[meteorite-list] Astronomers to Decide What Makes a Planet

[Ron Baalke]

> 
> Hi, Ron,
> 
>     You'll notice that I put quotes around the word "rules."

You also referred to is a game, which is not. Any classification scheme can
be revised - and in fact, should be allowed to be revised when new data
presents itself.
 
>     Yes, there is no formal definition for a planet. There never has been, only a
> working understanding of what was meant.
>     There were differences; it has been a topic of discussion. But, there are
> "working rules," by which I mean that one knows what others in the field think and
> why.

The 'working rules' varied depending on who you talked to.  Thus the need for a
formal definition.

>     Next week's IAU decision is only a momentary thing, always subject to revision.

The IAU decision will be first formal definition of a planet.  As I mentioned before,
any classification scheme can and should be revised as needed.

Ron Baalke