[meteorite-list] OT: HOW MANY PLANETS?

[MexicoDoug at aol.com]

Ron B. wrote:

>Incidently, if you demote Pluto from being a planet, then  the
>definition for a planet becomes much easier.  If you  include
>Pluto as a planet, then the definition is going to  get
>more complicated.
 
Complicated it can be, not dumbed down, with or without  Pluto.  Arbitrary 
numerical criteria are useless to science in the long run  whether they be "9 
units", "20 degrees" or "3025 miles".  They are more  like taxing authorities 
saying..."if you own more than 20% of the company's  stock, you must make 
special declarations".  That is a foolish angle for  the IAU to put itself in, and 
more typical of the thinking of mediocre  government employees or bureacrats 
looking to reduce their workloads (not that  we aren't all guilty at times).
 
My personal thoughts of a planet rely on a permanent atmosphere  or proven or 
potential geological process (major igneous activity,  liberally considered) 
basis and prime orbit about the Sun.  If Earth  suddenly was catapulted into a 
25 degree inclination ...would it cease being a  planet?  Perhaps my 
definition even excludes Pluto by not for a senseless  inclination cutoff, especially 
after its hypothetical encounter with Neptune  sent it there, or perhaps not.  
Vesta is always as bright or brighter than  Neptune, and occasionally trumps 
Uranus, so something is out of wack  here...the ancients would have called 
Vesta a wanderer if they didn't carelessly  overlook documenting it.  (It owes 
that brightness to 'geo'logical  processes, namely the reflectivity of eucrite.)
 
If Earth were catapulted into the Kuiper Belt would it cease being a  planet? 
 Wait until an Earth sized ball is found out there...How about  
Differentiated Planets, Gaseous Planets, and Frozen Planets to replace the  "inner" and 
"outer" planets?  Remember - for minor planets, a comet for all  practical 
purposes becomes an asteroid - but it is still a minor planet,  under current use...
Kids can still memorize the Inner, Gaseous and Pluto (because Pluto is  
sometimes closer than Neptune, a very very important criterion from an earthly  
viewpoint of numbering successively the billiard balls starting with  the bright 
white cue, and all you have to do is say the first 9 planets  out..)
Saludos, Doug