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(meteorobs) 'Double helix' meteor of Leonids 98

Hello list,
I just joined this list so please excuse me if similar
questions have been posted recently.

The title of this post does not have any thing to do with life in
extraterrestrial material, as I might have mislead some to believe.
Rather it's a special type of meteor I observed during
the (early - the bright ones) Leonids of last year.

It was seen around 3 am MET (= +1 GMT), that is about 
half an hour after the later calculated time of maximum rate.
What I saw was a very bright meteor, maybe about -5 to -8 mag. 
Definitely one of the many Leonids at that time, coming right 
from the radiant point. But this one was not only a very bright
meteor, it also had split in two. Added to that, each of the 
parts rotated at a fast rate, so as to make a close double 
helix. These were not intertwined (as in DNA), but
travelling in a spiraling but straight line side by side.
The apparent diameter of one helix I judge to be about 1/4-1/2 moon
diameter. Let's asume that they were formed at a height of about
100 km. I have not been thinking about this before lately, but these
figures means that the glowing particles must have been travelling a 
considerable distance - sideways, going in a helix path and considering
the helix was easily visible to me standing 100000 m below! 
Making a quick calculation assuming the helix diameter was ~10', we find
that it was travelling in a circle with a diameter of 291 m (~300 m) 
perpendicular to its forward path.
(I will not try to calculate its rotational speed, but it must have been 
considerable assuming 100 rev/sec - which is about the order of magnitude
I estimate I saw.)
I will only point to the fact that this observation could only be 
possible if the meteoroide material was volatile - that is cometary.
Why, because a particle going like that would have had to have a 
propulsive force of its own which would have had to be centered clearly
off the center of mass. The only material that fits these characteristica 
is - cometary. 
(We already knew of course that the Leonids were cometary).
By the way, the sight of this meteor reminds me very much of the paths of
charged subatomic particles spiraling along magnetic field lines..

I guess four characteristics would have to be present for such meteors
to be seen.
1) Be of cometary material ( most common )
2) There were many ( uncommon for bright ones )
3) They had to be bright (big particles) ( fairly uncommon )
4) They had to be rather fast ( a bit uncommon )

I guess it was the combination of the last 3 characteristics that produced
the special kind of meteor I observed.

I only wonder, how common is a meteor like this, and were many others seen
during the Leonids?
Also what is it possible to learn about the material from it producing the
propulsion 
(and the magnitude here observed - a ~300 m circle) effect.

Bjørn Sørheim,
partly meteorobserver,
Norway

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