[meteorite-list] Slow cooling rate of irons in space
From: Pete Shugar <pshugar_at_meteoritecentral.com>
Date: Sat, 5 Sep 2009 18:34:17 -0500 Message-ID: <5157889102A34873B4939D9B2E96EDCE_at_laptop> May I please inject just the one comment? In space, the side facing the star (in our case, the sun) can get quite hot, ie close to the sun --hotter, and further away---less hot. Conversly--the side away from the star can approach very high negative degrees, ie 250 to 400 below zero. This is the "so darn cold" you were thinking about. Pete ----- Original Message ----- From: "Carl 's" <carloselguapo1 at hotmail.com> To: <meteorite-list at meteoritecentral.com> Sent: Friday, September 04, 2009 8:18 PM Subject: [meteorite-list] Slow cooling rate of irons in space 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.. .. _________________________________________________________________ Hotmail? is up to 70% faster. Now good news travels really fast. http://windowslive.com/online/hotmail?ocid=PID23391::T:WLMTAGL:ON:WL:en-US:WM_HYGN_faster:082009 ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list Meteorite-list at meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list Received on Sat 05 Sep 2009 07:34:17 PM PDT |
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