[meteorite-list] 'Plutons' Push Planet Total Up To 12

[Larry Lebofsky]

Hi Daren:

I am reading these backwards, so have waded through Sterling's comments. 
Again, I was not on the committee, but have been (because of the Division for 
Planetary Sciences Committee) "briefed" by Rick Binzel who was on the 
committee and who we questioned.

Plutons: a class of planets. The committee used a star analogue like T-Tauri 
stars or Cepheid variables. So Plutons are PLANETS with orbital periods 
greater than 200 years. So, Pluto is a planet, it is a pluton, it is a KBO, 
and it is a TNO!

Ceres, as far as I can tell (do not know this for sure) will just be a planet. 
Since terrestrial and jovian (or gas giant) are not recognized by the IAU (see 
their Q&A), it is not a terrestrial planet (at least officially). So, there 
are the "classical" planets (not an offical term) and the plutons (an official 
term). Poor Ceres is in neither. IAU does use the term dwarf planet, but that 
will not be an official term. Also "minor planet" goes away. Asteroids and 
comets are now "small Solar System bodies." This just removes the word planet 
from anything that is not a planet. Sounds good to me.

Larry