[meteorite-list] Meteorites 101-Bolide

[MEM]

I largely agree, Chris, and like the overuse of the term "oriented", it seems 
everything has become a "bolide"-- minor fireballs and major impactors alike.  
The author on the work around the Chesapeake impactor adopted the term "bolide" 
in his works and I believe that was a bastardized usage-- not based in 
traditional usage.  IMO a crater producing impactor is NOT a bolide unless it 
produces an explosive terminus at altitude. An asteroid which excavates an 8 
mile deep crater likely doesn't "bolide" upon encountering maximum aerodynamic 
pressure, and no ground observer is likely to survive to tell us if there was 
one anyway!  Tagish Lake was by all accounts a super bolide having both the 
magnitude and the report. I remember seeing the term bolide used in 19th century 
descriptions, of course "areolite" was also a term used back then but I think 
bolide --suitably defined has a use in literature, still.

I think the IAU should probably adopt a definition for bolide which narrows the 
distinctions to reflect not just magnitude but disruption and audible report.  
Traditionally "bolide" was used to describe a fireball that terminated in a 
bright flash and /or explosive report.  Having seen a traditional "bolide" up 
close and personal, I can attest that it is not your regular fireball class 
event. The "explosive" event is distinct from a sonic boom.

In preparation for this reply, I revisited the wiki page and I have a lot of 
disagreement regarding the adequacy or magnitude alone being the distinction.  
If we are to abandon the term bolide then we need a convention to describe a 
fireball which terminates in an expanding/explosive disintegration with audible 
report. IMO.

Elton




----- Original Message ----
> From: Chris Peterson <clp at alumni.caltech.edu>
> To: Meteorite-list at meteoritecentral.com
> Sent: Sat, January 15, 2011 7:53:49 PM
> Subject: Re: [meteorite-list] Meteorites 101
> 
> Bolide is a term that it's good to avoid. It doesn't mean anything... or 
>rather,  it means too many different things. "Fireball" unambiguously means a 
>meteor of a  specific apparent brightness. "Bolide" is simply  confusing.
> 
> Chris