[meteorite-list] Re-2: Cali meteorite fall trajectory and offset of damage.

From: Michael Farmer <meteoriteguy_at_meteoritecentral.com>
Date: Sun, 29 Jul 2007 14:55:46 -0700 (PDT)
Message-ID: <274508.58196.qm_at_web33108.mail.mud.yahoo.com>

One thing about this fall, it came over the Andes
Mountains just to the north of the city, and then
impacted only ~8 km from the mountains. This was ~4:30
on a very sunny Friday afternoon, so in a city of ~2.5
- 3 million people, perhaps the sky was too bright and
the noise level too high to see or hear something.
Most people heard thunder to the north, but the
mountains would have blocked most of the view I would
think. Cali is a very noisy city on the ground, with
non-stop cars honking, music blaring and normal city
sounds of a third world country. A lot of this most
likely dulled any sense of what was passing overhead
as the meteorite flight path would have taken it over
an Air Force base and most of the downtown.
Michael Farmer

The body certainly disrupted many times, as every
piece I have seen has primary and secondary fusion
crust. Cali #003, 37 grams, has ~50 primary and ~50%
secondary crust, in several spots, so even the small
stones were fracturing or slamming against each other.

--- Chris Peterson <clp at alumni.caltech.edu> wrote:

> Yes, my thoughts are in the same general direction.
> I don't have any
> good sense of the mechanism by which energy is
> coupled into a falling
> meteorite in such a way as to actually produce an
> explosion capable of
> blowing off pieces at high speed (rather than just
> disrupting the
> object). So I'm thinking more along the lines of a
> large component
> surviving deep enough into the atmosphere that it
> could break apart
> above the strewn field at a low height (like
> Sikhote-Alin). It may have
> been slow enough by then (although still hypersonic)
> to not produce any
> sort of stunning overhead display, or the much more
> impressive display
> to the north may have still been a distraction.
>
> In any case, small fast objects do suggest a
> particularly large parent.
>
> Chris
>
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
>
> ----- Original Message -----
> From: <bernd.pauli at paulinet.de>
> To: <Meteorite-list at meteoritecentral.com>
> Sent: Sunday, July 29, 2007 12:27 PM
> Subject: [meteorite-list] Re-2: Cali meteorite fall
> trajectory and
> offsetofdamage.
>
>
> > Chris wrote:
> >
> > The material evidence of the fall does suggest
> that the components
> > still
> > carried some of their original velocity, but I
> can't see any mechanism
> > by
> > which such small stones could retain that over 30
> km of low altitude
> > travel.
> >
> > Mike wrote:
> >
> >>From all accounts, the body entering the
> atmosphere must have been
> > very large indeed to cause explosions loud enough
> to shatter windows.
> >
> > Let's now combine both comments, which could mean
> that the Cali
> > meteoroid:
> >
> > 1. still carried some of its original (cosmic)
> velocity
> > 2. must have been very large, in other words,
> > 3. the meteoroid's mass may have stayed intact
> down to a very low
> > altitude
> > 4. *exploded*, in the literal sense of the word,
> at a very low
> > altitude
> > 5. did not fall in free flight but was accelerated
> by its explosive
> > energy
> >
> > .. and finally, that the Cali meteorite:
> >
> > 6. should be the very opposite of a friable
> meteorite: very solid,
> > very coherent
> >
> >
> > Best wishes,
> >
> > Bernd
>
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Received on Sun 29 Jul 2007 05:55:46 PM PDT