'Stardust' Shatters
Comet Theory - Part 1
By David Talbott
This image shows a comet particle collected by the Stardust spacecraft. The particle is made up of the silicate mineral forsterite, also known as peridot in its gem form. It is surrounded by a thin rim of melted aerogel, the substance used to collect the comet dust samples. The particle is about 2 micrometers across.
The first results from NASA's Stardust mission are in, leaving mission scientists in a state of shock and awe. The tiny fragments of comet dust brought back to Earth did not accrete in the cold of space, but were formed under "astonishingly" high temperatures.
It seems that the gulf between the impressive successes of modern technology and the depressing failure of theory has grown by another giant leap.
NASA's celebrated Stardust mission was a technical triumph, achieved at a respectable cost. The mission collected the first samples ever of the dust discharged by comets. On January 2, 2004, the Stardust craft had entered the dusty clouds around Comet Wild 2 (pronounced VILT 2), gathering samples of the minute particles as they struck the "aerogel" in a 100-pound capsule. The capsule returned to Earth and parachuted to touchdown on a Utah desert January 15, 2006.
A surprise -- the particles revealed abundances of minerals that can only be formed at high temperatures. Mineral inclusions ranged from anorthite, which is made up of calcium, sodium, aluminum and silicate, to diopside, made of calcium magnesium and silicate. Formation of such minerals requires temperatures of thousands of degrees.
How could that be? For decades we have been assured that comets accreted uneventfully from the leftovers of a cold "nebular cloud" in the outermost regions of the solar system. The theoretical assumption has been stated as fact repeatedly in popular scientific media, and its proponents believed it. Indeed, the implication of a fiery past was so unexpected that an early sample of dust was thought to be contamination from the spacecraft.
"How did materials formed by fire end up on the outermost reaches of the solar system, where temperatures are the coldest?" asked Associated Press writer Pam Easton.
"That's a big surprise. People thought comets would just be cold stuff that formed out...where things are very cold," said NASA curator Michael Zolensky. "It was kind of a shock to not just find one but several of these, which implies they are pretty common in the comet".
Researchers were forced to conclude that the enigmatic particle material formed at a superheated region either close to our Sun, or close to an alien star. "In the coldest part of the solar system we've found samples that formed at extremely high temperatures," said Donald Brownlee, Stardust's principal investigator at the University of Washington in Seattle, during a Monday press conference. "When these minerals formed they were either red hot or white hot grains, and yet they were collected in a comet, the Siberia of the Solar System." reports that the finding "perplexed Stardust researchers and added a new wrinkle in astronomers' understanding of how comets, and possibly the Solar System, formed". But did it really? Paradigms do not die easily. Our own impression is that comet researchers have yet to revisit their "big picture" assumptions. A litany of surprises has not deterred them, and they continue to discuss the formation of comets "at the outermost regions of the solar system". The idea does not deserve such unyielding devotion. It was never more than a guess, and it never successfully predicted any of the milestone discoveries in cometology.
So the paradoxes and contradictions continue to accumulate. Michael Zolensky, Stardust curator and a mission co-investigator at NASA's Johnson Space Center (JSC), said astronomers believed that a sort of material "zoning" occurred during the Solar System's formation. In the eons-long collapse of the primordial "nebular cloud", material closer to the emerging "sun" formed under hotter conditions, while farther away from the sun everything remained dark and cold. The comet was supposed to be the case par excellence of a body accreted in the outermost region and constituted primarily of water ice and other volatiles.
Speculations erupted. Could it be that something occurred in or very near the Sun in its formative phase, flinging immense quantities of material out to the periphery of the Sun's domain (far, far beyond the orbit of Pluto), to the "Oort cloud", the legendary -- but never-witnessed -- sea of comets?
Then the researchers reminded themselves that this would produce a mixing and contradict the zoning that is evident in the asteroid belt. "If this mixing is occurring, as suggested by these results, then how do you preserve any kind of zoning in the solar system", Zolenksy asked. "It raises more mysteries."
Perhaps the paradigm could be redeemed by finding the signature of primordial water, whose existence is essential to the survival of official comet theory. (See Deep Impact -- Where's The Water?
