[meteorite-list] Wanted: Meteorites from Mercury

From: cdtucson at cox.net <cdtucson_at_meteoritecentral.com>
Date: Mon, 9 Jan 2012 10:18:55 -0500
Message-ID: <20120109101855.ZUB1Q.249723.imail_at_fed1rmwml108>

Carl,
 You make a very convincing argument against your Norton County Aubrite being from Mercury. Especially when you do consider it's very low Iron content and it's white color.
I have seen many Aubrites and I do not ever recall seeing one with zero observable iron.
But, What do you think about Mayo Belwa being mis-classified? It not only looks way different than most of the other Aubrites in that it has a lot of darker colored material but, it also has no visible metal at all (at least from photos I have seen). Including red rust spots. It was also studied by non- American scientists that may or may not have tested it for it's true age? So, maybe it is young enough to be a Mercurian candidate? Or maybe it is old but, still from Mercury?
Could it be mis-classified? I mean it happens. Look at ALH84001.
As a trained architect; I see a relationship between Art and Science and on the art side ( visible) Mayo Belwa looks much different than the other 62 known Aubrites. And on the Science side; Lets just say that I'd like to see more science done by Americans. Surely it has a lower total iron content than even Norton County has and according to the Messenger, Mercury also has extremely low iron (maybe none). Maybe the detected iron is exclusively from meteorite hits?

Carl
meteoritemax

--
Cheers
---- Carl Agee <agee at unm.edu> wrote: 
> Sterling makes some good points. The other thing besides trapped
> atmospheric gases that make the SNC's "planetary" is their relatively
> young igneous crystallization ages (except for ALH84001) -- indicating
> geologically long-lived volcanism on a large parent body. All angrites
> have ancient crystallization ages, in fact SAH99555 has perhaps the
> oldest crystallization age of any igneous rock in the known solar
> system. It is assumed that a body of Mercurian size would have at
> least a billion years of igneous activity and probably longer (like
> the Moon). If so it might take several 10's of millions of years to
> form a permanent crust from which to derive meteorites. Hence the
> "zero age" of angrites do not fit this picture well, more likely a
> smaller body, but not definitive. On the other hand, neither do the
> aubrites. As much as I would like our "low-FeO" 1-ton Norton County
> aubrite to be a Mercurian meteorite, this also seems unlikely because
> of it ancient age ~4.55 BY. The color argument is a tricky one because
> we have no idea what causes the Mercurian regolith to be darker than
> say an aubrite, and this is because of the intense stream of solar
> wind on rock surfaces which may have a huge on surface coloration.
> Another thing to remember is that none of the orbiters at Mars have
> ever spotted a terrain on the martian that is exactly the same as SNC
> meteorites, so based just on orbital data you would never know SNCs
> are from Mars -- dust coating is a big problem. There probably isn't
> as much dust on Mercury, but keep in mind that the interpretation of
> spectral data from orbit is as much art as it is science and
> ground-truth calibrations are hard to come by, so knowing the Sun's
> interaction with the Mercurian regolith maybe just as problematic.
> This is definitely a work in progress! Of course a NASA sample return
> mission would be my recommendation! I'm not picky, Mercury, Venus,
> Mars...
> 
> Carl Agee
> 
> 
> ---------------------------------------------------
> Message: 7
> Date: Sun, 8 Jan 2012 15:44:26 -0600
> From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
> Subject: Re: [meteorite-list] Wanted: Meteorites from Mercury
> To: "Galactic Stone & Ironworks" <meteoritemike at gmail.com>,     "Stuart
>        McDaniel" <actionshooting at carolina.rr.com>
> Cc: baalke at zagami.jpl.nasa.gov, meteoritelist meteoritelist
>        <meteorite-list at meteoritecentral.com>
> Message-ID: <8C3C0F61ACE547BAA3F7E2510550BA80 at ATARIENGINE2>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>        reply-type=original
> 
> Hi,
> 
> You may or may not remember that what made
> possible the positive identification of Martian
> meteorites AS Martian meteorites was that we
> had samples from the Martian surface.
> 
> No, not rock samples, nor any returned samples,
> but the isotopic composition of rare gases in the
> Martian atmosphere, which made a distinctive
> and unusual signature (particularly for Argon).
> 
> The SNC's shared this unique signature. It was
> like a fingerprint. And possible only because we
> had a lander on the surface.. Mercury has no
> atmosphere of any consequence and we have
> no lander there.
> 
> It's always possible that our present sensing
> capacity will turn up something as definite, but
> I can't think of what it could be. Believe me, I've
> tried.
> 
> 
> Sterling K. Webb
> 
> -- 
> Carl B. Agee
> Director and Curator, Institute of Meteoritics
> Professor, Earth and Planetary Sciences
> MSC03 2050
> University of New Mexico
> Albuquerque NM 87131-1126
> 
> Tel: (505) 750-7172
> Fax: (505) 277-3577
> Email: agee at unm.edu
> http://meteorite.unm.edu/people/carl_agee/
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Received on Mon 09 Jan 2012 10:18:55 AM PST