Study: Vaporized Earth formed the Moon from it’s mantle after ancient collision

From WASHINGTON UNIVERSITY IN ST. LOUIS

Chemistry says Moon is proto-Earth’s mantle, relocated

Data confirm model in which impact pulverizes Earth like a sledgehammer hitting a watermelon

Measurements of an element in Earth and Moon rocks have just disproved the leading hypotheses for the origin of the Moon.

Tiny differences in the segregation of the isotopes of potassium between the Moon and Earth were hidden below the detection limits of analytical techniques until recently. But in 2015, Washington University in St. Louis geochemist Kun Wang, then the Harvard Origins of Life Initiative Prize postdoctoral fellow, and Stein Jacobsen, professor of geochemistry at Harvard University, developed a technique for analyzing these isotopes that can hit precisions 10 times better than the best previous method .

Wang and Jacobsen now report isotopic differences between lunar and terrestrial rocks that provide the first experimental evidence that can discriminate between the two leading models for the Moon’s origin. In one model, a low-energy impact leaves the proto-Earth and Moon shrouded in a silicate atmosphere; in the other, a much more violent impact vaporizes the impactor and most of the proto-Earth, expanding to form an enormous superfluid disk out of which the Moon eventually crystallizes.

The isotopic study, which supports the high-energy model, is published in the advance online edition of Nature Sep.12, 2016. “Our results provide the first hard evidence that the impact really did (largely) vaporize Earth,” said Wang, assistant professor in Earth and Planetary Sciences in Arts & Sciences.

moon-models

Two recent models for the formation of the moon, one that allows exchange through a silicate atmosphere (top), and another that creates a more thoroughly mixed sphere of a supercritical fluid (bottom), lead to different predictions for potassium isotope ratios in lunar and terrestrial rocks (right). CREDIT Kun Wang

An isotopic crisis

In the mid-1970s, two groups of astrophysicists independently proposed that the Moon was formed by a grazing collision between a Mars-sized body and the proto-Earth. The giant impact hypothesis, which explains many observations, such as the large size of the Moon relative to the Earth and the rotation rates of the Earth and Moon, eventually became the leading hypothesis for the Moon’s origin.

In 2001, however, a team of scientists reported that the isotopic compositions of a variety of elements in terrestrial and lunar rocks are nearly identical. Analyses of samples brought back from the Apollo missions in the 1970s showed that the Moon has the same abundances of the three stable isotopes of oxygen as the Earth.

This was very strange. Numerical simulations of the impact predicted that most of the material (60-80 percent) that coalesced into the Moon came from the impactor rather than from Earth. But planetary bodies that formed in different parts of the solar system generally have different isotopic compositions, so different that the isotopic signatures serve as “fingerprints” for planets and meteorites from the same body.

The probability that the impactor just happened to have the same isotopic signature as the Earth was vanishingly small.

So the giant impact hypothesis had a major problem. It could match many physical characteristics of the Earth-Moon system but not their geochemistry. The isotopic composition studies had created an “isotopic crisis” for the hypothesis.

At first, scientists thought more precise measurements might resolve the crisis. But more accurate measurements of oxygen isotopes published in 2016 only confirmed that the isotopic compositions are not distinguishable. “These are the most precise measurements we can make, and they’re still identical,” Wang said.

A slap, a slug or a wallop?

“So people decided to change the giant impact hypothesis,” Wang said. “The goal was to find a way to make the Moon mostly from the Earth rather than mostly from the impactor. There are many new models — everyone is trying to come up with one — but two have been very influential.”

In the original giant impact model, the impact melted a part of the Earth and the entire impactor, flinging some of the melt outward, like clay from a potter’s wheel.

A model proposed in 2007 adds a silicate vapor atmosphere around the Earth and the lunar disk (the magma disk that is the residue of the impactor). The idea is that the silicate vapor allows exchange between the Earth, the vapor, and the material in the disk, before the Moon condenses from the melted disk.

“They’re trying to explain the isotopic similarities by addition of this atmosphere,” Wang said, “but they still start from a low-energy impact like the original model.”

But exchanging material through an atmosphere is really slow, Wang said. You’d never have enough time for the material to mix thoroughly before it started to fall back to Earth.

So another model, proposed in 2015, assumes the impact was extremely violent, so violent that the impactor and Earth’s mantle vaporized and mixed together to form a dense melt/vapor mantle atmosphere that expanded to fill a space more than 500 times bigger than today’s Earth. As this atmosphere cooled, the Moon condensed from it.

The thorough mixing of this atmosphere explains the identical isotope composition of the Earth and Moon, Wang said. The mantle atmosphere was a “supercritical fluid,” without distinct liquid and gas phases. Supercritical fluids can flow through solids like a gas and dissolve materials like a liquid.

Why potassium is decisive

The Nature paper reports high-precision potassium isotopic data for a representative sample of lunar and terrestrial rocks. Potassium has three stable isotopes, but only two of them, potassium-41 and potassium-39, are abundant enough to be measured with sufficient precision for this study.

Wang and Jacobsen examined seven lunar rock samples from different lunar missions and compared their potassium isotope ratios to those of eight terrestrial rocks representative of Earth’s mantle. They found that the lunar rocks were enriched by about 0.4 parts per thousand in the heavier isotope of potassium, potassium-41.

The only high-temperature process that could separate the potassium isotopes in this way, said Wang, is incomplete condensation of the potassium from the vapor phase during the Moon’s formation. Compared to the lighter isotope, the heavier isotope would preferentially fall out of the vapor and condense.

Calculations show, however, that if this process happened in an absolute vacuum, it would lead to an enrichment of heavy potassium isotopes in lunar samples of about 100 parts per thousand, much higher than the value Wang and Jacobsen found. But higher pressure would suppress fractionation, Wang said. For this reason, he and his colleague predict the Moon condensed in a pressure of more than 10 bar, or roughly 10 times the sea level atmospheric pressure on Earth.

Their finding that the lunar rocks are enriched in the heavier potassium isotope does not favor the silicate atmosphere model, which predicts lunar rocks will contain less of the heavier isotope than terrestrial rocks, the opposite of what the scientists found.

Instead it supports the mantle atmosphere model that predicts lunar rocks will contain more of the heavier isotope than terrestrial rocks.

Silent for billions of years, the potassium isotopes are finally found a voice, and they have quite a tale to tell.

###

Full study here: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature19341.html

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192 thoughts on “Study: Vaporized Earth formed the Moon from it’s mantle after ancient collision

  1. Measurements of an element in Earth and Moon rocks have just disproved the leading hypotheses for the origin of the Moon.
    This is much too strong. The giant impact is the salient point which has not been ‘disproved’. The details can be debated and that is what this is.

    • Yes, this sound like very inconclusive evidence to be make such certain statements. Seems like the new normal does not just apply to climatology.

      Wang and Jacobsen examined seven lunar rock samples from different lunar missions and compared their potassium isotope ratios to those of eight terrestrial rocks representative of Earth’s mantle. They found that the lunar rocks were enriched by about 0.4 parts per thousand in the heavier isotope of potassium, potassium-41.

      7 or one and 8 or the other and they detect a four per mil difference. I doubt that is even statistically significant.

      What was that paper saying in the week about natural selection of bad science and spectacular claims being more publishable ?

      • Well I would expect that there should be quite substantial differences in isotopic composition (especially in the outer rock layer) across most elements after 100’s of millions of years of bombardment with high energy cosmic & other rays that occurred without a blocking atmosphere relative to earth rocks. Question is are those differences quantifiable and if so are they printable so as not to call into question any improprieties on NASA (e.g. like those 3 buildings in NY).

      • Yes it is an extremely exclusive sample size. But the issue was one of similarity rather than difference. With the issue being isotope ratios and relative forming zone location within the proto solar system, what can’t be excluded is the possibility that this impactor also formed at the same solar orbital distance as Earth but opposite Earths location and in a slightly different plane

      • I haven’t read the paper, but I will bet the paper is a great deal more careful about its language than the press release. PR people at universities are about creating buzz rather than reporting good science. Our PR shop has written some pretty crazy things from some of our research, but it is about what one would expect from marketing people.

    • Nothing is ever proved or disproved, there is only a null hypothesis that can be rejected with some degree of significance. You can never even prove or disprove the hypothesis that you (not me) exist although if I see you coming at me with a meat cleaver in your hand and screaming, it is certainly a working hypothesis at the moment. The various theories of origin of the moon make for different hypotheses and predictions. Science (unlike the Eschatological Cargo Cult of the CAGW) moves towards the most likely ones which reject their null hypotheses with the greatest significance.

