[extropy-chat] SPACE: How many planets?

[Alan Eliasen]

Mike Lorrey wrote:
> Actually, roundness was the primary criteria I had stated here not so
> long ago...

   As I recall, that discussion dwindled off just as it started to get
interesting.  Nobody ever defined what "roundness" meant and how it was to be
defined.

   After all, Sedna is probably a lot "rounder" than Jupiter, which has an
equatorial radius of 71492 km, and a polar radius of 66854 km.  It's all squished.

   So what is the equation that quantifies "roundness," and what is the line
that differentiates planets from non-planets?

-- 
  Alan Eliasen                 | "You cannot reason a person out of a
  eliasen at mindspring.com       |  position he did not reason himself
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                               |     --Jonathan Swift