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

[Chris Peterson]

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.