      No idea what the statistical significance around this study is. An interesting study that points to further tests, no more.

    • “In 2001, however, a team of scientists reported that the isotopic compositions of a variety of elements in terrestrial and lunar rocks are nearly identical. Analyses of samples brought back from the Apollo missions in the 1970s showed that the Moon has the same abundances of the three stable isotopes of oxygen as the Earth.”
      Orrrr these are actually earth rocks (Apollo mission to moon never landed??). Yeah I know, just another wild speculation about a totally honest NASA & government :) :)

      • I know, as one that has/is familiar with/has close association with government entities, I also find it nearly impossible to believe that government could possibly be that corrupt/deceitful especially as the psychological/mental stress would be beyond overwhelming…….*rolls the eyes*…..

      • It isn’t a question of whether the government is capable of such a deception (of course it is), but whether the available evidence supports that claim. In my mind it does not. The overwhelming evidence in support of the moon landings being real is insurmountable. That is why people roll their eyes at your statements.

      • A conspiracy of that magnitude would require that thousands, perhaps 10’s of thousands be in on it.
        The idea that each and every one of them has kept their silence over decades stretches credulity to and past the breaking point.

      • My minimal training in science is trumped by my life in politics. We were in the Cold War. The USA could track Russian spacecraft and they could certainly track ours. Those who say we faked the moon landings would have us believe that the Russians wouldn’t embarrass Pres Nixon and the U.S. by letting the world know of the fakery? That would take their conspiracy rantings to an otherworldly level!

      • Ironically, the technology available at the time was not advanced enough to fake the technology required to visit the moon. So in order to fake the moon landings, the landings actually had to be done.

      • Well “Opie” faked the Apollo 13 launch well enough to fool the Apollo Astronauts, who wondered how he came by the film footage they had never even seen before they got a preview of Apollo 13: The Movie.

        G

  2. Scientists are getting quite good at fiddling with figures and hypotheses until they have a publishable paper, aren’t they?

      • Depends on what “science” really is. There is “fiddling” in science. Your “solid” makes you appear to believe that science is “absolute”, and of course that is horsehockey.

      • Your “Solid” is also an illusion as you are protons.and neutrons surrounded by mostly vast amounts a of space encompassed by electrons moving at relativistic speeds which prove that E=MC2

    • The difference is that this is testable. We have the lunar rocks and 50 years of lunar science to work with. Also, angular momentum and isotope ratios are not as squirrelly and chaotic as the climate. A hypothesis like this is considered a valid theory when the computer models match the observed data, and offer predictions that can be tested with the next lunar probe.

    • I agree with Leif.
      This is sound and exciting science as it ought to be.
      Skepticism should avoid the risk of tarring everything with the climate brush, and falling into the trap of “the dwarves are for the dwarves!”

      • Maybe it’s just me, but I have a hard time describing any debate regarding isotopic rations as “exciting”, but it is definitely interesting.

    • Your characterization of “scientists” lacks a lot. Many, in fact most scientists don’t publish anything. They like the work, the challenge, and the creative effort to bring a coherent explanation for some specific data set into existence, and getting together and getting around the outside of a few beers at conferences, which usually they pay for themselves. As a professional expense, vaca … ah, meetings are deductible. If you are lucky, have connections, or some really great stories about a mark who doesn’t want them told, maybe he or she has an expense account you will appear on later. Besides which, when you consider what scientists do publish and the profound difficulty often encountered in trying to coherently understand what a scientist has written and published, the bar to publication is really pretty low. Yes, I really am saying the majority of scientists, published or not, are $%^& at writing. Reading scientific literature is a prescription for insomnia. One of the editors of Scientific American wrote years ago about the stack of “righteous reading” he kept beside the bed. It made him feel righteous trying to read it, and being in bed while doing it reduced injury from forehead hitting desk.

    • That is Statusticians doing that fiddling.

      By Definition they are Artists, and not Scientists at all.

      Science is about observation and experimentation about the REAL universe; it has nothing to do with numerology or numerical Origami, which is all done with real known numbers. (ANY real finite numbers).

      G

      • The impacter must have come from a slightly different orbit, it seems unlikely two good-sized planets would have grown up in the exact same orbit. So the final momentum of the resulting planet would have been the combined momentums of the two impacters. (And if the impacter was indeed Mars-sized, the original “Earth” must have been smaller than the present Earth+Moon system.) At any rate, the resulting orbit would have been bigger or smaller than it was before, depending on whether the impactor came from inside the original Earth’s orbit, or outside.

        Of course the coalescence wouldn’t have affected the orbit any, only the impact would have.

      • So as the moon recedes from the earth, gaining angular momentum while the earth (rotation) slows down, will the moon remain phase locked to the earth always facing us the same way, or will it eventually break lock, and spin independently of earth rotation ??

        G

      • I’m guessing that the gravity lock will last for a long time.
        As the moon moves further out three things happen.

        1) The gravity difference between the side facing the earth and the side facing away from the earth gets smaller. All other things being the same, this would make it easier to break the gravity lock. However all other things are not equal.
        2) Changes in orbital speed for the same increase in orbital diameter get smaller. This means that the changes in the moon’s rotation in order to keep it locked with the earth, are reduced.
        3) Tidal forces get smaller. So the force transferring energy from the earth’s rotation to the moon’s orbit gets smaller. Which means that the speed at which the moon’s orbit is increasing, decreases.

        I haven’t put together a model on this, but my personal guess is that 2 and 3 combined will be sufficient to compensate for 1, at least until the sun’s expansion makes the point moot.

  3. When I first read the earth moon collision idea, I thought of how two blobs in a lava lamp collide, meld, then a smaller orb breaks off.
    Oil, wax and water in a jar is one thing, but, how would this work inside the vacuum of space where collisions usually end in a giant debris [field] traveling every which way?

  4. The vapour hypothesis would explain the ring of moon rocks cirkling around earth – had there been any.

    • I’m not sure if it rules out the georeactor theory.

      Here’s a quote from an article about the georeactor theory.

      The researchers suggest the hypothesis explains the identical isotopic composition of light and heavy elements, and further propose it could be tested, since the explosion would leave evidence such as xenon-136 and helium-3, which would have been produced in abundance in the georeactor. Confirmation will be complicated by the fact that solar wind deposits these isotopes onto the moon in vast quantities, and that would have to be compensated for.

      It looks like there may be confounding factors. Over the years I’ve heard lots of theories (about all kinds of things) that sounded convincing at the time but they just faded away and never became widely accepted.

    • If the core had exploded, one of two things would have happened.
      If the explosion was large enough so that the fragments would reach escape velocity, then the earth would have disappeared, permanantly.
      If the explosion wasn’t large enough so that the fragments reached escape velocity, all of the fragments would have fallen back into the earth.
      The georeactor theory does not provide the angular momentum needed to put some of those fragments into orbit.

    • What about the two NASA “gong” experiments adding evidence that the moon is hollow and an ancient alien satellite positioned to monitor we “children”.

  5. Quoting article:

    But planetary bodies that formed in different parts of the solar system generally have different isotopic compositions

    Who determined that the proto-earth and proto-moon formed in our Solar System at far different orbital distances from the Sun?

    What if, …… the earth and the moon formed from similar material but in their own specific orbits around the Sun, ….. but with their orbits in close proximity to one another, ….. but then, later on (a million years, a billion years), …… there was a “chance encounter of the close kind” …….. and the gravitational attraction of the earth captured the moon and it became an earthly satellite.

    • 1) close orbits of that kind are highly unstable. The planets are in the orbits that they are largely because of resonances in their periods; bodies in other orbits tended to be perturbed, especially by Jupiter. If the moon’s orbit was close enough to Earth’s for the isotope ratios to be this close then they would never have stayed that way for very long.
      2) there are some oddities about the Earth’s and the Moon’s rotational rates that are best explained by a collision, such as the Earth’s axial tilt.

      • I have seen gravity simulation model which was seeded with thousand of tiny satellites around the Earth. They rapidly condense into one moon.

      • Or why didn’t our moon form rings, if it was vaporised?

        According to current ideas , Jupiter could not have formed anywhere near it’s current orbit. There are many things we do not understand but scientists love to make grand statements with unwarranted certainty. The bits they have no idea about are reported as “we don’t yet completely understand …” .

        Hubris for the most part and unquestioning, fawning admiration for half educated media science writers ( note I don’t say journalists because they only parrot press releases and NEVER research or question as a journalist should ).

