Origin of the Moon: New evidence in old rocks for Lunar impact theory

Guest “wishing I could have been Jack Schmitt” by David Middleton

Earth Rocks and Moon Rocks Are More Different Than We Thought
New analyses of oxygen isotopes reveal terrestrial and lunar rocks aren’t as similar as previously thought, potentially changing the way we think the Moon formed.

By Javier Barbuzano

One of the most important scientific outcomes of the Apollo program was giving scientists the opportunity to explain our Moon’s origins.

Geochemical analysis of the Apollo lunar samples suggested that our Moon was formed 4.5 billion years ago, when a Mars-sized body known as Theia hit Earth when our planet had almost completely formed. Computer models indicate that in this “big splat,” most of the material that ended up forming the Moon—between 70% and 90% of the satellite’s composition—came from Theia.

Although most planetary scientists think the giant impact actually happened, evidence of Theia has been hard to find. Lab measurements of the isotopic ratios of multiple elements such as oxygen have found that Earth and the Moon are virtually indistinguishable. They couldn’t find a trace of Theia’s chemical signature.

[…]

A New Way of Looking at Lunar Rocks

Now a group of researchers has finally detected oxygen isotope differences between terrestrial and lunar rocks, something that could ease constraints when creating lunar formation models and rule out some of the most extreme scenarios.

Erik Cano, a graduate student at the University of New Mexico in Albuquerque, and his colleagues conducted new high-precision measurements of the oxygen isotope compositions of a variety of lunar samples from the Apollo missions. Although rock that formed near the lunar surface appeared to have an oxygen isotope composition identical to that of Earth rocks, rock types that formed deeper in the lunar mantle, such as volcanic glass and basalts, had a distinct isotopic composition. The new work, which originated as part of Cano’s master’s thesis, was published online on 9 March in Nature Geoscience.

[…]

Eos

This phrase doesn’t make any sense… “rock types that formed deeper in the lunar mantle, such as volcanic glass and basalts”… Volcanic glass and basalt form at the surface from rapidly cooling lava. The author has an MS in science journalism, so he may not have understood what he read or was told.

However, this article makes more sense…

We May Have Finally Found a Chunk of Theia Buried Deep Inside The Moon
MICHELLE STARR 9 MARCH 2020

[…]

Planetary scientist Erick Cano and colleagues went a different route: a careful reanalysis of the lunar samples.

They acquired a range of samples from different rock types gathered on the Moon – both high- and low-titanium basalts from the lunar mariaanorthosites from the highlands, and norites from the depths, brought upwards during a process called lunar mantle overturn; and volcanic glass.

[…]

For the new analysis, the research team modified a standard isotope analysis technique to produce high-precision oxygen isotope measurements. And they found something new indeed: that oxygen isotopic composition varied depending on the type of rock tested.

“We show,” they wrote in their paper, “that the method of averaging together lunar isotope data while ignoring lithological differences does not give an accurate picture of the differences between the Earth and Moon.”

In fact, the deeper the rock sample’s origins, the researchers found, the heavier the oxygen isotopes, compared to Earth’s.

This difference could be explained if only the outer surface of the Moon was pulverised and mixed during the impact, resulting in the similarity with Earth. But deep inside the Moon, the Theia chunk remained relatively intact, and its oxygen isotopes were left closer to their original state.

[…]

Science Alert

Norites are intrusive igneous rocks that would have formed deeper in the lunar crust and/or mantle. The oxygen isotope differential could be indicative of Theia having formed farther away from the Sun than the Earth. Unfortunately, the paper is pay-walled. Here’s the abstract:

Article
Published: 09 March 2020
Distinct oxygen isotope compositions of the Earth and Moon
Erick J. Cano, Zachary D. Sharp & Charles K. Shearer

Nature Geoscience (2020)

The virtually identical oxygen isotope compositions of the Earth and Moon revealed by Apollo return samples have been a challenging constraint for lunar formation models. For a giant impact scenario to explain this observation, either the precursors to the Earth and Moon had identical oxygen isotope values or extensive homogenization of the two bodies occurred following the impact event. Here we present high-precision oxygen isotope analyses of a range of lunar lithologies and show that the Earth and Moon in fact have distinctly different oxygen isotope compositions. Oxygen isotope values of lunar samples correlate with lithology, and we propose that the differences can be explained by mixing between isotopically light vapour, generated by the impact, and the outermost portion of the early lunar magma ocean. Our data suggest that samples derived from the deep lunar mantle, which are isotopically heavy compared to Earth, have isotopic compositions that are most representative of the proto-lunar impactor ‘Theia’. Our findings imply that the distinct oxygen isotope compositions of Theia and Earth were not completely homogenized by the Moon-forming impact, thus providing quantitative evidence that Theia could have formed farther from the Sun than did Earth.

Nature Geoscience

While Earth and Moon rocks are extremely similar, there are distinct diagnostic differences. The Lunar and Planetary Institute has a fantastic compendium of lunar sample data from the Apollo and Luna missions. Each report has pictures, photomicrographs of thin sections, x-ray diffraction, x-ray fluoresce and other geochemical, petrological and mineralogical data. One of my long-term projects has been to look at the differences in basalts from the Earth and the Moon.

Figure 1. Basalt ferrous oxide vs alumina

Terrestrial basalt plots below the lunar trend line in a fairly tight cluster, irrespective of where (mid-ocean ridges, island volcanoes or continental flood basalts) or when (recently, Miocene Epoch or Triassic Era). Whereas the mare basalt samples collected by the Apollo 11 and 12 missions plot in a cluster around the top left of the lunar trend line. The mare basalts most likely formed at the surface, billions of years ago, from impact-related melts.

Hopefully, in a few years, the Artemis missions will reinvigorate lunar science.

Reference

Cano, E.J., Sharp, Z.D. & Shearer, C.K. Distinct oxygen isotope compositions of the Earth and Moon. Nat. Geosci. (2020). https://doi.org/10.1038/s41561-020-0550-0

146 thoughts on “Origin of the Moon: New evidence in old rocks for Lunar impact theory

  1. Good lord.

    Its like even the Science community forgets that ¹⁴C is created here on Earth by cosmic ray spallation of Nitrogen in the upper stratosphere! Which is to say, that isotopic ratios of oxygen are bound to be different on Luna compared to Earth, because it has been exposed to 4.5 billion years of background cosmic rays, the catastrophic emissions of scores of close-by supernovæ, from much further distanced, but inauspiciously aimed gamma ray bursts and all the rest.

    Duh…
    ⋅-=≡ GoatGuy ✓ ≡=-⋅

    • The isotopic oxygen ratios for lunar rocks that formed at the surface are identical to Earth rocks.

      The heavier oxygen isotope ratios were found in rocks that had formed deeper in the lunar interior.

      Pretty well all of the lunar rocks brought back to Earth, with the exception of a few cores, were exposed on the lunar surface.

