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 ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://six.pairlist.net/mailman/listinfo/meteorite-list
