Excerpts From The Electric Universe
The following is one of a series of excerpts from The Electric Universe,
copyright © 2002, 2007 Wallace Thornhill and David Talbott and published by
Mikamar Publishing. Reproduced with the kind permission of the authors and publisher.
Presented by Dave Smith
April 25, 2010
When Comet Shoemaker-Levy 9 fragmented in 1992 upon a close approach to
Jupiter, it gave us indications that its changing electrical environment was responsible
for the breakup, as orthodox theories failed miserably with a comet so far from the Sun. When the fragments
returned to collide with Jupiter in 1994 it gave us unprecedented opportunity to evaluate
the validity of the models on offer.
Comet Shoemaker-Levy 9
The famous collisions of fragments of Comet
Shoemaker-Levy 9 (SL-9) with Jupiter provide a spectacular
confirmation that comets have a store of energy in
addition to their kinetic energy. On 7 July 1992, SL-9
grazed past the giant planet Jupiter a mere 20,000 km
above the cloud tops. It had penetrated deep into Jupiter's
huge plasma sheath. As it switched suddenly from the
Sun's electrical environment to that of Jupiter, it would
have experienced extraordinary internal electrical stress.
Unsurprisingly, it broke up. In fact, after the main disruption
event some of the fragments split further in the rapidly
changing electrical environment. It is this tendency
to fragment, when gravitational and rotational forces are
far too weak to explain it, that gives rise to the idea expressed
by some astronomers that comets are a pile of
The fragments of SL-9 returned to collide with Jupiter
during the week of 16–22 July 1994. Some astronomers
predicted that the fragments were too small to have much
effect. “There's a chance we will see very little,” hedged
Eugene Shoemaker, late of the Lowell Observatory in Flagstaff,
Arizona, and co-discoverer of the comet, shortly before the event.
Since SL-9 had done nothing to distinguish itself before it broke up—
it couldn't be found in images taken before the break-up—astronomer
Brian Marsden surmised that it was 1 to 2 kilometers in diameter. “It's
going to be tough to see much,” he concluded. “I don't think there's
going to be a very large explosion.” But planetary physicist Jay
Melosh summed up the uncertainty, “Theoreticians are often wrong,
especially in predicting things.”
117 As we know, the spectacle
exceeded all expectations. But were the collisions simply impacts in a
purely mechanical sense—or did the electric charge of the comet
fragments contribute significantly to the event?
(from Page 108)
[Click to enlarge]
Initially, the dazzling display baffled astronomers because there
were remarkable electrical phenomena. Renée Prange of the French
Institute Astrophysique Spatiale, a member of the Hubble upper
atmosphere imaging team, saw 'northern lights.' Ultraviolet images
showed glowing streaks in Jupiter's northern hemisphere which
appeared as almost mirror images of glows from the impact site of
fragment 'G' in the southern hemisphere. According to Dr. Prange, the
northern glows appeared farther south than ever before: “I think it's a
major discovery.” The Jovian auroral displays appeared to be triggered
by electrically charged particles released during the impacts in the
south following a looping arc northward along the planet's magnetic
field until they fell back into the planet's atmosphere, creating a glow
in the north. According to Dr. Prange, it is still unclear whether the
particles were comet dust that became electrically charged as it fell
through the planet's magnetic field or gas molecules from the planet
that became charged in the heat of the fragment's impact and
Then, after a year's analysis “by hundreds of talented scientists,”
issued a consensus report: “First seen was a faint glow that
slowly increased in brightness on a time-scale of tens of seconds, believed
to be due to a large number of small meteors in the coma surrounding
each SL-9 fragment. The meteor shower was followed by a
sharp increase in brightness as the main part of the fragment entered
the Jovian atmosphere…. A few tens of seconds later, a fireball exploded
up the 'chimney' created in the atmosphere by the bolide.”
The explanation for the initial glow, coming after the fact, only
served to confirm the power of ideology in comet science. In electrical
terms, the charged comet fragments would be expected to exhibit a
glowing coma as they approached Jupiter. The glow would increase
until a sudden arc discharge would occur between Jupiter and the
comet fragment. The steep increase in brightness that astronomers
observed has more in common with a lightning flash than the lightcurve
of a bright bolide's entry into the Earth's atmosphere. In fact, it
was expected that the fragments would flare several times like fireballs
that enter the Earth's
atmosphere.120 That didn't happen.
As we shall see, there is no evidence that the fragments entered
the atmosphere. That and the fireball exploding up a 'chimney' are
simply presuppositions of the impact model. And there were many
other anomalies for the impact model.
