[meteorite-list] Meteorites 101-Bolide

From: Jeff Kuyken <info_at_meteoritecentral.com>
Date: Mon, 17 Jan 2011 22:26:05 +1100
Message-ID: <A716CADF8E814291B53BD74A0704CFC3_at_JeffPC>

Hi Elton & all,

It's funny but I've always been under the same impression as Elton in
regards to the term bolide. I'm not sure why though! Basically I've always
believed the following to be an approximate summary:

"Meteor" - basically a generic term for all meteors and associated light
phenomena.
"Fireball" - exceptionally large and bright meteor at least as bright as
Venus (i.e. -3 to -4 mag). Disintegrating body / sparks etc is still
possible with a fireball.
"Bolide" - basically a "Fireball" PLUS an audible report.

I believe the term bolide originally stems from the Latin term "bolis" which
roughly translates to a very large fiery meteor with some sources also
referencing the associated audible phenomena. The earliest published
reference I found online for "bolis" was Webster's Revised Unabridged
Dictionary (1913) "(n.) A meteor or brilliant shooting star, followed by a
train of light or sparks; esp. one which explodes."

I guess there are many variations and opinions. For the most part... they're
probably all pretty much correct.

Cheers,

Jeff


----- Original Message -----
From: "MEM" <mstreman53 at yahoo.com>
To: "Mark Bowling" <minador at yahoo.com>; "metlist"
<meteorite-list at meteoritecentral.com>
Sent: Monday, January 17, 2011 8:56 AM
Subject: Re: [meteorite-list] Meteorites 101-Bolide


> We differ some Mark, in that a bolide is not just a fireball showing
> framentation-- such as we saw in the Peekskill fireball. IMO,
> historically and
> by traditional use: a bolide is not just a simple fragmentation but an
> explosive
> rupture which occurs at the practical end of incandescent flight--Like an
> upside
> down bottle rocket. Perhaps, it is somewhat subjective, and while it may
> occur
> out of ear shod, the explosive expansion part has a distinct sound/report
> different from a sonic boom. The term was adapted possibly from a
> discussion of
> military rocketry into early descriptions of meteor fireballs which
> exploded.
>
> Perhaps it is just me but I subscribe to these characteristics of a bolide
> because it describes a specific combination of conditions. The audible
> report
> component is most always associated with the early literature accounts
> describing a fireball as a bolide. In my bolide theory I believe there is
> an
> envelope of stress/shear as the meteoroid is undergoing, being
> dramatically
> slowed by the atmosphere. If the envelope is not violated the meator may
> fragment but it does not do so explosively. Around 5 miles above sea
> level the
> meteoroid encounters the boundary of that momentum /shear envelope which
> reflects maximum aerodynamic pressure at which the meteoroid can retain
> integrity. This transition is so abrupt for the meteoroid, that it
> literally
> shears along molecular bonds releasing a fair amount of heat and possibly
> rapid
> oxidation of iron particles, etc.
>
>
> Elton
>
>
>
> ----- Original Message ----
>> From: Mark Bowling <minador at yahoo.com>
>> To: meteorite-list at meteoritecentral.com
>> Sent: Sun, January 16, 2011 12:11:03 PM
>> Subject: Re: [meteorite-list] Meteorites 101-Bolide
>>
>> Hi all,
>> I have understood from my study that a bolide refers to a meteor that
>> breaks
>>up
>>
>> - not requiring the detection of an audible report because, if observed
>> from a
>>
>> distance, the sound may not be heard. It is not a bright meteor or
>> fireball
>>or
>>
>> large impactor, but simply a meteor that breaks up. Right or wrong,
>> that's
>>the
>>
>> way I've been using the term when I report seeing one on the list. Has
>>anybody
>>
>> else been using it that way? I've been lucky to have seen several dozen
>> over
>
>> the years (often colorful), but none up close like Elton (yet!).
>>
>> I would agree that the IAU should come up with a definition because the
>>term has
>>
>> come to mean too many things and its use is not going to go away any
>> time
>>soon.
>>
>> In fact with the current explosion of public interest (no pun intended),
>> more
>
>> people are going to find the term and grab onto it.
>>
>> See you all soon!
>> Mark B.
>> Vail, AZ
> ______________________________________________
> Visit the Archives at
> http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list
>
>
Received on Mon 17 Jan 2011 06:26:05 AM PST