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António Marques wrote:
> Leszek L. wrote:
>
> >> And you forgot that goofy, Disney dog in English. When are you
> >
> > Forgotten HIM? You must be joking. But I was only
> > listing the meanings of [P|p]luton, with an 'n',
> > the word that is IMHO unwisely being proposed
> > as a term for less-than-planetary bodies.
>
> wasn't suggested is quite intriguing.And the fact that such an obvious
> and available alternative as 'plutoid'. Derivational morphology is quite
> irrelevant at this point, also.
> I happen to think the definition proposed is a good start, especially in
> that it doesn't as yet resort to arbitrary continuous (as opposed to
> discrete) properties. I'd suggest that something were added to the
> roundness criterion, namely signoficant internal layering - which I
> suppose would throw out some smaller bodies, but I don't know ebough
> geology for that, other possibilities are to consider diversity of
> chemical elements present - and, in the case of binary systems, to
> consider only the largest as a planet (even if that would have us throw
> out large bodies, after all the Moon is just a moon - as the system's
> gravity centre is inside Earth - even if it is larger than other
> candidate planets).
>
> In short, to be a 'planet' (. kept, + added, - deleted),
>
> 1 . having a roughly round shape by virtue of its own gravity
> 2 . not being a star
> 3 . orbiting a star in a roughly round orbit
> 4 + having a core, mantle, etc, or similar geological / chemical criterion
>
> In binary systems, instead of
> 5 - the gravity centre being outside any of the bodies
> 5 + the planet is the largest body even if the gravity centre is outside
> of it, and the other(s) is/are moons
>
> 'Moon' would the be any body that meets at least 1, 2 and possibly 4,
> but fails one or more of the others.
>
> I see that this doesn't take rogue planets into account, but certainly
> (3) is rewritable.
> --
some size criterion shoudl also be included IMHO, which I think there
is.
> am
>
> laurus : rhodophyta : brezoneg : smalltalk : stargate
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