In Jupiter's plasma environment, we can expect electrical forces to
affect the trajectories of the charged comet fragments. Such forces
would cause deviations from expected impact times. And in fact
impact times were on average 8 minutes later than
One of the largest pieces, fragment G, showed spectral evidence
of magnesium when it was just 10 hours from impact. Such metals
only show up when comets graze around the Sun. But whatever was
tearing magnesium from the fragment as it sped in through Jupiter's
magnetosphere couldn't drive off enough water to be detectable. That
failure to observe water gave rise to questioning whether the comet
might be an asteroid. After all, only the fuzziness of SL-9 identified it
as a comet, and some asteroids have been observed occasionally to
The electrical comet model explains each and every mystery of
SL-9. An electric comet is as dry as an asteroid. The 'fuzziness' of a
comet is due to electric currents flowing in its plasma sheath, causing
the sheath to glow. When the electrical stress increases beyond a
threshold, the plasma in the sheath will establish arcs at the surface,
which will machine dust and atoms, such as magnesium, from the
minerals there. That this should occur shortly before the collision is
not surprising: Jupiter's magnetosphere is the most active electrical
environment for a comet outside a close encounter with the Sun.
Dr. Earl Milton, before the above paper was published, wrote,
“When comet Shoemaker-Levy 9 meets Jupiter, spectral changes in the
comet's tails might become conspicuous once the comet leaves the
solar wind and enters Jupiter's electrosphere [magnetosphere or
plasma sheath]. This part of the encounter precedes by hours the
meeting of the nuclei with Jupiter's
atmosphere.”123 Here we see the
contrast between an old hypothesis that should be discarded and a
better one. The electric comet hypothesis has explanatory and
The Galileo spacecraft on its way to Jupiter, the Hubble Space
Telescope, and many terrestrial observatories tracked the fragments as
they approached Jupiter. Their data highlighted another mystery. Some
collisions that were calculated to occur just beyond Jupiter's limb and
that should have been invisible to all but the Galileo spacecraft were
seen from the Earth. In a NASA news
report,124 Dr. Andrew Ingersoll
said, “In effect we are apparently seeing something we didn't think we
had any right to see.” “It seems clear that something was happening
high enough to be seen beyond the curve of the planet,” said Dr.
Torrence V. Johnson of JPL. The predictable electrical event prior to
the fragment striking Jupiter's upper atmosphere, did indeed occur.
Chemical analyses threw up more mysteries. Sulphur, ammonia,
carbon disulphide and glowing acetylene and methane heated by the
collisions were found—but no water or even an oxygen-bearing
molecule. This is a problem because the current theory of Jupiter's
structure requires a layer of water clouds below the top clouds of
ammonia. Present theories of the formation of the Solar System
require that both Jupiter and comets have water—yet no one found
signs of any water at all.
According to Dr. Lucy McFadden of the University of Maryland,
“It is disturbing. This means either that our modeling is not correct, or
the comet exploded before it reached Jupiter's water layers.” But SL-9
was originally classified as a comet because its
fragments each appeared to have a 'coma,'
assumed to be a halo of water vapor, dust and
gas.125 An explosion
above the hypothetical
water layers of Jupiter would still not explain
why none of the comet's own water turned up.
That leaves only the first half of McFadden's
either-or: “our modeling is not correct.”
What, then, were the vertical jets seen
rising three thousand kilometers above Jupiter's
atmosphere and known as 'plumes?' And
what were the crescent-shaped dark features that resulted from the
fallback of the plume onto the atmosphere? The dark material came to
be known technically as the 'brown stuff,' its nature unknown ([below]).
In this time-sequence image of SL-9
fragment G's collision with Jupiter. The
number is the time from impact in
hours. Note the strange 'rays.' The
wavelengths recorded from left to right
are 889 nm [infrared], 555 nm [visible],
and 336 nm [ultraviolet]. The infrared
image (LEFT) shows the dark material
to be warm (bright). North is up; Jovian
west longitude increases to the left.
Image Credit: NASA-ESA Hubble
Space Telescope, STScI.
Credit: H. B. Hammel et al., HST
Imaging of Atmospheric Phenomena
Created by the Impact of Comet
Science, Vol. 267,
3 March 1995, p. 1289.
[Click to enlarge]
Melosh suggested that the comet fragments would penetrate
Jupiter's atmosphere so deeply before exploding that they would be
swallowed up and we would see very little. Others proposed that each
fragment would dig a 'tunnel of fire' in Jupiter's atmosphere before
exploding and sending a plume of hot atmospheric and cometary
material from the top of the tunnel into space. This was the 'plume'
model that was explored to try to explain the strange dark fallout
However, the plume model could not explain the clear zone between
the dark core and the crescent. Nor could it explain the radial
lines dissecting the crescent.
Ironically, the answers to the puzzles come from Jupiter's closest
moon, Io. In November 1979, the noted astrophysicist Thomas Gold
proposed that the gigantic plumes on Io are not volcanic but evidence
of electrical discharging.126 Years later, a paper by Peratt and Alex
Dessler followed up Gold's suggestion, showing that the discharges
took the form of a 'plasma gun effect,' which produces a parabolic
plume profile, filamentation of the matter within the plume, and the
termination of the plume onto a thin annular ring.127 These are
precisely the effects seen in the encounter of SL-9 with Jupiter.
A so-called 'volcano' on Io shows the
typical penumbral fallout ring of a
plasma gun. It is a precise analog of the
fallout rings on Jupiter generated by
plasma arcs between Jupiter's ionosphere
and the comet fragments.
