[meteorite-list] Norway Meteorite Impact Site Believed to be Found

[Sterling K. Webb]

Hi, Doug,

    You're right, Doug, I did it again. Mea culpa, mea maxima culpa.
How many times you have to straighten me out? Post that link again
to where you work out the temperature of bodies in space so I can
go and read it again in the hope it will stick this time.

    It was laziness, Doug. What I really wanted was to find this
obscure reference about hydrogen enbrittlement of irons, and
I couldn't find it, so I threw in the cold at the last minute, too
tired to run down the reference, which had nice tables of data
about putting meteoric iron in those presses geophysicists use
to find out the crushing strength of materials.

    Turns out meteoric iron is often weaker than igneous rock
while terrestrial iron is like, well...  like iron! See, I can't
remember the numbers. It was surprising how weak meteoric
iron was, though, I remember that. There was a bunch of nice
chemistry about what caused it. Oh, well, I will dig it out
and post it when I find it.

    Right about weak irons; wrong about why.


Sterling
---------------------------------------------------------
----- Original Message ----- 
From: <MexicoDoug at aol.com>
To: <meteoritehunter at comcast.net>; <meteorite-list at meteoritecentral.com>
Sent: Monday, June 12, 2006 6:25 PM
Subject: Re: [meteorite-list] Norway Meteorite Impact Site Believed to be 
Found


> Sterling W. wrote:
>
> <<(Truth is, meteoritic iron, tough as it is, is
> often quite  brittle. Remember, inside it's only
> 50-100 deg K when it hits, so maybe no big
> chunks.) Even if it was "only" a ton or two, it
> would be worth looking for, obviously>>
>
> Hola Sterling, That temperature quoted probably would have the metal  a 
> tad
> more brittle.  However your temperature expressed in absolute  Kelvin 
> degrees
> corresponds to about 200 degrees below zero centigrade (and  a lot more 
> degrees
> below zero Farenheit)
>
> I don't mean to rehash this too much, but, no, a large meteoritic iron 
> comes
> in at the boiling temperature of water and is actually 273 - over 300
> degrees centigrade hotter than you say and certainly not brittle as you 
> indicate.
> Earth is not magically a comfortable 25 degrees C either, but  that's 
> another
> story.  Plenty of arguments for what happen in the upper  atmosphere 
> regarding
> heating and cooling from terrestrial atmospheric sources,  but that 50 - 
> 100
> K perpetuates misinformation where we have been and done that  before, 
> time to
> move on Saludos, Doug
>
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