- "It's a mystery to me how comets work at all."
- --Donald Brownlee, principal investigator of NASA's Stardust
Mission
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- No phenomenon in the observed Universe has been a source
of more continuous surprises than comets. In fact, despite the exterior
confidence by astronomers and astrophysicists that "all is well"
in mainstream cometology, researchers have been so baffled by unexpected
discoveries that conventional comet theory no longer exists! "We have
now had four close encounters with comets, and every one of them has thrown
astronomers onto their back foot." -Stuart Clark, New Scientist, September
09, 2005.
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- Yet comets are still touted as "Rosetta Stones"
allowing us to decipher the formation of the solar system. The "dirty
snowball" hypothesis, considered theoretical bedrock for decades,
has failed resoundingly at predicting comet behavior and, more recently,
comet composition.
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- The most dramatic surprises began in 1986 with the discovery
of negatively charged ions in the coma of Comet Halley, the signatures
of energetic electrical activity, and the absence of water on the nucleus.
In subsequent years, comets have produced a steady stream of "mysteries"
that have left astronomers groping for answers:
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- 1. Highly energetic supersonic jets exploding from comets'
nuclei.
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- 2. The inexplicable confinement of these jets into narrow
filaments, spanning great distances, up to MILLIONS of miles, defying the
behavior of neutral gases in a vacuum.
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- 3. Jets occurring on the dark sides of comet nuclei.
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- 4. Comet surfaces with sharply carved relief -- the exact
opposite of what astronomers expected under the "dirty snowball"
model.
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- 5. Unexpectedly high temperatures and X-ray emissions
from cometary comas.
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- 6. A short supply or complete absence of water and other
volatiles on comets' nuclei.
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- 7. Mounting evidence for the production of the OH radical
in cometary comas, due to charge exchange with the Sun (the process that
misled astronomers into thinking they were seeing evidence of water removed
from the surface.)
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- 8. Mineral particles that can only be formed under extremely
high temperatures -- the last thing one would expect from a chunk of dirty
ice arriving from the outermost reaches of the solar system.
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- 9. Comets flaring up while in "deep freeze,"
beyond the orbit of Saturn.
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- 10. Comets disintegrating many millions of miles from
the Sun.
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- 11. Comet dust particles more finely and evenly divided
than is plausible for sublimating "dirty ices."
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- 12. Ejection of larger particles and "gravel"
that was never anticipated under the idea that comets accreted from primordial
clouds of ice, gas, and dust.
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- 13. The unexplained ability of a relatively minuscule
comet nucleus to hold in place a highly spherical coma, up to millions
of miles in diamater, against the force of the solar wind.
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- All the above findings pose enormous problems for the
"dirty snowball" model; all are predictable features of the electric
model. Nevertheless, the odds are pretty good that you have never even
HEARD of the electric comet hypothesis (although had you lived in the 19th
century, when astrophysical journals frequently discussed the electric
properties of comets, you might have). This is because the space sciences
throughout most of the 20th century have been constructed on the theoretical
assumption that bodies in space are electrically neutral. An electric comet
would strike at the foundations of the theoretical sciences today.
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- The Electric Universe views comets as negatively charged
bodies moving through the radial electric field of the Sun, the most positively
charged object in the solar system. The most energetic cometary displays
occur with comets that spend the most time in the outer regions of the
solar system, where they acquire a strongly negative charge. As they race
toward the Sun, moving into a more positively charged environment, the
nucleus will be subjected to increasing electrical stresses, eventually
beginning to discharge.
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- But what might occur with a shorter-period comet that
does not move on a highly elliptical orbit? It happens that presently,
we are witnessing an excellent example accompanied by many enigmas. In
the past two weeks, the Comet Holmes 17P has made international headlines
with an energetic outburst that has left astronomers speechless. The website
skyandtelescope.com has called it "the weirdest new object to appear
in the sky in memory." "For no apparent reason," the comet
began to increase in luminosity, rapidly brightening from 17th magnitude
to about 2.5 -- approximately a million-fold increase in brightness. This
is the not the first such outburst by the comet -- its discoverer Edwin
Holmes witnessed a similar brightening in 1892 followed by a second eruption
2-and-a-half months later.
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- In the span of a few days, the comet's coma grew to such
an enormous and bright disk that it could be seen with the naked eye, though
it never gets as close to the Sun as the planet Mars, and when it
suddenly erupted, it was moving AWAY from the Sun.
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- As the structure of the coma has clarified itself, jets
have appeared streaming away from the center. The source of the jets is
entirely enigmatic, if not preposterous through the lens of the usual comet assumptions.
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- "This is truly a celestial surprise"..."Absolutely
amazing", said Paul Lewis, director of astronomy outreach at the University
of Tennessee.