A report by the journal Nature is illuminating. A writer for the journal spent a day with Phil Bland, a planetary scientist at Imperial College London, as he and his team analyzed part of a grain. When he found large amounts of calcium, Bland was excited. Could the calcium be present in the form of calcium carbonate, a mineral that almost always forms in water? He bet his colleague Matt Genge that this would indeed be the case.
Bland lost the bet, owing Genge a dinner. According to the Nature report NASA "scientists have not yet found any carbonates in their grains".
Today, the study of comets has reached a crisis. Every key finding comes as a surprise, but no one seems to realize that the surprises are not random -- they are predictable under a different perspective. The tragedy is the way inertia can leave well-intentioned scientists with their feet in the sand. The momentum of prior belief, working in concert with pressing demands of funding, creates nearly endless obstructions to open-minded exploration and discourse. Even a brief vacation from an oppressive paradigm could do wonders.
Coming March 18: Stardust Shatters Comet Theory (2)
Photo Credit: NASA/JPL-Caltech/University of Washington
'Stardust' Shatters
Comet Theory - Part 2
By David Talbott
When dust particles from Comet Wild 2 struck a sponge-like "aerogel" collector in the Stardust spacecraft, they left carrot-shaped imprints about a centimeter long.
Mythic "Oort Cloud" Finds No Support in Comet Dust
It's now official. Minerals found in Comet Wild 2 dust particles can form only at high temperatures, and they cannot be distinguished from minerals found in meteorites and on rocky planets.
Dust particles ejected by Comet Wild 2 have provoked another surprise, contradicting the underlying assumptions of popular comet theory. When the Stardust mission returned "pristine comet material" from Comet Wild 2, project scientists were astonished to discover minerals that can only form at high temperatures -- up to thousands of degrees Fahrenheit. And the dust particles reveal no indications of the water that cometologists expected.
Standard theory states that comets formed billions of years ago in an imagined icy "Oort cloud" at the very fringe of the Sun's domain, far beyond the orbit of Pluto. But the new findings require a quite different history. A NASA news release on March 13, 2006 summarized the problem with this understatement --
"Scientists have long thought of comets as cold, billowing clouds of ice, dust and gases formed on the edges of the solar system. But comets may not be so simple or similar. They may prove to be diverse bodies with complex histories. Comet Wild 2 seems to have had a more complex history than thought".
The disturbing discovery provoked a burst of creative attempts to rescue ideas stated as fact for at least thirty years. Michael Zolensky, Stardust curator and co-investigator at NASA's Johnson Space Center, Houston, suggested a novel interpretation that quickly caught on. "It seems that comets are not composed entirely of volatile rich materials but rather are a mixture of materials formed at all temperature ranges, at places very near the early sun and at places very remote from it." One science writer interpreted Zolensky's comment this way: "The findings suggest materials from the center of the solar system could have traveled to the outer reaches where comets formed".
So an obsolete theoretical conjecture persists in human imagination, despite an undeniable fact: Nothing discovered about comets -- over many years of profound discovery -- points to an origin in the remote region assumed. A rational response will not exclude the question shouted by the new data. Could something be wrong with earlier suppositions about the region of comet formation -- suppositions that never produced a successful prediction in the course of the space age?
As for the water (ice), that was supposed to be the primary constituent of comets. But the anticipated markers of water on the nucleus of Wild 2 are absent. One mineral present in the comet particles is olivine, an iron-magnesium silicate. In the presence of water and even modest heat, olivine will be converted to another mineral, serpentine. Place olivine in the presence of water (steam?) at the temperatures indicated for its formation, and it would be almost instantly converted to serpentine.
According to Stardust principal investigator Donald Brownlee, "no evidence of water has been detected in the particles". One sign of water, for example, would be the presence of hydrate silicates, Brownlee said, "but so far none of these have been found in the Stardust samples".
How, then, are we to reconcile the absence of water signatures in the comet dust with the fact that cometary comas often exude an abundance of water (or at least the hydroxyl radical OH). We answered that question in a three-part series, "Deep Impact --Where's the Water?" (first article here:
The OH and whatever actual water may have been present in the coma were manufactured in the coma -- an acknowledged "chemical factory". The vehicle for this process has already been observed -- reactions between the oxygen ions in the coma plasma and the hydrogen ions in the solar wind. Charge exchange is now known to occur.
