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Re: (meteorobs) Meteorites and Terminal velocity





  >>   I believe that sonic booms associatied with meteors indicates a 
possibility of high rates of speed in the lower atmosphere where heating 
can occur, however, it does not reveal how fast a meteor is traveling only 
that it's traveling faster than sound. << 

A meteorite will produce a sonic boom if it reaches an altitude of about 30 
miles above the earth and traveling faster than sound at that altitude. 
Whether you will hear it or not is dependent upon a variety of reasons. The 
program on the history channel did mention that Joe Kittenger broke the sound 
barrier during his free fall. Over 700 mph was mentioned and  I chose to 
simply use this figure instead of saying he broke the sound barrier. By the 
time he reached the lower atmosphere of the last 5 miles, his terminal 
velocity was a lot slower than 700 mph as would a falling meteorite.

>>The meteor would have to be traveling 
several times the speed of sound to generate heating so sonic booms may be 
only an indication that a hot meteorite may strike the ground.<<

A sonic boom means it at least reached about 30 miles above the earth...hot 
or cold. 

 >>In working with iron the red heat of a metal will reappear 
after sudden cooling if the interior is red heat hot or more, so exterior 
cooling during freefall may not last long enough to cool the interior of the 
meteorite if it is hot from solar heating (prior to entering the shadow of 
the Earth), heated in the upper atmosphere while approaching the state of 
ablation, and heated during the period of 3X supersonic flight if any speed 
occurred.<<

If the interior of a meteorite got red hot, wouldn't the crystal structure of 
the interior change and show rapid crystallization with smaller crystals? 
GeoZay
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