On Sat, 24 Nov 2007 21:05:27 GMT, Ralph Hertle
wrote:

Quotation from: alt.astronomy , subject: Beauuutiful! Full Selene


Painius wrote
Selene is a major planet.

Planet Selene orbits Earth and Sun on the ,
not on Earth's equator. Selene always falls toward
the Sun, never away from the Sun. Several people,
including Isaac Asimov and other scientists, have
already decided that the Moon is really a planet.


That's probably a significant fact in support of the Moon as a planet in
a binary planet system with the earth.

The belief of prominent people is not a fact in support of a theory.
Asimov said this as a way of illustrating the uniqueness of Earth, not
as an assertion of any particular theory. It was a way of changing
perspective on our view of Earth and Moon, not as some basis for
calling Luna a planet or defining it as such. Isaac Asimov was famous
for taking unique ideas and toying with them in this manner.


I am not the originator of the co-planet or convex orbit concepts. The
ecliptic observation is probably a significant fact in support of the
orbit of Selene as a planet.

I made CAD drawings of the orbits of the Moon and the Earth, and these
were posted on alt.binaries.pictures.astro.
Due to lack of interest I removed them. Perhaps you saw them. The 12-gon
shaped orbit of the Moon is completely convex, There are no circles,
loops or concavities in the orbit.

The Earth-moon system revolves around the barycenter, this is a result
of the relative masses, not whether or not a body orbiting a planet is
a moon or not.

I the CAD model rendered images the binary planet system can be seen as
co-planets and there is no circular orbiting of the Moon around the
Earth visible at all. It is pretty clear that Selene is still a separate
planet.

The Moon has a diameter of 3,474 km slightly more than a quarter that
of the Earth. This means that the volume of the Moon is about 2
percent that of Earth. The gravitational pull at its surface is about
17 percent of the Earth's. As a planet, it's pitifully small.


My conclusion or hypothesis is that the Moon was a planet in a similar
orbit to Earth's, and that as the eons went by the Moon gradually
approached the Earth in an orbit similar to Earth's. The Moon went
closely past the Earth on the inside of Earth's orbit so slowly or with
a small speed differential that the mutual attraction caused the two to
counter orbit. I suspect that the combination was gradual. The
elliptical orbits may have become more even in time.


This theory failed because it could not explain why the moon lacks
iron.

It is clear from the visual evidence of the CAD drawn curvatures of the
Moon's orbit that it is a separate planet and that it is only
co-coincidently a captured entity that became a satellite of Earth.

A CAD model does not explain capture, it only shows a static model.
Drawn curvatures? Or were the lines drawn from the heliocentric
orbital elements? The orbit of the moon is best described from Earth
centered coordinates, the path around the sun is a coincidence arising
from the mechanics of the Earth-Luna system and the distance from the
sun. If the sun did not exist the earth and its moon would still orbit
each other.


There has been a computer dynamic mass properties modeling of a
hypothetical collision. That was really impressive. I wish that was
available to see again. Who made that computer demonstration video of
Selene and Earth?

All the modeling in the world will not make a theory true or prove it
true. Models are an illustration, not a reality.


Is there a possibility that the capture of Selene was merely a near
miss, and that a violent collision did not occur? There may have been
some transfer of materials from rings to both planets.


The chemical composition of the samples returned from Apollo missions
supports the theory that Luna was formed from a collision of Earth
with another body and the moon most resembles properties of the
Earth's crust and not its core. Had the moon formed from accretion of
material contemporary with Earth, it would be much larger and contain
more iron.