[meteorite-list] Experts Skeptical of Peruvian Meteorite Impact

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Thu, 20 Sep 2007 23:17:18 -0500
Message-ID: <0dd301c7fc06$4d8b0bf0$a025e146_at_ATARIENGINE>

Hi, Jason, List

> relative abundances of such stony bodies to irons...

    Remember that the relative abundances usually cited
are from "fall" statistics (or combined fall and find statistics),
which means they're derived from those meteorites that
make it to the ground without making a crater. That's
a different dynamic population than the crater-forming
objects.

    Before objects encounter the atmosphere, the ratio
of stones to irons is even greater than in the "fall" statistics,
as stones get dusted in complete fragmentation in greater
numbers than irons. The ratio of stones to irons is much
less in "finds" than in "falls" because of irons' greater
durability. And if we had the data on small crater-forming
objects, the percentage of irons would be much higher
still.

    All these variations are difficult to quantify. Anybody
knew if there are any studies that try? Hardest of all to
determine would be the "space" abundances before
encounter with the Earth.

    As for the Peruvian Crater so far, nothing adds up.
It is exceedingly foolish for experts far away with zero
data and conflicting press reports to hypothesize on
its reality. I guess those reporters can really get to you.
It's going to be a while before it gets sorted out. Until we
know the story, try not to breathe any of the radioactive
sulfurous gas from the boiling liquid in the bottom of
your craters...


Sterling K. Webb
--------------------------------------------------------------------
----- Original Message -----
From: "Jason Utas" <meteoritekid at gmail.com>
To: "Chris Peterson" <clp at alumni.caltech.edu>; "Meteorite-list"
<meteorite-list at meteoritecentral.com>; "Sterling K. Webb"
<sterling_k_webb at sbcglobal.net>
Sent: Thursday, September 20, 2007 7:20 PM
Subject: Re: [meteorite-list] Experts Skeptical of Peruvian Meteorite Impact


> Maybe he meant (or said, and was misreported) that a small crater forming
> event was much more likely to involve an iron parent? That might be a
> reasonable statement.

Given that any given falling meteorite is ~950% more likely to be a
stone than an iron, I don't see this as likely...

With regards to the smaller likelihood of such a small crater being
produced by a stone rather than an iron (Sterling), I would have to
say that without some comparisons as to the relative abundances of
such stony bodies to irons, and without knowing any information such
as entry angle or velocity, not to mention the fact that without such
data, we don't even know what size the body initially was to any
reasonable degree, I would conclude that any such statement would have
had to have been made -very- prematurely.

Jason

On 9/20/07, Chris Peterson <clp at alumni.caltech.edu> wrote:
> Maybe he meant (or said, and was misreported) that a small crater forming
> event was much more likely to involve an iron parent? That might be a
> reasonable statement.
>
> Chris
> ________________________________
> Chris L Peterson
> http://www.cloudbait.com
>
> ----- Original Message -----
> From: "Jason Utas" <meteoritekid at gmail.com>
> To: "Meteorite-list" <meteorite-list at meteoritecentral.com>
> Sent: Thursday, September 20, 2007 5:29 PM
> Subject: Re: [meteorite-list] Experts Skeptical of Peruvian Meteorite
> Impact
>
>
> > Hello All,
> >
> > This particular bit really makes me wonder about those fellows up at
> > JPL...
> >
> >>It's not impossible that the crater was left by a meteorite, Yeomans
> > said, but if so, then the impact object most likely was small, based
> > on the size of the crater. It would also probably have been a metal
> > meteorite, because those are the only kind of small meteorites that
> > don't burn up as they plummet through Earth's atmosphere, he added.
> > Small stony meteorites rarely make it to the surface.
> >
> > ...Does anyone else find his statement...completely wrong? I mean -
> > I'm used to such stuff coming out of reporters from god-knows-where,
> > but from a JPL employee...
> >
> > Jason
>
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Received on Fri 21 Sep 2007 12:17:18 AM PDT