(meteorobs) Bolides

[meteors at comcast.net]

I knew there was a reason I called them electrophonic fireballs.... ;-)

Mark Davis, South Carolina, USA
meteors at comcast.net
namn at namnmeteors.org

North American Meteor Network (NAMN)
http://www.namnmeteors.org/

On 8/13/2013 7:58 PM, MEM wrote:
> A couple of points regarding "Bolide" historically and presently.
>
> The term bolide was well constrained in the literature of meteorites in
> the 1800s and up to the middle of the 1900s by my recollection to be
> bright, exploding and audible. It is the definition I used for years and
> which members of both the Smithsonian and British Museum used in citing
> specific fireballs.  Be it remembered that "missile" back then did not
> mean "guided missile" such as folks use the word now days. The etymology
> of bolide may be bolus or missile but it wasn't used to describe just
> any missile, rocket, mortar or artillery round. A bolide was a star
> shell or exploding mortar ball under common usage of the 1800s and as an
> allegory to exploding fireball I presume that being a familiar term,
> bolide was used to help communicate the experience in the days before
> digital print and email.
>
> The definition quoted by Dan is from the Wikipedia article on Bolides
> which I was a contributor to.  I left when the lead author failed to
> consider early literature which wasn't readily found in digital format
> was this was pre-digital age.  That is sources were used from the
> internet alone.  I disagree with the definition used by the page owner
> and if you look at that page you'll see that it is missing citations and
> hasn't been edited for many years. (FWIW: The newly edited page on
> Meteors, Meteoroids and Meteorites is now more accurate).  If you
> understand how Wikipedia articles are generated you will understand how
> this definition came into being, ignoring traditional use.
>
> An non-geologist(?) author from Woods Hole Institute wrote a paper about
> the Chesapeake Bay Asteroid Swam Impactors, 34 mybp and used the term
> "Chesapeake" Bolide. When an asteroid excavates an 8-mile deep crater I
> think "bolide" is an understatement.  This was the first ( and only?)use
> of the term "Bolide" to describe an impactor.  However, it was the usage
> which showed up on Internet search engines so this bastardization
> stuck.  No geologist nor planetary scientist I know uses "bolide" to
> describe impactors.
>
> This is the reason it needs to be tackled by the IAU.  Consistency in
> the literature to describe exploding fireballs which have an audible
> report which is not attributed to mere sonic boom.  These
> characteristics have specific information important to recovery and are
> consistent with historical  records.
>
> I agree it is best to avoid the term given the recent misuse and
> aggrandizement by non-geologist and lay astronomers.  I would also
> recommend that the term "fireball"  not used for  just any and every
> brighter than usual shower-based meteor.
>
> Unfortunately, just relying on magnitude thresholds do not capture the
> typical characteristics of fireballs and/or bolides such as persistent
> trains, bow waves and electrophoric(sp?) phenomenon.   Ergo a good
> fireball report should have these ancillary characteristics spelled out
> if we restrict the definition of fireball to apparent magnitude alone.
>
> Elton
>
>
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