[meteorite-list] There are no silly questions? Wait until you have read that :-)

From: Bernhard Rems <rendelius_at_meteoritecentral.com>
Date: Tue Oct 19 15:11:10 2004
Message-ID: <001b01c4b60f$5de68690$bc4a2fd5_at_rendhome>

Ok, there are some questions going through my mind concerning
meteorites. My knowledge is based on what I have read and heard (not on
study), and some things do not fit together for me.

1) HEDs are from Vesta.

Fine. All of them? How comes that with 50.000+ known asteroids, all HEDs
come from a single one? As far as I know, spectroscopic evidence points
to Vesta, yes - but how large is the chance that HEDs do NOT come from
Vesta.

2) Meteorites have been ejected towards earth by collisions between
asteroids.

Fine again. But does this mean that all meteorites result from high
speed collisions of asteroids? Isn't there a chance that some have been
sent on a trajectory towards earth simply by perturbations and chaos?

3) Carbonaceous chondrites are much older than ordinary chondrites.

Ok. Once again: fine. So they must be "leftovers" from the accretion
disk, matter that hasn't formed into larger bodies. So at least they
aren't asteroid material, right?

4) Iron meteorites originate from the core of a large and destroyed
planetoid.

Mhm. How large must this thing have been? Or let me put the question
like this: what is the minimum size for a body to be able to create a
metal core? And are those main belt asteroids the remnants of the
"planetary crust" of this planetoid?

Furthermore - there must have been at least two bodies of that size
(because planetoids do not explode, they have to collide to eject core
material into the solar system. Is this assumption right or wrong?

5) Pallasites

How did the olivine get into the nickel/iron?

6) Seymchan

>From pictures I have seen on the net, There are pieces of Seymchan which
are just iron, some with very sparse olivine inclusions and some with
lots of olivine. How can it be that such a variety of compositions can
be within one fall? Is the Seymchan iron in the Seymchan iron meteorites
the same iron as in the pallasites?


Now, kind fellow collectors, please help me :-)


Bernhard
Received on Tue 19 Oct 2004 03:10:52 PM PDT