      • Great synthesis David! By the way, what data analysis package are you using in Figure1.? Or is it from one of the papers discussed.
        When I was a lad in sixth form college (Senior High School -I think) doing my Geology A-Level igneous petrology class, our geology teacher had arranged for us to look at a subset of the Moon samples bought back from one of the Apollo missions. Looking at those thin sections under cross-polarized light was really inspiring.
        Keep up your funny and insightful posts please!
        Cheers, Mark

      • Our data suggest that samples derived from the deep lunar mantle, which are isotopically heavy compared to Earth, … thus providing quantitative evidence that Theia could have formed farther from the Sun than did Earth.

        Heavier isotopes typically condense first, at higher temperatures than lighter isotopes. D2O vapor condenses at 101.4 C and D2O liquid freezes at 3.82 C (Wikipedia).

        Wouldn’t heavier isotopes on Theia imply that it condensed at higher temperatures and so closer to the sun?

          • Difficult to credit a photochemical mechanism involving CO to oxygen isotope ratios reflecting condensation from the primordial solar nebula.

            Earth condensed at about 700 K within an optically dense nebula (here. It’s hard to credit photochemical dissociative control of isotopes during condensation of FeO and other oxides.

          • They really don’t know why the 17 O ratio varies from planetary body to planetary body. A photochemical reaction is one hypothesis…

            If you go to Mars and repeat the experiment you will find that the oxygen isotopic ratios follow the same relationship, but with one important difference. When you compare an Earth rock to a Mars rock with the same 18O / 16O ratio, you will find that the Martian rock has a slightly higher 17O / 16O ratio, as shown in the diagram above. The difference is small, about 3 parts in 10,000, but significant because oxygen is the only element that shows this effect, and because geological processes on the two planets cannot be responsible for the difference. (On Vesta, the largest melted asteroid, the corresponding 17O / 16O ratio is about 3 parts in 10,000 lower, and on the Moon, the isotopic ratios appear to be identical to terrestrial values: any difference is less than 0.2 parts per 10,000.)

            The anomalous behavior of oxygen in extraterrestrial materials was not discovered originally in Martian rocks. It was discovered in chondritic meteorites. Chondrites come from asteroids that were never melted or heated significantly, but contain particles that formed at high temperatures (~1500 oC) when the solar system was growing from a disk of dust and gas called the solar nebula. These particles show enormous oxygen isotopic anomalies (also called ‘mass-independent’ isotopic effects). Two types of particles are present: those containing abundant oxides of calcium and aluminum, called calcium-aluminum-rich inclusions or CAIs, which show the largest oxygen isotopic effects, and the much more abundant variety composed largely of oxides of iron, magnesium and silicon called chondrules. Most of the chondrules and some of the CAIs formed from millimeter-sized globs of molten material that cooled in a few hours or less in the solar nebula before the planets formed.

            http://www.psrd.hawaii.edu/Dec01/Oisotopes.html

             

             

            oisotopesemvtall

            Before this work, no one had identified a 17 O ratio difference between Earth and Moon rocks.

      • So how many samples is this new “evidence” based on? How deep are the cores.

        In view of the crater field, I would have thought that at least 50% of surface material is of extra-lunar origin anyway.

        Although most planetary scientists think the giant impact actually happened, evidence of Theia has been hard to find.

        Wait, that sounds familiar. Ah yes, just like globull warming.

      • David Middleton – March 10, 2020 at 10:29 am

        The isotopic oxygen ratios for lunar rocks that formed at the surface are identical to Earth rocks.

        The heavier oxygen isotope ratios were found in rocks that had formed deeper in the lunar interior.

        What about “heavier oxygen isotope ratios” obtained from asteroid “strike” locations here on earth, …… such as the claimed Gulf of Mexico strike?

  2. Not green cheese, then.

    Clever of NASA conspirators to fake rocks with an oxygen isotopic ratio distinct from that of Earth’s crust! Here in Chile, it’s hard for me to persuade young people that American astronauts really did go to the Moon repeatedly.

    If the finding be confirmed, then the hypothesized impacting planetoid not only was similar in size to Mars, but formed in its neighborhood.

    • Fake the rocks and then plant fake lunar meteorites all over Antarctica and North Africa… And fake the samples from the Soviet Luna probes… The perfect conspiracy theory… 😉

      • The 2009 NASA Lunar Reconissance Orbiter photos, taken on a lunar orbital cycle, show module base, rover tracks, and astronaut footprints. The Russians also photographed the footprints during a flyby. That having been established, some people just won’t accept anything that their feeble minds say they themselves can’t do.

    • Now what caused this Mars size planet, that formed at the distance of Mars, to lose speed or become eccentric and collide with Earth?

      Perhaps it’s connected to the planetary orbit shifts ~ 4 billion years ago? Planet Nine?

      • Apparently Jupiter in those early times after the basic formation of the solar system wandered in closer to where Venus is in its present orbit, before wandering back out to its present location. Which supposedly caused this earlier protoplanet to collide with Earth and perhaps had something to do with why Venus rotates clockwise in retrograde rotation once every 243 Earth days. Perhaps the same reason why Uranus is also rotating retro to the rest of the solar system and rotating over on its side, when Saturn wandered out towards the outer solar system before wandering back in to its present location.

        All pure speculation of course, but perhaps based upon some logical analysis. Thats what I think I understood from that TV series called the Planets. But please correct me if I misunderstood any of that. It is all very interesting.

        • There has been past no large scale wanderings in or out from essentially where they are today of the Gas giants.

          Jupiter is held in place in our system because of the fortuitous formation of Saturn in a stabilizing 1:2 orbital resonance. Without Saturn, Jupiter would have likely wandered into the inner system and sent Mars, Earth, Venus and Mercury scattered to outer solar system Oort cloud, maybe even ejected completely. The fact that we are here is evidence Jupiter never wandered in.

          The asteroid belt is mostly rubble because of the proximity to Jupiter’s gravitational disruptions prevented any large scale coalescence beyond the 4 biggest asteroids: Ceres, Vesta, Pallas and Hygiea. But it was Jupiter’s gravitational disruptions that makes it an exceptionally efficient comet absorber, protecting the inner planets from most of the icy wrath of the Oort Cloud.

        • If Jupiter had wandered all the way to the orbit of Venus, all of the inner planets would have either been absorbed by Jupiter or kicked out of the solar system completely.

          Where did the energy needed to lift Jupiter from the orbit of Venus out to where it currently is come from?

          The idea that Jupiter once wandered into the inner solar system is beyond nutso.

          • It was on that PBS NOVA program called the Planets…episode was called Jupiter, and they did a whole series from the inner rocky planets, to the outer gas giants. I also wondered where the causation would have come from to have Jupiter and Saturn wandering around the early solar system. It was a good series, and NOVA generally does good a good job when making a science doc.

            https://www.pbs.org/video/the-planets-jupiter-dokro5/

          • While it seems Jupiter did wander in from further out in the solar system, it stopped pretty much where it is today. Just because it was on NOVA, assuming you remember it correctly, doesn’t mean it was correct.

