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Moon Earth Space Science

Our Moon May Have Formed From Multiple Small Ones, Says Report (go.com) 90

An anonymous reader quotes a report from ABC News: A series of cosmic collisions may have spawned multiple moonlets that morphed into the one big moon we know today. Rather than one giant impact that knocked off part of early Earth and created the moon, a number of smaller collisions may have produced lots of mini-moons, Israeli scientists reported Monday. And those mini-moons, over millions of years, may have clumped together to make one large one. The researchers conducted nearly 1,000 computer simulations and estimate about 20 impacts could do the job. They say that would explain why the moon seems to be composed of material from Earth, rather than some other planet, too. It's actually an old theory revitalized now by the Weizmann Institute of Science's Raluca Rufu in Rehovot, Israel, and his team. Their findings were published in Nature Geoscience.
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Our Moon May Have Formed From Multiple Small Ones, Says Report

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  • by Anonymous Coward

    I should go find old theories and republish them as new ideas, then I can brag I was published in scientific journals.

    • by sittingnut ( 88521 ) <sittingnut@NoSpAM.gmail.com> on Tuesday January 10, 2017 @03:49AM (#53640003) Homepage

      I should go find old theories and republish them as new ideas, then I can brag I was published in scientific journals.

      "The researchers conducted nearly 1,000 computer simulations and estimate about 20 impacts could do the job."

      this is what modern science is reduced to, old theories joined to faddish techs that can be easily trailered to fit the theory.

      • by jandersen ( 462034 ) on Tuesday January 10, 2017 @04:48AM (#53640117)

        this is what modern science is reduced to, old theories joined to faddish techs that can be easily trailered to fit the theory.

        No, this is what science has always been: chasing existing theories, testing them from different angles, trying to find weak points. Only a vanishingly small part of scientific discovery is about making a huge, new discovery. But what we see here, and what you are complaining about is really the poor journalism that tries to inflate good, but humdrum scientific results and make a sexy sounding headline out of it. And once again it has served its purpose: to attract clicks to slashdot's website, which translates into advertising revenue. From their point of view scientific accuracy only matters in as much as it increases revenue - they don't care if the clicks come from real scientists and engineers or clueless teenagers.

        • by Anonymous Coward

          this is what modern science is reduced to, old theories joined to faddish techs that can be easily trailered to fit the theory.

          No, this is what science has always been: chasing existing theories, testing them from different angles, trying to find weak points ....

          Well, unless that theory is AGW.

          That's settled. The only thing in "science" ever to be "settled".</SARC>

          And you got modded up, and this will get modded down - because HERETIC!, errr, DENIER!

          • by JonnyCalcutta ( 524825 ) on Tuesday January 10, 2017 @07:57AM (#53640575)

            No, he will get modded up because he's right and you will be ignored because you're spouting shite.

          • by bmo ( 77928 )

            Maybe you should verify the theory of gravity by stepping off from a great height?

            Because it really is still being studied. Maybe you will find some ground-breaking data?

            HTH.

            --
            BMO

            • More likely some bone-breaking data...

            • Maybe you should verify the theory of gravity by stepping off from a great height?

              Because it really is still being studied. Maybe you will find some ground-breaking data?

              HTH.

              -- BMO

              I see what you did there.....

          • Well, unless that theory is AGW.

            That's settled. The only thing in "science" ever to be "settled".

            And you got modded up, and this will get modded down - because HERETIC!, errr, DENIER!

            No, not really; no science is settled in the sense that it will never be scrutinised and probed again. AGW is only settled in the sense that although the scientists are constantly doing exactly what I said above, they don't find major weaknesses. To put it into context: anthropogenic climate change doesn't come out of thin air and a desire for funding; it is the result of work with models, and not just any old model. These climate models are based on the same physical theories that are used for a very wide

            • by Applehu Akbar ( 2968043 ) on Tuesday January 10, 2017 @09:23AM (#53640923)

              The problem is getting the AGW political activists out there to treat the problem in a scientific way, rather than another excuse to scream doomsday. "Deniers" are those of us who have seen these people be wrong about all their other apocalypses, and therefore find it easy to assume that they have to be wrong about this one too.

