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From: brent@phoenix.UUCP (Brent P. Callaghan)
Newsgroups: net.aviation,net.astro
Subject: Re: Something else to watch out for!
Message-ID: <1199@phoenix.UUCP>
Date: Fri, 14-Jun-85 09:24:45 EDT
Article-I.D.: phoenix.1199
Posted: Fri Jun 14 09:24:45 1985
Date-Received: Sat, 15-Jun-85 08:03:15 EDT
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Xref: watmath net.aviation:1635 net.astro:669

> Anyway, this JAL flight was cruising at some normal jet-type altitude
> (like 30,000 ft or thereabouts) some distance above a rather dense cloud 
> layer. Suddenly, directly ahead, the pilot saw the clouds begin to rise up
> in an enormous bulge. The cloud bulge grew at fantastic speed, and 
> soon reached up and sideways for distances measureable in miles. The pilot
> took evasive action, but could not avoid flying through the cloud; he
> was convinced that he was flying through the results of an atomic
> explosion, so he had the crew go on emergency oxygen, and he landed
> at the next available site to have the plane checked and decontaminated
> if necessary.
> 
> Well, there was no evidence of radioactivity, and no ground-based
> phenomenon reported that would explain this occurrence. Normal atmospheric
> changes, like the formation of cumulus clouds, cannot occur at the rate
> observed. The JAL flight eventually continued on to its destination.
> 
> What caused this? Well, the theory is that that airplane had the first 
> observed encounter with a meteor. A several-ton meteor, of several meters
> diameter, perhaps composed of mostly ice with some stony fragments, could
> have hit that cloud layer on its way down through the atmosphere. At
> meteoric speeds, hitting a dense cloud layer is almost equivalent to 
> hitting the ground. The meteor would have fragmented and probably
> vaporized, transfering all its enormous kinetic and thermal energy
> to the cloud structure in the form of heat. This would have caused the 
> observed huge boiling-up of the clouds and the formation of such an
> atmospheric structure.

I can't imagine how hitting a cloud layer - no matter how
dense - would be like hitting the ground (even at meteoric speeds).
Supersonic aircraft, space-shuttles etc fly regularly through
dense clouds without a bump.  As a skydiver I've fallen through
dense clouds without feeling a thing (although I've often wished
they really were like soft fluffy cotton wool :-)  )

Perhaps the boiling-up was due just to a ginormous thermal
from the atmospheric heating in its wake.

(Bet those pilots were glad it WASN'T a nuclear explosion !)
-- 
				
Made in New Zealand -->		Brent Callaghan
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