Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Constraints on the volatile distribution within Shackleton crater at the lunar south pole

Abstract

Shackleton crater is nearly coincident with the Moon’s south pole. Its interior receives almost no direct sunlight and is a perennial cold trap1,2, making Shackleton a promising candidate location in which to seek sequestered volatiles3. However, previous orbital and Earth-based radar mapping4,5,6,7,8 and orbital optical imaging9 have yielded conflicting interpretations about the existence of volatiles. Here we present observations from the Lunar Orbiter Laser Altimeter on board the Lunar Reconnaissance Orbiter, revealing Shackleton to be an ancient, unusually well-preserved simple crater whose interior walls are fresher than its floor and rim. Shackleton floor deposits are nearly the same age as the rim, suggesting that little floor deposition has occurred since the crater formed more than three billion years ago. At a wavelength of 1,064 nanometres, the floor of Shackleton is brighter than the surrounding terrain and the interiors of nearby craters, but not as bright as the interior walls. The combined observations are explicable primarily by downslope movement of regolith on the walls exposing fresher underlying material. The relatively brighter crater floor is most simply explained by decreased space weathering due to shadowing, but a one-micrometre-thick layer containing about 20 per cent surficial ice is an alternative possibility.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Detailed characterization of Shackleton crater.
Figure 2: High-resolution elevation map in stereographic projection of the floor of Shackleton.

Similar content being viewed by others

References

  1. Watson, K., Murray, B. C. & Brown, H. The behavior of volatiles on the lunar surface. J. Geophys. Res. 66, 3033–3045 (1961)

    Article  ADS  Google Scholar 

  2. Arnold, J. R. Ice in the lunar polar regions. J. Geophys. Res. 84, 5659–5668 (1979)

    Article  ADS  Google Scholar 

  3. Spudis, P. D., Plescia, J., Josset, J.-L. & Beauvivre, S. Geology of Shackleton Crater and the south pole of the Moon. Geophys. Res. Lett.. 36, L14201, http://dx.doi.org/10.1029/2008GL034468 (2008)

  4. Nozette, S. et al. The Clementine bistatic radar experiment. Science 274, 1495–1498 (1996)

    Article  ADS  CAS  Google Scholar 

  5. Stacy, N. J. S., Campbell, D. B. & Ford, P. G. Arecibo radar mapping of the lunar poles: a search for ice deposits. Science 276, 1527–1530 (1997)

    Article  ADS  CAS  Google Scholar 

  6. Campbell, D. B., Campbell, B. A., Carter, L. M., Margot, J.-L. & Stacy, N. J. S. No evidence for thick deposits of ice at the lunar south pole. Nature 443, 835–837 (2006)

    Article  ADS  CAS  Google Scholar 

  7. Simpson, R. & Tyler, G. L. Reanalysis of Clementine bistatic radar data from the lunar south pole. J. Geophys. Res. 104, 3845–3862 (1999)

    Article  ADS  Google Scholar 

  8. Nozette, S. et al. Integration of lunar polar remote-sensing data sets: evidence for ice at the lunar south pole. J. Geophys. Res. 106 (E10). 23253–23266 (2001)

    Article  ADS  CAS  Google Scholar 

  9. Haruyama, J. et al. Lack of exposed ice inside lunar south pole Shackleton crater. Science 322, 938–939 (2008)

    Article  ADS  CAS  Google Scholar 

  10. Smith, D. E. et al. The Lunar Orbiter Laser Altimeter investigation on the Lunar Reconnaissance Orbiter mission. Space Sci. Rev. 150, 209–241 (2010)

    Article  ADS  Google Scholar 

  11. Smith, D. E. et al. Results from the Lunar Orbiter Laser Altimeter (LOLA): global, high resolution topographic mapping of the Moon. Lunar Planet. Sci. Conf. XLII, 2350 (2011)

    ADS  Google Scholar 

  12. Mazarico, E. et al. Orbit determination of the Lunar Reconnaissance Orbiter. J. Geod. 86, 193–207 (2012)

    Article  ADS  Google Scholar 

  13. Sun, X. et al. The Laser Ranging Subsystem on the Lunar Reconnaissance Orbiter. Report No. GSC-15884-1 (NASA New Technology Report, Washington DC, 2009)

  14. Zuber, M. T. et al. The Lunar Reconnaissance Orbiter laser ranging investigation. Space Sci. Rev. 150, 63–80 (2010)

    Article  ADS  Google Scholar 

  15. Neumann, G. A., Rowlands, D. D., Lemoine, F. G., Smith, D. E. & Zuber, M. T. Crossover analysis of MOLA altimetric data. J. Geophys. Res. 106 (E10). 23753–23768 (2001)

    Article  ADS  Google Scholar 

  16. Thomson, B. J. et al. The interior of Shackleton crater as revealed by Mini-RF orbital radar. Lunar Planet. Sci. Conf. XLII, 1626 (2011)