            If Jupiter had ever reached the orbit of Venus, none of the inner planets, including Mercury would remain in this solar system. Period. That’s not up for discussion.

            As to why Jupiter “wandered”, that had to do with collisions with dust caused it to slowly spiral in. What stopped this spiraling was a gravitational resonance with Saturn, Jupiter doing 3 orbits in the time it took Saturn to do 2. This stole energy from Saturn and added it to Jupiter, lifting it up to an area that it had already cleared of dust, ending Jupiter’s spiraling ways.

          • I didn’t say it was it correct, only that it seemed to be what they were saying which is that it did enter the inner solar system, according to that NOVA documentary. Why don’t you just watch the episode and let us all know if they know anything or not?

          • Pop science reporting generally presents speculative hypothesis as established scientific “fact”.

            Most of this is wild speculation, trying to build a house around the two grains of observational evidence which exist.

          • Agreed. They sure had some good graphics…The CGI sure has developed to the point some people think it is actual video of what happened. Yes, there is a lot of Pop Sci out there, and that is a very apt description. In fact, climate science is turning into Sci Fi, on a Pop basis. You right.

          • If they claim that Jupiter entered the inner solar system, then they know nothing.
            That could not have happened. Period. End of discussion.
            If Jupiter had entered the inner solar system, all of the inner planets would either have been destroyed or ejected. That’s not opinion, it’s fact.
            If Jupiter had entered the inner solar system, it would still be there. That’s not opinion, it’s fact.

      • Gravity.

        A key trait of planets is that they clear their orbits. The hypothesized planetoid got captured by Earth’s gravity and ended up orbiting in the same plane as our planet. Harmonics set up, which brought the Mars-like body closer and farther away until collision. The dance has been modelled using real physics rather than GIGO assumptions, as in Climate Science (TM) GCMs.

        No blundering back and forth by Jupiter required. If there were indeed a Late Heavy Bombardment, however, Jupiter might have played a role in that, as the planet trying to form between the giant and little Mars was torn apart and bits of what would have been it were ejected, some inward toward the four inner, rocky worlds.

        • So Earth’s gravity pulled an object the size of our moon from the orbital distance of Mars? That sounds unlikely. You have a link to this model?

          • The model is for how the body behaved once in Earth’s area of operation.

            It got in that region thanks to the gravitational effects of Jupiter, the Sun and maybe even Mars, just as do Earth-crossing asteroids today.

    • Well, John, you can say you read a comment directed to you from a Physicist who, as a college intern, worked for NASA on the very Apollo Program that sent men to the moon. The lead for the team to which I was assigned was 29 years old and had 3 PhDs. If it was faked, they certainly had a WHOLE LOT of us playing along with the gag.

      • Thanks, but I’m afraid they’re impenetrable. I know lunar astronauts, but that doesn’t convince them. I point out that it would have been impossible to fake the lighting on a sound stage in 1969. I add that the Soviets tracked the three stages of Saturn rockets all the way to the Moon and would have called BS on the US had we tried to fake missions there. Plus, of course the Moon rocks.

        That the objects left behind and human trackways are visible from NASA’s orbiting telescope also doesn’t cut it, either, because NASA.

        • Very frustrating… It usually revolves around the Van Allen radiation belts being impenetrable… So, the rocks don’t matter.

          • Young Chileans, and not so young, don’t get that pseudoscientific about it. They’re Commies, so the US is lying. That’s all they know and all they need to know.

            It’s such an article of faith with them that, among the grafitti of protest marchers painted everywhere, are denunciations of the movie, “First Man”.

        • As I recall, the moon landings were also tracked by a large number of highly competent independent amateur astronomers.

          Maybe some of them were even Chilean. 🙂

          But their testimony ought to be neutral enough even for commies.

          • Commies know no neutrality.

            Hard to say what it would take to persuade Moon landing deniers.

            When astronauts land again and pose for pictures next to the 1969 et seq vintage remains, those photos too will be derided as fake.

        • How facetious. “Knowing an astronaut” proves nothing. No wonder you can’t convince anyone…

      • fwiw, i know someone who worked for nasa on the viking probe back in the seventies. He was an MIT grad who wrote the software and he would be called upon whenever something went wrong. He told me that everything was done behind closed doors and that mission control was just a prop for the journalists. Kind of makes sense. If there’s gonna be a screw up, you don’t want the eyes of the world looking over your shoulder when fixing it. Kind of makes you wonder what else they do that we don’t know about. (never a straight answer)…

      • Which was never a Moon rock…

        The Rijksmuseum, more noted as a repository for 17th century Dutch paintings, announced last month it had had its plum-sized “moon” rock tested, only to discover it was a piece of petrified wood, possibly from Arizona. The museum said it inherited the rock from the estate of a former prime minister.

        The real Dutch moon rocks are in a natural history museum. But the misidentification raised questions about how well countries have safeguarded their presents from Washington.

        https://abcnews.go.com/Technology/apollo-moon-rocks-lost-space-lost-earth/story?id=8595858

    • Depressing how many nominally highly professionals still query the moon landing.

      I know an otherwise very good engineer who disbelieves because he claims the Van Allen Belt would have fried them instantly when they tried to pass through.

      The fact it is a ‘belt’ not a wall should be enough to explain that falsehood – they went around it.

      Still, if it is easier for people to believe that every one working on the project, plus everyone monitoring the project (aka THE SOVIETS during the middle of the COLD WAR) were in on the cover up AND have kept silent on it ever since. I mean honestly, do these people want to believe the entire moon landing(s) were a massive practical joke by both the USA and USSR to mess with the heads of the Europeans or something?

      • They went around the most dangerous part of it and were traveling so fast, that they didn’t spend much time in it. Even then, the astronauts received elevated radiation exposures, particularly Apollo 14, if I remember correctly.

    • Rhoda, my thought exactly.
      PhD stamped all over it despite for a masters program.
      True story. My Harvard undergrad thesis not only was good for a Summa, the econ faculty was so impressed with the math (I time lagged [tricky matrix algebra] Leontief’s static input/ output matrix equations for which he won the 1972 Econ Nobel) and my new data (a year paid by DoE at Leontiefs HERP institute at Harvard to collect new reduced 32×32 I/O matrix data on coal, nat gas, and nuclear generation inputs and outputs to show conclusively (only by my new model) that nuclear would not prove economic) that they deemed it an accepted PhD thesis.
      Long story short, I could have stayed one more year to complete Harvard econ PhD (history of econ, teach a class) or go to the Harvard Law/Business joint program where I had also been accepted. Thought the latter would be more profitable than the former, and never regretted the decision.
      Old joke, any two economists will offer three opinions, because on the one hand, but then on the other hand.

