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Jupiter, Saturn Plowed Through Asteroids, Study Says


Artist's depiction of the asteroid belt between Mars and Jupiter. Credit: David Minton and Renu Malhotra

Artist's depiction of the asteroid belt between Mars and Jupiter. Credit: David Minton and Renu Malhotra

When Mars and Jupiter migrated to their present orbits around 4 billion years ago, they left scars in the asteroids belt that are still visible today.

The evidence is unveiled in a new paper in this week’s issue of the journal Nature, by planetary scientists David Minton and Renu Malhotra from the University of Arizona in Tucson.  

The asteroid belt has long been known to harbor gaps, called Kirkwood gaps, in distinct locations. Some of these gaps correspond to unstable zones, where the modern-day gravitational influence of Jupiter and Saturn eject asteroids. But for the first time, Minton and Malhotra have noticed that some clearings don’t fit the bill.

“What we found was that many regions are depleted in asteroids relative to other regions, not just in the previously known Kirkwood gaps that are explained by the current planetary orbits,” Minton wrote in an email. In an editorial accompanying the paper, author Kevin Walsh added, “Qualitatively, it looks as if a snow plough were driven through the main asteroid belt, kicking out asteroids along the way and slowing to a stop at the inner edge of the belt.” 

Walsh hails from the Observatoire de la Côte d’Azur in France. In his News and Views piece, he explains that the known Kirkwood gaps, discovered by Daniel Kirkwood in 1867, “correspond to the location of orbital resonances with Jupiter — that is, of orbits whose periods are integer ratios of Jupiter’s orbital period.” For example, if an asteroid orbited the Sun three times for every time Jupiter did, it would be in a 3:1 orbital resonance with the planet, he wrote. Objects in resonance with a giant planet have inherently unstable orbits, and are likely to be ejected from the solar system. When planets migrated, astronomers believe objects in resonance with them also shifted, affecting different parts of the asteroid belt at different times. 

“Thus, if nothing has completely reshaped the asteroid belt since the planets settled into their current orbits, signatures of past planetary orbital migration may still remain,” Walsh wrote. And that’s exactly what Minton and Malhotra sought.

The asteroid belt easily gave up its secrets, showing the lingering evidence of planetary billiards on the inner edge of the asteroid belt and at the outer edge of each Kirkwood gap. The new finding, based on computer models, lends additional support to the theory that the giant planets — Jupiter, Saturn, Uranus and Neptune — formed twice as close to the sun as they are now and in a tighter configuration, and moved slowly outward. 

“The orbit of Pluto and other Kuiper belt objects that are trapped in [orbits that resonate] with Neptune can be explained by the outward migration of Neptune,” Minton and Malhotra write in the new study. “The exchange of angular momentum between planetesimals and the four giant planets caused the orbital migration of the giant planets until the outer planetesimal disk was depleted.”  Planetesimals are rocky and icy objects left over from planet formation.

“As Jupiter and Saturn migrated,” the authors continue, they wreaked havoc on the young asteroid belt, “exciting asteroids into terrestrial planet-crossing orbits, thereby greatly depleting the asteroid belt population and perhaps also causing a late heavy bombardment in the inner Solar System.”

The late heavy bombardment is proposed to have occurred about 3.9 billion years ago, or 600 million years after the birth of the Solar System, and it’s believed to account for many of the Moon’s oldest craters. Walsh said a reasonable next step, to corroborate the theory about the newly described clearings in the asteroid belt, is to link them chronologically with the bombardment.

LEAD PHOTO CAPTION: Artist’s depiction of the asteroid belt between Mars and Jupiter. Credit: David Minton and Renu Malhotra

Source: Nature

Comments on this entry are closed.

  • Anaconda February 27, 2009, 10:07 AM

    Notice Salacious B. Crumb, aka Curmedgeon, while offering the usual abuse, declined to challenge any of the substance of my comment. Namely, that the timing of the orbital migrations can’t be pinpointed with any degree of certainty by relying on crater data from the Moon.

    Nor did Curmudgeon even touch the facial evidence of elecetromagnetism I offered for consideration.

    That’s the science, yet ,Curmudgeon in a “shuck and jive” manner offered personal abuse to distract from his failure to address the scientific merits of the issue.

    My views are different than OilIsMastery.