      • Paul of Alexandria – September 25, 2016 at 12:10 pm

        If the moon’s orbit was close enough to Earth’s for the isotope ratios to be this close then they would never have stayed that way for very long.

        How long is long, …… iffen their orbiting speeds were almost equal with the earth’s being slightly greater than the Moon’s and they were orbiting the Sun with the Moon being, say 200 degrees out-of-phase or trailing behind the earth ……. then how long would it take the earth to “catch-up” that 200 degree difference in orbital position and capture the Moon?

        Or is that also a highly improbable if not impossible scenario?

      • E.M.Smith
        September 26, 2016 at 12:21 am

        Also, the rings, which consist mostly of water ice particles, are constantly replenished by water from the moons.

      • There’s a solid theory that explains how Jupiter would have moved from where it formed to where it is now.
        Basically large bodies like Jupiter spiral into their sun after they are formed because of interactions with smaller bodies. Jupiter was doing this, as was Saturn. Jupiter and Saturn got lucky and they hit a point where Jupiter was orbiting the sun exactly 3 times for every two times that Saturn orbited.
        This transfered some of Saturn’s orbital energy to Saturn. The result of this was that Jupiter and Saturn were now in orbits that had already been cleared out by Jupiter, so the orbital decay for both of them was stopped.
        At the same time, the dance between Jupiter and Saturn also kicked Neptune so that it was kicked to a higher orbit, eventually getting further away from the sun than Uranus. According to the theory you mentioned, Neptune and Uranus are in the wrong order.

      • MarkW
        September 26, 2016 at 9:16 am

        There’s also the hypothesis that Jupiter formed close to the sun, as with often observed of “hot Jupiter” gas giant exoplanets, but drifted into its present location, causing the hypothesized Late Heavy Bombardment in the process.

        Others say that there wasn’t a LHB, but that’s it’s just an artifact of collecting moon rocks from the same impact or impacts close in time.

      • Gabro, where did the energy necessary to lift Jupiter from an orbit close to the sun to it’s present orbit come from? If you took all of the orbital energy from all the other planets in our current solar system, it wouldn’t have been enough. Beyond that. Any planet between where Jupiter formed and where it is now would either have been swallowed by Jupiter or expelled from the solar system as Jupiter drifted outwards.
        The so called hot Jupiters were more likely formed as large bodies formed further out in their solar systems drifted inward, via the mechanism that I mentioned earlier.

      • If that close thee body problem is unstable, as you say, perhaps it would change from that unstable three body orbit (around the sun) by having earth capture the wandering moon.

        If they had formed from the same protochunk of material and somehow split apart into a Trojan like Equilateral Triangle situation, that presumably could stabilize, but if not far enough apart in solar orbit, the unstable wandering would presumably lead to moon and earth moving towards each other with enough mutual angular momentum to result in capture rather than collision.

        So I am suggesting your thesis is plausible. That they formed perhaps from an extended wisp of the same material, and broke into two to form two bodies, not far enough apart to get trojanized, so they drifted the other way into a capture encounter.

        G

  6. Achilles heal, “developed a technique for analyzing these isotopes that can hit precisions 10 times better than the best previous method”.

    Who says the “new technique” is correct?

    It’s all in the error.

    But on the bright side they should be about to fool NSF for money to invest in stocks, half in day-trade stocks and half in high-dividend stocks for at least 10 years and then retire.

    • Well something as common as radio-carbon dating, when it is available, also went through the development of a new technique which was far more accurate (mass spectrometry).

      So who are you to suggest they don’t know what they are doing.

      I’m not endorsing their theory. But I have no grounds to pooh pooh their laboratory methodology.

      G

  7. I know these guys n gals are clever at what they do and all that, but I’m very skeptical when ‘hard evidence’ is claimed for something (many things) that happened billions (4?) of years ago. Many processes, even minuscule moment to moment, but significant in seriously long term, cosmic scale, time frames, could affect the chemistry, especially isotopic. For instance an exploded planetary debris/dust cloud would have different volumes and precipitation times, assuming condensation into two bodies, whereby exposure to cosmic radiation would alter preferentially (diff elements have different target cross section) the isotopic fractions. The suggested preferential fall out of heavier potassium isotope in the moon to be sphere would happen in the earth to be sphere too, so this does not provide the reader with a ‘reason’ why the impact, if there was one, of any given violence, gives rise to the potassium difference between earth and moon.
    So much that we don’t know makes this a dubious call in my limited opinion. In cosmic timescales, the more you ‘know’ really does reveal the ‘more’ you don’t know. Still, in a young discipline, especially one where the objects/subjects are almost always light years away, they have to start somewhere, put something together. I just wish some measure of the truth, the possibilities and the context, was available. Because of so much unknown, it is impossible to present a finding with +/- % error. CAGW is in a similar situation. I’m not sure the tools, the raw data or the ‘intelligence’ are anywhere near sufficient to address this or these issue(s) now or in the near future. To appear so confident is deceptive.

    • Yes, cosmologists are about as good as archaeologists for building wild speculative hypotheses from the tiniest grain of evidence and stating them with great certainty.
      Most of the time they require as much faith and as saying ‘God did it’.

      Science was originally created to replace religion. After 400 years, the assimilation is almost complete. It’s hard to tell the difference.

      • Greg
        “God did it”
        Yes the drift of the critical response here to the article is “golly ain’t it hard to find out anything about what happened so long ago, I bet they’re trying to fool us, let’s all go back to good old 6 day creation and that old time religion is good enough for me!

        Science was originally created to replace religion”

        Bollocks! Science was created primarily by religious people, confucianist, islamic, christian, hindu. What was created to replace religion was Soviet dialectic materialism starring Lysenko, and Hit1er’s retro Norse Aryan nonsense.

      • ptolemy2,

        “Bollocks! Science was created primarily by religious people, confucianist, islamic, christian, hindu.”

        Huh? Confucianists, islamics, or hindus early scientists? Who? When?

        Christian early scientists sure, we all recognize many names of them, but I suspect you’re expanding the definition of the term ‘science’ far beyond what we now think of as science . . including things like math and logic perhaps . .

      • Louis,

        “JohnKnight, what kind of science do you envision existing without math or logic … ?”

        None. When did you stop beating your wife? ; )

      • “Bollocks! Science was created primarily by religious people”

        Everyone was “religious” at that time otherwise you got burnt. The point was logical analysis was supposed to replace the belief based worldview.

        Heroic efforts to replace superstitious beliefs by test and logical validation, born with the age of enlightenment, seem to have degenerated into a new belief system with very similar orthodoxies, high-priests, heretics and witch-hunts.

        Man just seems to prefer that kind of social structure.

      • This statement, posted by Greg, to wit:

        Science was originally created to replace religion

        Is, IMLO, an absolutely, positively factually correct and truthful statement.

        Religious beliefs and practices, ….. with Gods and Goddesses of all sorts and for all things …… were created by the imaginations of early humans, …… to explain the cause of the un-explainables, …… when they were still in the “tribal” phase of their population increases …… which was a long, long time before science was ever created to discredit the aforesaid Gods n’ Goddesses and explain the wonders of the natural world.

        Multitheism was rampant among the early human tribal groups and it persisted in “parts n’ pieces” up to the 1st Century AD, ….. as science kept “killing off” their Gods and Goddesses, one (1) at a time, …. and only monotheism has survived that scientific “slaughter”.

        Cheers

      • The above points are all fair enough, but the point is that the purpose of true science is not a hidden parallel agenda such as killing off religion, or fabricating doom to impose global socialistic eco-totalitarianism or anything else. All these are distorted pseudo-science.

        The purpose of real science is simple child-like curiosity. What causes this? How did that get formed? Science is its own justification, needing nothing other than curiosity.

        Whether people are religious or not has little to do with their practice of science.

        It remains true that the belief systems created with the specific aim of destroying religion include Soviet dialectic materialism starring Lysenko, and Hit1er’s retro Norse Aryan religion.

        Samuel
        Multitheism was rampant among the early human tribal groups and it persisted in “parts n’ pieces” up to the 1st Century AD, ….. as science kept “killing off” their Gods and Goddesses, one (1) at a time, …. and only monotheism has survived that scientific “slaughter”.