  3. Back when I was a geology undergraduate in the dark ages , we had a chance to look at some moon rock samples that did the rounds of the universities . The thin sections looked lovely as the rocks were un-weathered , even after billions of years. It was a real treat to hold a piece of another world in your hand and look at it down a microscope.

    • For anyone who might be interested, the Midwest Chapter of Friends of Mineralogy will be hosting their 8th annual symposium at Miami University (Oxford, OH) this coming Saturday. One of the speakers, Dr. Claire McLeod, will be talking about insights from 5 new lunar meteorites. Anyone is welcome and there is no fee to attend the all-day event. I’m certain thin-sections will be on display.

      http://www.fommidwest.org/wp-content/uploads/2020/02/8th-Symposium-Announcement.pdf

      • I just discovered that, out of an overabundance of caution, Miami University has cancelled our symposium scheduled for Saturday. With 3 reported cases of COVID 19, 200 miles away from the campus, the administration is concerned about large gatherings.

          • It is escalating very rapidly. Our annual MSHA hazard and safety training class, necessary for mineral collecting in quarries, has been cancelled because the host institution, Wittenberg University, has cancelled group meetings on campus.

            Similarly, the Bay Area Mineralogists, which meets monthly at the USGS in Menlo Park, has been told that they have to cancel tonight’s scheduled meeting because the government is not allowing group meetings.

  4. How about the Earth and Moon were already formed and something either hit the Earth or one or more cataclysmic explosions from the Earth’s crust (below the oceans where the ridges are now) sent out rocks, etc… which hit the Moon, (creating many of the craters which face the Earth?). Such rocks sent from the Earth and found close to or on the Moon’s surface would be more similar to those found on Earth than rocks which had been heaved up to the Moon’s surface by impacts from extra-lunar sources?

    • The oceans that exist now did not exist billions of years ago, and neither did the mid-ocean ridges.

      Where did the energy come from to lift the mass of the moon from the earth’s surface all the way to where it is now.

      If the craters on the front of the moon were caused by these so called projectiles from the earth, why are there just as many craters on the back side of the moon?

      • Great questions.

        Also, the dark side of the Moon appears to have attracted its uplands in a low speed gravitational rockfall onto its surface from a smaller body. That would have been quite a spectacle to witness,

        • John,
          There is no “dark side of the moon” except in song lyrics. The Far Side (not a comic) is illuminated regularly.

          • I know that the side of the Moon that Earthlings never see is illuminated half of the time. But dark side or far side are the best terms we have. Maybe away side would be better.

      • Good thoughts, but I do not agree the Moon was “lifted” from the Earth. I am positing that the more “protected” side of the Moon (that which faces the Earth) might have received many of its craters from some cataclysmic explosion (either an impact or super volcanic eruptions from below the ocean floors. The Earth would shield the Moon’s surface facing the Earth from many hits outside of those coming from the Earth itself.

        • Do have any concept of how much energy it would take to “launch” something from the surface of the earth into lunar orbit?
          Even the biggest volcanoes can only get gas up to the stratosphere. Rocks and dust don’t even make it that far.

          Think back to the Apollo craft. Those huge vehicles were figuratively, nothing more than big gas tanks. Of the entire weight of the vehicle at launch, much less than 1% made it to lunar orbit. And those vehicles were hundreds of times more efficient than any explosion could hope to be.

          Finally, no, the Earth does not shield one side of the moon from meteorites. Not even close.

          • Why does the “far side” of the moon have more craters than the side facing us? And, yes, the force to launch parts of the Earth out of our atmosphere would have to be incredible: but so are some of the Earth’s forces. How about the force that would need to rip open the mid-Atlantic ridge which in turn would separate the continents from one another, collapse the ocean floor and allow sub-plate waters to erupt and create vast oceans (hydroplate theory)?

            The present is not always the key to the past: unless one believes Charles Lyell and his falsifications against human observation.

      • Craters on the other side of the moon could be explained simply:

        Our moon only faces a small portion of the planet. If there was a cataclysmic (or several at once or over a period of time) explosion, it does not have to be aimed only at the moon. Explosion(s) would send debris from wherever they were projected. This gives the possibility of comets which come fairly close to mimicking the mineral content (type and percentages) of the planet Earth’s. Such projectiles are placed into their own orbits (influenced by the solar system’s various gravities) and eventually collide with the Moon, Earth, other planets and moons, etc… Same thing could happen from other planets and their satellites.

    • If the Moon formed from a collision of another planetary body with Earth, it should be formed of material from both planetary bodies.

      Unless Theia formed from the same part of the accretionary disk as Earth, there should be some distinct geochemical differences, particularly in oxygen isotope ratios.

      If you go to Mars and repeat the experiment you will find that the oxygen isotopic ratios follow the same relationship, but with one important difference. When you compare an Earth rock to a Mars rock with the same 18O / 16O ratio, you will find that the Martian rock has a slightly higher 17O / 16O ratio, as shown in the diagram above. The difference is small, about 3 parts in 10,000, but significant because oxygen is the only element that shows this effect, and because geological processes on the two planets cannot be responsible for the difference. (On Vesta, the largest melted asteroid, the corresponding 17O / 16O ratio is about 3 parts in 10,000 lower, and on the Moon, the isotopic ratios appear to be identical to terrestrial values: any difference is less than 0.2 parts per 10,000.)

      The anomalous behavior of oxygen in extraterrestrial materials was not discovered originally in Martian rocks. It was discovered in chondritic meteorites. Chondrites come from asteroids that were never melted or heated significantly, but contain particles that formed at high temperatures (~1500 oC) when the solar system was growing from a disk of dust and gas called the solar nebula. These particles show enormous oxygen isotopic anomalies (also called ‘mass-independent’ isotopic effects). Two types of particles are present: those containing abundant oxides of calcium and aluminum, called calcium-aluminum-rich inclusions or CAIs, which show the largest oxygen isotopic effects, and the much more abundant variety composed largely of oxides of iron, magnesium and silicon called chondrules. Most of the chondrules and some of the CAIs formed from millimeter-sized globs of molten material that cooled in a few hours or less in the solar nebula before the planets formed.

      http://www.psrd.hawaii.edu/Dec01/Oisotopes.html

       

       

      oisotopesemvtall

      Prior to this work, no one had been able to differentiate the oxygen isotope ratios of Earth and Moon rocks. However, when this team compared deep intrusive lunar rocks to lithologically similar Earth rocks, they found what they were looking for,

      Does this prove the collision theory? No. It’s a theory that really can’t be proven. Theories about exactly how the Earth, Moon and planets formed will always be theories. There just aren’t enough pieces of the puzzle old enough to ever be certain. But it is a solid piece of evidence to support it.

    • Zoe…I bit, and looked at your website, but it was all just looking like a bunch of gobbledygook numbers that meant nothing to me.