    For one, I don’t believe in the Velikovskian timing for orbital migrations — planetary electrical discharges at a steady dose would likely wipe-out nearly all higher forms of life on any “worlds” being visited by those planetary “thunderbolts.”


    While evidence of electrical discharge dependent on planetary orbital migrations is substantial, the evidence for it’s timing is uncertain at best and likely does stretch into the distant astrophysical past.

    The challenge is to increase the data and knowledge of past solar and interplanetary events, thus hopefully also increasing science’s knowledge of the timing of events, not dismiss the evidence entirely as Curmudgeon would have us do.

    But dismissal of an idea without even studying it would entirley be in line with a curmudgeon’s way of thinking.

    As to gravity, yes I am convinced gravity exists, and Newton did an admirable job of describing its mechanics (particularly in reference to the general state of scientific knowledge at the time) and developing mathematical equations (calculus) to predict gravity’s effects. After all, with little modification those equations took Man to the Moon and back, alive!

    No small achievement.

    But Newton specifically stated he offerered no opinion about the cause of gravity.

    So, the question placed on the table is thus: Is gravity an intrinsic property of matter, itself; or, is gravity a result of a geometric or spatial relationship of matter, space, and time?

    In my opinion, it’s scientifically fruitful to examine the properties of matter, itself, especially when one considers the alternative theory puts science at a dead end of investigation. The idea that geometry dictates gravity simply can’t be investigated further, it is, what it is. But investigation of the intrinsic properties of matter, itself, follows lines of scientific inquiry that are already being investigated in sub-atomic physics — only slight modification in investigatory emphasis be made to possibly discover the fundamental principles of gravity, and thus possibly also evidenciary leads to a Unified Theory of the Four Fundamental Forces of Nature.

    I suspect the objectors to electromagetism as a basic force of large scale structures in the Universe are content to allow OilIsMastery to spout his quotes and obscure datum knowing the average casual observer will write him off as pedantic if not worse.

    I consider OilIsMastery as a kind of savant: Specialized knowledge about somethings, but wholly incapable of grasping the logic and reason of issues that he already has contrarily decided (think Dustin Hoffman’s rain man).

    So, while it’s easy to blow OilIsMastery off, or better still, lead him on and allow him to sink his own credibility, there are nuggets where his savant capability should be followed up and investigated.

    The question is seperating the “wheat from the chaff.” Gold prospecting has always involved seperating loads of worthless rock in order to find the gold nuggests. I suggest OilIsMastery’s comments should be viewed in similar context.

    Curmudgeon, whenever you engage in abuse without debating the scientific issues — you lose. Because while a curmudgeon can carry a well reasoned argument, their fall back tactic of personal invective, brings out all their worst qualities that repel even thoses sympathetic with their views.

    And reminds people of instances in their own personal lives when some mulish individual simply would not accept what was evidently the case.

    But in the spirit of scientific cooperation and offering a token to the idea of shared reason, I offer a paraphrase of yours that I agreed with and thought was actually made in the spirit of scientific advance (although given in a typically curmudgeon fashion): All the forces of nature need to be investigated in Man’s quest to understand his world and now the Universe.

    To dismiss any one force from science’s inquiry is to tie one arm behind the back.

    And, I for one, believe Man needs both hands for the scientific quest ahead.

    And, deep in that Curmudgeon’s heart of yours, you know that, too.

  • OilIsMastery February 27, 2009, 4:49 AM


    Your characterization of Faraday, Tesla, Poincaré, Lodge, the United States Microgravity Laboratory, and NASA as “jackasses” is hilarious.


    “If EU was true the way you explain it, satellites would fail to orbit.”

    If you were alive in Copernicus’s time you would be saying, “If heliocentrism were true they way you explain it, we wouldn’t be able to predict eclipses.”

  • Excalibur February 27, 2009, 5:18 AM

    OilsMastery: Is it correct to say that EU can not properly explain orbital mechanics ?

    If you claim that is not true, then provide the mechanism that ‘mimics’ gravity to such a degree that gravitational based orbital mechanics work within measurable degree of accuracy.

    And Oils – If the village idiot says EU is true, does it make it so ?

  • Salacious B. Crumb February 27, 2009, 5:34 AM

    OilIsMastery said
    “Your characterization of Faraday, Tesla, Poincaré, Lodge, the United States Microgravity Laboratory, and NASA as “jackasses” is hilarious.”
    Oh dear, did you also fail basic comprehension at school too?

