by David Talbott and Wallace
May 05, 2006
It is happening for "no apparent reasons", scientists say, but the
comet Schwassmann-Wachmann 3 has been rapidly breaking apart,
provoking another round of second-guessing by astronomers.
The images above, captured by NASA's Hubble Space Telescope,
are the best pictures yet of an event that has astronomers
scratching their heads. The comet Schwassmann-Wachmann 3,
otherwise known as Comet 73P, is disintegrating in front of their
eyes. But what is the cause of this extraordinary event? Not one of
the theoretical surmises offered so far has satisfied the community
of astronomers as a whole.
From all standard vantage points such an
event presents inherent - some would say insurmountable - dilemmas.
Schwassmann-Wachmann 3, first observed in 1930 and named
after its two German discoverers, completes an orbit every 5.4
years. Following its discovery it was little more than a footnote in
comet science until 1995. The first appearance of the comet that
year was so bright that astronomers hailed it as a new comet. But as
it turned out, the "newcomer" was Schwassmann-Wachmann 3,
presenting itself in more glorious dress than ever before, despite
the fact that conditions were not favorable.
It was 150 million miles away, but
shining hundreds of times more brightly than expected.
In early 1996 astronomers discovered
that the comet had fragmented into at least three pieces, an
occurrence clearly linked to the spectacular brightening, though no
one could say what caused the event.
It also appeared as if one or
more of the pieces was breaking into secondary fragments.
When the comet returned in 2000 it was again brighter than expected,
with indications that the disintegration was continuing - or even
accelerating. And now, with its most recent appearance, the best
Hubble images show dozens of fragments, suggesting the possibility
of complete dissolution in a single remaining passage around the
Meanwhile, the "explanations" proposed for the comet's catastrophic
fate can only diminish confidence in today's comet science. Even in
the face of falsifying discoveries, the specialists appear unwilling
to reconsider their theoretical starting point.
One astronomer, from
the Sydney Observatory, offered this explanation of the comet's
"It's like pouring hot coffee into a
glass that's been in the fridge. The glass shatters from the
But there is no rational comparison of
the two phenomena. Any explanation by resort to "thermal stress"
must provide for heat transfer rapidly through thousands of feet of
insulating material, something inconceivable even if you ignore the
deep freeze of the vacuum through which the comet is moving, with
its sunward face continually changing due to rotation.
Another astronomer, from University of Western Ontario, suggested,
"The most likely explanation is
thermal stress, with the icy nucleus cracking like an ice cube
dropped into hot soup".
All that this "explanation" requires is
a little home experiment. The ice cube will not shatter explosively,
or any way display effects comparable to the disintegration of
Schwassmann- Wachmann 3 - not even if dropped into boiling water.
It will melt. And no matter what a comet is composed of, the heat
transfer the "theory" implies for a mile-wide solid object is beyond
In addition to citing possible "thermal stresses", the Hubble
Space Telescope website offers other possibilities as to
why comets might disintegrate so explosively:
"They can also fly apart from rapid
rotation of the nucleus, or explosively pop apart like corks
from champagne bottles due to the outburst of trapped volatile
But the centrifugal forces acting on
comet nuclei are close to zero. And to posit heating in the middle
of a mile-wide dirty ice cube is, again, scientifically indefensible.
Perhaps then, Schwassmann-Wachmann 3 "was shattered by a hit
from a small interplanetary boulder?" offered one of the astronomers
"But make that a series of
one-in-a-trillion hits", mused a critic of today's comet
science. "That way we can explain the continuing fragmentation
Comet science is indeed in trouble, and
it is particularly dismaying to see spokesmen for the Hubble site
announcing that their telescope may help to,
"reveal which of these breakup
mechanisms are contributing to the disintegration of 73P/Schwassmann-Wachmann
Neither NASA, nor the Hubble
folks in particular will find evidence for any of the "hypotheses"
offered, say the electrical theorists.
From an electrical viewpoint the periodic breakup of comets is no
surprise. Fragmentation and disintegration illustrate the same
dynamic forces observed in the "surprising" outbursts of comets.
Electrical outbursts and complete disintegration are merely matters
of degree in a discharging or
exploding capacitor, which is
exactly what an "active comet" is in the electrical interpretation.
A capacitor, one of the most commonly used devices in electrical
engineering, stores electrical charge between layers of insulating
material. And that is what a comet moving through regions of
different charge will do - it will store electric charge.
nucleus can be compared to the insulating material, the dielectric,
in a capacitor.
As charge is exchanged from the cometís
surface to the solar "wind" (actually an electrically active
plasma), electrical energy is stored in the nucleus in the form of
charge polarization. This can easily build up intense mechanical
stress in the comet nucleus, which may be released catastrophically.
And just as a capacitor can explode when its insulation suffers
rapid breakdown, a comet can do precisely the same.
As suggested by electrical theorist Wallace Thornhill,
"comets break up not because they
are chunks of ice 'warming' in the Sun, and not because they are
loose aggregations of smaller bodies, but because of electrical
discharge within the nucleus itself".
Schwassmann-Wachmann 3, first
observed in 1930 and named after its two German discoverers, has
never put on a spectacular display comparable to such "Great Comets"
of the twentieth century as Halley, Hale-Bopp, and Hyakutake.
a short-period comet: for electrical theorists that means a
lower-voltage comet - and, as a rule, less drama.
Schwassmann-Wachmann 3 completes an orbit every 5.4 years.
Its path takes it from just beyond the orbit of Jupiter to inside
the orbit of Earth. But it does not visit the more remote regions of
the solar system, while the spectacular "Great Comets" spend long
periods adjusting in that more negative environment of the Sun's
domain before racing sunward.
What Schwassmann-Wachmann 3 does
exhibit, however, is a highly elliptical (elongated) orbit, so in
electrical terms that means more rapid transit through the Sun's
electric field and more intense stresses on the capacitor than would
be the case were the comet moving on a less eccentric path between
the regions of Jupiter's and Earth's orbits.
The comet is presently headed toward perihelion, or closest approach
to the Sun (within 87.3 million miles), on June 6, 2006. Well before then,
on May 12th it will pass within 7.3 million miles of Earth.
Though that is roughly 30 times the
distance of the Moon from Earth, many earthbound and space
telescopes should capture images of the comet in sufficient
resolution to provide additional critical tests of the electrical