[meteorite-list] Images of UK contrail (not fireball)

From: Tom aka James Knudson <knudson911_at_meteoritecentral.com>
Date: Thu Apr 22 10:28:21 2004
Message-ID: <00d901c389e6$e32f09e0$2ed143d8_at_malcolm>

Hello Rob and list, one question can it be a contrail, wouldn't the
contrail continue out the other side? I still think it's a Scud missile
fired by Iraq! : )
Thanks, Tom
Peregrineflier <><
The proudest member of the IMCA 6168
----- Original Message -----
From: Matson, Robert <ROBERT.D.MATSON_at_saic.com>
To: <meteorite-list_at_meteoritecentral.com>
Cc: <marco.langbroek_at_wanadoo.nl>; 'Bj?rn S?rheim' <bsoerhei@online.no>
Sent: Friday, October 03, 2003 12:30 PM
Subject: [meteorite-list] Images of UK contrail (not fireball)


> Hi All,
>
> My turn to chime in on the Wales photos. First of all, it's great
> that it's now photos PLURAL, since this rules out Photoshop mischief,
> and it allows some degree of triangulation which can be used to
> approximate altitude.
>
> I'm leaning toward backlit aircraft contrail for three reasons --
> the first of which has been mentioned, but the other two have not:
>
> 1. No sonic boom. If this was a bolide, it should have produced
> a whopper! Not a single report of a sonic boom.
>
> 2. Where are all the observers? This occurred near sunset -- an
> optimum time for people to be outdoors in (evidently) nice weather.
> If you think the contrail is impressive, consider what the brightness
> of the bolide should have been to produce it -- we're talking at
> least magnitude -20, probably considerably brighter. People don't
> miss fast-moving second suns. How is it that witnesses would be
> attentive enough to spot the contrail, yet inexplicably miss the
> far more spectacular bolide that produced it just seconds or minutes
> before?
>
> 3. Perhaps the best evidence is the nature of the contrail itself.
> Because a bolide has a downward component, any contrail it produces
> will also. Differential velocities of upper atmospheric winds versus
> altitude will cause the contrail to corkscrew and scramble fairly
> rapidly, much like the contrails we see from Vandenberg rocket
> launches on the west coast. In contrast, jet contrails are at
> relatively constant altitude, so while they, too, get blown by the
> wind, all portions of the contrail are exposed to roughly the same
> wind direction and velocity. The result is that jet contrails
> keep their shape longer, merely getting "fuzzier" with time. The
> minutes-later image of the Wales contrail doesn't show any evidence
> of kinking/corkscrewing, and that perhaps is the strongest evidence
> against it being of space origin.
>
> Best,
> Rob
>
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Received on Fri 03 Oct 2003 03:45:20 PM PDT