[meteorite-list] WHAT IS A PLANET?

[MexicoDoug at aol.com]

Martin A. wrote:

>To decide, how to call it, is more a question of history, guess 
>Doug will write us a nice homework about.
 
Hola Martin, Sterling, Al, Chris, Alex, Darren, Xena, List,
 
Thanks, Martin, I'll mostly pass on this planetary round - been there, done  
that when Tom was helping his kid debate Pluto last time on the metlist - 
except  (!!), to generally agree with Sterling about having an open mind for 
different  classes of planets, why not?  The more we learn about our Solar System  
in this nearly unprecedented age of discovery, the more we need to extend our  
vocabulary to cover and accomodate.  I am still having problems figuring  out 
why Vesta isn't called a planet but I don't want to takes sides in a  
senslessly manufactured debate!  Vesta is cool, differentiated and fits my  tastes.  
Ceres, the first asteroid identified from earth was called a  planet for a 
while, but then was weaseled down to a planetoid whatever that is  supposed to 
mean, and from what I can tell the rationale was because it was not  the main 
mass in its orbit (however that is defined - someone from Caltech  had recently 
formalized this definition for a planet and probably has nicely fit  the 
random history, nomenclature and structure to agree with his opinion).   The new 
discovery's planetary _status_ is just a _status_ symbol like calling a  
particular astronomical brew a good beer.  The obvious ones are hard to  dispute, and 
then there are all the others, which resemble other liquids more  than the 
original type specimens - to each her own.  So whether being less  filling in 
its orbit, or tasting great for someone else, the discoverer's  comment on kid's 
textbooks is the only real issue I see here.  Fairy tale  explanations of 
Snow White (Earth) and the seven dwarfs and their  now sometimes informally 
downgraded Dog, Pluto, are no longer as easy to  explain as a Disney cartoon.  
Great!  As education migrates from  senselessly memorizing mnemonics like "My Very 
Earnest Mother Just Served Us  Nine Pickles" to having kids fire up the mind 
for the complexities of life, I'll  be happy to watch the cheerleaders in the 
great planetary contest from  the sidelines.  Maybe the Gods are just laughing 
and the new discovery is  just a gift of a golden apple from Venus to set the 
astronomical community  straight that she is the most beautiful planet of all 
(and perhaps jealous of  her status as the only woman planet in the 
heavens?)...
Saludos, Doug