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Siegler MA, Miller RS, Keane JT, et al. Lunar true polar wander inferred from polar hydrogen. Nature. 2016;531(7595):480-4doi: 10.1038/nature17166.
Siegler, M. A., Miller, R. S., Keane, J. T., Laneuville, M., Paige, D. A., Matsuyama, I., Lawrence, D. J., Crotts, A., & Poston, M. J. (2016). Lunar true polar wander inferred from polar hydrogen. Nature, 531(7595), 480-4. https://doi.org/10.1038/nature17166
Siegler, M A, et al. "Lunar true polar wander inferred from polar hydrogen." Nature vol. 531,7595 (2016): 480-4. doi: https://doi.org/10.1038/nature17166
Siegler MA, Miller RS, Keane JT, Laneuville M, Paige DA, Matsuyama I, Lawrence DJ, Crotts A, Poston MJ. Lunar true polar wander inferred from polar hydrogen. Nature. 2016 Mar 24;531(7595):480-4. doi: 10.1038/nature17166. PMID: 27008966.
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Nature. 2016 Mar 24;531(7595):480-4. doi: 10.1038/nature17166.

Lunar true polar wander inferred from polar hydrogen.

Nature

M A Siegler, R S Miller, J T Keane, M Laneuville, D A Paige, I Matsuyama, D J Lawrence, A Crotts, M J Poston

Affiliations

  1. Planetary Science Institute, Tucson, Arizona 85719, USA.
  2. Southern Methodist University, Dallas, Texas 75275, USA.
  3. University of Alabama in Huntsville, Huntsville, Alabama 35899, USA.
  4. Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, USA.
  5. Earth Life Sciences Institute, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
  6. University of California, Los Angeles, California 90095, USA.
  7. The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723, USA.
  8. Columbia University, New York, New York 10027, USA.
  9. California Institute of Technology, Pasadena, California 91125, USA.

PMID: 27008966 DOI: 10.1038/nature17166

Abstract

The earliest dynamic and thermal history of the Moon is not well understood. The hydrogen content of deposits near the lunar poles may yield insight into this history, because these deposits (which are probably composed of water ice) survive only if they remain in permanent shadow. If the orientation of the Moon has changed, then the locations of the shadowed regions will also have changed. The polar hydrogen deposits have been mapped by orbiting neutron spectrometers, and their observed spatial distribution does not match the expected distribution of water ice inferred from present-day lunar temperatures. This finding is in contrast to the distribution of volatiles observed in similar thermal environments at Mercury's poles. Here we show that polar hydrogen preserves evidence that the spin axis of the Moon has shifted: the hydrogen deposits are antipodal and displaced equally from each pole along opposite longitudes. From the direction and magnitude of the inferred reorientation, and from analysis of the moments of inertia of the Moon, we hypothesize that this change in the spin axis, known as true polar wander, was caused by a low-density thermal anomaly beneath the Procellarum region. Radiogenic heating within this region resulted in the bulk of lunar mare volcanism and altered the density structure of the Moon, changing its moments of inertia. This resulted in true polar wander consistent with the observed remnant polar hydrogen. This thermal anomaly still exists and, in part, controls the current orientation of the Moon. The Procellarum region was most geologically active early in lunar history, which implies that polar wander initiated billions of years ago and that a large portion of the measured polar hydrogen is ancient, recording early delivery of water to the inner Solar System. Our hypothesis provides an explanation for the antipodal distribution of lunar polar hydrogen, and connects polar volatiles to the geologic and geophysical evolution of the Moon and the bombardment history of the early Solar System.

References

  1. Science. 2010 Oct 22;330(6003):479-82 - PubMed
  2. Science. 2014 Apr 4;344(6179):78-80 - PubMed
  3. Science. 2014 Dec 5;346(6214):1246753 - PubMed
  4. Astrobiology. 2010 Mar;10(2):183-200 - PubMed
  5. Astrobiology. 2008 Aug;8(4):793-804 - PubMed
  6. Nature. 2008 May 15;453(7193):368-71 - PubMed
  7. Nature. 2014 Aug 14;512(7513):181-4 - PubMed
  8. Science. 1998 Sep 4;281(5382):1476-80 - PubMed
  9. Science. 2013 Jan 18;339(6117):292-6 - PubMed
  10. Science. 2010 Oct 22;330(6003):463-8 - PubMed
  11. Science. 2010 Oct 22;330(6003):483-6 - PubMed
  12. Science. 1998 Sep 4;281(5382):1496-500 - PubMed
  13. Science. 2011 Nov 25;334(6059):1058-c - PubMed
  14. Science. 2013 Jun 28;340(6140):1552-5 - PubMed
  15. Science. 1968 Aug 16;161(3842):680-4 - PubMed
  16. Nature. 2007 Jun 14;447(7146):840-3 - PubMed
  17. Nature. 2014 Oct 2;514(7520):68-71 - PubMed
  18. Science. 2013 Feb 8;339(6120):668-71 - PubMed
  19. Science. 1975 Aug 1;189(4200):377-9 - PubMed
  20. Science. 2013 Jan 18;339(6117):300-3 - PubMed

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