[meteorite-list] tek. response to Matson
From: Darryl S. Futrell <futrelds_at_meteoritecentral.com>
Date: Thu Apr 22 09:37:37 2004
If anyone out there cared enough about tektite origin to look up D.
Chapman's 1971 JGR paper, they would find that he was well aware of
Keplerian motion laws, and other relevant laws as well. In the first place,
if he hadn't been aware of the various "laws", the reviewers of his paper
would have stopped him, and secondly, once it had been published, others
would have been lined up to take a crack at him. No one ever published a
criticism. Back in the 1960s the various NASA bases, including Ames, all
had the computers and data to calculate pinpoint trajectories to and from
the Moon. Chapman states: "In order to obtain a check on (Ames computer)
accuracy, seven test cases were run both on the present program and on the
Apollo program of the Real Time Computer Complex at the Manned Spacecraft
Center, Houston. The agreement in all cases was satisfactory."
In 1964, Chapman et al published specific gravitites in G & C Acta on about
47,000 Australasian tektites from known localities. This enabled Chapman
and Scheiber (1969 JGR 74, 6737-6776) ran chemical analyses on 507 of these.
They found compositional streaks sometimes thousands of km long of either
HMg, HCa, HNa/K, LCaHAl, HCu, etc. These streaks formed a particular
pattern over the Australasian strewnfield that could only have formed from a
certain ejection trajectory from the Rosse ray of Tycho (a ray which easily
could have resulted from a large volcanic eruption long after Tycho was
originally formed by asteroid impact - but that's a whole different topic
than the one we are on).
Chapman was well aware of what would happen to a swarm of splashform and
layered tektite fragments ejected from the Moon, and, in this case, towards
Earth. On pg 6332 is ab eight part diagram, on two planes, of how such a
swarm would become stretched out in different dimensions on it's way to
Earth. "...at 2.9 days, when the leading particle hits Earth, the remaining
particles are strewn in space over a third of the distance to the Moon." At
3 1/2 days, the fall is complete. Velocities less than 2.55, and greater
than 2.73 km sec. would miss the Earth. "The Earth's rotation also happens
to be in a direction as to compress the geographic longitude spread of the
Chapman states that the tektites that miss the Earth (pg 6333) would
require, on the average, 10 to the sixth power before another encounter with
Earth. However, they would be turned to dust in several orders of magnitude
less, by either meteorite impacts, or the mechanism of 'rotational bursting'
More in a later post.
Received on Sat 23 Dec 2000 02:24:58 AM PST