        You just made this up without any evidence or examples because there are none. There are two principal types of global religion, pantheist and monotheistic. Pantheism has thousands of gods and the mono’s have one. There is no process of “one by one” pruning of the pantheon in response to scientific discoveries. Do you think practicing Hindu’s spend their time on Google Scholar looking out for titles such as:

        Inductively coupled mass spectroscopic evidence for non-existence of Saraswati
        Simulation of galactic collision trajectories fails to demonstrate a role for Sri Ramachandra
        Existence of Mahabharata disproved by comprehensive mapping of the genome of C. elegans

        Have you published any such papers?

      • So claimith: ptolemy2 – September 26, 2016 at 7:44 am

        Quoting Samuel C: “Multitheism was rampant among the early human tribal groups and it persisted in “parts n’ pieces” up to the 1st Century AD, ….. as science kept “killing off” their Gods and Goddesses, one (1) at a time, …. and only monotheism has survived that scientific “slaughter”.

        You just made this up without any evidence or examples because there are none.

        Fer shame, fer shame, ptolemy2, …… accusing me of dastardly deeds ……. simply because of your pee-poor nurturing and your utterly pathetic education in/of the history of human evolution from their time of being “hunter-gathers” to becoming members of tribes, clans, societies and finally nations.

        Heree ya go, ptolemy2, educate yourself about some of the hundreds and hundreds of different named Gods and Goddesses of yesteryear by “clicking” on the url link at the bottom of this list …. and then “click” the matching “hyperlink” thereon, to wit:

        Lists of Names of Gods and Goddesses for:
         NORSE GODS & GODDESSES
         ROMAN GODS & GODDESSES
         GREEK GODS & GODDESSES
         CELTIC GODS & GODDESSES
         CELTIC DEITIES
         JAPANESE GODS & GODDESSES
         HAWAIIAN GODS & GODDESSES
         POLYNESIAN GODS
         IRISH GODS & GODDESSES
         WELSH GODS & GODDESSES
         GODS & GODDESSES OF WAR
         GODS & GODDESSES OF LOVE & SEXUALITY
         SLAVIC GODS & GODDESSES
         GODS OF PANTHEON
         CHINESE GODS
         GODS OF THUNDER
        Source link for the above links: http://www.lowchensaustralia.com/names/gods.htm

      • Samuel C Cogar
        September 26, 2016 at 4:43 am

        Nothing even remotely like your fractured fairy tale happened.

        Greek science started around 600 BC. The pagan Greek and Roman deities survived for about a thousand years. Meanwhile, Jewish, Mithraist and Zoroastrian (also arguably dualistic) monotheists persisted in pre-scientific thinking. What killed off paganism was the adoption of Christianity as the Roman state religion. Early Christians were far more anti-science than their pagan predecessors had been. Even pagans however felt that heliocentric hypotheses were impious, which is one reason why the Ptolemaic system won favor.

        After about AD 400, the Church found ways to incorporate some elements of pagan science into its doctrine, such that the Ptolemaic system became orthodox despite the biblical flat earth advocated by Early Church Fathers. St. Augustine was as much responsible for this shift as any Christian theologian, arguing in his “On the Literal Interpretation of Genesis” that it was more important to propagate the faith than insist on the literal truth of Bible passages clearly contrary to scientific observation. He worried that educated pagans wouldn’t convert if forced to maintain that the sky was a tent, that stars fell to earth as humanoids, that God walked on the vault of heaven to operate the levers of the storehouses of rain and snow, that He sat on the edge of the earth, looking down on the insect-like people, that the sun and moon pass through doors in the dome of heaven, that earth had four corners, that all of it could be seen from one high place, that animals talk, etc.

        This accommodation with pagan science lasted until Copernicus and Vesalius in 1543, et seq, with conflict especially turbulent in the 17th to 19th centuries. Official Church opposition to heliocentrism ended in 1835 when works advocating it as reality were finally dropped from the Index. But in practice the prohibition was a dead letter from 1820, when a Catholic canon was granted permission to publish a work maintaining that earth goes around the sun as a physical fact rather than mathematical fiction. Heliocentrism had by then already been shown a physical fact by observation in the 18th century. In 1851, Foucault’s pendulum demonstrated the actual rotation of the earth as well, finally vindicating Galileo and other Copernicans over their critics.

      • Samuel

        Now that’s the spirit!

        Wow – if your upbringing and education involved intimacy with all those deities you listed then it was surely a colourful one!

        But Gabro is correct – the monotheistic path was not always the one to scientific enlightenment – until it had no choice.

        For example I live Brahmagupts’s solution to the polynomial quadratic equation which in 628 AD he expressed in prose:

        “To the absolute number multiplied by four times the square, add the square of the middle term; the square root of the same, less the middle term, being divided by twice the square, is the value”

        While having respect for Christian monotheism having been brought up on it, I admire the celebration and thankfulness for life that is at the heart of polytheistic Hinduism, still very much alive today:

        http://petapixel.com/2014/12/13/maha-kumbh-mela-largest-peaceful-gathering-history-world/

      • It seems to me science as established primarily by Christians, is currently under assault primarily by atheists.

      • John,

        In the (at least) 2600 year history of science, there were indeed advances made by nominal Christians (often highly heretical, like Newton) from the mid-16th century to the late 18th to 19th century, along with pagans, Hindus, Buddhists, Confucianists, Taoists, Muslims and Jews. Since then, however, most scientific advances have been made by atheists or agnostics.

        But the Scientific Revolution of c. 1550-1750 took place in a Christian context. But starting in the mid-18th century, scientists were increasingly atheistic to one degree or another. This is perhaps more true early on among geologists and life scientists than physicists, but by the late 19th century, they too joined their colleagues in religious skepticism.

      • Gabro,

        “In the (at least) 2600 year history of science…”

        I’m talking about what is often called modern science, as in what Mr. Newton called “the experimental philosophy”, as in Greg’s comment about “After 400 years…”.

        It seems to me science as established primarily by Christians, is currently under assault primarily by atheists. I think it’s intimately linked to an assault on Western civilization itself, by what are often called “globalists”, who essentially despise the concept of “rule by consent of the governed”.

        I think most here can “see” the assault in something like the heavy duty propaganda for the CAGW, and the SJW stuff now being administered to young folks, but tend to fail to question what they might have been exposed to along the same general lines. They tend to think that whatever pops into their heads came from infallible gods of some sort (if they like it ; )

      • So claimith: Gabro – September 26, 2016 at 10:07 am

        Directed at Sam C:

        Nothing even remotely like your fractured fairy tale happened.

        Greek science started around 600 BC.

        Gabo, who the hell cares what the Greeks were doing in 600 BC given the fact that they were being educated in the science of the Sumerians and Babylonians that originated nigh onto 3,000 years earlier (3500 BC). To wit:

        Mesopotamia had already enjoyed a long history prior to the emergence of Babylon, with Sumerian civilisation emerging in the region c. 3500 BC,

        The earliest mention of the city of Babylon can be found in a clay tablet from the reign of Sargon of Akkad (2334–2279 BC), dating back to the 23rd century BC. Babylon was merely a religious and cultural centre at this point and neither an independent state nor a large city;

        Babylonian astronomy was the basis for much of what was done in ancient Greek astronomy, in classical Indian astronomy, in Sasanian, Byzantine and Syrian astronomy, astronomy in the medieval Islamic world, and in Central Asian and Western European astronomy.[17] Neo-Babylonian astronomy can thus be considered the direct predecessor of much of ancient Greek mathematics and astronomy, which in turn is the historical predecessor of the European (Western) scientific revolution.[29]

        Source: https://en.wikipedia.org/wiki/Babylonia

        And Gabor, if science emerged in Babylonia like 5,500 BP ….. that would still be, at the very least, 7,500 year after Religious beliefs and their Gods and Goddesses were being worshiped by ancient humans.

        And Gabor, as far as anyone knows at present, the World’s First Religious Temple is located at Gobekli Tepe ……… a pre-historic site, about 15 km away from the city of Sanliurfa, Southeastern Turkiye. What makes Gobekl tepe unique in its class is the date it was built, which is roughly twelve thousand years ago (12,000 BP) circa 10,000 BC.

        The site isn’t just old, it redefines old: the temple was built 11,500 BP—a staggering 7,000 years before the Great Pyramid, and more than 6,000 years before Stonehenge first took shape.

        Carbon-dating shows that the Gobekli Tepe complex is at least 12,000 years old, maybe even 13,000 years old.
        Source reference and excerpted text @ http://gobeklitepe.info/

        And as a side note, the Great Pyramid of Giza is far, far older than 3,000 years and was not constructed by the Egyptians.

