(meteorobs) Long path meteor -spiraling- *Magnified*

[gmlobdell at seanet.com]

Chris, Thomas, et al.,

I believe spiral meteors do exist, though they are extremely rare.  I
believe because I've seen one.  The meteor in question was a Perseid, very
close to the radiant.  This was a number of years ago, but it was during
the annual Table Mountain Star Party in Washington State, and within a day
or so of the peak time.  A group of astronomers were standing around
talking, generally facing the radiant.  This meteor was seen by multiple
people, who all commented on the odd path.  To me the path was a very
small arc, approximately 270 degrees, and about 1/4 of an angular degree
in diameter (half the size of the moon).

Looking at Thomas' video, I agree that this case is a video artifact.  I
believe that to capture a spiral meteor would require a high definition
camera pointed at the radiant.  Then any spiral motion would be
unmistakable.

I am certainly willing to entertain any explanation for what I saw,
including naked eye optical artifacts, atmospheric refraction, or wind
shear to name a few.

Gregg Lobdell

> Meteoroids do tumble, although they usually stabilize quickly. But it is
> difficult to imagine what would be required to get spiraling. Obviously,
> the meteoroid can't be spiraling in space. So you need to assume it has
> some peculiar shape that results in aerodynamic effects that lead to
> spiraling, which seems unlikely. Then, you need to assume it will
> maintain that odd shape, even as it is rapidly ablating away. Even more
> unlikely. Finally, you need to consider that in order to be seen
> spiraling with typical cameras and lenses (as opposed to telescopes),
> the physical diameter of the spiral needs to be somewhere between tens
> and hundreds of meters. Given a typical period of a second or less, the
> forces involved are huge- beyond the material strength of most meteoroids.
>
> Given all that, it seems unlikely that spiraling meteoroids exist, or if
> they do, they are extremely rare. (I'm not talking about very tight
> spirals- mm or cm, as you might get from a combination of aerodynamics
> and rotation- although even those must be uncommon, and only spiral
> along a brief section of their path before they stabilize.)
>
> Chris
>
> *******************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
> On 12/5/2011 11:30 AM, eric at meteoritesusa.com wrote:
>> Just curious...
>>
>> Almost all of the videos/movies claiming spiraling meteoroids have
>> been "explained away" as either equipment malfunction (shaking) and/or
>> software issues, and even operator error.
>>
>> Is there some bias against spiraling meteoroids or something? Why it's
>> so hard for people to believe that spiraling/tumbling meteoroids happen?
>>
>> Regards,
>> Eric
>>
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