      As Einstein said, Can you explain it to a 5th grader? (or something like that)

      I am certainly ready to listen if you are willing to explain it the best you can. I don’t see the circular reasoning you refer to, unless it is sort of pun on orbiting planets etc. Not sure what you mean? I am not trying to sound rude or anything, just wondering what your condensed hypothesis would be? You do have a platform here to tell us, just as I try to do to the best of my ability.

  5. Sounds like another just-so story. The impactor just happened to hit at the proper angle to give the earth rotational momentum. And it needs the moon to stabilize that rotation. Without which there wouldn’t be any life. The debris field just happened to form a sphere 400x smaller than the sun and 400x closer to the earth such that the earth enjoys total solar eclipses. The earth is the only planet in the solar system with that feature- total solar eclipses. The most habitable place in the Solar System yields the best view of solar eclipses just when observers can best appreciate them.

    Just an accident?

    • I could write a Tolstoy-long book about all of the things in the Universe that had to be just right, at just the right time, for me to sit here in my office in Houston and be able to find oil, thousands of feet below the seafloor of the Gulf of Mexico, because of the “unreasonable effectiveness of mathematics in the natural sciences”…

      https://www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html

      https://web.njit.edu/~akansu/PAPERS/The%20Unreasonable%20Effectiveness%20of%20Mathematics%20(RW%20Hamming).pdf

    • We just happen to live when the Moon and Sun appear about the same size from Earth. The Moon started out much closer to Earth, which spun faster then, but has steadily receded in the intervening ~4.5 billion years. In another 4.5 billion years, should the planet and satellite last that long, the Moon will be much farther away.

      • Moon’s recession rate from Earth is 3.8 cm per year. By coincidence, its mean value at opposition from Earth presently happens to be 378,000 km.

        • Starting with that recession rate, and assuming constant gravitational/tidal forces, the moon was impossibly close to the earth somewhere about one to one and a half billion years ago. Uniformitarians have a problem with the physics.

          • At 3.8 cm/yr, the Moon would have been 215,288 miles away from Earth a billion years ago. It is currently an average of 238,900 miles away. At 3.8 cm/yr, it still would have been 132,646 miles away 4.5 BY.

            If the Moon did did originate from a collision with Earth, it would have been a lost closer to Earth 4.5 BY than 100,000 miles.

            cm/yr Years cm km mi/km mi Earth-Moon (mi)
            3.8    4,500,000,000    17,100,000,000    171,000 0.621371    106,254                   132,646
            3.8
          • Moon’s recession rate isn’t constant.

            Moon recessed more rapidly from Earth early in its history. It started out very close indeed.

          • If the collision theory is right, the recession would have to have been decelerating since the collision..

          • The recession rate depends on tidal forces.
            Tidal forces depend on gravity.
            The closer the moon, the stronger the gravity and hence the tidal forces.
            It’s a given that the recession rate is and has been slowing.

          • Please, David! The physics is that the current recession rate of the moon corresponds to the tidal/gravitational energy transferred from the earth to the moon, causing the earth’s rotation to slow and the moon to reach a higher orbit. These tidal forces decrease as the orbit distance increases. Working backward in time, using tidal forces alone, the moon could reach its current position in no more than 1.5 billion years. At that starting point, the earth would rotate every 4 hours and the tides would be high enough to completely erode the continents. Geologists would object, LOL. We’ve measured the “physical constants” for a few centuries, and project those values for 5 billion years? Riiiight!

      • That’s right. The coincidence is not accidental.

        The most habitable place in the Solar System yields the best view of solar eclipses just when observers can best appreciate them.

    • So much wrong with that comment, it’s hard to know where to begin. So how about “Strong Anthropomorphism”? That’s your ‘accident’ sorted.

    • The Earth already had a rotation when it was first formed. How much the impactor changed this rotation is open to speculation.

      Once objects get larger than a certain mass they form sphere’s. Basic physics.

      When the moon was first formed, it was a lot closer to the Earth than it is today. Because of tidal forces it’s been drifting outward ever since. Measurements made using a mirror that the Apollo astronauts left on the moon show that moon is continuing to drift further from the Earth even today.
      A million years ago, total solar eclipses were bigger and more frequent.
      A million years from now, total eclipses will be things of the past.

  6. David Middleton – off topic. Could you recommend a set of rocks for geology studies to go with Press & Seiver. I am at the stage where I need to actually see and hold some samples to go any further.

    • Amazon has a wide selection…

      https://www.amazon.com/American-Educational-Classroom-Collection-Minerals/dp/B07MQRQ5WM

      I never actually had a set of study rocks. However, I spent a ton of time looking at them in school… They had rooms full of rocks. If there’s a college with a geology or Earth science department near where you live, you might see if one of the professors or even students would be willing to give you a tour of the department and examine some of their rock & mineral samples.

      • Unfortunately on an island in BC – when we retired from Neuroscience at McGill, we picked a place with at least a primary production base (limestone, including the black stuff for pharmaceuticals, and lumber) rather than a yuppie place with tourism and summer cottages. People go by on their fancy boats and deplore the big quarries, but they are only 5-10 km2 out of >500, and along one road is several miles of piles of scrap rock – the new ones are raw, but those 50 years old are hard to tell from the surroundings – nature takes back its own. Here when the water system put in by a now mined out iron mine needs upgrading, the question is ‘What can we do ourselves and source locally to save money?’ There are more F150’s than fancy cars.

        Our island is geologically distinct from Vancouver Is and the other gulf islands and the mainland. I think it got pushed up from a trench between the two.

        • You might check to see if your province or national geological survey has any geological maps of your island available for purchase. A bedrock geology map will give you a good idea about where you might find outcrops of specific rock types. Pick up a rocks & minerals guide book like this one:

          https://www.amazon.com/Field-Guide-Minerals-Peterson-Guides/dp/039591096X

          Peterson Field Guides are generally very good. Field geology is a lot of fun. When my wife and I used to travel a lot (she’s a geo too) almost all of our vacations were planned around the local geology. Since we’ve accumulated 11 dogs, we don’t get to travel much any more.

          • My wife and I went to Gubbio, Italy last year, David, and brought back some of Luis Alvarez’ KT clay. 🙂

            The hillside where the layer is exposed is a series of sedimentary layers that have been heavily sampled for geological study. The older drill-holes have become tiny bonsai gardens.

  7. Is kinda of strange when considering the isotope “finger print” of Earth,
    and not realizing it consist as that of a water based planetary body.

    That “finger print” consist as very reach and complex in consideration of any other ones there,
    no quite easy for compering… in any way played.

    cheers

  8. Following up on the linked ‘Artemis Missions’, it is very reassuring to know that the folks at NASA will include a … “sustainable” architecture, the likes of which has never been built before.

    (They have crawled so far up diversity’s ass that they don’t feel a need to mention how diverse they will be. And to date, the PR folks there haven’t figured out how to bring up the benefit yield from a triple bottom line approach to the whole thing).

