[meteorite-list] Re: The IAU Draft Definition of 'Planet' and 'Plutons'

[Larry Lebofsky]

Hi Ron:

I do think that I brought this up before, but it is worth repeating:

1. It is common practice to name a group of objects after the "type" object: T-
Tauri stars and RR Lyrae stars come to mind. The same has been done for 
plutons, from the French word for Pluto (Pluton).

2. Terms are used for different things in different fields because they may be 
derived from the same root, in this case god of the Underworld, Pluto.

I have been trying to come up with other examples, not coming up with many, 
though I am sure there are: hill vs. Hill Sphere (region of gravitational 
influence) planet vs. planetary gears and planetary nebula, Mercury the planet 
and mercury the metal. I am sure there are others.

I do not think anyone will get confused if the term is accepted.

Larry

Quoting Ron Baalke <baalke at zagami.jpl.nasa.gov>:

> 
> 
> >The IAU draft Resolution also defines a new category of planet for
> >official use: "pluton". Plutons are distinguished from classical planets
> >in that they reside in orbits around the Sun that take longer than 200
> >years to complete (i.e. they orbit beyond Neptune). Plutons typically
> >have orbits that are highly tilted with respect to the classical planets
> >(technically referred to as a large orbital inclination). Plutons also
> >typically have orbits that are far from being perfectly circular
> >(technically referred to as having a large orbital eccentricity). All of
> >these distinguishing characteristics for plutons are scientifically
> >interesting in that they suggest a different origin from the classical
> >planets.
> 
> The word 'pluton' is already defined as a geoligic term.
> 
> http://dictionary.reference.com/browse/pluton
> 
> pluton - n. A body of igneous rock formed beneath the surface of the earth 
> by consolidation of magma.
> 
> pluton - n. large mass of intrusive igneous rock believed to have 
> solidified deep within the earth [syn: batholith, batholite, plutonic rock]
> 
> Ron Baalke
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