[meteorite-list] New Hoba Search
From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Sun, 21 Sep 2014 18:17:43 -0700 Message-ID: <1411348663.65282.YahooMailBasic_at_web163301.mail.gq1.yahoo.com> Hi Bob - 100-150 parent bodies now, but was there a parent body for them? One whose disruption led to the LPBE, and the shift of the outer gas giants? How does a person account for the formation of peridot in iron without one? No doubt gravitational effects shift Long Period Comets onto the plane of the planets, but perhaps many don't get that far and "accrete" before then. It is interesting that Hoba has no crater. I guess we'll see how this meteorite search goes. Such Grand Problems. I tend to work with the little ones. E.P. E.P., There are many more parent bodies for meteorites - at least 100-150 at last count. As for comets, they have orbital inclinations at every imaginable angle, so his hypothesis that most impacts are at 23.5? can't be due to comets. You're right about not knowing the composition of comet centers, but given their generally tiny size, the likelihood of them differentiating to produce an iron core is very remote. Their very iciness implies they didn't differentiate to a significant degree. Asteroids are also inclined at a variety of angles with the average inclination of 8.2? of the ecliptic plane. While I wish him well in his research and hope he finds meteorite fragments in every dry lake, his understanding of comets vs. asteroids seems flawed to me as does the idealized 23.5? angle of entry. Best wishes and good luck with the Brenham artifact project. Bob Received on Sun 21 Sep 2014 09:17:43 PM PDT |
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