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Origin of the Moon in a giant impact near the end of the Earth's formation

Abstract

The Moon is generally believed to have formed from debris ejected by a large off-centre collision with the early Earth1,2. The impact orientation and size are constrained by the angular momentum contained in both the Earth's spin and the Moon's orbit, a quantity that has been nearly conserved over the past 4.5 billion years. Simulations of potential moon-forming impacts now achieve resolutions sufficient to study the production of bound debris. However, identifying impacts capable of yielding the Earth–Moon system has proved difficult3,4,5,6. Previous works4,5 found that forming the Moon with an appropriate impact angular momentum required the impact to occur when the Earth was only about half formed, a more restrictive and problematic model than that originally envisaged. Here we report a class of impacts that yield an iron-poor Moon, as well as the current masses and angular momentum of the Earth–Moon system. This class of impacts involves a smaller—and thus more likely—object than previously considered viable, and suggests that the Moon formed near the very end of Earth's accumulation.

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Figure 1: Time series of a Moon-forming impact simulation.
Figure 2: Scaled smooth particle hydrodynamics simulation results.

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References

  1. Cameron, A. G. W. & Ward, W. R. The origin of the Moon. Lunar Sci. 7, 120–122 (1976).

    Google Scholar 

  2. Hartmann, W. K. & Davis, D. R. Satellite-sized planetesimals and lunar origin. Icarus 24, 504–515 (1975).

    Article  Google Scholar 

  3. Cameron, A. G. W. The origin of the Moon and the single impact hypothesis V. Icarus 126, 126–137 (1997).

    Article  Google Scholar 

  4. Cameron, A. G. W. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 133–144 (Univ. Arizona Press, Tucson, 2000).

    Google Scholar 

  5. Cameron, A. G. W. From interstellar gas to the Earth–Moon system. Meteor. Planet. Sci. 36, 9–22 (2001).

    Article  CAS  Google Scholar 

  6. Canup, R. M., Ward, W. R. & Cameron, A. G. W. A scaling law for satellite-forming impacts. Icarus 150, 288–296 (2001).

    Article  Google Scholar 

  7. Hood, L. L. & Zuber, M. T. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 397–409 (Univ. Arizona Press, Tucson, 2000).

    Google Scholar 

  8. Benz, W., Slattery, W. L. & Cameron, A. G. W. The origin of the Moon and the single impact hypothesis I. Icarus 66, 515–535 (1986).

    Article  Google Scholar 

  9. Benz, W., Slattery, W. L. & Cameron, A. G. W. The origin of the Moon and the single impact hypothesis II. Icarus 71, 30–45 (1987).

    Article  CAS  Google Scholar 

  10. Benz, W., Cameron, A. G. W. & Melosh, H. J. The origin of the Moon and the single impact hypothesis III. Icarus 81, 113–131 (1989).

    Article  CAS  Google Scholar 

  11. Cameron, A. G. W. & Benz, W. The origin of the Moon and the single impact hypothesis IV. Icarus 92, 204–216 (1991).

    Article  Google Scholar 

  12. Melosh, H. J. & Kipp, M. E. Giant impact theory of the Moon's origin: first 3-D hydrocode results. Lunar Sci. 20, 685–686 (1989).

    Google Scholar 

  13. Lucy, L. B. A numerical approach to the testing of the fission hypothesis. Astron. J. 82, 1013–1024 (1977).

    Article  Google Scholar 

  14. Stewart, G. R. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 217–223 (Univ. Arizona Press, Tucson, 2000).

    Google Scholar 

  15. Tillotson, J. H. Metallic equations of state for hypervelocity impact. Report No. GA-3216, July 18 (General Atomic, San Diego, California, 1962).

  16. Canup, R. M. & Asphaug, E. Outcomes of planet-scale collisions. Lunar Sci. [CD-ROM] 32, (2001).

  17. Melosh, H. J. & Pierazzo, E. Impact vapor plume expansion with realistic geometry and equation of state. Lunar Sci. 28, 935 (1997).

    Google Scholar 

  18. Melosh, H. J. A new and improved equation of state for impact computations. Lunar Sci. 31, 1903 (2000).

    Google Scholar 

  19. Asphaug, E. & Benz, W. Size, density, and structure of comet Shoemaker-Levy 9 inferred from the physics of tidal breakup. Icarus 121, 225–248 (1996).

    Article  Google Scholar 

  20. Ida, S., Canup, R. M. & Stewart, G. Formation of the Moon from an impact-generated disk. Nature 389, 353–357 (1997).

    Article  CAS  Google Scholar 

  21. Kokubo, E., Canup, R. M. & Ida, S. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 145–163 (Univ. Arizona Press, Tucson, 2000).

    Google Scholar 

  22. Kokubo, E., Makino, J. & Ida, S. Evolution of a circumterrestrial disk and formation of a single Moon. Icarus 148, 419–436 (2001).

    Article  Google Scholar 

  23. Greenberg, R. in Origin and Evolution of Planetary and Satellite Atmospheres (eds Atreya, S. K., Pollack, J. B. & Matthews, M. S.) 137–164 (Univ. Arizona Press, Tucson, 1989).

    Google Scholar 

  24. Nelson, A., Benz, W., Adams, F. & Arnett, D. Dynamics of circumstellar disks. Astrophys. J. 502, 342–371 (1998).

    Article  Google Scholar 

  25. Hernquist, L. & Katz, N. TREESPH—A unification of SPH with the hierarchical tree method. Astrophys. J. Suppl. 70, 419–446 (1989).

    Article  Google Scholar 

  26. Benz, W. in Proc. NATO Adv. Res. Workshop on Numerical Modelling of Nonlinear Stellar Pulsations (ed. Buchler, J. R.) 1–54 (Kluwer Academic, Boston, 1990).

    Google Scholar 

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Acknowledgements

We wish to thank Southwest Research Institute's Internal Research program for its support of development efforts for the methods utilized here, D. Terrell for securing a portion of the computational time, and P. Tamblyn for aid with some of the analysis software. A review by A. Halliday and comments provided by W. Ward, C. Agnor, D. Korycansky and R. Mihran helped to improve the paper. This research was supported by the National Science Foundation and NASA.

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Correspondence to Robin M. Canup.

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Canup, R., Asphaug, E. Origin of the Moon in a giant impact near the end of the Earth's formation. Nature 412, 708–712 (2001). https://doi.org/10.1038/35089010

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