[meteorite-list] Fireballs, meteor sounds, nomenclature, etc.

From: Robert Verish <bolidechaser_at_meteoritecentral.com>
Date: Thu Apr 22 09:52:16 2004
Message-ID: <20020816054142.94899.qmail_at_web10404.mail.yahoo.com>

Ed Majden wrote:

"Generally we term a meteor a fireball if it is
brighter than -3.0 magnitude or so. Depending on the
type of fireball your taking about, shower type or
meteorite dropping kind, this should be re-defined.
A -3.0 fireball is not likely to drop a meteorite.
These definitions should be refined by the
professional nomenclature groups so when people talk
about these things we are talking about the same
thing!"

Here, here, Ed!

I (and many others in the meteorite community) are in
total agreement with you.

We feel that this has been long overdue.

With best regards,
Bob Verish

-----------------------------
Date: Wed, 14 Aug 2002 10:29:00 -0700
From: Ed Majden
Subject: (meteorobs) Fireballs ,meteor sounds,
nomenclature etc,

   We need some way to differentiate between cometary
(shower) fireball meteors and asteroidal fireballs.
These are quite different phenomenon.
   Shower meteors are considered to generally be loose
conglomerates of small particles some what akin to
cigarette ash. They make their appearance high in the
atmosphere, generally in the region of 120 km to 60
km. High velocity Perseid and Leonid meteors become
visible at higher altitudes than their slower
counterparts. Simultaneous sound has been reported
from one Leonid member.
     On the other hand, asteroidal meteors are
generally solid objects often travelling at lower
velocities and they penetrate much lower into the
atmosphere. These are the type of object that may
produce a meteorite on the ground. Are they
associated with simultaneous sound phenomenon also?
It is difficult for a visual observer to estimate the
velocity of a meteor with any certainty. A near head
on, high velocity Leonid may appear slow to an
observer if it is nearly head-on where it appears fast
further from the radiant.
    Generally we term a meteor a fireball if it is
brighter than -3.0 magnitude or so. Depending on the
type of fireball your taking about, shower type or
meteorite dropping kind, this should be re-defined.
A -3.0 fireball is not likely to drop a meteorite.
     These definitions should be refined by the
professional nomenclature groups so when people talk
about these things we are talking about the same
thing!

                      Ed Majden


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Received on Fri 16 Aug 2002 01:41:42 AM PDT