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Re: (meteorobs) Nov. 12/13 Summary
>Original fireball report from Mark:
>I was able to observe this morning under clear skies for 3.40 hours
>beginning at 0600 UT. The highlight of the morning came at 0744 UT when I
>recorded my brightest fireball ever. This sporadic appeared almost due east
>at approximately 25o in altitude and began as -9.0 but about midway along
>its path, flared to -11. Color alternated from yellow to green and back to
>yellow. I immediately froze all of my movement to listen for any possible
>sounds and was rewarded 11 to 12 seconds later with one short, faint "boom,"
>my first ever recorded sound. A complete report will be sent to FIDAC as
>soon as possible.
>
>>At 10:10 AM 11/13/96 -0500, you wrote:
>>>Judging by the short time of 11 or 12 seconds from meteor sighting to booming
>>>noise...the meteor had to be very close to you somewhere along it's
>>>trajectory(about 2 miles). Right off hand, if the meteor came that close to
>>>you, I'd expect a possible louder sonic boom....
>Can a meteor really get this close to you and still be visible? I thought
the general limit would be around 20 miles! The one Povenmire heard in 1972
(I saw it but from further west) he determined it ended at 14 miles true
height which he considered to be unusually low. At 25o elevation I would
expect it to be much further away than 2 miles, even 20 miles. I suspect
some coincidental ground sound here. Sounds from meteors ought not be less
than about 2 full minutes.
>
I have been long overdue...10+ years and only a -6.0 to show for it before
>>this one. But didn't you and Bob catch a -12.0 last year I think? Still have
>>to catch up to that one....
One famous Povenmire trademark is the tenth-of-a-magnitude accuracy on
fireballs, but always "-x.0". Hence, the ".0" is not justifiable! He never
mastered significant figures.
I have only two -12's in 36 years of observing. First was a blue -12 Leonid
1979 Nov 22 with a ten-minute train. Second was a blue -12 Taurid in 1994 (
I forget which branch) with a brief train. Since Povenmire sees almost
every meteor 2 magnitudes brighter than mere mortals, he has a whole bunch
of -12's (several in 1974 alone). And I'm still waiting to hear one. Seems
like it would have to be very high in the sky to be close enough for you to
hear. Povenmire was right under the one in 1972, and again in 1973 Aug for
a repeat performance! I saw the latter one as well, again from much further
west thus putting it only 15o up from my site.
Norman