🚀 go-pugleaf

-From: cain@geomag.gly.fsu.edu (Joe Cain)
-Subject: Re: asteroids beyond Jupiter
-Date: 27 Dec 92 18:56:46 GMT
-Organization: Florida State University Geology Dept.

->In article <1992Dec24.193342.29953@hpcvaac.cv.hp.com>, 
->billn@hpcvaac.cv.hp.com (bill nelson) writes:
->> My definition of asteriod is: any body that orginated in the
->> "asteriod belt" (between Mars and Jupiter). etc etc

-	Help! It would be useful to learn what are the "official" uses
-of the words according the IAU (and IUGG?). I have a hard enough time helping
-students try to keep meteor, meteorite, and meteoroid straight when
-there seems to be general disagreement on the distinctions between the
-meaning of the words asteroids, comets and, yes, planets. I posted
-this question recently in sci.astro but so far no one has come to the
-rescue. 

I posted a quote from a (1960s-1970s) astronomy textbook last week. 
Basically, "asteroid" and "minor planet" are considered synonyms.
The speculation that some comets eventually become covered with tar, dust,
etc. and become icy asteroids has tended to blur the distinction. 
Asteroids appear to have a variety of compositions.

-	Is anyone willing to demote Pluto/Charon to asteroid status,
-change Chiron from "asteroid" to comet, buck public sentiment to
-avoid naming a body orbiting mostly a little beyond Pluto "Planet X", or
-think about the use of the term "worlds" that some seem to favor for
-large bodies even if not orbiting the Sun?

Fitting things into definitions is an attempt to simplify one's model of
the universe. I'm not sure that's particularly useful in this situation.
It seems more practical in this case to not take definitions too seriously -
just treat them as a sort of loose and informal classification, and 
evaluate individual objects on a case-by-case basis. If you want to be
more formal, you have to divide "asteroid" into at least three categories.

John Roberts
roberts@cmr.ncsl.nist.gov