        Gabor, you have been seriously miseducated on the evolution of Homo sapiens sapiens …. and now it has become obvious that you have been seriously miseducated on the origin of scientific beliefs verses religious beliefs.

      • John,

        The fact is that science as practiced now is largely by atheists. Far from being under assault by atheists, modern science is atheistic. As well is should be. The whole point is to find rational, natural explanations for observations of nature, not to make up stories to explain phenomena such as the rainbow, which in the Bible is a reminder of the non-existent global flood rather than a result of the refraction of light. The Bible is entirely pre-scientific, even the New Testament, which is remarkable, given the advances in pagan science by the first century AD.

        Samuel C Cogar
        September 26, 2016 at 5:11 pm

        Your alternative archaeology is laughable. Sorry, but there it is. There is not a shred of evidence that the Giza pyramids are older than about 4600 years, not the 3000 you so erroneously suggest, along with your easily shown false assertion that the Egyptians didn’t build them.

        That humans evolved from smaller, bipedal African apes is a fact, readily demonstrated by genetics, paleontology, anatomy, embryology, biogeography and every other possible source of evidence. That you disagree with science says everything we need to know about you and nothing at all about the overwhelming, incontrovertible evidence.

        I don’t know why our gracious host is so gracious that anti-scientific garbage such as yours is permitted here. It only gives ammo to climate alarmists.

      • Science wasn’t created to replace religion.
        Many early “scientists” were religious.
        Copernicus was a Dominican but fortunately or unfortunately, depending on your perspective, with an enquiring mind.
        He recognised problems with Ptomelaic astronomy and developed a system that better explained planetary movements, the heliocentric system.
        Copernicus had no intention of challenging religion and the church took 60 years before it took any official action against what became known as Copercanism

      • Greg,

        Copernicus wasn’t a Dominican. He was a church canon, very much involved in secular issues. His equivalent for the life sciences, Vesalius, was an imperial physician, so not a churchman, but presumably a faithful Catholic. There has been some suggestion that he was persecuted for diverging from the ancient authority of Galen, and died therefrom, but I’m dubious.

      • Well Religion arose from primitive science. A witch doctor who figured out that the sun and moon followed some more or less repeated paths, and was able to guess what a solar eclipse actually was, could take advantage of that discovery to press the masses to do his bidding.

        I’m not suggesting (S)he predicted the eclipse, but once it began it clicked what must be happening.

        G

      • Greg,

        I should add that Copernicus knew that his beliefs that the earth moves and goes around the sun ran contrary to Church doctrine, which explains why he waited 36 years before publishing his theory. And then only at the instigation of a Protestant pupil and from a Lutheran press. And at literally the very end of his life.

      • george e. smith
        September 26, 2016 at 6:03 pm

        Science arose from a change in mindset from prescientific to scientific. The prescientific mind, as in the Bible, makes up stories to explain observed phenomena. The scientific mindset tries to come up with naturalistic explanations of observed phenomena, based upon evidence and reason therefrom.

        In the Bible, God walks upon the vault of heaven, opening and closing the windows of the storehouses of rain and snow. In science, there is the hydrological cycle, with condensation and freezing under different temperature regimes.

        For instance.

      • Readers, please note how Gabro speaks in terms of science as a “consensus” affair;

        “The fact is that science as practiced now is largely by atheists. Far from being under assault by atheists, modern science is atheistic. ”

        Sound familiar? A group of people decided their belief that there is no Creator, is as scientific fact, to the point of excluding any consideration of the potential that there is. Just decided that . . sound familiar, climate deniers ; )

        It’s the same con, I say, employing the same techniques of proclaiming stuff as absolute truth, and using ridicule and exclusion for the same reasons, by people who are experts at conning others. That ain’t the scientific method. it’s gangnam style ; )

      • Gabro – September 26, 2016 at 5:45 pm

        Samuel C Cogar,

        Your alternative archaeology is laughable. Sorry, but there it is.

        “HA”, it is an inherited female emotional attribute to “laugh” when confronted with “the truth” about something that they had been adamantly denying.

        There is not a shred of evidence that the Giza pyramids are older than about 4600 years, not the 3000 you so erroneously suggest, along with your easily shown false assertion that the Egyptians didn’t build them.

        Try again, Gabro, ….. your dastardly deceptive comment, as noted above, is quite revealing about your personality flaws and your “win-at-all-cost” attitude.

        Gabro, I made no mention whatsoever pertaining to (inclusively) “the Giza pyramids” of which there are several of them, ……. with the majority of them most likely constructed by the Egyptians.

        So, Gabro, this time, you be sure to CORRECTLY read my writing, which I will state that, ….. it is absolutely, positively an unquestionable FACT that the Egyptians DID NOT construct The Great Pyramid of Giza …… simply because historical facts tell us that none of the Egyptian Dynasties possessed the mathematics, tools or the technology required for said construction.

        Common sense thinking, logical reasoning, intelligent deductions and knowledge of the Great Pyramid’s past and present physical attributes is all that one needs to prove that it was not constructed by mandate of an Egyptian Pharaoh and that it is therefore far, far, FAR older than 3,000 BC (5,000 BP).

        First of all, ….. Gabro, …… there was never an Egyptian Pharaoh that mandated the constructing of an “edifice” of any size or shape that DIDN’T HAVE his/her “name & picture” plastered(sic) all over both the outside and inside of said “edifice” ……. and that aforesaid “signature” does not and never did exist anywhere on or inside the Great Pyramid.

        And 2ndly, ….. Gabro, ……which you apparently are not knowledgeable of, is the FACT that the The Great Pyramid of Giza was ORIGINALLY covered with pure white limestone “casing stones”, ……. all four (4) sides, … top to bottom, …… a perfectly flat, unblemished surface without any doors or portals for entry into the interior.

        Given said, Gabro, …….. excluding the million+ “sandstone” block construction of the basic structure, ………. the tools and technology REQUIRED just for the “cutting & installing” of the required thousands of “casing stones” …… is what the Egyptians did not have and therefore they could not possibly have constructed the The Great Pyramid of Giza.

        Gabro, and I am sure that you don’t, and/or WON’T admit to believing, any of what I have told you, …. so, ….. I suggest that you ask one of your knowledgeable peer Professors to explain to you the “problems” associated with installing said “casing stones” on the “jagged” sides of the Great Pyramid. And I didn ‘t mean a peer Professor of English Literature, Geography, Music or Gymnastics.

        That humans evolved from smaller, bipedal African apes is a fact.

        “Wrong”, Gabro, …. the above statement of yours is an ASSUMED fact, nothing more, ….. simply because there has never been any fossil evidence found that DIRECTLY links our early ancestor species with another hominid species. And you damn well should know that.

        That you disagree with science says everything we need to know about you ….

        “Horsefeathers”, Gabro, that was a dastardly devious accusation meant to defame my good name and reputation. I never disagree with factual science, ….. but, more often than not, I disagree with the “consensus of opinions”, such as you have been touting, that defines what said opinionated persons claim as being “factual science”, …… such as your beloved Savannah Theory as well as your beloved CAGW Theory.

        I don’t know why our gracious host is so gracious that anti-scientific garbage such as yours is permitted here. It only gives ammo to climate alarmists.

        Gabro, you really need to be staring into a mirror, at yourself, when you utter the above thoughts.

    • @ JohnKnight – September 26, 2016 at 6:24 pm

      Readers, please note how Gabro speaks in terms of science as a “consensus” affair;

      JohnK, me thinks he/she is forced to “speak in said terms” simply because he/she is employed in and by one (1) of the many “socialist thinking” liberal controlled Institutions of Learning …. and any employee that doesn’t abide by their rules and teach the students their “consensus” determined junk-science ….. will likely be out on their arse at the start of the next semester.

      Gabro refuses to admit to the existence of Gobekli Tepe …… and ignores the fact that Charles Darwin was a Christian Religion believing scientist until he went cruising on the Beagle to the South Seas.

  8. It seems like a pretty large amount of extrapolation to make this level of conclusion from a handful of moon rocks, especially given the level of bombardment the moon has had from other celestial bodies over the eons. I’d be a lot more circumspect rather than announcing it as such a certain conclusion.

  9. … But planetary bodies that formed in different parts of the solar system generally have different isotopic compositions, so different that the isotopic signatures serve as “fingerprints” for planets and meteorites from the same body.

    The probability that the impactor just happened to have the same isotopic signature as the Earth was vanishingly small….

    Ok….I understand that different parts of the Solar System – that is, different distances out from the Sun – are going to be associated with different chemistries. Presumably due to the system acting like a centrifuge? So objects which form in Saturn’s orbit will have different isotopes to objects forming in Venus’s orbit.