Image credit: JPL & NASA
[Click to enlarge]
All of the unexplained oddities begin to make sense, if a plasma
discharge occurred between the highly charged comet fragments and
Jupiter's ionosphere. The electromagnetic pinch of the plasma gun
effect preferentially heats ions to temperatures far hotter than the Sun
and produces the bright, lightning-like flash and subsequent glow. That
is why the light from fragments that were expected to impact beyond
the limb was unexpectedly visible. The light from a discharge at 3,000
km above Jupiter's cloud tops would have been visible from Earth.
The electrical nature of the event will also explain why comet
fragments of different sizes created fireballs of the
same height.128 The
discharges occurred as different fragments penetrated the same 'double
layer' of Jupiter's plasma sheath.
A plasma discharge would also explain why the expected compounds,
such as water, from deeper cloud layers were not seen in the
plumes. The comet fragment is vaporized and ionized by the energy of
the discharge. Constrained by powerful electromagnetic forces, the
silicate particles and other ionized compounds from the rocky comet
form the warm plume and crescent-shaped fallout pattern of 'brown
What was the 'brown stuff?' The Hubble Space Telescope found
“most surprising were the strong signatures from sulfur-bearing
compounds like diatomic sulfur (S2)...”129 However, S2 is a molecule
with a very short lifetime and its origin is unknown. “The origin of
sulfur in ..comets remains enigmatic.”130 If we return to Io, we find
that the 'plasma gun' effect there has covered the moon with colorful
sulfur molecules, including red and brown variants. A large quantity of
oxygen was observed in the SL-9 events at Jupiter. So it seems likely
that the sulfur was formed by fusing two oxygen atoms together in the
powerful plasma discharges to form one sulfur atom. Originally, Io
was probably an icy moon like its Galilean siblings.
There was no water from the comet, and Jupiter's deeper cloud
layers, if they did contain water, were not pulled into the plume.
Jupiter's magnetic field is probably responsible for most of the
rotation, asymmetry, and offset of the plasma gun discharge pattern.
It may be that children listening on their school's radio telescope
provided the most significant observation of all: they said that the SL-9
collisions were accompanied by bursts of radio emissions “just like
those from sunspot activity on the sun.”131
The New Scientist called this “Jupiter's surprise radio
broadcast.”132 Astronomers had expected radio emissions at high
frequencies to diminish and to hear the comet crash clearly at low
frequencies. Instead, nothing happened at low frequencies while
emissions around 2–3 gigahertz rose by 20 to 30%. “Never in 23 years
of Jupiter observations have we seen such a rapid and intense increase
in radio emission,” said Michael Klein of JPL. The radio emission
peaked on 23 July, just after the last comet fragment hit, and it
declined thereafter. Klein had expected dust from the comet to absorb
electrons, which otherwise might contribute to radio emissions.
“Instead, extra electrons were supplied by a source which, as yet, is a
mystery.” But it is no mystery. Like all comets, SL-9 was negatively
charged, its fragments supplying copious electrons for the radio
The fate of SL-9 thus provides a consistent picture of the electric
comet. The picture includes the original break-up and and subsequent
further fragmentation of the comet, plus the surprising events that
occurred in the 1994 impact with Jupiter: the bright plumes above the
Jovian atmosphere; the sightings of 'impossibly' energetic events from
Earth; the associated Jovian auroral displays; the absence of water in
the vaporized debris; and the lack of the expected constituents from
Jupiter's atmosphere, all pointing to the termination of each fragment's
flight in spectacular flashes before it entered Jupiter's atmosphere.
The famous 'string of pearls' of
comet Shoemaker-Levy 9 fragments
Credit: NASA, Hubble Space
Telescope (courtesy of H.
[Click to enlarge]
R. A. Kerr, Science, Vol. 265, 1 July 1994, pp. 31-2.
The Baltimore Sun, 21 July 1994, p. 12A.
P. J. T. Leonard, “Impact consensus emerges,”
Nature, Vol. 375, 1 June 1995, p. 358.
Z. Sekanina, “Disintegration Phenomena Expected
During Collision of Comet Shoemaker-Levy 9 with Jupiter,”
Science Vol. 262, 15 October 1993, pp. 382-3.
H. B. Hammel et al, “HST Imaging of Atmospheric
Phenomena Created by the Impact of Comet Shoemaker-Levy
9,” Science, Vol. 267, 3 March 1995, p. 1288.
Science, Vol. 265, 19 August 1994, p. 1030.
E. R. Milton, private correspondence, 24 July 1994.
Baltimore Evening Sun, 20 July 1994, p. 9A.
T. Gold, “Electrical Origin of the Outbursts on
Io,” Science, Vol. 206, 30 November 1979, pp. 1071-3.
A. L. Peratt, A. J. Dessler, “Filamentation of
Volcanic Plumes on the Jovian Satellite Io,”
Astrophysics and Space Science 144 (1988) pp. 451-61.
Sky & Telescope News, “Astronomers
discuss Comet Crash,” November 4, 1994.
NASA News Release 94-161, “Hubble
Observations Shed New Light on Jupiter Collision,” p. 3.2.
J. Crovisier & T. Encrenaz, Comet Science, p. 49.
BBC Radio 4 Science Now, 19 July 1994.
New Scientist, 20th August 1994, p. 17.
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