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

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Aug 3 15:19:06 2005
Message-ID: <200508031918.j73JIBF06877_at_zagami.jpl.nasa.gov>

>
> 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
Received on Wed 03 Aug 2005 03:18:11 PM PDT