[meteorite-list] re: Images of Wales meteor (no boring aeroplane)

From: Marco Langbroek <marco.langbroek_at_meteoritecentral.com>
Date: Thu Apr 22 10:28:22 2004
Message-ID: <007f01c38b2c$73f3b840$c9caea3e_at_HAL>

Bjorn,

A good scientist (and I do hope I am a good scientist) should be willing to
reconsider things if new evidence suggests so. In this case, following the
publication of the pictures, some good alternatives were presented, some
things didn't seem to fit, and now there's a second picture showing much
more than the first.

you wrote:

> You must clearly also explain why it can't be a meteor.
> And you can't. Meteors do look exactly like that.

....and here is where I and a number of other people from the meteor scene
clearly disagree with you. Meteors do NOT look like this. Even when the
first pictures, zooming in on the strange phenomena at the end, hit the
internet it was clear that this was *not* showing an actual bolide
appearing, such as was suggested by the NASA APOD team on their website.
Instead, several meteor astronomers (professional and amateur) pointed out
that it *could* be the sunlit dust-trail left after a bolide appearance. The
*first picture* by Jonathan Burnett (please note- this was before the second
picture showing the early part of the trail became available) looks similar
to photographs of such dust-trails.

The point is, that the second picture by Julian Heywood, which is a
wide-field image contrary to Burnett's, shows a lot more of the trail and on
this picture it *doesn't* look like such a dust-trail. It shows a very long
narrow, only gently curving, sometimes interrupted trail. Which in all
reality just looks like a contrail. To add to the chorus on this
mailinglist, but in another voice: I lived my whole life right under the
main route to one of the biggest airports of Europe: and I have seen many
contrails looking like the trail in the second picture, the Haywood
picture - except that the glow at the end is a bit odd. That glow however,
can be explained.

I also want to point out, that for a dust-trail to form (most of the trail
is *dark* in Heywood's picture. This is therefore NOT a glowing persistent
train) you need to have a meteoroid of considerable size, as Rob Matson
pointed out. Only meteoroids big enough to produce bolides deep into the
negative magnitudes do. Because such a trail is formed from evaporation
material of the meteoroid itself. You need a Big, with a capital B,
meteoroid to produce enough dust for a clearly visible trail.

And then there is the absence of other reports & sightings, what led Neil
Bone very early on to have doubts. Rob Matson has already pointed this out,
and I strongly second his opinion, that an event strong enough to cause a
profound dust-trail, should be seen and reported by many. Even much less
spectacular fireballs than the kind needed to produce a profound dust-cloud,
appearing at much more unlikely moments in the night, produce reports
pouring in with organizations such as our Dutch Meteor Society, or Neil
Bones BAA meteor section. Contrary to Bjorns assertions, I would rather
suggest that the internet helps with that. It is so easy nowadays for
people, having seen something strange, to hit the internet and search. They
end up on the websites of organizations like the BAA, IMO or our DMS which
thanks to internet are much easier to find nowadays than in the old days,
and the treshold to put out an e-mail with a report and question is much
lower than to ring someone up or write a letter, as in the old days.

The fact that the only confirmation so far has come from a location very
close to the first report, does point out that this appears to have been a
very "local" phenomenon, not visible nation-wide. I also want to point out
that the moment this all happened, a wednesday around 7 pm, is a busy
moment, with lots of people commuting home from their work. This should have
been seen by more people would it have been an upper atmospheric phenomena,
which is visible over hundreds of miles. I also want to point out that at
the end of last week the event got quite some media attention in Britain, so
many people failing to have submitted a report might have been pursuaded to
do so at that moment, such as was the case for Haywood. The BBC has been
explicitly solliciting comments from the public on their website.

Bjorn wrote:

> Bone and others seemed to have made some big mistakes:
> They thought the orange head of the cloud was the terminal burst as it
> happened, making the picture a true sensation. Added to that they made the
> mistake to think it was huge, since on the picture it was huge. Mistake
no. 2.
> It was merely zoomed! No -20 fireball, sorry!! Just the average one.

Neil Bone NEVER thought this was a terminal burst being pictured. And I
never thought this was a terminal burst being pictured. And for example
meteor astronomer Rob McNaught never thought that. Meteor astronomoner Peter
Jenniskens never thought that either. If there was one consensus right on
among people knowledgeable on meteors, then it was that the picture by
Burnett certainly did not show an actual fireball caught in the act. All
suggestions have been on the possibility that it showed a sun-lit dusttrail
left after a bolide appearance. And Neil Bone right on opted for the
alternative, the aircraft contrail hypothesis.
The only people who apparently thought it was a fireball caught in the act,
were the people responsible for the text on the NASA APOD webpage. I can
positively say that I think this points out that a meteor expert was NEVER
involved in the judgement of this picture within NASA. And that is amazing.

Considering the size of this event, I already have commented on this above,
and so did Rob Matson. An 'average one' certainly could not produce things
like those in these pictures.

Considering the visual sighting by Jonathan Burnett and his skateboarding
friends, Geert Barendtsen, who had direct contact with Jonathan Burnett
right after the picture appeared on the APOD website, reports that his
description, unlike the press statements, would be rather of a stationary
phenomenon. I have inquired by e-mail with Jonathan whether he saw a moving
fireball or not, as this might clearify between the options of a
'sundog'/sun-illuminated contrail end, or the aircraft fuel dump. So far
there has been no reply, I reckon the boy is flooded with mails on his
photographs.

- Marco Langbroek

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Marco Langbroek
Leiden, the Netherlands
52.15896 N, 4.48884 E (WGS 84)

meteorites_at_dmsweb.org
http://home.wanadoo.nl/marco.langbroek
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Received on Sun 05 Oct 2003 06:32:46 AM PDT