  • Anaconda February 27, 2009, 12:41 PM

    @ David Minton:

    Thank you for answering my response. You’re gracious to answer an amateur’s comments on an open website. I commend you for your devotion to communicating your ideas and facilitating dialogue which hopefully attracts popular interest and spreads knowledge and understanding.

    As well as on the off-hand chance the dialogue will raise scientific questions that merit further investigation.

    David Minton states: “…[I]t [lunar crater dating] is exact enough that we have a general picture of the cratering history of the Moon (and by extension, the inner solar system). ”

    Because you disagree (“I would say that this is almost exactly backwards. It’s the cratering history between 4.5-3.5 Gyr that has been the source of much of the contention in the field for the last forty years or so.”) with the quote I offered substantiating my contention that lunar crater dating is problematic, I tender the paper the quote comes from:


    In a friendly suggestion, I would submit that the idea that the early history of the solar system accounts for the majority of so-called “impact” craters, results more from assumptions based on the “accretion” theory of planetary formation than on actual direct physical in situ observation and measurement.

    Therefore, drawing conclusions based on that assumption are also problematic.

    David Minton states: “It’s been my experience that most scientists love to argue and disagree with each other, but we like it best when the arguments are backed up by rigorous science.”

    I whole heartedly agree with the latter part of the quote, “…backed up by rigorous science.” But humbly suggest there are bright lines in scientific discussion which are taboo to cross. In other words, vigorous dispute inside the “box” is welcome, but challenging certain basic assumptions can be heavily frowned upon.

    David Minton states: “I’m not sure what you mean by ‘blurred’…”?

    Of course, rhetorically, what does, “…snow plough were driven through…” mean?

    However, your answer is in essence a response to what I meant.

    And I appreciate your answer.

    David Minton states: “In fact, our main conclusion is that there are regions in the main belt where Jupiter’s influence is small and that these regions are perfectly capable of keeping asteroids around for 4 billion years, yet they seem to be depleted in asteroids.”

    If such is the case, and I have no reason to dispute your conclusion regarding gravity’s influence, is it possible that another force, much stronger than the ‘weak’ force of gravity could have a role?

    As you know electromagnetism is a much stronger force than gravity, and recent NASA, in situ observations & measurements have confirmed the ubiquitous presence of electromagnetic forces in the interplanetary medium.

    It seems premature to readily dismiss such a ubiquitous fundamental force when at present, it seems almost weekly, NASA announces an observation & measurement that confirms electromagnetism’s significant interaction in interplanetary space.

    “Surprise” is a repeated refrain in response to these observations & measurements.

    David, I appreciate your concern and highlighting of the lack of quantitative analysis of Electric Universe theory. You are right to point that weakness out.

    But are you aware of the work of Dr. Anthony Peratt of the Los Alamos National Laboratory? Dr. Peratt has applied rigorous quantitative analysis to what he labels the “Plasma Universe.”

    In fact, the principles of plasma physics has been quantified in the laboratory in much more rigorous fashion than astronomers have been able to quantify in situ observations & measurements of space objects and processes.

    And the history of these plasma physics laboratory quantified phenomenon being confirmed by NASA in situ observations & measurements of near-space phenomenon is remarkable.

    This remarkable prediction success rate is due to the scalability of electromagnetism. As EM is known to scale up to 14 orders of magnitude, but may scale many orders of magnitude larger than that.

    A theory’s utility in large measure is it’s ability to predict future observations & measurements. Dr. Peratt and his colleague’s work has demonstrated electomagnetism’s utilitiy and I respectfully and strongly disagree with your dismissive, “I have found that the evidence put forth by its proponents is lacking in any rigor, and fails to stand up to real scrutiny,” throw away line at the end of your comment.

    I suspect Dr. Peratt would disagree. too.

    Quantitative rigor is needed for various hypothesis of Electric Universe theory, But there has also been little if no quantitative analysis that demonstratively refutes Electric Universe theory.

    And as your co-author stated, “qualitative” observation can be a valuble starting point for further scientific investigation.

    Perhaps, a rigorous quantitative investigation would go along way towards laying to rest my questions, one way or the other.

