[meteorite-list] Any Meteorites of Earth Origin?

From: Jeff Grossman <jgrossman_at_meteoritecentral.com>
Date: Thu Apr 22 09:47:10 2004
Message-ID: <5.1.0.14.2.20011112114834.03eb7d08_at_pop3.norton.antivirus>

At 10:46 AM 11/12/2001, meteorites_at_space.com wrote:
>On Sun, 11 November 2001, Jeff Grossman wrote:
>
> >
> > At 04:34 PM 11/11/2001, meteorites_at_space.com wrote:
> > >On Sun, 11 November 2001, Jeff Grossman wrote:
> > >
> > > >
> > > > Alan Rubin and I wrote a definition of "meteorite" for Meteorite! a
> while
> > > > back that allowed for terrestrial meteorites. Our current thinking is
> > > that
> > > > the object would have to have left Earth by natural processes
> > > > (impact-launching seems the only option, although this is highly
> > > > improbable), either by achieving escape velocity, or by insertion into
> > > > Earth orbit via some secondary change to its trajectory (we want to
> > > > eliminate material on ballistic paths that take it immediately back to
> > > > Earth, e.g., tektites). If such material later reaccretes to Earth or
> > > > accretes to another body (like the Moon or an asteroid), we would
> define
> > > > this as a terrestrial meteorite.
> > > >
> > > > Of course, we already have terrestrial meteorites in our
> collections if
> > > the
> > > > well-accepted theory of lunar formation is correct. But that's just
> > > > semantics. There is no evidence for more recent events on Earth
> producing
> > > > terrestrial meteorites.
> > > >
> > > > jeff
> > >
> > >
> > >Tektites, the Australites in particular are "terrestrial meteorites."
> > >
> > >Steve Schoner.
> > >AMS
> >
> > What makes you say that?
> >
> > Jeff
> >
> > Dr. Jeffrey N. Grossman phone: (703) 648-6184
> > US Geological Survey fax: (703) 648-6383
> > 954 National Center
> > Reston, VA 20192, USA
> >
>
>
>The morphological structure of the Australites (Flanged buttons, flanged
>dumbells, propeller types) all indicate hypersonic entry into the
>atmosphere. They were produced in SE Asia, ejected to high altitude,
>perhpas thousands of miles, traveled in ballistic trajectories to fall in
>Australia where they are found today.
>
>The closest thing to "terrestrial meteorites" if you ask me.
>...

Close, but no cigar. They did not achieve escape velocity or orbit the
Earth. They are tektites, not meteorites, by our definition.

jeff
Received on Mon 12 Nov 2001 11:51:41 AM PST