The least we can say today is that most comets contain no appreciable levels of water (i.e., most comets are neither "dirty snowballs" nor "icy dirtballs"). Additionally, it needs to be emphasized that there is no conflict between Stardust and Deep Impact data. Brownlee, who is not prone to overstate theoretical implications, points out that Stardust collected dust that was released directly from the surface in jets. "We're confident that the things coming out [of Comet Wild 2] are the same as those that went in", he told
That means the material has not been processed by the chemical factory of the coma. "We believe that we collected the most pristine samples of a comet", he said. Hence, the failure to find a signature of water in the comet dust is consistent with all of the facts we have presented in previous discussion.
It is not unreasonable to suggest, therefore, that only one comet model can make sense of what is otherwise a hopelessly confused picture. This model is electric. And thanks to the technological successes of the space age, all of the markers reasonably expected of an electric comet have been found. (See Comets: The Loose Thread,
Of course the implications of the electric model do not end with the origin and dynamics of comets. They extend to virtually all of the theoretical sciences, and range from questions of electricity in remote space, to the nature of stars and the violent history of the solar system.
Additionally, as we intend to make clear, human memories of cometary and planetary catastrophe cannot be excluded from this investigation.
Coming March 23: Of Comets and Planetary Catastrophe
Photo Credit: NASA
'Stardust' Shatters
Comet Theory - Part 3
By David Talbott
NASA scientists produced this illustration of the "solar nebula", called upon to resolve mysteries posed by the dust from Comet Wild 2.
Of Comets and Planetary Catastrophe
Reverberations of the Stardust mission continue to rock the scientific community in the weeks following the recovery of dust samples from Comet Wild 2. Minerals in the dust were not what comet experts had expected.
Guided by longstanding theoretical assumptions, scientists expressed great confidence that comets formed at the outer margins of the solar system billions of years ago, at the time of the system's birth. And they believed they would find the required indicators of water, since water ices were assumed to be the primary constituent of comets.
The shock came from the discovery of minerals that can only form at extremely high temperatures, up to thousands of degrees Fahrenheit. The minerals could not have been created in the cold depths scientists had envisioned. Also, the investigators have yet to find any markers left by water, and some components appear to exclude the presence of water in their formative phase.
An article in Aviation Week and Space Technology (March 19, 2006) summed up the present situation: "The new Stardust sample data are themselves colliding headlong with previous comet theories compiled without the benefit of samples".
"The findings stunned the more than 1,500 international planetary scientists and managers at the 37th annual Lunar and Planetary Science Conference (LPSC) here near the Johnson Space Center (JSC)", the article states. In fact, the findings are the "opposite of existing models of comet formation", and they will "affect broad theories on the formation of this and other solar systems".
But already the "explanations" cobbled together reveal the persistence of the very concepts that set comet experts on a dead-end path. While acknowledging the stunning surprise, the AWST story says, "The analysis shows the diverse minerals found in the Wild 2 Stardust samples had to have been formed as extremely hot materials near the core of a primordial planetary nebula around a star -- either the Sun or some other distant star".
A "primordial planetary nebula"? The reference here is not to something known, but to an age-old conjecture about the birthing of stars. Searching through official and quasi-official comments on the Stardust findings, we do not find any NASA scientists wondering if something might be amiss in the speculative framework that spawned the now-defunct comet theory. Rather, NASA investigators quickly settled on the idea that the Wild 2 minerals were created in an early stage of star formation (gravitational collapse of a nebular cloud to form our Sun) only to be catapulted out to the Oort Cloud far beyond the orbit of Pluto where, billions of years ago, it mixed with primordial ices that slowly gathered into chunks to became a comet.
Skeptics suggest that this confusion of fact and theory in popular science can only end in an embarrassment. No one ever proved the nebular hypothesis or even showed that it deserved to be honored as a "default" position. No one ever demonstrated that the "Oort Cloud" exists. No one ever established that comets formed billions of years ago. And no one ever demonstrated that comets are constituted primarily of water ice and other volatiles. (As we have already noted, all of the evidence so far is against the abundance of water -- or the hydroxyl radical OH. Water in the coma of comets does not mean water in the nucleus).