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- The reason for astronomers' amazement is that, given
the comet's distance from the Sun, solar heating cannot offer a plausible
explanation for the eruption. Worse than that, it has been moving AWAY
from the Sun! So now, astronomers trying to explain these anomalies have
begun grasping at straws. After a bit of hair tearing, the most common
speculation is that the source of the outburst is "sinkholes"
in the comet nucleus. But the trivial, almost immeasurable, gravity of
a comet could hardly justify this "explanation" -- no force is
available to cause the surface to "sink"!
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- The only other "explanation" could be that
another object struck the comet, a scenario that, by the astronomers' own
estimates, is virtually inconceivable.
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- If, however, cometary displays are almost exclusively
due to electrical stresses, the question remains as to why a comet moving
AWAY from the Sun might exhibit a sudden discharge. In the case of Comet
Holmes, one might suppose that neither the conventional view of comets
nor the electric hypothesis can explain what we're seeing. But in fact,
the electric view, based on new knowledge of the solar system environment,
does offer a plausible interpretation of Holmes' behavior.
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- In its most recent visitation, the comet Halley provided
an important clue. As it moved away from the Sun out beyond the orbit of
Saturn, Halley experienced a major eruption that not only remains unexplained
today, but seems to have conveniently slipped from astronomers' memory.
Other comets such as Hale-Bopp began erupting "prematurely,"
while still in the icy depths beyond Jupiter's orbit. And numerous comets
have exhibited unpredictable outbursts exceedingly difficult to explain
in terms of an evaporating chunk of ice. And several comets have, quite
unexpectedly, exploded into fragments. (See When Comets Break Apart,
- http://www.thunderbolts.info/tpod/2006/arch06/060119comets.htm)
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- In electrical terms, such unpredictable behavior can
be related to the breakdown of the plasma sheath that forms around a charged
body in space. This behavior is well documented in the laboratory. A plasma
sheath insulates the charged body from the charge of the surrounding plasma,
and across the wall of the sheath, called a "double layer," there
is a strong electric field. But when that wall breaks down, the result
can be an explosive instability with accompanying electric discharge. In
other words, the charged body may exhibit little unusual behavior until
the breakdown occurs.
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- Such a breakdown can be provoked as one plasma sheath
penetrates into another. This phenomenon seen in the laboratory draws our
attention to the structure of the Sun's plasma environment and to the unique
plasma sheaths of the planets themselves. Wherever our probes have taken
us, we have found new levels of structure, all with electrical implications.
Within the "magnetosphere" of Venus, astronomers were amazed
to find coherent ropes or "stringy things." The New Horizons
probe found curious cellular blobs moving down the vast plasma tail of
Jupiter. The Sun itself is immersed in plasma structure with boundaries
and double layers, a laboratory in space for intense investigation today.
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- So what might have happened to Comet Holmes? It is not
a typical comet. The eccentricity of its orbit is minimal. It is always
outside the orbit of Mars and inside the orbit of Jupiter. In fact, it
is virtually as close to being an asteroid as it is to being a comet. And
astronomers are slowly realizing that the distinctions between asteroids
and comets are not as clear as they had once believed. Occasionally, asteroids
sport cometary tails, like the asteroid Chiron, which was seen to develop
a tail while orbiting between Saturn and Uranus around 1988 and 1989. It
is now officially classified as both an asteroid and a comet. Since the
electrical stresses on Holmes would be minimal, much like those on asteroids
with modestly elliptical orbits, it is not unreasonable to assume that
its plasma sheath remains largely undisturbed -- unless it penetrates into
or is penetrated by another sheath with sufficient differential across
its double layer to cause an explosive breakdown.
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- It's interesting to note that the diagram of Holmes'
orbit shows that it crossed the ecliptic (the plane of the planets movement
around the Sun) quite close to the time of its closest approach to Mars.
So it is certainly conceivable that Mars' own plasma sheath, by penetrating
that of Holmes, provoked the fateful breakdown. Though this would not qualify
as a coherent hypothesis today, it is the kind of issue raised by the electric
model that is systematically ignored by mainstream astronomers.
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- As of this writing, the space science community has fallen
virtually mute on the enigma(s) of Comet Holmes. Comet science is in an
undeniable state of crisis, and nothing short of an intellectual revolution
will save officialdom from irredeemable embarrassment. It is the hope of
the electric specialists that the failures of the standard comet model,
so nakedly obvious in the face of discovery, will inspire astronomers and
astrophysicists to reconsider the real-world disciplines of electrodynamics
and experimental plasma science -- disciplines that should never have been
excluded in the first place.
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- For a review of the electric comet, see the index of
comet pages on the Thunderbolts site:
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- http://www.thunderbolts.info/tpod/00subjectx.htm#Comets
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