[meteorite-list] Park Forest Fireball Question

From: Rob McCafferty <rob_mccafferty_at_meteoritecentral.com>
Date: Wed Mar 8 17:08:40 2006
Message-ID: <20060308220837.10129.qmail_at_web50908.mail.yahoo.com>

My understanding would make normal velovity for
meteorites is strange concept because the speed need
not likely to be the 12km/s which the earths gravity
provides, nor the 42km/s which is the escape velocity
from the solar system at the earths orbit (30km/s
+12km/s = earths orbital speed + earth escape
velocity)

As a meteor can strike the earth from any direction it
can vary between 12km/s and 72km/s (72km/s is the
escape velocity at earth's orbit 42km/s + the earth
orbital speed 30km/s which is the collision speed
you'd get if an object hit the earth going in the
complete opposite orbital direction to the earths
orbit)

As for using a stopwatch to time it, due to the way
everything moves, you'd likely find the average speed
depended on the time of day you were measuring it, for
the same reason that you see more meteors after
midnight than before.

Someone please correct me if I'm wrong. (again)

Rob McC



--- drtanuki <drtanuki_at_yahoo.com> wrote:

> Greetings and Salutations Geoff and List Members,
>
> A rhetorical question, but what is "higher than
> normal velocity (for a meteorite "fall")? We assume
> that the velocity for most "falls" to be at
> gravitational velocity, but I suspect that this is
> an
> incorrect assumption based on speculation and not
> fact. Very few "falls" have someone with a
> stopwatch
> observing (timing) the fall velocity. Even the use
> of
> the word "fall" is perhaps a slightly incorrect use
> of
> the word, since the word "fall" indicates or assumes
> that the object is falling at gravational velocity.
> Not much sleep, so am a bit punchy this early
> morning; and the Leno headline (Thanks Paul!!!) set
> me
> off with a whacky frame of mind too early in the
> morning. LOL!
> Have a good afternoon and evening, Dirk...Tokyo
>
> PS. Geoff is the Paleolist getting any traffic? I
> have not been getting any postings recently.
>
> --- Notkin <geoking_at_notkin.net> wrote:
>
> > Greetings All:
> >
> > Anyone know if a study has been made regarding
> > velocity of the Park
> > Forest fireball? I read/heard somewhere that the
> PF
> > fireball was
> > thought to be traveling at a "higher than normal
> > velocity." Any more
> > info on that, or any links to a published work
> > regarding its entry
> > velocity? This is research for something I'm
> > writing.
> >
> > Any info much appreciated, even theories or
> > speculation.
> >
> > I also heard the sonic boom here in Tucson last
> > night, which Mike
> > Farmer reported. Didn't see anything in the papers
> > this morning,
> > though.
> >
> >
> > Regards,
> >
> > Geoff N.
> > www.aerolite.org
> >
> > ______________________________________________
> > Meteorite-list mailing list
> > Meteorite-list_at_meteoritecentral.com
> >
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
> >
>
> ______________________________________________
> Meteorite-list mailing list
> Meteorite-list_at_meteoritecentral.com
>
http://six.pairlist.net/mailman/listinfo/meteorite-list
>


__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
Received on Wed 08 Mar 2006 05:08:37 PM PST