    Thanks, again, for your engagement in give and take discussion, I’ve enjoyed it.

    David Minton states: “

  • OilIsMastery February 27, 2009, 6:13 AM


    “Is it correct to say that EU can not properly explain orbital mechanics?”

    Define properly.

    I think it’s correct to say that Newton’s occult force which relies upon divine intervention and miracles doesn’t exaplin anything.

    “All planets revolve in approximately one plane. They revolve in a plane perpendicular to the lines of force of the sun’s magnetic field.” — Immanuel Velikovsky, cosmologist, 1946

    “If you claim that is not true, then provide the mechanism that ‘mimics’ gravity to such a degree that gravitational based orbital mechanics work within measurable degree of accuracy.”

    I refer you to the Geophysical Fluid Flow Cell experiment you are deliberately ignoring posted above.

  • OilIsMastery February 27, 2009, 6:19 AM


    “And Oils – If the village idiot says EU is true, does it make it so?”

    Yes. If an idiot says 2+2=4 does that mean 2+2=5?

  • Salacious B. Crumb February 27, 2009, 6:31 AM

    OilIsMastery said;
    “Yes. If an idiot says 2+2=4 does that mean 2+2=5?”
    So even the jackass can’t add up either.
    Every one knows that 2+2=100

  • Anaconda February 27, 2009, 1:31 PM

    @ Salacious B. Crumb:

    Any fair reading of your prior comments directed at me reveal a string of abusive personal invective. My nicknaming you, “Curmudgeon” was an attempt to diffuse your unpleasant personal attacks in a humorous and hopefully lighthearted fashion.

    But all you do is confirm my characterization of your comments and perhaps your personality as well.

    I stand corrected and acknowledge you did offer a confirmational perspective regarding “exchange of angular momentum.”

    But frankly, the scientific evidence doesn’t support the “accretion” theory. It was so flawed that at one point, it was all but discarded, but with the lack of an alternative theory in the early 20th centruy it was resurrected.

    (Early in the 20th century, electromagnetism simply wasn’t understood well enough to offer a counter alternative theory at that time.)

    But the contradictions and paradoxes of “accretion” theory still remain .

    Don’t like my nickname for you? Hits to close to home? simple, grow up and carry on a scientific conversation like an adult and knock-off the personal invective.

    Salacious B. Crumb states: “Electromagnetism (whatever) is mostly irrelevant to the story presented.”

    You might be right except for one salient point left silent in the paper’s abstract and the further discussion in the post with the authors: They never discuss the cause for the orbital migration.

    You would think that would be relevant to any discussion of evidence of orbital migration. Might even provide evidence that confirms orbital migration or to the contrary, disprove it.

    I started this discussion thread by posing questions that could lead to a possible hypothesis and concordant results of that hypothesis. And one of the authors was gracious enough to respond to my posed questions.

    I respect his willingness to respond even to a comment that implied a disagreement to his postition.

    That is mature scientific discussion.

    Too bad, Salacious, you quickly engage in personal attacks at people who disagree with your position.

    Salacious B. Crumb offers this quote: “Presently explanations of astrophysical phenomena seem mostly and significantly influenced by gravity, and that the effects of electromagnetic forces are fairly minor.”

    NASA’s in situ observations & measurements of near-space and the interplanetary medium refute your quote in its entirety.

  • Salacious B. Crumb February 27, 2009, 6:43 AM

    “I refer you to the Geophysical Fluid Flow Cell experiment you are deliberately ignoring posted above”
    Your precious “Geophysical Fluid Flow Cell experiment” was that, an simulation experiment. Moreover it was a simulation of gravity and NOT a generator of gravity.
    As for that chimpanzee that is helping you to translate your ambiguous diatribe and writing you own material for you. Why don’t you ask him what the following might actually means;
    “diuef fi oos sokfmu udnns, jackass.”
    At least he will get the actual joke, because clearly you haven’t a clue.

  • Excalibur February 27, 2009, 6:51 AM


    Not understanding how gravity works does not make you look very clever. Every satellite in orbit shows that EU as you explain it is incorrect, and on a repetetive basis, with high accuracy. Show numbers, or formulas, Oils!

