(meteorobs) Bolides

MEM mstreman53 at yahoo.com
Tue Aug 13 19:58:12 EDT 2013


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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.meteorobs.org/pipermail/meteorobs/attachments/20130813/a0063a9a/attachment.html 


More information about the meteorobs mailing list