    “reinvigorating lunar science, one social equity catch phrase at a time”

  9. I’ll apologize in advance for the length of this post. It is completely opinion, and not truly based on any facts or figures, or anything, other than just the random thoughts of a fellow geologist (perhaps you remember that we both used Dott & Batten in our undergrad studies, oh those many decades ago … … … )

    I’m a Petroleum Exploration Geologist and Geophysicist (living in Casper), and I teach part-time at our local community college (mostly Math, but also some Aviation Ground School [yes — — a pilot w/ 11,000 hours] and have been known to participate in local geology field trips).

    Here are my thoughts:

    I’ve always had a difficult time trying to wrap my head around an ‘impact’ as the causative process for forming the moon. The competing theory is that the two planetesimals co-formed at about the same time, with the proto-Earth “winning” in accreting more material than the proto-moon. In many respects, Astrophysics considers the system to be a ‘binary’ planet, not unlike the Pluto-Charon system (similarities end there, as the Pluto-Charon system has its own satellite entourage).

    I am NOT disparaging any geochemical differences; I’m NOT a geochemist. My knowledge of geochem is restricted to what we got in iggy-pet (igneous petrology) and meta-pet (metamorphic petrology). I trust that there are geochemical differences between the two worlds. I do NOT have any explanations for why there are differences.

    But let us examine this hypothesis (and Dr. Middleton is right, they are all hypotheses; we are likely never to have sufficient definitive evidence to decide which hypothesis is correct; but, is this NOT the essence of science? Investigation? Hypothesizing? Testing? Refinement? … … … … … ).

    For the impact hypothesis to stand we have to have the following:

    1) The impactor would have to be within a narrow range of sizes: if it was too “large”, it would have completely disintegrated the proto-Earth, and if it had been too “small”, it would not have ‘dislodged’ the mass that became the moon. Yes, a sort-of “Goldilocks” problem, except applied to mass.

    2) The impactor would have had to have the correct velocity to achieve the result of creating a separate mass the size of the moon (or approximately so — — — we know there was a heavy bombardment of ‘leftover’ material from the original formation of the solar system objects, a few hundred million years after the solar system achieved some stability, so this added some measurable mass to Earth and Moon after formation). Isolating the mass (above) and concentrating on just the velocity of the impact, if it had been too “fast”, there would have, again, been disintegration of the proto-Earth, and too “slow”, it might have become a captured object itself, or eventually part of proto-Earth itself. [Sounds like another Goldilocks problem, doesn’t it?]

    3) We can reasonably assume that the proto-solar-system had something approximating a disk shape, albeit with some fair dispersion of material above and below some defined “center” of the disk itself. This brings in the problem of the angle that the impactor had when (if) it impacted the proto-Earth. We know the orbit of the Moon is inclined to the ecliptic by about five degrees (that’s why we only have eclipses a couple of times per year, instead of every month — — perfect alignment of the celestial bodies would produce lunar and solar eclipses about every 28 days or so, and solar eclipses only along the equator). So, what was the angle the impactor had when (if) it collided with the proto-Earth? Isolating the problems of mass and velocity (above), wouldn’t this almost have to be just one, or a very few, “perfect” angles to create the effect of dislodging a lunar-sized mass from the proto-Earth? Outside of a narrow range of angles, I’m dubious of creating a proto-moon with the characteristics of our Moon today.

    All scientists should know and consider Occam’s Razor, and when I do, it causes me to think that of the various competing hypotheses for where our Moon came from, the simplest one would seem to be either that the two masses accreted together, in the same vicinity, or that the Moon is a captured object itself. In the above discussion, I did not even bother to bring in the degree of consolidation of the impactor (was it a regular planetoid with define crust, mantle, core, or just a large aggregation of material — this would affect the effect of an impact, with less consolidated material having less force to transfer to the proto-Earth than a completed, solid mass; the problem is subordinate to the other three issues).

    So, there you have my thoughts, and I most certainly welcome yours. I’m a fan of the co-accretion hypothesis, and personally, I think that if you want to look at some impact hypothesis, then what we should look at is if there was an impact on Venus, which caused a dislodged mass to migrate to the vicinity of Earth (i.e., capture), and caused that excessively weird retrograde rotation of Venus. We do not (yet) have any solid geochemical analysis of Venusian rocks (though they seem to be mostly basic in composition), and I wonder if we might some day find some similarities between lunar and Venusian rocks. I’ve heard there are some proposals to do a sample-return mission to Venus; this should be impetus for such a mission.

    And, to head off any objection to a Venus-impactor, yes, the same problems (1 – 3 above) apply equally well to a Venus impact, as they do to an Earth-impact. But, the question remains, why does Venus rotate opposite to the rest of the solar system? Something happened there, and, anyone’s guess is as good as anyone else’s.

    My regards and appreciation to all for your comments,

    Vlad

    • A plausible explanation for Venus’ counter-rotation is that it started out slow, but in the “right” direction, then kept slowing so much that it switched direction.

      https://www.scientificamerican.com/article/why-venus-spins-the-wrong/

      Although hypotheses of one large or multiple smaller impacts can’t be ruled out, as has been proposed for Uranus’ retrograde motion:

      https://www.scientificamerican.com/article/why-venus-spins-the-wrong/

      Then there are more out there suggestions:

      http://www.sjsu.edu/faculty/watkins/venusretro.htm

      • Earth doesn’t have a monolithic crust, as Mercury, Venus, and Mars do. Earth has visible tectonics as the remaining islands of crust get pushed around. The others do not.

        Some 70% or so of the proto-Earth’s crust got vaulted away. That doesn’t seem possible in a co-accretion Earth-Moon model.

    • The problem any two body, no collision hypothesis, is how do you slow down the moon so that the earth can capture it.

      Occam’s razor only works on theories that are actually possible. Scientists have been puzzling out countless versions of both of your hypothesis and have been unable to make them work.

      While complex, the collision theory is the only one found to date that can actually be made to work.

    • With the co-accretion hypotheses, the orbiting binary should be rotating on the same plane as the accretion disc that the bodies were formed from which would result in the perfect alignment for solar eclipses that you mentioned as well as no seasons on Earth.

      I find the Goldilocks sequence more likely than a disruption to the inclinations of the rotations of the Earth and Earth/Moon system.

  10. Random collisions would most likely counsel each other out resulting in a very slow rotation as in Venus and Mercury. We currently have 365 days a year ans we have been slowing down since the formation of the moon.
    But our rate of rotation is evidence of one very massive collision. If we rotated like Venus and Mercury we could not exist. Also the slowing up in rotation would also release heat, so in some part is why we are also here. The tidal action on the oceans is visible evidence of an effect also. In reverse thinking think of how much heat energy would be required to move that mush water up and sown each day. Just thinking.

