(meteorobs) "Corkscrew Meteor" on Space.com Image of the Day7thJan

[Swift, Wesley]

All,

	The small "ears" on the stars imply that the vibration is for a
small part of the exposure.  The wiggles on the meteor trail seem to build
and decay with the meteor.  This implies that the wiggles are somehow
coordinated with the meteor.   Although I have no idea of the plate scale of
this image, I assume it is fairly small so that the squiggles are less then
an arc minute.  If the scope tube is 4 feet long then the end would be
mooving less than 1/100 inch, which would be heard as a very low humm.  Such
small vibrations of the scope could be caused by meteor electrophonics.
Wild idea, I know, but not out of the realm of possibility.

http://luna.tau.ac.il/~colin/research/Meteor/meteor.html
http://www2.hunterlink.net.au/~ddcsk/gelphonx.htm
http://homepages.primex.co.uk/~sproston/sstar8e.htm

or not:
http://www.meteorobs.org/maillist/msg25898.html

Wes

============================================
        Wesley R. Swift, Jr
     Raytheon ITSS / Sverdrup MSFC Group
     Marshall Space Flight Center
     EV13, Bldg 4487, room C-151a
     Huntsville, Al 35812
     (256) 544-1392 Fax 544-0242
 
       Home:
      704 Dellwood Rd.
      Huntsville, Al 35802
      wesley.swift at comcast.net
        (256) 881-4438
===========================================




-----Original Message-----
From: R Kramer [mailto:sria at sria.com] 
Sent: Sunday, January 09, 2005 6:01 PM
To: Global Meteor Observing Forum
Subject: RE: (meteorobs) "Corkscrew Meteor" on Space.com Image of the
Day7thJan

On Sun, 9 Jan 2005, Jim Pettit wrote:

> Seems to me that, if the appearance of the corskcrew is simply due to 
> the oscillation of the drive motor, it would have to be a pretty 
> erratic mechanism to display such a wide variation in that oscillation 
> over such a small period of time (a tiny fraction of a second). The 
> left end of the trail shows very little 'corkscrewing'; there are just 
> a few waves and crests just left of middle; the line is fairly flat to 
> the right of the middle; and, obviously, the right 30% of the trail is 
> very 'corkscrewed'. In my many years of observation, I've seen several 
> meteors which displayed aerodynamic inflight changes to their 
> ballistic trajectories; while I've never seen a meteor corkscrew, I 
> have no trouble believing that such a thing could certainly happen, 
> given the correct meteor composition, shape, and angle of entry.

The apparent blurring of the star images which appears to be coangular with
the corkscrew axis would seem to support the suggestion that periodic camera
displacement (i.e. vibration) is a likely explanation. Further, there is no
reason that any such displacement need manifest as a single frequency,
sinusoidal displacement. If more than one resonance were active (not
unlikely) net camera displacement, and the resulting corkscrew, could easily
appear to be "irregular" in amplitude or period or both.

Even granting the assumption that a source of lateral acceleration
sufficient to produce a corkscrew trajectory could exist, it would take a
truly bizarre set of coincidences to produce a trajectory consitent with the
image, i.e. a corkscrew with a fairly constant radius but inconstant period.

Richard

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