[meteorite-list] Just Another Question

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Fri, 30 May 2008 23:08:34 -0500
Message-ID: <013001c8c2d3$ff07d310$5056e146_at_ATARIENGINE>

Hi, All,

    This is an old Post of mine from 2003
(and quotes from an even earlier one):

    "Actually, there are a number of
sedimentary meteorites. It's just that
they are not acknowledged to be meteorites.
If you have the CDROM of the Catalogue,
have the software assemble you a
list of "pseudometeorites" that are not irons.
Or just search for BLECKENSTAD
(April 11, 1925) SWEDEN, a sedimentary
meteorite of white limestone complete with
fossil shells. It was reported on by Dr. Assar
Hadding of the Swedish Geological Institute
in 1939 who, after a long investigation, decided
it really was a meteorite. The chief reason for
so believing is that it is a WITNESSED FALL
and you really can't get much better than that.

> BLECKENSTAD,
> Ostergotland, Sweden, April 11, 1925
>
> "A meteor was observed, leaving a trail
> of smoke. Stones are said to have
> fallen, and fragments of a white, porous
> limestone were picked up, differing from
> the local rocks. The possibly meteoritic
> nature of this material has been the subject
> of considerable discussion, N. Zenzen
> (1942, 1943); A. Hadding (1943); F.C. Cross
> (1947). Pseudometeorite, F.E. Wickman
> & A. Uddenberg-Anderson (1982)."
>
    However, he was widely regarded as whacky
and shut up about it for 20 years. Hadding was so
discouraged by the reception of his earlier paper
that, when he discovered another sedimentary
meteorite, he threw it away! Only much later,
in the 1950's, when he realized that they could
have been "Earthites," did he write about the two
stones again.

    ["Earthites" are meteorites blasted off the Earth
into independent orbit, then later encounter the
Earth as a meteoroid. Simulations by Jay Melosh
suggested the process could take from 100,000
years to 5 million years.]

    The modern SGU official report on the stone:
http://www.sgu.se/cgi-bin/egwcgi/53210/screen.tcl/name=show_record&format=normal&host=georeg&entry1=0560&field1=kom&logic1=&attr1=&page=2&norec=1&service=sgu&lang=eng
    "The stone described as a limestone...
      hence is a pseudometeorite." (1982)

    Boy, there's nothing like dogma for settling
an issue quickly, is there?

    Here is an article by Nininger that contains a
fuller account of Bleckenstad's fall:
http://articles.adsabs.harvard.edu//full/1967Metic...3..239N/0000245.000.html
    I can't cut'n'paste from this article because it's
an image; jump ahead to page 245. A "smooth gloss"
of a fusion crust is reported. Multiple witnesses to
the fall. No native limestone in the area.

    Monica Grady discusses sedimentary meteorites
in this 1994 Workshop (p.77):
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960027473_1996032004.pdf

    Nininger is said to have found a small sedimentary
meteorite, on March 24, 1933, while searching
for fragments of Pasamonte. The stone in
question was a dirty grey limestone with
fragmentary shell bits fossilized in it and
sporting a black fusion crust. He ruled out
an artificial origin for the crust but was unwilling
to claim it was a meteorite, apparently not because
he didn't think it was a meteorite but because
it wasn't worth the noise...

    Frank Cross wrote about sedimentary
meteorites at length in the journal
"Popular Astronomy" (Vol. 55, 1947,
pp. 96-102), citing Trevlac (Indiana)
and Montrose (West Virginia), two
independently discovered sedimentary
meteorites with identical green glassy crusts.

    The whereabouts of most of the
sedimentary "pseudometeorites" is
unknown, not surprising considering
their reception, so the sophisticated
tests that could be performed today
are impossible. There's a kind of
self-reinforcing judgement at work
in that."

1. fusion crust, Check.
2. evidence for cosmic-ray exposure in space, Not Tested.
3. lithology that is completely exotic for its find location, Check.
4. being an observed fall, Check.
5. whereabouts, Unknown.



Sterling K. Webb
--------------------------------------------------------------------------
----- Original Message -----
From: "AL Mitterling" <almitt at kconline.com>
To: <Meteorite-list at meteoritecentral.com>
Sent: Friday, May 30, 2008 7:51 PM
Subject: Re: [meteorite-list] Just Another Question


Hi Pete,

> some material omitted

Jeff states: Nothing like this has ever been found. Its distinguishing
properties might be a fusion crust, evidence for cosmic-ray exposure in
space, and lithology that is completely exotic for its find location.
Without an exposure history (or being an observed fall) it would be a
very tough sell.

Hope that helps. All my best!

--AL Mitterling

Pete Shugar wrote:

> So if an object were to be taken into orbit and given excape velosity
> from earth's gravitational well such that it was not in orbit around
> earth, but in orbit around the sun and at a later time reentered
> earth's gravity well, passed thru the atmosphere and survived to
> impact the earth, it would not be a meteorite simply because it was
> not ejected fron terra firma by natural means? Granted that man made
> debri isn't classed as a meteorite but non man made material
> shouldn't be penalized because an astronaught decided to impart
> excape velosity to a rock,puting it into orbit around the sun.
> I say material surviving to impact from any source (excluding man
> made) would and should be called a meteorite.
> Pete

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Received on Sat 31 May 2008 12:08:34 AM PDT