  11. David, thanks for flagging this new research. The new research plus your incredible chart I find persuasive.
    I never thought the alternative vaporization/recondensation alternative hypothesis made much sense also posted here at WUWT some years ago, because there was no gravitational ‘condensation nucleus’ around which the moon could form. The energetic vapor’ would have just drifted off info space leaving no moon. A major Theia fragment around which the collision vapor could condense is intuitive common sense. And, at any oblique strike angle, there would have been a sizable Theia fragment bounced off Earth.

  12. I always wondered when looking at Google Earth, if the large groove in the sea floor along the Marianas Trench and up to Japan was carved by such an impact. The long groove reminds me a router cut.

      • I once read a summary of an old paper that claimed the entire Pacific Ocean (almost half the earth’s surface) was the point of the glancing impact, and explained why the Pacific Ocean is so big including the thinner oceanic crust. Would the deep hotspot of Hawaii having upwelling magma from a single point for so long still be applicable to that if there is something to this hypothesis? Or is that some random large impactor that just punched a whole through the local crust. Would that older line of thinking still be applicable with what we know today?

        • Any glancing blow solid enough to dig out the Pacific basin would have completely melted the entire surface of the planet.

          Plate tectonics is sufficient to completely explain the Pacific basin.

          • I forget to mention that paper also postulated that the glancing blow was also the original process that also created plate tectonics in the first place. Deeply fracturing the earth’s crust, which exists to this day, or so they thought. That was about 25-30 years ago I read that paper so have no way of supplying any link, but I have read about that hypothesis more recently a few other places too. I am not saying it is correct, but surely others must have of read this same thing. I only asked an innocent question and then others start insinuating (sarcastically) the Pacific Basin must also be a moon sized crater. Geez…

          • “then others start insinuating (sarcastically) the Pacific Basin must also be a moon sized crater. Geez…”

            I see only two responses to your post, and neither say nor insinuate that.
            Regardless, some questions are so dumb as to engender sarcastic responses.

            As to the impact fracturing the crust, also nonsense.

            Try thinking for a bit. The Pacific ocean runs almost pole to pole, try to imagine an impact that would carve that out ON A SPHERICAL PLANET. Exactly how did this impactor manage to curve it’s path precisely to carve out this basin over almost 180 degrees of the earth’s circumfrence?

            Also how exactly did animal life avoid getting completely wiped out from this impact? Since the Pacific basin is only about 100 million years old.

            It only takes a few minutes of thought to realize how both of your questions are physically impossible.

          • I was never advocating that these things had actually happened. Only that I had read a paper 25-30 years ago, (maybe longer) and watched an interesting science documentary. I wasn’t saying that this was what happened. And then you start thinking I am advocating these ideas. Get a grip…and learn to tell the difference between someone introducing ideas that are perhaps old, but maybe still have some something to them. At least in the case of that fairly old paper I recall reading about these concepts. You aren’t an expert in this field anyway, and I am not either. As for the NOVA science doc, I already questioned what was the mechanism for the two largest planets roaming around the inner and outer solar system, which does seem a little fanciful but who really knows. Surely not you or me. So I am not advocating anything, contrary to your accusation that I am. As many say, the only dumb question is the one you don’t ask.

          • Why on earth would anyone want to embarrass themselves by introducing ideas that are so clearly wrong and nonsensical?

            Even a few minutes of thought should be sufficient for anyone familiar with basic physics to recognize how absolutely impossible both of those ideas are.

          • Just to clarify MarkW, you are the one embarrassing yourself with making such comments as for me introducing different ideas that you then call me dumb and I should be embarrassed for asking any potential dumb questions as to what is being speculated may have happened in the early solar system and how our Moon formed, or the Pacific Basin. Dragging things into the gutter just to make yourself look superior than others, is a condition known as”Little Penis Syndrome”. Just when I thought you were getting better the last year, you relapse into ad hominem, as your only defence. That is obvious.

      • Correctamundo. Even if the Pacific Basin were a wound left over from the glancing impactor blow, the Marianas Trench is clearly a fairly recent tectonic structure. Plus, all seafloor is less than a mere 200 million years old.

        Thanks for injecting an element of sanity and science into pure wild speculation.

        • The funny thing about this, is the similarities to the puzzle-piece relationship of South America and Africa. The Pacific Basin looks to be about Moon-sized to the typical amateur crater hunter… 😎

          • I always considered the “puzzle piece”s of the continental linking to be false. Look at the mid-Atlantic Ridge and Pacific Rim and you see a closer puzzle piece fit. This clearly shows where the plates moved. Still moving, too if you consider the Himalayas getting higher every year and they are aligned with the ridge in the Indian Ocean..A

          • I suppose that we can’t rule out the Pacific having been made by the impact, but its seafloor having then been subsequently remade 20 times since then.

    • I got a wig from my girlfriend, and put a nose ring in my nose, and go to a lot of these protest rallies with a big sign that says CO2 IS POISON. And all these leftist protesters give me a High 5 and cheer, Right On Man! Just unbelievable. But what they don’t know is that I have 3 special body cams taking pics of them for facial recognition purposes. Which makes me also smile about all the agencies world wide monitoring every word we right here, thinking what an education they must be getting.

  13. “Now a group of researchers has finally detected oxygen isotope differences between terrestrial and lunar rocks, something that could ease constraints when creating lunar formation models and rule out some of the most extreme scenarios.”

    Yawn!

    So a Mars sized planet collided with the Earth and the debris that scattered in all directions started rotating in a single direction and coalesced into the moon.

    The direction and speed was exactly right (I be in a billion) to settle into a perfect orbit of the earth and , amazingly this coalesced body (the moon) started rotating at exactly the right speed to always show the same face to the Earth.

    The new moon enabled tides in Earth and became an integral part of the cycle of life.

    Common sense should tell you and physics should tell you that it is impossible but you can’t argue with oxygen isotopes.

    PS. I’m not a creationist or a Christian.

    • Actually physics explains how all of the things you ridicule could happen.

      1) Debris is not scattered in all directions, almost all of it is scattered in the direction that the impactor was travelling.

      2) What the heck is a perfect orbit? I’ve never run across the concept in any of the astronomical texts that I have read.

      3) That debris in an orbit would tend to coalesce is not a new concept.

      4) Objects getting tidally locked happens all the time. A number of the moons of Jupiter and Saturn are also tidally locked.

      5) Since the moon exists, the fact that it interacts with life on this planet is hardly surprising. Had it not existed, life would still have existed, but it probably would have been different.

      6) I don’t know what you are, but scientist or someone familiar with math is not on the list of possibilities.

    • Common sense and physics show that a glancing blow from a Mars-sized object most likely gave us our Moon.