              A surefire sign of the unthinking activist is their automatic rejection of any real-world solution to the carbon problem.

              • The problem is getting the AGW political activists

                OK, so you're critical of activists.

                "Deniers" are those of us who have seen

                Ah so because you don't like the activists, you're denying the science done by a completely different set of people. Yeah, that's a totally logical proposition.

                Are you going to deny evoltion too because you found someone who was wrong about it?

              • by jandersen ( 462034 ) on Tuesday January 10, 2017 @11:38AM (#53641757)

                A surefire sign of the unthinking activist is their automatic rejection of any real-world solution to the carbon problem.

                I don't think there is all that much difference between the doomsdayers on the one hand and the conspiracy theorist deniers on the other. Both sides have decided on their 'conclusion' a priori and mangle the available data to fit. The only real sceptics in all of this are the climate scientists; scepticism is at the very core of what science is. Blindly denying the observable facts - which both dommsdayers and deniers do - has nothing to do with being sceptical or thinking critically; it is nothing more than blind faith and represents the extreme of gullibility.

                That said, it makes good sense to listen to the balanced, scientific viewpoints that are presented by climate science: humans do cause climate change, it is getting dangerous now, and we can actually do something constructive about it, not just in terms of short term mitigation, but also in terms of changing the stupid and wasteful habits that are a significant part of the reasons why we have climate change.

                • it is getting dangerous now,

                  What makes you say that? What danger exactly does it pose?

                  You sound like an alarmist, rather than a science oriented person. AGW is speeding up the climate change that was already occuring. We are exiting an ice age still, unless we never actually get out of the ice age, all the effects of AGW are things that were already going to happen. The projected sea level rise is not something that will cause massive problems to avoid...unless we keep building on land that should be sea like New Orleans.

          • by Maritz ( 1829006 )

            And you got modded up, and this will get modded down - because HERETIC!, errr, DENIER!

            Bollocks. There's far more of you intellectual cowards on slashdot than anyone who accepts the science.

          • An AC trying to use sarcasm. What an absolute waste of effort. Even more so than normal AC comments.
      • "The researchers conducted nearly 1,000 computer simulations and estimate about 20 impacts could do the job."

        this is what modern science is reduced to, old theories joined to faddish techs that can be easily trailered to fit the theory.

        Yeah, when is this Monte Carlo fad going to die anyway??? It's worse than bell bottoms.

      • I should go find old theories and republish them as new ideas, then I can brag I was published in scientific journals.

        "The researchers conducted nearly 1,000 computer simulations and estimate about 20 impacts could do the job."

        this is what modern science is reduced to, old theories joined to faddish techs that can be easily trailered to fit the theory.

        :) News flash: Upon conducting 3,000 more computer simulations, the models indicate that the moon could have been formed from quadrillions of smaller moons. Wait, more runs have shown that it could be in the septillion smaller moon range. Wait..."

    • by Maritz ( 1829006 )
      Try it and let us know how you get on. Actually, I already know how you'll get on. But you don't.
    • I should go find old theories and republish them as new ideas, then I can brag I was published in scientific journals.

      Let's do Phlogiston theory! Just the name reeks of awesomeness.

    • This is obviously false though regardless of the age of the theory. It is well known that our moon was created when Nibiru (also known as Marduk) struck the planet Tiamat. Does no one read the ancient Sumerian texts anymore?
  • by Anonymous Coward

    An old theory no more proven today than then.

  • Someone had to say it.

  • by Mostly a lurker ( 634878 ) on Tuesday January 10, 2017 @05:15AM (#53640183)

    As I understand it, the Giant Impact Hypothesis has Theia's impact creating debris that gradually coalesced into the moon. That this debris formed several smaller moons before they joined up seems plausible, but I am not sure what is really different about what they are proposing.