    But I understand that Theia (the name given to the Earth impactor) was formed essentially in the SAME orbit as Earth, and consequently eventually collided with it. So you would expect the chemistries to be practically identical anyway…

  10. You always misspell the possessive pronoun its, Anthony. There is no apostrophe in the pronoun its. “It’s” is the contracted form of “it is”.

    [It’s dat a prolbem? .mod]

    • Yep,
      It’ S a problem for all authors seeking accuracy where possible, as these scientists writing about moon isotopes are. Minute deviations are important.
      The automatic spell check on this Acer tablet inserts the wrong “it’s” so I sympathise, or sympathize.
      Geoff.

      • We Don’t do Typology here; unless the episode is comical enough to all have a good laugh at.

        If you can figure out why it is rong, it stands to reason that you must have understood what the transgressor meant anyhow; so just be happy that you are one of the ones who can figure out what was ment.

        G

      • Sorry to disagree, but you can kill people if you spell “inulin” where “insulin” was meant. You can get an orbiting telescope mirror focal length wrong with small errors of conversion from one number set to another as in decimal and metric. You can have a wrong and ineffective stereoisomer if you mix your alphas and betas. There are many scientific activities where near enough is not good enough. If you carry that standard through to everyday spelling, you create a good mental discipline.
        Papers with crass spelling errors are a turn off to the person seeking quality.
        Geoff.

      • Well I don’t mind if people worry more about spelling than about science or other things.

        So just what sort of a drug is ” Inulin ” and what is it used to treat ??

        Just in case, I should ever need a shot of Inulin, and want to be sure they have spelled it correctly.

        I guess one should be careful to check what country one is in, because different people who all speak the same language, spell the same words in entirely different ways, so you could do the wrong thing, if you don’t know what country you are in.

        Even in the same country, you might encounter a given word spelled correctly (in that area) but differently from some other place.

        For example, nobody in California, would have any idea what to do about a drouth or proper behavior in its presence.

        They won’t even know what you a talking about when you say the word; which is ” drouth ” and would sound rhyming with ” mouth “.

        Who the hell would even suspect that those Missourians were talking about a drought ?

        So Geoff, just remember that WUWT is attended by people from all over the world, and they might be horrified, if we get our Umlauts over the wrong letter, and forget to capitalize a word just because it is a noun.

        And don’t let the French bawl you out for getting your ” Y s ” and your ” Z s ” confused. Excuse me, I meant “confused”

  11. So another model, proposed in 2015, assumes the impact was extremely violent, so violent that the impactor and Earth’s mantle vaporized and mixed together to form a dense melt/vapor mantle atmosphere that expanded to fill a space more than 500 times bigger than today’s Earth. As this atmosphere cooled, the Moon condensed from it.

    Were both vaporized? Text says impactor and Earth’s mantle. So part of earth was still there. Why then did not just one planet condense onto the part that remained? Was there a 2nd big lump that is now the core of the Moon?

    ” sledgehammer hitting a watermelon” — Doesn’t work for me. Many pieces, no vapor. Try it.

    • The impact had to have been off center, otherwise there’s no force to give the expelled fragments the angular momentum necessary to go into orbit rather than just fall back.

      • Even a dead center of mass head on can transmit angular momentum, if one of the bodies is spinning , or both spinning for that matter.

        G

  12. Interesting, of course this is the useful use of modeling to allow speculation about the REAL physical world and then compare it to actual empirical evidence. So long as you aren’t being deceived by artifacts in the math our comprehension of the cosmos progresses. The model doesn’t “prove” anything in and of itself.

  13. Potassium has three stable isotopes, but only two of them, potassium-41 and potassium-39, are abundant enough to be measured with sufficient precision for this study.

    I smell a rat. Potassium only has two stable isotopes K-41 and K-39.

    They should write a paper about the new stable Potassium isotope they’ve discovered.

    (Hint: it ain’t K-40; half life 1.2519 billion years)

  14. Nobody knows how many collisions constituted the aggregation and eventual separation of the earth and the moon.

    My mother made a Christmas fruitcake and a pound cake. On new year’s eve she chopped them up and poured a sauce on the mixture, which was yummy.

    The next day, after my visceral chemistry, I could not discriminate between the the flour and baking powder of which ever cake in my p00p. (not that I actually looked) ;)

    • “In today’s science, it’s “cosmic accidents” all the way down”

      Heh heh. That reminds me of a story Lawrence Krauss told about Richard Feynman and coincidence in general:

      BTW, the whole talk is fascinating, if you have the time.

    • No, it isn’t accidents all the way down.

      It is I guess an accident that we just happen to live at a time in which the moon just covers the sun. The moon has been receding from earth since its formation. Earlier it was much larger in our sky and in future will be much smaller. Its rate of recession has now been measured with great precision.

      No need for divine intervention to explain this “accident”.

      • Accidents are things that happen after a long period of being impossible (so they didn’t happen) when they finally be come possible, they happen immediately so nobody knew it was going to happen.

        Well the system also didn’t know it was going to happen. it just knew that before hand it wasn’t possible so it didn’t happen (yet).

        G

  15. From my admittedly extremely amateurish views of the moon using a Mark I eyeball, there are a lot of impact craters visible.

    What effect have these made to the moon’s surface composition and one would expect that the causal meteorites also hit the Earth in larger numbers due to their relative sizes?

    (Confession – I have not read the paper)

    • Nothing wrong with using the Mk I Eyeball for making observations, of all types. Why, I have used mine for many activities from the serious to the frivolous. Unfortunately, I am going to have to submit mine to the repair depot for additional optics fairly soon. My Mk I Eyeballs have aged over the years of continual use and are no longer capable of making the clear and precise observations I am accustomed too.

  16. This shows why we should spend some time on the moon exploring it more thoroughly. A manned expedition would bring home all manor of material, both from the service and underground, to be analyzed now and in the future.

  17. This was very strange. Numerical simulations of the impact predicted that most of the material (60-80 percent) that coalesced into the Moon came from the impactor rather than from Earth

    I had to laugh at this. the leading hypotheses came from numerical simulations. At least they are taking into account contrary evidence in this field of science

    • These simulations only had to calculate gravity. Admittedly, they had to calculate the affect of 100’s of thousands of objects. But still it’s a single simple equation for each pair of objects. ( A really, really complex problem, but solvable if you are willing to wait long enough.)
      Which makes it a radically different problem compared to the climate in which neither the major factors, nor the equations controlling them are all that well known.

  18. This is pretty cool stuff. It’s likely we’ll never know for sure, we can’t time travel, yet. But, until we do a heck of a lot more exploration of the moon and gather a lot more data it’ll remain a plausible theory, and nothing more. Still, pretty cool stuff.

    • I’d be afraid to send anything back to look. From current theories, it looks like it was far from a sure thing that our solar system would end up as friendly to life as ours is. Even a small perturbation, over 4+ billion years could result in a big change today.

  19. But higher pressure would suppress fractionation, Wang said. For this reason, he and his colleague predict the Moon condensed in a pressure of more than 10 bar, or roughly 10 times the sea level atmospheric pressure on Earth.

    I have problems with this theory based upon the above quote. Here are my questions:
    The hypothesis is that we have “supercritical-fluid” silicates at 10+ bar and sufficiently high temperature to be above the critical point …. at an earth radii in the vicinity of the moon.

    1. How much energy is required to vaporize all that mantle and impactor? (note, the earth’s mantle was already hot and under thousands of atmospheres of pressure at initial conditions — it probably matters.)

    2. Does that much energy exist in the collision of two planetary masses coming together at, say 15-18 km per sec? We aren’t talking about the energy to fling a mass as large as the moon to near earth escape velocity. No. We need that much energy PLUS the energy to vaporize that mass to the point of supercritical-fluid and 10bar at the radii of the moon.
    2a — what lunar formation radii is compatible with this theory. It would be much closer to the earth than the moon is today. But how close CAN it be for the condensation to work?

    3. Suppose you got an ‘atmosphere’ of silicates at that temperature and pressure. Wouldn’t a large bulk of the mass reach escape velocity from thermodynamics alone?

    4. If things were that hot and gaseous, how is it the earth has any light elements at all? These elements would preferentially escape gravity. (see Q3 above).

    • Addendum: Why 15-18 km per sec?
      Earth escape velocity is about 11.5 km per sec. So any body striking earth would have that speed as a minimum. A smaller body (the impactor) would have it’s own escape speed and would add to that 11.5.

