[meteorite-list] Meteorite Questions

[Walter Branch]

Happy Labor Day to Americans!

I spent the day laboring the yard.

I wanted to thank everyone who sent me email (public and private) regarding 
my meteorite questions last week.  I now have more things to research.

-Walter Branch
________________________
----- Original Message ----- 
From: "Walter Branch" <waltbranch at bellsouth.net>
To: "Meteorite List" <meteorite-list at meteoritecentral.com>
Sent: Wednesday, August 29, 2007 7:14 PM
Subject: [meteorite-list] Meteorite Questions


> Hello Everyone,
>
> I have had plenty of time recently to ponder things such as meteorites.  I 
> am also alone at home at present and am bored.  Would some kind, 
> more-knowledgeable-than-me soul help me with some meteoritical questions.
>
> For example, why does the rim of meteor crater appear "squared" in some 
> photos, while in others it appears very round?  Perspective?  Lighting? 
> Extremely highly localized tectonic shifting (back and forth)?
>
> Also, why is Tatahouine so green? Olivine? Krylon?
>
> I am looking at a slice of NWA 4664 right now (thank you Eric Olson) and I 
> don't see any much green.  Maybe that one is a bad example because NWA 
> 4664 doesn't even look like at Diogenite!
>
> Also, I have read that some meteoroids travel through space in streams and 
> impact the Earth simultaneously (i.e., they have already broken up before 
> they hit the Earth's atmosphere).  How can this be?  I would think that 
> once a meteoroid has broken in space (most likely due to impact), minute 
> deviations of the individual pieces in the initial trajectory would 
> translate into ever increasing deviations in the individual piece's 
> trajectory, over time.  Unless two pieces were traveling in EXACTLY 
> parallel lines, over time the pieces would be widely dispersed in space.
>
> Remember comet Shoemaker-Levy 9?  It was broken apart by gravitational 
> forces from Jupiter only a year prior to impact, yet by the time it had 
> encountered the Jovian atmosphere the separation between the pieces was 
> wider than the diameter of the Earth!  After only a year.
>
> Traveling over eons to make it to the inner solar system, how can a 
> meteoroid stream stay intact enough to cause a tiny strewnfield on the 
> Earth? I would not think that the Earth's gravitational field would be 
> strong enough to do what Jupiter did.
>
> Also, I know I have asked this before but I still don't understand how 
> researchers can determine cosmic ray exposure ages for a meteorite which 
> ablated a significant portion of the material that absorbed most of the 
> cosmic rays and which may have fragmented in flight through the Earth's 
> atmosphere.
>
> Anyone?
>
> -Walter Branch
> ________________________
>
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