      • These are not “aimed” at you John, but the theory of a glancing blow hitting the Eatrh and creating the Moon begs lots of questions: What happened to the “object” which gave the planet a glancing blow? Is it in orbit? Was it fragmented and these fragments are in orbit? Where did it come from? I would imagine something creating an impact such as this hitting a mass as great as the Earth’s would remain in orbit in our solar system (in pieces, I would assume)? Did this kick up Earth debris and send it beyond Earth’s orbit (comets, perhaps?)? How much of a “glancing blow” would need to impact to send up enough debris to be collected by Earth’s gravity to form into the Moon? Would such an impact have to be so great to send up enough of Earth’s debris to form the Moon that the result of such an impact would more likely project most everything out of the Earth’s gravitational force, and so could never form the Moon? How did such an impact affect Earth’s orbit?

        Seriously, does anyone have the answers to these questions?

        • All of those questions were answered by the original paper.

          The original impactor shattered/melted/vaporized. Some of the debris from the impactor fell back to earth, some of it had sufficient velocity to escape and the rest of it settled into orbit around the planet, eventually forming the moon.

          Where did it come from? An orbit not to far away, probably between Earth and Mars.

        • “Begging the question” is the name of a logical fallacy. It doesn’t mean”raising the question”.

          Mark answered your questions.

          Early solar system history, there were more and bigger objects hitting each other. That’s how the planets and smaller spherical bodies formed. The hypothesized Moon-creating impact occurred after Earth had coalesced, but while there were still unabsorbed planetesimals.

          • These answers are conjecture. The paper did not answer these questions: it hypothesized. Circular reasoning does not prove anything. I was asking serious questions hoping to get serious responses. If I had thought the main piece and/or comments had answered these questions, I would not have posed them. Show me the science based on reasonable witness or evidence and I will digest it, please. And, thank you.

  14. With out the collision, we might have only 2 days a year in rotation like Venus and Mercury. Heating for months and then cooling for months. visible life would not exist in my humble opinion.
    With out the tidal action, we would not have desalinate the oceans. High tides fill flat lands that evaporate leaving slat layers hundreds of feet deep Paradox basin has thirty three cycles if lime stone, salt and then sand.
    With out the Moon, Giving us short days from the collision event resulting in 12 hours of cooling followed by 12 hours of warming, what would our earth e like.

    After our molten state (some say 600 million years) rain finally was able to reach the earth and once the mantel was saturated tectonics began. Pushing up dry land so that the desalination period could exist.

    With out the rapid rotation from the collision. our magnetic shield that protects us from the solar winds, would be too weak,and the hydrogen in out atmosphere would have been lost to space and we would be much more like Venus. Hydrogen of course is needed for water.

    Just random thoughts.
    Roy

    • Given our orbit, our spin rate probably would never have been as slow as Mercury or Venus. Mars rotates similarly to Earth, for instance.

    • Hydrogen in our atmosphere was lost and is still being lost. Earth’s gravity is too weak to keep hydrogen from being lost to space.

  15. Regarding comments on the Pacific basin. Nick Zentner of Central Washington University has excellent lectures on geology. This one is related to continental drift throughout time:

  16. This is for anyone, but I write this especially for you, David Middleton, as your background on this matter (geophysics) is superb; 100 times better than mine.

    Okay, I now have a little time to refute the impact theory. I look forward to any responses. Here we go:

    1. The moon’s orbit is too close to being circular to have been created by an impact.
    2. Why are there no other satellites revolving around the Earth?
    3. Why does our Moon (which is quite large) not have any satellites of its own?
    4. If the moon was formed by the an impact (which would have scattered debris which would then have coalesced to be our Moon), what happened to the Moon’s rotation needed to “collect” the debris. The current gravity of the Moon and no spin do not allow for such to happen.
    5. Seismology clearly shows the “impact” sites of the Pacific trenches are much less dense than would be expected below their surfaces showing subduction rather than an impact which would have shown great compression.

    A little more detail for each point:

    1. A great impact with the Earth (glancing blow is not enough as a “glancing” blow would not be sufficient to dislodge enough material to create one of the largest satellites in this solar system) should cause an orbit to be elliptical or quite close. There has not been enough time for the orbit to be brought into an almost circle (as it currently is) if it is even possible over an extended period of time. (See below, point 6 concerning evidence of a “young” Moon, or certainly not a very old Moon.)
    2. A great impact or great “glancing blow” big enough to produce our satellite (“instantaneously” or over time) should leave evidence by there being many other orbiting much smaller satellites around the Earth. But, they are lacking.
    3. Satellites orbit several other “satellites” (moons) in our solar system. Ours has nothing revolving around it.
    4. Would not the moon have some rotation, some gravity still to have formed from a propulsion from the Earth? One might state over time it has lost both, but the Moon is not that old (see point 6 below).
    5. a. The western Pacific Ocean contains the most concentrated number of deep trenches on the planet. The center of this region is concentrated at approximately 159 E longitude and 10 north latitude. The Atlantic Ocean is centered near 21.5 W longitude and 10 S latitude. These are almost exactly opposite each other. Simply put, the mid-Atlantic Ridge rose opposite where the concentrated western Pacific trench region collapsed. No blow, strike or cataclysmic hit from an extra-terrestrial body.
    b. Seismography clearly shows the areas below trenches to be less dense. The continental plates tend to shift towards these less dense areas when seismic events occur because there is less resistance and “nature hates a partial ‘vacuum.'” A blow, strike, series of blows big enough to eject enough material to create our Moon would have compressed the trenches to be denser than most of the rest of the Earth’s crust.
    c. There are many problems with subduction, though, so another theory is subsidencce caused by a rapidly rising Atlantic Ocean floor. Gravity then pulls down on the western Pacific and trenches drop (are pulled). This reply is not the space for getting into more detail at the moment.

    6. Questions concerning a very old Moon which is necessary to explain why some of my questions might seem moot.
    a. A surprising amount of heat flows out of the Moon just below its surface while its interior is relatively cold. The Moon has not cooled off yet because it is relatively young.
    b. Astronomers note that the Moon’s craters should not be as steep as they are given its supposed age. According to calculations , large high-rimmed craters should have leveled out in only tens of thousands of years. *By the way, large steep-walled craters exist on Venus and Mercury despite that their gravities are even greater than our Moon’s.)
    c. Moon dust and debris: yes, here we go again on this one, but there should be a lot more of it on the surface if it was as old as purported. Scientists have calculated that there should have been dust possibly a mile in thickness before they discovered with the Apollo landings it was not anywhere near that thick. Dust and debris from outer space accounts for only 1/67th of our Moon’s surface and recent measurements of the influx rate of meteoric material do not support an old Moon.

    There could be many more things to write on this, such as the relative abundances of its elements are too different from Earth’s, its orbital plane is too inclined to have “spun off the Earth.”

    Simply, put, the reason Earth-like minerals, rocks, etc… are found on the Moon is because they were either propelled from the Earth from extra-terrestrial collisions (must have been amazing), or propelled by one or more cataclysmic explosions from the Earth, the likes we have never seen, nor, I hope, will ever see again.

    Thank you all for your patience. I look forward to responses.

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