      The earth’s velocity around the sun is 30 km per sec. So it is theoretically possible to have a head on collision (60 km/sec) , but that would require the impactor to be in retrograde motion. A more realistic assumption is that the impactor is moving roughly in the same direction around the sun as Earth, but the orbits chaotically intersected at some point. In this case, the differences in orbital speeds are small and the impact speed is govern by mutual gravitation.

      Another possibility, I suppose, is that the impactor was in a cometary orbit. In which case the collision speed would be in the 40-55 km/sec range. But then wouldn’t post collision gravitational capture be most unlikely?

      • The earth as we know has an almost circular orbit. A major collision with an object in a cometary orbit would have significantly perturbed the earth’s orbit, making it much less circular.

      • Good answer, MarkW. But wouldn’t 4 billion years of orbital resonances circularize the orbit?

        It does beg the question of why Mercury’s orbit is so elliptical. Was it hit by something comparatively big and fast?

    • Answer to 2a: There is a table -in Wikipedia [Roche limit (fluid)] which states the Roche limit for a comet sized body with a “fluidized” rather than solid composition is greater than 34,000 km. Since the theory is that the Moon condensed out of an atmosphere, it started out small and grew. Therefore by this theory, the moon had to condense at a radius of at least 34,000 km. Geosynchronous orbits are at 42,164 km.

      From this Delta-V chart of the solar system: https://i.imgur.com/WGOy3qT.png
      it seems that the energy to reach geosynchronous is about 90% of the energy to reach escape velocity. So the fluid Roche-limit must be 80-85% of escape velocity.

      To me that is too little margin for error for the “high-impact” supercritical fluid theory. You must get matter beyond the fluid Roche radius, but give it 20% more and the matter escapes into space. That theory won’t hunt.

      The Roche radius is smaller ( under 19,000 km) if you start with solid cores around which ejecta can accumulate. But that is the Scenario 1 and the magma disk.

      • We aren’t launching a single body to a single orbit.

        I would presume that a non-trivial amount of matter was given enough energy to reach escape velocity.
        There was a lot of matter that was given little enough energy that it fell back to earth over the next few centuries.
        Other matter that was given energy to reach orbits both higher and lower than the moons were eventually pulled into the forming moon. Other objects had their orbits perturbed enough so that they were either ejected from the earth/moon system, or fell back to the earth.

      • @MarkW. Yes, I agree with all that, but the argument applies to both the subject scenarios, and on balance applies to Scenario 1 more than Scenario 2. I prefer Scenario 1 since I don’t have to vaporize all the rock. — I just have to “launch” and scatter it into obit.

    • Re point 2. The Moon has been moving outward due to tidal orbital decay, so it is much further out now than it was billions of years ago. By the same mechanism, Earth is rotating considerably slower. A much faster rotating Earth means the the geosynchronous orbital distance would have been much closer in. We know that the Moon formed outside the then geosynchronous orbital distance, because that is a requirement of tidal orbital decay moving it outward, if it had been inside the distance, the Moon would have been pulled inward.

      • @LarryD — The moon had to form above the geosynchronous orbit (at the faster early Earth rate) or tidal friction would have worked in reverse, causing the moon to slow down and fall closer to the earth and eventually cross the Roche limit and break up.

        My main point about Geosynchronous orbits was to compare the Roche (cometary fluid) radius of 38,000 km to a known orbit (42,164 km) with known energy levels compared to escape velocity. Geosynchronous orbit was used for an energy benchmark.

  20. Measurements of an element in Earth and Moon rocks…

    First you have to assume those moon rocks actually came from the moon…

    • … and then you have to assume for this purpose that a sample of seven rocks a few hundred rocks scooped up from the surface at only six clusters, that is manned landing locations that were practically accessible (1), is an adequate representation of what the moon is made of.

      (1) Crater Tycho for instance was considered for a landing site, but the orbit and lunar lander flight path was judged risky and used too much fuel and weight. Tycho was kept on the list for the last “J” mission, probably Apollo 20.

  21. Has anyone ever wondered why the moon’s craters are so uniform in depth? That always seemed strange to me.

    • I have wondered about that as well but if all these impacts happen all in the same time frame ( a short geological time frame) so they would have hit when the surface of the moon would have reacted the same for each impact. I would compare it to something hitting a soft surface but a few “days” later that same surface would be “frozen” and so react differently, does that make sense?

      • Nonsense on stilts. I gave up when they declared that a single rock could conclusively prove that the entire moon had been bombarded at various times in it’s history.
        A single rock would record local impacts, and that’s all.
        PS: A grand total of nobody has ever claimed that Jupiter and Saturn combined to eject another large body from the solar system.

  22. Sorry gotta go…hit run or drive by as someone refers to my posts like this. But impactors can be fun…

    “”The moon is not round—it is shaped like an egg. e

    The volume of Earth’s moon is the same as the volume of the Pacific Ocean. e

    e Graham, Ian. 1999. The Best Book of the Moon. New York, NY: Kingfisher Chambers Inc.””

    http://facts.randomhistory.com/moon-facts.html

    • The volume of Earth’s moon is the same as the volume of the Pacific Ocean
      No.
      The area of the moon is less than that of the Pacific Ocean. About 1/4 the area.
      But the volume of the moon is about 30 time bigger than the volume of the Pacific. The Pacific is on average only 4 km deep.

      In fact, all the worlds oceans make up only about 1/16 of the moon’s volume.

    • We don’t even know where nor if there were continents prior to an impact of this magnitude. Comparing modern earth features to some imaginary impact and imaginary earth long ago doesn’t seem like science. I have to admit being previously impressed by the Pacific Ocean/Moon conjecture forty years ago or so, but it makes little sense now.

      • Even if they earth had continents at that early date, it wouldn’t have mattered since the impact would have completely melted the earth’s surface.

  23. The most pertinent comment above is whether 7 lunar rocks is sufficient sample size to conclude they represent the make up of the entire moon. Not very convincing in my book. Same for the Earth samples.

  24. The observation that “planetary bodies that formed in different parts of the solar system generally have different isotopic compositions” is quite reasonable, given that the entire solar system condensed from the plasma cloud formed in a nova. The similarity of the isotopic compositions of the proto-earth and Theia could be accounted for if they both formed at about the distance from the sun – co-orbitally. A co-orbital origin would also account for the relatively low kinetic energy of the impact required to leave the present earth-moon system rather than a belt of shattered planetoids.

  25. Roche Limit: “The shortest distance at which a satellite not held together by any force other than its own gravity can orbit another celestial body without being torn apart by the tidal force between them. The distance depends on the densities of the two bodies and the orbit of the satellite. If the satellite and the object are of similar densities, the Roche limit is about two and a half times the radius of the larger object. Since most natural satellites are rigid bodies, their tensile strength allows them to orbit much closer than their Roche limit; however, rigid bodies too may be broken up by tidal forces.”

    Small particles can form inside the Roche Limit, as atoms form molecules and molecules bind to one another, the Roche Limit just imposes a size limit on the particles. If tidal friction moves the cloud of particles outward, then they can aggregate to form a moon, after they move outside the Roche Limit.

    Using the rule of thumb and Earth’s current radius (6,371 km), the Roche Limit is somewhat over 15,000 km (from Earth’s center, or over 9,000 km from the surface).

    The hardest part of the new theory to swallow is the 10 bar extended silicate atmosphere.

    • I would imagine that the size of the object would impact the Roche limit. After all, the larger the object, the greater the gravitational difference between the inner most and outer most points of the object.
      As an example, we have quite a few satellites that orbit only about 100 miles or so up, yet they aren’t being torn apart.

    • The Roche limit of a two body problem is dependent upon the primary mass and the mass and composition of the secondary. The greater the mass of the secondary the smaller will be the Roche limit of the pair because the secondary has its own greater mass to hold itself together.

      The Scenario 2 discussed in the main paper, is the absolute worst case (largest value) for the Roche limit. The secondary must start out as a greater-than-average density cloud in the “silicate atmosphere”. Therefore the fluid Roche limit should be used, greater than 38,000 km for the (current) mass of the Earth. The seed of the Moon in this scenario is a cloud with no tensile strength and weak gravity.

      Earth satellites hold together because they have high tensile strength. But should a satellite split in two, like a tethered satellite, the two parts will separate. The miniscule mutual gravitation of the two parts are no match for the tidal forces of Low Earth Orbit.

