[meteorite-list] Slow cooling rate of irons in space

From: Carl 's <carloselguapo1_at_meteoritecentral.com>
Date: Fri, 4 Sep 2009 18:18:33 -0700
Message-ID: <COL108-W62C7E9E821F360745132DA9BED0_at_phx.gbl>

Hi Elton and All,

I've read about the very slow cooling rate of the molten iron in various books but I don't understand why this is so. Why would it take millions of years for just a few drops of degrees? It's hard for me to envision this even accounting for bombardments and radioactive decay. Radioactivity from the original super nova event, right? Maybe it's because I think of space as being so darned cold it wouldn't take anything long to lose heat and freeze up. I realize radioactivity takes a long time to decay but would it take a lot or so little to keep a large planetary body hot for so long? Thanks.

Carl



Eman wrote:
>I think this theory has a potential fatal flaw if what we think we know about
taenite/kamacite growth is valid. Without an insulating blanket the molten
pool will not exist in a molten state long enough to permit crystallization aka
Widmanstatten patterns.

Be it remembered that Widmanstatten pattern/crystal growth is very very slow on
the order of 10's of degrees cooling per million years. It is difficult to
develop a scenario that integrates a large crater on an Goldilocks Asteroid
which works.. ..


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Received on Fri 04 Sep 2009 09:18:33 PM PDT