What all this makes rather clear is that out gassing from the comet as
recently observed in action is carbon rich, but that the gasses are broken down
into their constituent elements and accelerated through their interaction with
the solar wind. Thus we get the classic
long tail associated with young comets.
This as I anticipated must consist of substantial quantities of
elemental carbon. It always amazes me
though when the actual picture of a phenomena is pieced together how much
richer it all is.
It is frustrating to not be able yet to travel in exploratory expeditions
to the Oort cloud. I suspect that the gross mass of the Oort cloud has been
seriously underestimated and much is simply unassembled
Question? Does the Oort cloud
acquire more interstellar gas than it loses?
One assumes we are somewhat in dynamic equilibrium with our place in the
galaxy but we will be passing through dusty regions.
People born today will live to travel in MEV craft travelling at one G
acceleration to explore the Oort cloud.
The solar system will be fully explored in person in this century with
such craft. (read my article on reverse
engineering the UFO here or in Viewzone.com)
Research Points To Better
Understanding Of Carbon In Comets
by Staff
Writers
Researchers have used the presence of long-chain carbon-containing molecules in comets, including some simple
amino acids, as evidence that comets may have brought the seeds of life to
Earth.
Using a
comet as a far-flung laboratory, a Planetary Science Institute researcher has
shown that the ionization lifetime of carbon is much shorter than what is
currently used in calculations by comet scientists.
An accurate ionization
lifetime is critical to understanding the amount of carbon released from
comets, said Jeff Morgenthaler, senior scientist at PSI.
A shorter lifetime
suggests that the carbon content of some comets may be lower than previously estimated. This
work could affect current ideas about where comets formed in the early solar
system and the role they may have played in bringing the seeds of life to
Earth.
"Carbon is an
important atom for lots of reasons," Morgenthaler said. "We need to
know how much carbon there is in comets and in what molecules it can be found to
answer some of the questions that have been posed."
Using wide-field
images recorded by the Galaxy Evolution Explorer (GALEX) satellite,
Morgenthaler produced extremely high-quality radial profiles of atomic carbon
emissions from comet C/2004 Q2 (Machholz).
Unlike conditions seen
on Earth, a comet's coma, or envelope around its nucleus, is a very simple
atmosphere with no gravity and no magnetic field, and is only affected by the
solar photon and solar wind environment, Morgenthaler said.
"Since other
researchers have established how fast the carbon moves away from the comet, we
could use the fall-off of the light as a function of distance to measure how
long the carbon lives in the interplanetary medium before it is ionized,"
said Morgenthaler, lead author of a recent paper on the topic that appeared in
the Astrophysical Journal.
"We got a chance
to check a lot of calculations at once with our measurement," he said.
"We found that a carbon atom is ionized after seven to 16 days, depending
on solar activity and solar wind conditions."
This marks the end
point of the destruction of all of the more complex carbon-bearing molecules
found in comets.
Researchers have used
the presence of long-chain carbon-containing molecules in comets, including
some simple amino acids, as evidence that comets may have brought the seeds of
life to Earth.
"We need to pull
back a few more layers of the onion to see if the signatures of the long-chain
carbon-bearing molecules are detectable in these data," Morgenthaler said.
"We definitely see the signatures of carbon monoxide and methane."
The research found
that more than just sunlight was affecting the carbon from the comet.
"Something was
hitting the carbon: the solar wind," he said. "This had been
predicted earlier, but until now no one had quantitatively put all the pieces
together and done a measurement that confirmed it."
The research was
funded by a grant to PSI from the GALEX Guest Investigator program.
GALEX's wide field of
view at 1 degree is 10 times larger than the typical ultraviolet telescopes
used for similar research, he said. This allows GALEX to capture essentially
all the emission from the comet, resulting in far more accurate results.
Co-authors of the
Astrophysical Journal paper are Walter M. Harris, Department of Applied
Sciences, University of California at Davis; Michael R. Combi, Department of
Atmospheric, Oceanic and Space Sciences, The University of Michigan;
Paul D. Feldman, Department of Physics and Astronomy, The Johns Hopkins
University; Harold A. Weaver, Space Department, Johns Hopkins University
Applied Physics Laboratory.
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