    • @LarryD, Yes, the 10 bar silicate atmosphere at the radius consistent with a fluid Roche limit is very hard to swallow. But let’s suppose we do swallow it: 10 bar silicate atmo (at greater than 3000+ degrees C). What should be the pressure curve as a function of Earth radius? I think you would be forced to have many thousands of bar (at an incredible temperature!) will above the current surface of the earth. There isn’t that much mass available in our current Earth – Moon system. Scenario 2 has far too many problems compared to Scenario 1.

  26. We have 4B yrs (proto-earth) of the same meteoritic material raining down on both bodies and likely bombardment of
    a large amount bolides in the early years. The surface samples taken by astronauts represent this material. Why would we be surprised they had similar geochemistry? S’Truth! As a mining exploration geologist, I’d be fired for a sampling job like this?

  27. Bodies have different isotopic ratios if they form at different distances from the sun. If the body that collided with the earth formed in a similar orbit as did the earth, than it’s isotopic rations would be very nearly identical.

  28. My favorite hypothesis about how the Moon formed was as the result of a massive fission explosion that blew out one side of the planet, leaving a hole that eventually filled in with ocean, the resulting crustal fractures on the opposite side of the planet kicked off plate tectonics,brought some heavier elements closer to the surface and it left the Moon in its wake. In effect, the Earth is the remnants of a very short lived fission star.

    4.5 B years ago, the U235/U238 ratio was at least 3-4% which as it was separated by gravity in the core to become a shell of U235 surrounding a core of U238 and lead and this shell went critical.

    An interesting feature of this hypothesis is that its far more likely to occur than the extremely precise collision otherwise required, which means that there are likely to be many other planets in the Universe that have a similar moon.

    • An explosion of sufficient magnitude to launch an object the size of the moon into an orbit out past the Roche limit, would have completely shattered the rest of the planet, leaving just an expanding cloud of debris in it’s wake.

      • Markw,

        “leaving just an expanding cloud of debris”

        This is more or less what the article says happened, except that the cloud was gaseous although gravity will surely pull it back together. If the explosion was uniform, you can envision the surface expanding outwards and collapsing back in without forming a Moon, which is a possibility for what happened on Venus when its U235/U238 ratio was high enough for gravity to induce fission. An asymmetric explosion would blow out only one side of the planet and that could be what happened on Earth.

      • First off, I said expanding. The violence of the explosion would have been sufficient to give the remaining particles enough energy to escape the mutual gravitation.

    • PS: You don’t need to fracture the crust in order to get plate tectonics started.
      Secondly, how do you get those radioactive elements close enough together to create the explosion.
      In the real world, as those elements got closer together over thousands to 10’s of thousands of years, the rate of decay would gradually increase, as the rate of neutron bombardment very gradually increased.
      As a result, even as concentration increased due to some mythical forces, the concentration was decreasing due to the interaction of the uranium atoms.
      The end result is an increase in heat, but no boom. Despite what Ivanova says, there is not always a boom.

      • “Secondly, how do you get those radioactive elements close enough together to create the explosion.”

        Gravitational separation, similar to the way that a centrifuge works.

        “due to some mythical forces,”

        Gravity is not a mystery.

        “the rate of decay would gradually increase, as the rate of neutron bombardment very gradually increased.”

        Once neutron bombardment gets high enough, it’s the definition of going critical.

      • First off, gravity would take millions of years to concentrate the uranium sufficiently. And that’s without convection constantly keeping things stirred up.

        Due to the time it takes to concentrate, neutron bombardment will never get high enough to create an explosion. As I explained earlier, when the concentration proceeds slowly, the gradual increase in neutron bombardment burns off the uranium long, long before it can reach critical mass.
        If an atomic bomb took 100 years to bring the masses together, and the two masses in this case is pretty close to 100% pure, the bomb would never explode. It would be pure lead long before the two masses got close enough.

      • “neutron bombardment will never get high enough to create an explosion”

        You need to reassess this in light of a much higher primordial U235/U238 ratio, which would even be far larger than a few percent if the primordial U235 was also being consumed at a significantly faster rate then it would ordinarily decay at its half life of about 700M years. It’s also quite possible that an ordinary impact event could have been the trigger as a shock wave from a surface impact passes through the core.

      • Doesn’t matter. It can’t get together fast enough to reach critical mass. EVER.
        Unless you can figure out a way to concentrate all of the unstable U isotopes in a small area, IE no more than 100 feet across, and do it in a matter of minutes, you will not be able to reach critical mass.
        That reminds me. Merely have more uranium is meaningless if you can’t seperate the fissionable isotopes from the non-fissionable ones. Gravity isn’t going to do it. The difference in mass is way, way, way to small.
        The best you could ever hope for is a bit more heat than might otherwise have been generated.

      • I agree with you, Mark.

        The force of gravity gets smaller and smaller as you approach to core. It is for this reason I am not a fan of convection as the primary driver of plate tectonics. I am a [“Slab Pull” with “Ridge Push” assistance] adherent. I think it best explains the formation of back-arc island chains, horst-graben landscapes, and continental rifting and volcanic chains.

        I do like the low-level core fission model. Fission must be going on in the core, if even at very low activity levels. The question is how much of the core’s heat generation is by
        A) radio-active decay of the primordial soup material,
        B) how much is direct fission energy release, and
        C) how much is radio-active decay of fission daughter products?
        None of these quantities are zero, but are B and C significant compared to A?

        What really attracts me to the core fission model is it provides a way for the earth to have a NON_CONSTANT, oscillating radius over geologic time scales. I’m no “Expanding Earther”, but a radius that oscillates one part in 3000 over a period of 10,000 years helps the mechanism of plate tectonics immensely.

        Early on in the Manhattan Project, the reactor physicists got a nasty surprise when their first plutonium breeder reactor at Hanford went into unexpected oscillation. Fission daughter products were poisoning the reactor. Some of these poisons had half-lives in the units of hours or days. So once the reactor created the daughters, it dropped in intensity until the poisons dropped below a threshold, then the reactor would spin up again. They solved the problem by putting more U-235 in the reactor than originally designed by the physicists. The reactor design engineers had allowed for more uranium because they new the physicists were guessing at a lot of the specs since it had never been done before.

        Those reactor poisons would also exist in any core fission reaction. Given the immense size of the core that could participate in fission (hundreds of miles in diameter), the concentration of poison products could vary over a long time. So, it become possible for the fission in the core to be non-constant. It follows, then that the temperature of the core would oscillate with the rate of fission. If the temperature of the core oscillates, then the radius of the earth would oscillate, too, from thermal expansion.

        The radius of the earth wouldn’t have to change much…. maybe one part in 5000 over the span of 10,000 years. But what would that buy you? It give a circumference of the earth that is not constant, expanding and contracting over a geologic time scale. This give us a ratchet mechanism to initiate and perpetuate plate tectonics via rifting (during expansion) and subduction (during contraction) in addition to the other proposed tectonic forces.

        The test of this theory can come from geoneutrino experiments and discovery that their detection level changes over decades.

  29. I think WUWT commenters have collectively given a better context to the serious doubt one should read such reports with. Question is – how much should the tax payer be contributing to these science fiction/fantasy essaying scientits? – oops typo, but, wait a minute, perhaps not… :)

  30. I think Pluto and Charon are an excellent example to take notice of in moon creation theory. They act as two bodies circling a central point between them. It could be a death spiral that would lead them to smash into each other or they could be an example of how similar, yet different bodies can attract one another from within the same orbital path.
    What bothers me about the cosmic marble game theory is the exacting conditions that needed to occur to produce the required results. The universe is chaotic, not exacting. We took our moon rocks from impact sites. We have yet to see much of anything below the surface of the bombardment debris. Even the recent detonation to search for water possibilities only managed to stir up surface dust. I’m glad their model is working for them but its reality may not necessarily be what actually occurred. We learn more by sending out probes then we ever do by modeling anything. I have an old science book where they set out Saturn’s ring composition and how they formed… one fly by and all of that was proved to be the flight of imagination that it was. I suspect this will be much the same.

  31. Saturn’s rings are maintained by something, EM maybe, that is patently obvious. To uniform and undisturbed to be “gravity” alone

  32. Earth may have just captured the moon from another body in the past. While you’re theory can disprove another theory, no one can prove their own theory on the moon.

    • First off, the fact that the material that the moon and the earth are made of is nearly identical is solid evidence that the moon did not form in another part of the solar system.
      Secondly, it’s impossible for the earth to have captured the moon without the help of a third body to siphon off enough of the moon’s momentum so that it could be captured.

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