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

Posted by BeauHD on from the revised-theories dept.

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.

4 of 90 comments (clear)

  1. Re:An old theory, revitalized! by jandersen · · Score: 5, Insightful

    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.

  2. Basically, the mainstream theory, or not? by Mostly+a+lurker · · Score: 4, Informative

    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.

    1. Re:Basically, the mainstream theory, or not? by NotAPK · · Score: 5, Informative

      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 which is fortunately funded to be open access.

  3. Re:An old theory, revitalized! by jandersen · · Score: 4, Insightful

    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.