    • Comment removed based on user account deletion
      • by Anonymous Coward

        Its probably confusing to people who the word 'coalescing' and imagine the process to be gradual and organised when in reality it is very chaotic.

        Will the asteriod belt someday coalesce and become something more significant??

        The reason why we have an asteroid belt there instead of a planet is because of the gravitational tug between Jupiter and the Sun keeps those asteroids from coalescing.

      • Kind of like people who accidentally a whole word?

      • The whole asteroid belt could coalesce into one body - and it would be considerably smaller than the Moon. If it's a "failed planet", then if it were lumped into a single planet, it would be similar to or smaller than Pluto. Maybe smaller than Charon - I haven't checked the numbers.
    • by NotAPK ( 4529127 ) on Tuesday January 10, 2017 @07:45AM (#53640551)

      I read the article.

      The main problem is that they claim "the problem" with the impact is that we can't find any evidence or residue from Theia. Well, a lot of the models show that the impacter's core (which would have already differentiated and have a metal core) mostly goes into the core of the earth, and the silicate portion mixes with the bulk silicate earth (BSE). The moon is mostly formed from the earth's mantel, not from the impactor, and this is why the moon has the same composition as the BSE. The problem is working out why there is little to no isotopic fractionation between the moon and the earth, since conventional wisdom suggests a hot violent process such as the giant impact would have resulted in such fractionation.

      The most useful part of the article is the suggestion that we go to venus. The similarities and differences in isotopic fractionation between the moon and the earth can only really be interpreted with a greater understanding of isotopic variation among the terrestrial planets, and failed planets (e.g. Vesta) in the asteroid belt.

      For more information I recommend reading this paper [sciencedirect.com] which is fortunately funded to be open access.

  • Raluca Rufu in Rehovot, Israel, and his team.

    As "Raluca" is a female name, it should be written "her team".

  • I know it's a cliche these days but isn't the idea of two bodies colliding somewhat more plausible than twenty? I would say of course the composition is similar to the Earth's. No doubt the bollide formed in a similar orbit and attracted similar materials to the Earth. It just lost the battle of accretion and eventually collided with it.
    • by Anonymous Coward

      You are right with but for the wrong reason according to the paper. Idea is that smalls collision was very frequent and "ordinary" at that early time. The collision with a rare and big bolid was "extraordinary". Occam's Razor choose lots of common and small collision.

      That said, Its my turn to ask : If its so obvius as process then Venus which is the twin of Earth minus the Moon should have also form a noon also as a ordinary process. Proximity of Sun protect Venus?

      The question should be if we accept this th

      • There's a pretty high probability that Venus also had a large late impact. It's axial rotation is not only the slowest in the planets, but it's also retrograde (in the opposite direction to the rotation of the other planets).

        Uranus is also thought to have had a large late impact - it's rotation axis is flipped at 98 degrees to the orbital axis, which is often described as "orbiting on it's side".

        The Pluto-Charon system is also likely the result of a late large impact. Their size difference is even smaller

  • Bah..everybody knows the Moon was once the satellite of Minerva...the planet that existed in between Mars and Jupiter and then was destroyed causing the asteroid belt. The moon was pushed out of orbit and caught by the earth as it fell inward.
  • So the moon is made of cheese?
  • This was presented more than 50 years ago by Gordan J. F. MacDonald, at that time professor of geophysics at UCLA's Institute of Geophysics and Planetary Physics. His paper "Origin of the Moon: Dynamical Considerations" appeared in Annals of the New York Academy of Sciences on 7 May 1965. As one of his computer programmers, I did the calculations for that paper. I think, however, that I might have done those calculations a few years earlier and that MacDonald published the same theory earlier than 1965.

  • Finally, a cheap and effective way to move a large number of people out of Earth's gravity well! When the next strike is going to occur, pile on to the to-be-ejected chunk and: BANG, ZOOM! Straight to the moon!

Get hold of portable property. -- Charles Dickens, "Great Expectations"

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