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Re: (meteorobs) Firball Noise



George,

The details of the 1973 meteor are not extensive. I wasn't that
experienced, and, as I noted, I definitely do not claim that the magnitude
estimate was accurate. As I said the meteor flashed like a camera
flashbulb, but I did not hazard a guess as to the brightness of the flash.
I remember it noticeably lit up that portion of the sky (I have no clue as
to the area lit up, as I didn't make a note of it), so the maximum
brightness was considerably greater than what the average brightness had
been as it moved across the sky.

The fact that the "mid-1980s" meteor (this should read 1986, now that I am
at home with my records) was noted to have sped up as it passed overhead,
would bring me to agree with your assessment that it was close. I only knew
of a few others in the St. Louis region who observed meteors, but no one I
talked to at that time had been observing that night. I had no way to
triangulate a position. When I say the sound was "like distance thunder" I
am not saying it was necessarily faint, I was actually quite impressed with
the sound I heard, but it certainly was not like what a person would hear
if in the storm.  :-)  No, George, I wasn't plotting, but I did note the
time on my tape recorder, made an estimate of the duration of its travel,
the length of the path, and the names of three stars that it passed very
close to.

I have seen numerous other bright meteors in the -5 to -8 range, without
ever noting a sound. I have also never heard a booming or thunderous sound
at night while observing that I could not identify with something like an
approaching storm (like my observation of the Perseids a couple of years
ago, when I observed for an hour in skies three-quarters covered with
clouds and lightning and thunder almost overhead from an approaching storm.
:-)  )

If I remember correctly from something I read several years ago, sound
intensity will have something to do with the composition of the meteor.
Iron, stony-iron, and stony meteors will not produce the same sound
intensity. I do not have the article in front of me, but I think the
premise was that stony meteors will not produce a sound as loud as an iron
meteor, and it had something to do with the likely fragmentation of the
stony meteors as they fell. As I said, the article is not in front of me, I
am not sure who the author was.

Gary W. Kronk