Re-2: [meteorite-list] Moss Meteorite From A Comet?

From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Mon Aug 21 09:52:35 2006
Message-ID: <20060821135232.15465.qmail_at_web36902.mail.mud.yahoo.com>

Hi Larry, List -

It appears we have at least one other comet sample:
Cheimgau.

good hunting,
Ed


--- Larry Lebofsky <lebofsky_at_lpl.arizona.edu> wrote:

> Hi all:
>
> Defending Tim Swindle and Humberto Campins. I have
> known them for years and
> they are very conservative scientists. Their work is
> good and they are well-
> respected scientists. They do not go off (too often)
> to make wild,
> unsubstantiated, claims., hence, the conclusions in
> their article. They based
> their Meteorite paper (and their original scientific
> paper) on what we know.
> We have observations of many comets (Campins has
> done a lot of this), but we
> have "samples" from only one comet (Halley), are
> just now studying Stardust
> material (so too early to say much), and IDPs which
> are thought to be, at
> least in part, cometary in origin.
>
> Clearly, we need multiple samples from multiple
> comets --- good luck in our
> lifetime. Therefore you base your "theories" on the
> existing information, not
> onwhat you hope to have in the future. That is why
> people propose new missions
> to comets and asteroids!
>
> We know that not all comets are the same based on
> our observations and where
> we think they came from. Some of this may be because
> of how many times they
> have been close to the Sun, some may have to be
> related to where they came
> from (Kuiper Belt or Oort cloud), and some may have
> to do with where they were
> formed (which may not have been where we see them
> coming from). Clearly, a
> chunk of a "fresh" comet would look very different
> from a "dead" comet. Or, as
> been on this listserv recently, could we tell the
> difference between a chunk
> of a comet or a piece of Ceres? I am not sure I
> would be willing to say
> anything in print even though I have studied Ceres
> for years. What, from
> either, would we expect to make it through the
> atmosphere?
>
> Even if we were to bring back samples from two or
> three comets, I doubt if
> anyone I know would be willing to say (with respect
> to the composition of
> comets) that that was their "final answer." That is
> the nature of science.
>
> I really have to stop writing these a 5:00 in the
> morning, no breakfast and no
> soffee, but this is the quiet time of the day.
>
> Larry
>
>
>
> Quoting bernd.pauli_at_paulinet.de:
>
> > "Comets ... being 'primitive material' ... we
> would need
> > to have known multiple samples of multiple comets
> before
> > we could say for sure."
> >
> > Hi Mark and List,
> >
> > I couldn't agree more and that's why I felt a bit
> uneasy when I read
> > Campins' and Swindle's article in this issue of
> our METEORITE magazine:
> >
> > CAMPINS H. and SWINDLE T.D.(2006) Where are the
> cometary
> > meteorites? (Meteorite, May 2006, Vol. 12, No.2,
> pp. 17-19).
> >
> > They solely refer repeatedly to Comet Halley and
> to Halley dust (plus to
> > cometary IDPs). Many more comets need to be
> sampled before we can draw
> > definite conclusions!
> >
> > Best,
> >
> > Bernd
> >
> > ______________________________________________
> > Meteorite-list mailing list
> > Meteorite-list_at_meteoritecentral.com
> >
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
> >
>
>
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>
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Received on Mon 21 Aug 2006 09:52:32 AM PDT