(meteorobs) Chris of Cloudbait Observatory. Your thoughts onN.M.10/09 Fireball....?

[Larry]

I read not long ago on a Scientific discussion under a global search for 
"Fireball emission" that fragmentation is definitely considered a mode of 
ablation. I find that  to be creditable.

I believe that is because the reduction in volume (size/mass) from a 
Meteoroid state to a Meteor state in the atmosphere does essentially the 
same thing....reduces. Only the manner in which the greater reduction vs 
time is occuring establishes which is more dominant between fragmentation 
and vaporization.

My estimate that it could be as bright as the Sun was only my initial 
opinion.

YCSentinel

----- Original Message ----- 
From: "Chris Peterson" <clp at alumni.caltech.edu>
To: "Global Meteor Observing Forum" <meteorobs at meteorobs.org>
Sent: 2009/10/12 08:43
Subject: Re: (meteorobs) Chris of Cloudbait Observatory. Your thoughts 
onN.M.10/09 Fireball....?


> There is nothing to suggest that this fireball was any different from the
> vast majority of fireballs: a chunk of stony material. It was brighter
> because it was bigger, and its fragmentation was very typical of many 
> larger
> meteoroids.
>
> Fragmentation is not a mode of ablation. When you have a meteoroid larger
> than a few centimeters, it builds up huge pressure on the leading face. 
> The
> resulting forces are generally greater than the material strength of the
> body, so it fragments. This exposes more surface for ablation, which is 
> seen
> as a transient increase in brightness. Most of the material suddenly 
> exposed
> in this way is vaporized, and will never end up as meteorites. It is
> entirely possible that a large fireball like this produced no meteorites.
> The likelihood of meteorites is very difficult to determine without
> additional information about the height, entry angle, and speed of this
> body, and that is largely unknown unless data from another location 
> becomes
> available.
>
> This fireball was impressive, but not particularly unusual. Its peak
> brightness was about that of the full Moon (not the Sun), and it does not
> show a terminal explosion. The general nature of the light curve- dim to
> bright back to dim, combined with the extensive fragmentation during the
> flight, suggests to me that this isn't the best candidate for a meteorite
> producer.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message ----- 
> From: "Larry" <ycsentinel at att.net>
> To: <meteorobs at meteorobs.org>
> Sent: Monday, October 12, 2009 1:28 AM
> Subject: (meteorobs) Chris of Cloudbait Observatory. Your thoughts on
> N.M.10/09 Fireball....?
>
>
>> Chris do you have any preliminary thoughts on the COMPOSITION of this
>> fireball with so many large explosions with many smaller visual flareups
>> and/or detonations?
>>
>> It is rather intuitive that fragmentation is the principle mode of
>> ablation
>> in this instance. Likely the ground beneath this is littered with
>> meteorite
>> fragments....IMO.
>
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