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

[MexicoDoug at aol.com]

Hola Sterling,
 
>Turns out meteoric iron is often weaker than igneous 
>rock while terrestrial iron is like, well...  like iron!
 
That is an interesting idea you have (and of course has nothing to do with  
temperature).  On-the-surface, the crystalline structure giving rise  to the 
Widmanstatten, and other figures, does seem like it could introduce  planes of 
cleavage, especially when oxidation starts along the interfaces, but  as sexy 
as a thought as that might be (and limiting to planar-'seeded'  fractures) I'll 
definitely look forward to your posting on the issue not  have an opinion 
until at least I read what you and that link have to say on this  subject subject 
of iron meteorite brittleness.  What is ringing and  resonating in my ear as 
I type this, though are thoughts of the Tucson Ring and  no shortage of other 
meteoritic irons like Zacatecas (1969 )in history that have  be favored to be 
used as anvils specifically for their superior properties vs.  other materials 
when struck with a hammer.  Also the arduous chiseled  inscription on the 
iron meteorite La Morita (apparently dating back to  at least 1821) comes to 
mind: "Only God with His power --- this  iron shall destroy --- because in this 
world there won't be --- another who  can undo it."  So field evidence and the 
difficulty of even meteorite  hunters getting a piece of iron to take home as a 
specimen might be at odds with  that...
 
OK, here's the link you asked for:
_http://www.diogenite.com/met-temp.html_ 
(http://www.diogenite.com/met-temp.html) 
 
Remember the meteoroid shield failure (not due to a strike) of Skylab in  the 
mid 70's?  Here is another link for fun, related to the coldness of  space 
(NOT) for those who forget we have a Sun in the neighborhood and why  skylab 
could reach 165 deg C:
 
_http://history.nasa.gov/SP-4208/ch14.htm_ 
(http://history.nasa.gov/SP-4208/ch14.htm) 
_http://history.nasa.gov/SP-4208/ch14.htm#t3_ 
(http://history.nasa.gov/SP-4208/ch14.htm#t3) 
(actually all the links provide a great primer coat for thermal control in  
space:-)
 
Extracted from the link text:  "The power shortage drew most attention  at an 
evening press conference; little was said about an even more serious  
problem, the apparent loss of the micrometeoroid shield. No one was particularly  
worried about damage from a meteoroid strike, since the chances of a hit were  
slim. i But the shield's secondary function, thermal control, loomed large in  
the aftermath of the launch. The shield had been designed to keep the workshop  
on the cool side of the comfort zone, heating being easier than cooling. The  
outside of the shield was a black-and-white pattern designed to absorb the  
desired amount of heat. The inside of the shield and the outside of the 
workshop  were covered with gold foil, which regulated the flow of heat between the 
two.  It was an admirable system as long as the shield stayed in place. Without 
it,  the gold coating on the workshop would rapidly absorb excessive heat, 
making the  interior uninhabitable.4
 
The shield had failed to deploy at the scheduled time and subsequent ground  
commands had no effect. While officials were debating further action, Saturn  
engineers discovered flight data indicating an anomalous lateral acceleration  
about a minute after liftoff. The data, coming just before the space vehicle  
reached its maximum dynamic pressure, suggested some structural failure. A 
short  time later, workshop temperatures began rising, strong evidence that the 
shield  was gone. Within a few hours, readings on many of the outside sensors 
exceeded  82°C, the maximum scale reading. Internal temperatures moved above 
38° C.  Working from the thermal model, Huntsville engineers figured that 
workshop  temperatures would go as high as 77°C internally and 165°C on the 
outside,  endangering food, film, perhaps even the structure itself. Mission Control  
therefore began maneuvering the exposed area out of direct sunlight, and some 
 cooling occurred.5
 
Saludos, Doug