[meteorite-list] Re: Something Different To Consider About (meteorite streams)

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:30 2004
Message-ID: <20020427191407.97657.qmail_at_web11603.mail.yahoo.com>

Hello Mark -

While it is true that any meteorite stream is likely
to be differentiated to one degree or another, it
would seem to me that usually the differences would
not be that great.

Thus, given the complexities of trying to identify a
stream from the data assembled so far, probably the
way to go is to do it by strict types at first, and
then maybe much later look for differentiation in the
stream.

ep

--- Mark Fox <unclefireballmtf_at_yahoo.com> wrote:
> April 26, 2002
>
> Greetings Meteorite Enthusiasts!
>
> With the startling news announced by European
> Fireball
> researchers in regard to the EN060402 bolide being
> linked with the Pribram chondrite, fellow
> enthusiasts
> on the Meteorite-list are likewise trying to make
> "connections". However, I must say something that
> may not have been considered. When trying to
> discover
> a "meteorite" stream (meteoroid is the better term
> here) we should not just consider or try to link
> meteorite falls of only one distinct type with each
> other. In reality, the composition of such a stream
> composed of asteroid matter is quite likely not to
> be
> homogenous! Dr. Pavel Spurny in his history making
> e-mail had this little footnote to add:
>
> "Finally, from the perfect similarity of both
> heliocentric orbits we can predicate, that both
> bodies had also the same composition and therefore
> we
> can expect that meteorites produced by the April 6
> fireball are H5 ordinary chondrites."
>
> Astounding! I was intrigued that such a bold
> statement was made, especially in such a mysterious
> and sparsely understood whelm. However, in this
> case,
> I believe the logic which drew the conclusion should
>
> be revised. Just because the orbital data and/or
> fireball information of both meteorite falls are so
> similar doesn't mean that they are one in the same
> meteorite, petrologic type and all! Asteroids
> almost
> undoubtedly vary in overall composition as one nears
> the core, which does of course assume we are talking
> about a good sized asteroid body to begin with or a
> big fragment from such. With the discovery of so
> many asteroid moon systems recently, we again should
> not be so certain that the two linked meteorite
> falls
> have almost equal compositions. For all we know
> these
> asteroid moons could form a hefty percentage of a
> rocky meteoroid stream, ones with slight petrologic
> and composition differences or entirely different
> classes! Gravitational pulls by our planet could be
> prying them loose from the "mother ship" asteroid
> during close encounters. As a result, the behavior
> of
> such a stream could be noticeably different from
> that
> of a normal cometary meteoroid stream. Something
> else
> to keep in mind.
>
> In conclusion, chondrites of different petrologic
> types (or possibly even meteorites of different
> classes) should not necessarily be excluded when
> trying to identify a date(s) that a possible
> meteoroid
> swarm is encountering Earth. Also, EN060402 does
> not
> necessarily have to be an H5 chondrite as is Pribram
> when one "digs" more deeply into the compositional
> nature of asteroids. Lastly, the behavior of an
> asteroid meteoroid stream may involve new methods of
> sending material to Earth.
>
> All the above is my personal slant and I am open to
> all comments on this matter. Please correct me for
> any possible errors.
>
> Long strewn fields!
>
> Mark Fox
> Newaygo, MI USA
>
>
> __________________________________________________
> Do You Yahoo!?
> Yahoo! Health - your guide to health and wellness
> http://health.yahoo.com
>
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
>
http://www.pairlist.net/mailman/listinfo/meteorite-list


__________________________________________________
Do You Yahoo!?
Yahoo! Health - your guide to health and wellness
http://health.yahoo.com
Received on Sat 27 Apr 2002 03:14:07 PM PDT