[meteorite-list] Mercury?

From: Ed Majden <epmajden_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:28 2004
Message-ID: <006e01c101ea$830e1dc0$34974318_at_cc.shawcable.net>

> On Sat, 30 June 2001, "Ed Majden" wrote:
>
> >
> > According to my sources 16 Psyche is a main belt asteroid.
> >
> > Ed Majden
> >
>
> Well, if that is the case and the spectroscopic trace is correct and ABEE
is indeed from that asteroid--
> That would pretty much put a dent in the theory that it and other E
metorites came from the inner Solar System.
>
> Steve Schoner, AMS
>

    Saying that Abee is indeed from that asteroid because the reflection
spectrum is a close match is indeed a stretch! A reflection spectrum is not
a finger print or a DNA test. It only tells you that the material in
question is probably similar. I take spectra of meteors burning up in the
atmosphere. These emission spectra are much more detailed than a reflection
spectrum. It is difficult to say that a particular spectrum is from a
specific meteor shower. Millman classified meteor spectra in four
categories:

    Type Y - the H&K lines are the strongest feature in the blue-violet
    Type X - if not as above, then either the D lines of NaI or MgI are the
strongest
    Type Z - if not as above, then FeI or CrI are the strongest features
    Type W - none of the above

Type Y spectra are higher excitation, Type X are lower excitation, Type Z
exhibit the absents of the elements common in shower meteors and stony
meteorites, Type W include peculiar spectra or weak spectra where features
are not well developed.
    You would think that all Perseid spectra would be very similar because
the meteoroids are from the same progenitor comet. They can in fact differ
in detail from one spectrum to another. What is needed is a high dispersion
spectrum of a large fireball. Then recover the meteorite and compare the
laboratory spectrum of this sample to its in flight spectrum. This would be
a first! A sample spectrum of an asteroid brought back by a space craft
would help clear up many questions I would think. Hopefully this will occur
in the not too distant future.

Ed Majden
http://www.amsmeteors.org/spectra/majdenobs.html
Received on Sun 01 Jul 2001 12:58:47 AM PDT