[meteorite-list] WHAT IS A PLANET?

From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Sun Jul 31 09:59:18 2005
Message-ID: <042301c595d8$040be490$f551040a_at_bellatrix>

I'm happy enough for now keeping the definition loose. We have nine objects
that we call planets for historical reasons; I'd be cautious adding more
until we have a better understanding of their formation. I would lean away
from calling anything significantly off the ecliptic a planet, unless we
know that they it formed in the same process that produced the other
planets.

The reason this whole question comes up is because "planet" has a powerful
colloquial meaning quite independent of any possible scientific definition.
Perhaps the best solution is simply to remove "planet" from the table and
leave it to its traditional use. All we need is a formal definition for
bodies orbiting stars (possibly on a common plane), with enough mass to form
near-spherical surfaces (and maybe a few other criteria). Perhaps
"planetoid" could be used for that.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message -----
From: "Sterling K. Webb" <kelly_at_bhil.com>
To: "Meteorite List" <meteorite-list_at_meteoritecentral.com>
Sent: Sunday, July 31, 2005 2:16 AM
Subject: [meteorite-list] WHAT IS A PLANET?


> These recent discoveries of new "planets" is going to heat up the
> on-going quarrel about what is and isn't a planet, with its increasingly
> long definitions and conditions statements designed to trim reality in
> the mold of the arguer's mind.
>
>...
>
> So, here goes: if it goes around the Sun and is demonstrably (the
> entire range of error bars above the Ceres diameter) larger than Ceres,
> it's a planet. Welcome to The Club!
Received on Sun 31 Jul 2005 09:59:05 AM PDT