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Bolide size versus recovered ...



A) Phil wrote: It would be useful to get rid of this obsolete term
"bolide" as it has no real
scientific meaning.

What makes this term  o b s o l e t e ?

The RANDOM HOUSE WEBSTER says:
1. no longer in general use; fallen into disuse: an obsolete expression.

2. of a discarded or outmoded type; out of date: an obsolete battleship.

Now, the last time I came across the term ‘bolide’ was in:
F.T. Kyte (1996) Should we expect to find more pieces of the K/T bolide?
(Meteoritics 31, 1996, p. A076)

O.P. Popova et al. (1996) Estimates of Prairie Network bolide
characteristics based on the light curves (Meteoritics 31, 1996, p.
A110)



B) Jim wrote: It makes one wonder what it would have been like to see
one of the truly
 great bolides such as Gibeon, Hoba, Odessa, etc.

and George answered: Jim, look for the video of the great 1972 fireball
over Montana. That should give you some idea...although it was daylight.

The fireball over Jackson Lake, Wyoming, Aug 10, 1972 had an entry
velocity about 15 km/s and a diameter about 13 m with an estimated mass
of about 4000 metric tons corresponding to a stony meteorite of 3.5
g/cm^3. Assuming a mass loss of about 34% by ablation, the fireball’s
magnitude would have been about -18.2 at a height of ca. 58 km.
If it was an iron, a radius of about 10 m and a mass loss of about 20%
would result in a magnitude of about -17.7


C) Jim wrote: I didn't realise that the Peekskill was a -15:  I thought
it was somewhat
brighter.

Eyewitness accounts indicate that the fireball associated with the
Peekskill meteorite first appeared over West Virginia at 23:48 UT (+/- 1
min.). The fireball, which traveled in an approximately northeasterly
direction had a pronounced greenish colour, and attained an estimated
peak visual magnitude of  - 13 (comparable to the Full Moon). During a
luminous flight time that exceeded 40 seconds the fireball covered a
ground path of some 700 to 800 km (Brown P. et al., 1994).

D) Ron wrote: The video shows that the Peekskill meteorite broke up into
at least
16 pieces

CEPLECHA Z. et al. (1994) Video Observations Of The Peekskill Meteorite
Fireball: Atmospheric Trajectory And Orbit: At least 70   p i e c e s
(!) are visible on two high-resolution still photographs of the event
(Meteoritics 29-4, 1994, 455).

Regards, Bernd