[meteorite-list] Suspected Meteorite Goes ThroughWindowinIllinois

From: Chris Peterson <clp_at_meteoritecentral.com>
Date: Tue, 6 Mar 2007 16:43:21 -0700
Message-ID: <00b201c76049$e5331dc0$2721500a_at_bellatrix>

> But Chris, if you are that generous with the benefit of doubt...

I'm just seeking an explanation. If we discount outright fraud, the fact
remains that a chunk of metal came through a window and hit a desk with
enough speed to knock a hole in it. That's fairly difficult to do via
any prosaic mechanisms that come to mind. I think it's a reasonable
assumption that this was a falling object, and if so, its path deviated
rather substantially from the vertical. So how can that be explained?
Well, there could have been a stiff wind that day. If the object were
falling at 50 m/s, an 18 mph wind would be sufficient to give it a 20?
deviation. Or, as I suggested before, an object with a high surface area
to mass ratio could experience significant aerodynamic effects. Neither
of these explanations seem to be stretching things too far.

> what general effect would the lift, drag, and related
> turbulence, have caused on this fragile lightweight during the final
> part
> of ablating 'flight' - as there are no signs of orientation and
> density
> could have reached up to 10% sea level :-)

Who can say? Certainly these effects _do_ influence the flight of
meteoroids while they are still in their ablative flight. Drag is
usually approximated based on a spherical body, and lift and turbulence
largely ignored. But not all meteoroids are spherical, and the existence
of oriented meteorites is evidence of the influence of aerodynamics.
While the little photographic evidence I've seen doesn't really suggest
a meteorite (I'd guess something like a chunk of runway debris that fell
off an airplane tire when the gear went down), if it actually is a
meteorite I'd guess its history is similar to this one:
http://www.cloudbait.com/misc/cp.jpg (recognize it?), which rather
obviously was shaped, distorted, and generally ripped apart _after_
ablation stopped. That is, a piece of shrapnel ripped off at the very
end, and which had no time to experience significant surface melting.
I'd assume it was part of a much larger object until that point- an
object not as sensitive to aerodynamics.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message -----
From: "MexicoDoug" <MexicoDoug at aim.com>
To: "Meteorite Mailing List" <meteorite-list at meteoritecentral.com>
Sent: Tuesday, March 06, 2007 3:08 PM
Subject: Re: [meteorite-list] Suspected Meteorite Goes
ThroughWindowinIllinois


> Hi Chris, Rob, List,
>
> Meteorite goes through the window ... or science thrown out the
> window?
>
> But Chris, if you are that generous with the benefit of doubt, to be
> consistent, what general effect would the lift, drag, and related
> turbulence, have caused on this fragile lightweight during the final
> part
> of ablating 'flight' - as there are no signs of orientation and
> density
> could have reached up to 10% sea level :-)
>
> Quick someone better classify that airfoil integrity for the DoD :-)
>
> Did the (dust) devil done it? Chicago is the 'Windy' City, though
> this
> historically refers to all the 'hot air'.
>
> Best wishes,
> Doug
Received on Tue 06 Mar 2007 06:43:21 PM PST