[meteorite-list] Cold Asteroids May Have A Soft Heart (AllendeMeteorite)

From: MEM <mstreman53_at_meteoritecentral.com>
Date: Wed, 13 Apr 2011 19:31:13 -0700 (PDT)
Message-ID: <64809.59949.qm_at_web161901.mail.bf1.yahoo.com>

Let me play politician and ask to "revise and extend my remarks". There are
asteroid gurus on the list who are more likely able to address this and I'd like
to hear from them. Your theory/question is partially in the right direction so
let me re-frame it. I believe we have "likely" detected all the existent
asteroids in our inner solar system which are large enough to have formed
basalt/cores--aka differentiated. That size is hard overlook(100-300km
minimum?). I read somewhere that as many as 12-20 major/minor planets would
have formed in the early solar system that are no longer with us as major/minor
intact bodies.( i.e. absorbed or ejected)

As to meteorite parent bodies, what we have yet to inventory and, for which we
have not had a specimen drop by Earth for comparison, are these long ago
disrupted bodies. These bodies which now are represented only by minor,
irregular, slivers, slices, and rubble piles within certain swarms of asteroids
in different sectors of the solar system.

There is a "diogenite-like" spectrum coming from an outer-belt asteroid whose
orbit proves it cannot be related to Vesta. I mentioned the caveat that there
may be some remnants of asteroids which were differentiated in the early solar
system and for whatever reason are no longer in tact. We may only have a
fraction of the original large body such that while we have located all the
differentiated intact ergo larger asteroids, we may need to be looking for
shards of former bodies to match meteorites from our collections. The reason
all our "HED"s are from Vesta is probably that Vesta is on our "mail route" and
quantum transport from Vesta to Earth is a favorable happenstance.

"1459 Magnya: Orbits in the outer main belt, too far from Vesta to be
genetically related. May be the remains of a different ancient differentiated
body that was shattered long ago." Spectrum is diogenite-like

Another candidate which may be the source of olivine-diogenites but is a chunk
off Vesta:
"2579 Spartacus ? contains a significant portion of olivine, which may indicate
origin deeper within Vesta than other V-types."
See list at:
<http://en.wikipedia.org/wiki/V-type_asteroid>
<http://en.wikipedia.org/wiki/4_Vesta>

Pallas and its family of asteroids is certainly a candidate for one of the
Carbonaceous parent body, even thought it shows no major excavations.
"2 Pallas is a large and most certainly differentiated body but lacks evidence
of a deep
excavation and its spectrum shows carbonaceous chondrite affinities. However
75% of the astrtoids out there whose spectra we've measured fall in the C or
Carbonaceous class."
<http://en.wikipedia.org/wiki/2_Pallas>
<http://en.wikipedia.org/wiki/Carbonaceous_chondrite>
 Also in my reading there is good indication that the Martian moons are captured
carbonaceous asteroids
<http://en.wikipedia.org/wiki/Moons_of_Mars>

Asteroid types More than I can retain in my head:
<http://nineplanets.org/asteroids.html>
<http://en.wikipedia.org/wiki/Asteroid_spectral_types>
        * C-type, includes more than 75% of known asteroids: extremely dark
(albedo 0.03); similar to carbonaceous chondrite meteorites;
approximately the same chemical composition as the Sun minus hydrogen, helium
and other volatiles;

        * S-type, 17%: relatively bright (albedo .10-.22); metallic nickel-iron
mixed with iron- and magnesium-silicates;

        * M-type, most of the rest: bright (albedo .10-.18); pure nickel-iron.
        * There are also a dozen or so other rare types.

Read more about Asteroids l Asteroid facts, pictures and information by
nineplanets.org * C-type, includes more than 75% of known asteroids:
extremely dark (albedo 0.03); similar to carbonaceous chondrite
meteorites; approximately the same chemical composition as the Sun minus
hydrogen, helium and other volatiles;

        * S-type, 17%: relatively bright (albedo .10-.22); metallic nickel-iron
mixed with iron- and magnesium-silicates;

        * M-type, most of the rest: bright (albedo .10-.18); pure nickel-iron.
        * There are also a dozen or so other rare types.

Read more about Asteroids l Asteroid facts, pictures and information by
nineplanets.org

Meteorites and their Parent Bodies 2nd Edition. Harry Mc Sween which I think us
a google book online.

Elton



----- Original Message ----
> From: Richard Montgomery <rickmont at earthlink.net>
> To: Ron Baalke <baalke at zagami.jpl.nasa.gov>; Meteorite Mailing List
><meteorite-list at meteoritecentral.com>
> Sent: Wed, April 13, 2011 8:39:46 PM
> Subject: Re: [meteorite-list] Cold Asteroids May Have A Soft Heart
>(AllendeMeteorite)
>
> Ron and List,
>
> This new evidence fits exactly into the recent question I posted, 'Vesta,
> for sure?'
>
> I only heard back from Elton (thanks, sincerely!) and yet now with this
> hypothesis, my question lingers as to the absolute recognition of parent
> bodies, with my query as to the yet-undiscovered potential pairings of
> undiscovered asteroids.
>
> MEM pointed out that the largest asteroids (aka Vesta etal) have already
> been located, with tell-tale impact and reflective signatures that rule out
> other parents for our HEDs.
>
> My new question, neophyte layman as I am, is:
>
> Does this new data/theory bring my initial question about
> Vesta-for-sure-as-parent-for-HEDs back into play?
>
> -Richard Montgomery
>
Received on Wed 13 Apr 2011 10:31:13 PM PDT