[meteorite-list] "Gravitational focusing"
From: Starbits_at_aol.com <Starbits_at_meteoritecentral.com>
Date: Thu Apr 22 09:37:32 2004
In a message dated 05-Dec-00 6:51:04 PM Pacific Standard Time,
<< An additional related point: what are the sizes and geographical shapes of
tektite "strewn fields"? Unless they are highly elliptical, covering
hundreds of kilometers in the long-axis, I would have to pretty much rule out
a lunar origin just from an orbital dynamics standpoint. >>
I agreed with what you said up to this point. The tektite strewn fields
do cover hundreds of kilometers and even 1000+ kilometers in long-axis.
However orbital mechanics still does not allow a lunar origin based upon
strewn field size.
A lunar eruption would either blow out a single chunk or a spray of
lunar ejecta. A single chunk would enter like a meteorite and would have a
similar strewn field pattern. As far as I know the smallest tektite strewn
field is larger than the largest stone meteorite strewn field.
A spray, even from a volcanic cone with a extremely narrow cone of 1
degree spread, would expand to 5000 miles across by the time it reached earth
on a direct straight shot. Entry into the atmosphere would increase this
significantly because not all particles would enter at the same time even for
a staight shot (imagine a ruler approaching a basketball). Any kind of off
line or orbital path would just increase the effect causing a wider spread.
Even a direct staight line shot spread of 5000+ miles exceeds the long-axis
of most if not all tektite strewn fields.
The lunar volcano theory either produces strewn fields that are too
large or too small, but never just right.
Received on Wed 06 Dec 2000 02:08:09 AM PST