How, then, would the NASA scientists save the "big picture" in the face of the Stardust revelations? The illustration above suggests an unwitting step toward the Electric Universe, combined with a new leap of faith. In this case, the scientists moved the imagined place of the comet's origin inward to the Kuiper belt, a ring of objects beyond the orbit of icy Neptune, but much closer to the Sun than the legendary Oort Cloud. Then they took a page, or a portion thereof, from plasma cosmology, envisioning a bi-polar nebula (innumerable examples now known in our galaxy) whose magnetic fields produced electric currents and polar jets while heating nearby material to produce the minerals discovered in the Wild 2 dust. The jets then supposedly ejected the heated material out to the Kuiper belt. And here the minerals supposedly mixed with ices to provide the building blocks of Wild 2.
Michael Zolensky, Stardust curator and co-investigator at NASA's Johnson Space Center, Houston, put it this way: "We have found very high-temperature minerals, which supports a particular model where strong bipolar jets coming out of the early sun propelled material formed near to the sun outward to the outer reaches of the solar system".
The "model" given traces to the "The X-wind model" of Frank Shu a few years ago when he was at the University of California in Berkeley. Shu and his colleagues suggested that "intense electrical currents" and magnetic fields might have been generated by a rotating dusty disc interacting with the magnetic field of the infant Sun. But Shu's group was seeking to account for the composition of meteorites and did not find that its computer models worked for comets.
Of course, it was just a computer simulation, and no doubt the input can be adjusted enough to achieve the desired results. The real problem is that the entire framework for rescuing the standard "big picture" is arbitrary. The reasoning begins with an electrically neutral universe, despite the rapidly accumulating evidence of electricity at every observable scale. It then seeks to create regional electric and magnetic fields through the paltry force of gravity. It thus keeps gravity in the driver's seat, and saves the cosmologists' underlying equations for another day. But it requires them to ignore what the best experts on plasma and electricity in space have been telling us for too long now: Bi-polar nebulas show every expected feature of plasma discharge. The discharge is energized by vastly larger electric fields than could be generated by gravity acting on such a minimal scale. It is electric currents threading through the galaxy that provide the observed nebula energies, not mere particles of dust in a diffuse local cloud.
The most compelling message of Stardust, the point many theorists may be eager to overlook, is that all ideas in the sciences must be judged by their predictive ability. On this ultimate test, modern comet theory has failed completely. Not just on a few ideas about the "Oort Cloud", but on every fundamental principle. And if someone tells you this statement is excessive ask him to enumerate just two or three discoveries about comets since the beginning of the space age that the accepted models predicted.
The only answer to this conundrum is to allow for the fair consideration of another vantage point, one that has not failed. Over the past ten years, the electric theorist Wallace Thornhill has stated scientific predictions again and again. The predictions have held up extraordinarily well.
It is only to be expected that in the minds of most space scientists today the Electric Universe is too far removed from things already "known". This mistaken perception will not be easily corrected, but we have the advantage of contrast. On an issue-by-issue comparison, the predictions of the Electric Universe are highly specific, and most are unique to its vantage point. They will be easily distinguished from the predictions of "standard theory".
In the electric model, a comet has nothing to do with the imagined beginnings of the solar system billions of years ago. Most comets are, when placed on a geologic timescale, newcomers to the solar system. Most comets are neither dirty snowballs nor icy dirtballs. Like asteroids and meteors, they are pieces of planets and moons, tracing to intensely energetic violence in an earlier phase of solar system history. The events were electrical. Charged bodies moved through a dense plasma and engaged each other with cosmic thunderbolts.
Planets were carved electrically from pole to pole, and the only force that can replicate the patterns as a whole is electric discharge. (See Discharges and Scars,
Smaller moons exploded or disintegrated under the electric stresses, just as comets, even today, at times explode as they move through the electric field of the Sun. The comet is a residue of planetary instability and violence.
In this sense the comet can tell us more about planetary history than space scientists ever imagined. If you want to know what force sculpted the diverse and battle-scarred surfaces of planets and moons, look at the surfaces of comets carved by electric discharge. The most common features of rocky planets and their satellites will be there -- craters, crater chains, rilles, ridges, spires, mesas, and mountains. But in the case of the comet, we have a laboratory in space ready to yield its secrets. If we will devote the resources that comet investigation deserves -- and ask the questions science forgot to ask -- the comet will be the fulcrum for a sweeping revolution in the sciences. Old ideas about the formation of stars and galaxies, the origins of the solar system, and the history of our Earth will all be subject to critical examination. And mere conjectures in the sciences will not be permitted to continue masquerading as fact.
Photo Credit: NASA



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