronomy,sci.astro,alt.astronomy.solar
George Dishman[_1_]
external usenet poster
 
Posts: 2,509
Default Pluto is out from planet dictionary

Margo Schulter wrote:

snip text

The one thing that might be added -- especially if
you or others can improve on my first quick attempt --
is a set of diagrams to show visually the levels of
definition we're discussing. Here's that crude first
try; note, by the way, that after the diagrams of
5A and 5B, there's a diagram for the kind of compromise
I've proposed, where the term "planet" actually appears
twice, once in a generic meaning (like the defeated 5B)
and once in a specific meaning (like the adopted 5A),
allowing a choice between the two usages.


Margo, having had a longer look myself, I think
your diagrams don't quite reflect the linguistics.
The following shows how I see the intended
outcome of 5B and illustrate how your version
is really the same other than the choice of name.
I have also indicated the priority of the 'satellite'
criterion.

[composed with monospaced font]

-----------------------
Resolution 5A (Adopted)
-----------------------


Solar system bodies
|
---------------------------------------
| |
Is not a Satellite
satellite of another
| body [other
---------------------------------- than Sun]
| | |
Hydrostatic equilibrium, Not enough mass for |
self-gravity produces hydrostatic equilibrium; |
"nearly round" shape; and not a satellite of another |
not a satellite of another body [other than Sun] |
body [other than Sun] | |
| | |
-------------- | |
| | | |
Clears Doesn't | |
orbit clear orbit | |
| | | |
| | | |
"Planet" "Dwarf Planet" "Small Solar System Body" "Satellite"
(e.g. most Solar System (e.g. Moon,
asteroids, TNOs, comets) Titan)

TNO = "Trans-Neptunian Object"


------------------------
Resolution 5B (defeated)
------------------------

Solar system bodies
|
---------------------------------------
| |
Is not a Satellite
satellite of another
| body [other
---------------------------------- than Sun]
| | |
Hydrostatic equilibrium, Not enough mass for |
self-gravity produces hydrostatic equilibrium; |
"nearly round" shape; and not a satellite of another |
not a satellite of another body [other than Sun] |
body [other than Sun] | |
| | |
"Planet" | |
| | |
-------------- | |
| | | |
Clears Doesn't | |
orbit clear orbit | |
| | | |
"Classical" "Dwarf" "Small Solar System Body" "Satellite"
(e.g. most Solar System (e.g. Moon,
asteroids, TNOs, comets) Titan)



--------------------------------
Possible compromise proposal
for future consideration
--------------------------------

Solar system bodies
|
---------------------------------------
| |
Is not a Satellite
satellite of another
| body [other
---------------------------------- than Sun]
| | |
Hydrostatic equilibrium, Not enough mass for |
self-gravity produces hydrostatic equilibrium; |
"nearly round" shape; and not a satellite of another |
not a satellite of another body [other than Sun] |
body [other than Sun] | |
| | |
"Planet" | |
| | |
-------------- | |
| | | |
Clears Doesn't | |
orbit clear orbit | |
| | | |
"Major" "Dwarf" "Small Solar System Body" "Satellite"
(e.g. most Solar System (e.g. Moon,
asteroids, TNOs, comets) Titan)


George