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(meteorobs) Acoustic observations of Iridium re-entries sought

So far, I haven't seen a schedule for the Iridium satellite re-entries,
but I assume that it will be publicized when the re-entry schedule
has been established.
____________________________________________________________________

Return-Path: <chuck@lunarcolony.com>
From: "Charles J. Bonner" <chuck@lunarcolony.com>
To: "'dunham@erols.com'" <dunham@erols.com>
Subject: Electroacoustics and Iridium
Date: Sat, 18 Mar 2000 15:26:37 -0500

Dear Mr. Dunham:

The upcoming decommissioning of the Iridium satellite constellation 
provides a tremendous opportunity for the study of meteor astronomy.  Here 
we have about seventy "fireballs" about to enter the Earth's atmosphere, 
and we will know exactly when and where they will occur.

In particular, I believe that the "electroacoustic" phenomenon requires 
more study, and these satellites provide an opportunity to do just that.

Probably, these "fireballs" will not produce sounds detectable to the human 
ear, as they are not extremely large and they will be moving very slowly, 
compared to natural fireballs.  Nevertheless, I believe they are worth 
studying.

With the proper equipment, observers can record any acoustic signals that 
might be too quiet for human hearing.  More importantly, electronic 
recording equipment can detect any VLF radio waves emanating from the 
"fireball" or its "train," and all relevant properties.  Are these signals 
modulated?  Directional?  Polarized?  What is their exact frequency range? 
 Exactly what mechanism can convert similar electronic signals into audible 
sound in larger fireballs?

I have read very little about this electroacoustic effect (apparently, 
little information is available), but I have heard a fireball myself once. 
 The official scientific explanation of the phenomenon does not seem to 
match my own experience, and therefore I am sure that there is much more to 
be learned about electroacoustics.

Specifically, I do not think that the "official" explanation accounts for 
the strongly directional nature of the sound.  It seemed to be coming from 
the fireball itself (though that was obviously too far away), and not from 
the surrounding large objects (houses), nor from the hairs inside my ears. 
 In my one experience with electroacoustics, I heard the fireball several 
seconds before I saw it, and the directional nature of the sound enabled me 
to pinpoint the fireball.  Along with perhaps a dozen other "observers" 
(kids playing stickball, that is), I ran around a house expecting to see an 
aircraft in distress, and saw a moon-sized green fireball crossing the sky 
from northwest to south-southeast.

Please e-mail me at chuck@lunarcolony.com if you would like more 
information on my experience or my idea.  You can also read my on-line 
article on the subject at 
http://www.lunarcolony.com/musing/1999/art_swoosh.htm

I am hopeful that your readers, members, and other visitors to your Web 
site might be able to get this idea into the right people's minds and that 
research into electroacoustic fireballs will actually be done on these 
satellite re-entries.  Please spread the word!

Sincerely,

Chuck Bonner, Head Lunatic
http://www.lunarcolony.com/


Joan and David Dunham
7006 Megan Lane
Greenbelt, MD 20770
(301) 474-4722
dunham@erols.com
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