    I am not ignoring http://wwwghcc.msfc.nasa.gov/gffc.html. You are not showing that this experiment has any relevance to the orbital mechanics that you are claiming – there is a huge difference between artificially creating a random field, with arbitrary value, and the field implied by gravitational theory. Again this random quoting or linking into nothingness…

    Quoting someone who did not understand how gravity worked doesnt make you look very clever either.

    “Yes. If an idiot says 2+2=4 does that mean 2+2=5?”

    Well Oils, it seems you are claiming 2+2=9 when gravity claims that 2+2=4 within observational accuracy, and you simply not understanding what you are claiming. Luckily most people do understand though…

  • Pat Donnelly February 27, 2009, 6:52 AM

    If we are to award victory in these debates I usually give it based on their perceived aplomb. Insults lose massive marks on this scale!
    I understand that those who advocate a theory often fall into error as they must know their experimental and observational history very well and it is difficult to find references to others experiments in time for a thorough debate, let alone a resolution. Poor advocacy on one side or another means that frustration often wins.
    I will say what I think we can all agree that scientific method acknowledges that current theories are likely to fall to more relevant ones as experimental and observational evidence increases.

  • OilIsMastery February 27, 2009, 6:54 AM


    Have you ever observed a graviton?

  • OilIsMastery February 27, 2009, 6:56 AM


    Thx for going easy on me…=)

  • Pat Donnelly February 27, 2009, 6:57 AM

    To explore the relevance of EU theory, there should be an event or experiment that clearly wounds or vindicates it. To ascertain a suitable proof requires that experts from both “sides” acknowledge this and agree on the test, do you agree? I understand that EU theory have predicted matters on likely results of the collision by comet Tempel and a man made impactor. I doubt that this would prove or disprove EU theory but perhaps it would encourage constructive debate about a test that would amount to such proof?

  • ND February 27, 2009, 7:03 AM


    Zero-g does not mean no gravity. Gravity is in affect.

    You really did not address that satelites and any object for that matter is put in to orbit based on our understanding of gravity. And gravity is in affect there as much as it is now keeping you on the Earth’s surface.

    You did not answer my question regarding. Based on what you’ve brought up, is gravity actually the same as electromagnetism or are they different phenomenon but related?

    Please read the following, it should clear up some misconceptions you apparently have about orbiting the earth.

  • Salacious B. Crumb February 27, 2009, 7:08 AM

    OilIsMastery said:
    “Have you ever observed a graviton?”
    Actualliy, more to the point;
    Have you ever observed a photon?

  • Pat Donnelly February 27, 2009, 7:10 AM

    While it is inevitable that future generations of scientist will dismiss this debate with what is eventually established to be the truth, there is an undercurrent of conspiracy theory about EU proponents that disturbs me.
    I do not say that they are wrong, merely that it suggests that paranoia is vital in view of powerful vested (and would be vested say the green lobby, as a poor example) interests who would distort matters by suppression.
    I would dismiss this paranoia were it not for a poor knowledge of history, which suggests that Popes and non-christian arbiters also perhaps, were wont to interfere in these matters at will. They treated theory as dogma. There are other types of vested interests who operate and the most implacable of these is those with the urge to protect, as in another example, to ensure humanity is controlled into preventing self-annihilation. There are almost industries devoted to this noble pursuit. To add effective scientific knowledge is to endanger humanity or profits from variations from existing medical treatments as another poor example.
    To make my point again, the EU theorists tend to want to establish electro-magnetism and that it is being attacked suppressed. A double burden?
    I am, unlike some who contribute to this debate, open to and welcome contradiction!

  • Pat Donnelly February 27, 2009, 7:14 AM

    EU theory says (what I understand to be possibly factual) electro-magnetism, (in mainly electrical form?) is 10^39 times stronger than gravity and that a small effect of electricity, observationally difficult to discen, given the enormous disparity in magnitude of power/effect, might account for all that we know or ascribe to what we call gravity. I think that I should use e, m and g for the obvious terms as I tire easily.

  • Pat Donnelly February 27, 2009, 7:20 AM

    e & m have been misdescribed in Heaviside’s simplified em equations, according to EU theory, is this correct? Clerk-Maxwell put up ?42? equations which use quaternions (and thereby cause headaches for non-engineers) and these original equations have more solutions than appear as a result of the Heaviside equations.
    This is an example of the possible paranoia of EU adherants, but is simple to address: why abandon the original equations if not to hamper future experimental encounters?