Ron Baalke wrote: <Since Mercury and Venus are inside of Earth's orbit, then by the process of elimination, that would indicate the parent body for E chondrites are either Mercury or Venus. OK, fair enough.>
and <While it is still possible the parent body for the E chondrites and NWA 011 may be Mercury or Venus, you can't rule out asteroids just yet either. > Both of these statements are incorrect. Both Mercury and Venus are differentiated bodies. Neither can be the source of "chondrites" of any kind. They could however the the source of various "achondrites". If people are interested in a mystery here is a big one. Pallasites are generally assumed to be from the core / mantle boundry. There are quite a few pallasites so their formation doesn't appear to be an unusual occurance. There are also a lot of irons from the core side of the boundry. There are however no, as in zero, meteorites with pallasitic type olivine crystals with out an iron matrix. The mantle by volume would be larger than the core of most differentiated bodies. So where are the olivine meteorites? One would think they would be at least as abundent as the pallasites. Is the pallasite theory incorrect? Is there a yet undiscovered class of meteorites? Is there a mechanism that prevents the formation of a pure olivine region or destroys them after formation, preventing a pure olivine meteorite from reaching earth? There are no answers. The big mystery isn't whether we have a meteorite from mecury, it is where is the olivine? Eric Olson http://www.star-bits.com ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
