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

[Carl 's]

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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