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CHAPTER 2.9
THE CREATION OF THE
MOON
The moon appears to be more complicated than we
thought.
Up until a few years ago, everything related to the creation
of the moon seemed pretty much settled.
In 1975, William Hart and
Donald Davis put forth the giant impact hypothesis, whereby a glancing impact
between the Earth and a planetesimal or larger object caused the Earth and the
impact object to shed enough material to form a moon. Much of the hypothesis
seemed to be confirmed by the Apollo moon rocks.
So, for more than 30
years, everything seemed settled.
But now, an article entitled "Impact
Theory Gets Whacked" by Daniel Clery in the 11 October 2013 issue of Science
reports that there are unsolvable flaws in the theory.
It seems that
the isotopic composition of the moon rocks does not vary from the isotopic
composition of rocks from the Earth, whereas all other rocks from space do vary
noticeably. The giant impact hypothesis would require a large amount of the
unearthlike material from the impact object to be present in the moon rocks.
But it's not there.
This controversial information resulted in the
first meeting in 15 years devoted to the formation of the moon at the Royal
Society of London in September of 2013.
Several alternatives were
suggested, but each alternative involved complicated side issues. The article
quotes two of the participants: "We don't have a single scenario which stands
out because of its simplicity," Canup said. Malosh agreed. "The solutions are
contrived; they're not natural," he said. "We want a solution where isotopic
similarity is a natural consequence of the model." 133pg183-185
Well, if they want isotopic similarity as a natural consequence of the
model, then we can give it to them.
When I was first presenting my
antipodal impact ideas to the Yahoo geology2 group, I proposed that simple
impact extrusion would force material from the mantle to the surface at the
antipode of a large impact. ChuckB disabused me of the notion that I could use
simple impact extrusion of material from the mantle at the antipode of an
impact for impacts that were the size of the Chicxulub impact object. The
object would have to be much larger. ChuckB noted that impact extrusion is a
near field phenomenon and that with much greater distances involved (in
relation to the size of the impactor), the pressure and shear waves would be
refracted in many directions.
However, in the case of the creation of
the moon, we have no limitation on the size of the impact object. It can be as
big as we need it to be in order to create a moon-sized object through the
process of impact extrusion.
IMPACT EXTRUSION
A few words
of explanation about the impact extrusion process in modern industry would be
appropriate here.
Used in the cold formed fastener business, the
process of impact extrusion (also called trapped extrusion) involves the
extrusion of metal at the other side of the impact, when using an impact header
(see Illustration 7-A).
In the case of the impact header, the cold
(room temperature, not heated) mild steel blank is trapped within a hardened
steel die and then hit with a hardened steel punch, using great force. At the
antipode of the impact, the steel blank's metal is forced to "flow" into the
reduced diameter opening at the back of the die, resulting in a steel blank
with an extruded section that has a smaller diameter (NOTE: In industry, this
process is often used to create a shoulder bolt that has a shoulder diameter
that is considerably larger in diameter than the smaller, extruded diameter,
which is usually roll threaded [a process that creates screw threads] later.
Using impact extrusion is a faster, less costly and less wasteful process than
shaving the extra material away. Impact extrusion also provides better
concentric tolerances, as well as keeping the steel grain structure intact).
The process of extreme antipodal uplift, in effect, would involve
trapped extrusion. In the case of the impact header, the steel blank is trapped
within a hardened steel die.
In the case of extreme antipodal uplift,
the trapping is done by gravity (the weight of the rock of the lithosphere) and
the shear strength of the rock of the lithosphere. The energy of the cosmic
impact would, in effect, explosively extrude massive quantities of crust and
mantle material at and near the antipode of the impact site, with the Earth's
interior acting as an energy transfer mechanism.
Since the moon rock
material would be extruded from the mantle, along with some material from the
surface of the Earth, all of the moon rock would be rock from the Earth and
none of the moon rock would be from the impact object.
To quote
ChuckB.:
"the only way the opposite side of the Earth
would display near field impulse phenomena, is if the bollide were on a
planetary scale, enough to overwhelm the dispersive properties of the rock.
This would necessarily throw ejecta into orbit to create a satellite and
liquify a portion of the planet. The evidence, in the form of a single moon,
suggests that this at most only happened once, and it was at a time when the
mantle was already mostly liquid." The article by Daniel Clery
also states that there is difficulty in coming up with a theory where the moon
would be a hot object in its early formation. Well, if the material is ejected
from a partially molten mantle, that should solve that problem.
So it
looks like I might get to use my original impact extrusion mechanism on a
one-time-only basis after all. See
Illustration 7 - A for a graphic depiction of the impact extrusion process.
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