[meteorite-list] The Pribram/Neuschwanstein Meteoroid Stream Is Not Dead

From: Herbert Raab <herbert.raab_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:30 2004
Message-ID: <1cff21f010.1f0101cff2_at_utanet.at>

Mark Fox writes:
> In theory then, a collision-formed stream of Pribrams
> with an occasional Neuschwanstein in it "is" possible.
> It would be splendid to know if any brecciation
> (including clasts) exist in Neuschwanstein or
> Pribram, as that may give credence to the asteroid
> impact possibility.

The classification of Neuschwanstein as E6 is certainly
puzzling. But the very different class of two meteorites
(Pribram H5, Neuschwanstein E6) coming from the same
orbit might indicate a "rubble pile" asteroid as the
source. Observations with radar and spacecraft have
indicated rubble pile asteroids before. It's probably
safe to say that such rubble piles are made up of rocks
coming from different sources (planetesimals).

So, maybe Pribram and Neuschwanstein were formed on/in
different planetesimals in the early solar system, and
were only later mixed ito one rubble pile asteroid.
Finally, they were ejected from that asteroid into
an Earth-crossing orbit.

Note that there is the possibility of soft collisions
among small bodies, so a rubble pile of H and E material
is still a possibility, even if there are not heavily
brecciated and if there are no E-clasts in Pribram or
H-clasts in Neuschwanstein.

I admit that, even in a rubble pile asteroid, we probably
would expect on class of material to dominate over others.
The chances that we get two completely fifferent meteorites
from the same rubble pile asteroid are probably small, but
maybe it's only a first hint on how complex the history of
the asteroid belt and the meteorite parent bodies really
is...?

Hopefully, further research (e.g., CRE ages, O-isotopes)
will shed more light on the relation between Pribram and
Neuschwanstein...

Best greetings,
  Herbert Raab
Received on Tue 24 Sep 2002 03:32:46 AM PDT