    ADS  Google Scholar 

  17. Pike, R. J. in Impact and Explosion Cratering (eds Roddy, D. J., Pepin, R. O. & Merrill R. B., ) 489–509 (Pergamon, 1977)

    Google Scholar 

  18. Squyres, S. W. et al. Exploration of Victoria crater by the Mars Rover Opportunity. Science 324, 1058–1061 (2009)

    Article  ADS  CAS  Google Scholar 

  19. Wilhelms, D. E., Howard, K. A. & Wilshire, H. G. Geologic Map of the South Side of the Moon (Map I-1162, US Geological Survey, 1979)

    Google Scholar 

  20. Ward, W. R. Past orientation of the lunar spin axis. Science 189, 377–379 (1975)

    Article  ADS  CAS  Google Scholar 

  21. Howard, K. A. Fresh lunar impact craters — review of variations with size. In Proc. 5th Lunar Sci. Conf. 61–69 (Pergamon, 1974)

    Google Scholar 

  22. Pike, R. J. Depth/diameter relations of fresh lunar craters: revision from spacecraft data. Geophys. Res. Lett. 1, 291–294 (1974)

    Article  ADS  Google Scholar 

  23. Hapke, B. Space weathering from Mercury to the asteroid belt. J. Geophys. Res. 106 (E5). 10039–10073 (2001)

    Article  ADS  CAS  Google Scholar 

  24. Zimmerman, M. I. Farrell, W. M., Stubbs, T. J., Halekas, J. S. & Jackson, T. L. Solar wind access to polar craters: feedback between surface charging and plasma expansion. Geophys. Res. Lett.. 38, L19202, http://dx.doi.org/10.1029/2011GL048880 (2011)

  25. Kwok, R., Cunningham, G. F., Zwally, H. J. & Yi, D. ICESat over Arctic sea ice: Interpretation of altimetric and reflectivity profiles. J. Geophys. Res.. 111, C06006, http://dx.doi.org/10.1029/2005JC003175 (2006)

  26. Pieters, C. M. et al. Character and spatial distribution of OH/H2O on the surface of the Moon seen by M3 on Chandrayaan-1. Science 326, 568–572 (2009)

    Article  ADS  CAS  Google Scholar 

  27. Gladstone, G. R. et al. Far-ultraviolet reflectance properties of the Moon’s permanently shadowed regions. J. Geophys. Res.. 117, E00H04, http://dx.doi.org/10.1029/2011JE003913 (2012)

    Article  Google Scholar 

  28. Folkner, W. M., Williams, J. G. & Boggs, D. H. The Planetary and Lunar Ephemeris DE421 (Jet Propulsion Laboratory, Pasadena, 2008)

    Google Scholar 

  29. Pavlis, D. E., Poulouse, S. G. & McCarthy, J. J. GEODYN Operations Manuals (SGT, Inc., Greenbelt, 2009)

    Google Scholar 

  30. Mazarico, E., Lemoine, F. G., Han, S.-C. & Smith, D. E. GLGM-3, a degree-150 lunar gravity model from the historical tracking data of NASA Moon orbiters. J. Geophys. Res.. 115, E05001, http://dx.doi.org/10.1029/2009JE003472 (2010)

  31. Williams, J. G., Boggs, D. H. & Folkner, W. M. Lunar Orbit, Physical Librations and Surface Coordinates (Jet Propulsion Laboratory, Pasadena, 2008)

    Google Scholar 

Download references

Acknowledgements

The LOLA investigation is supported by the Lunar Reconnaissance Orbiter Mission under the auspices of NASA’s Exploration Systems Mission Directorate and Science Mission Directorate. We thank T. Perron for discussions.

Author information

Authors and Affiliations

Authors

Contributions

M.T.Z. led and participated in all aspects of the analysis and wrote the paper. J.W.H. oversaw the relative age dating analysis and participated in geologic interpretation of topography, slopes and roughness. D.E.S. led the acquisition and correction of the LOLA observations. G.A.N. led the slope and roughness analysis and contributed to the development of the topographic grid. E.M. performed refined orbit adjustments and led the analysis of illumination. A.R.T. and C.I.F. performed the crater counts used in the relative age date analysis. O.A. and M.A.R. contributed to the analysis and interpretation of slopes and roughness. H.J.M. contributed to the interpretation of the crater morphology in the context of Shackleton’s geological history and volatile sequestration.

Corresponding author

Correspondence to Maria T. Zuber.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text, Supplementary Table 1, Supplementary Figures 1-2 and additional references. (PDF 402 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zuber, M., Head, J., Smith, D. et al. Constraints on the volatile distribution within Shackleton crater at the lunar south pole. Nature 486, 378–381 (2012). https://doi.org/10.1038/nature11216

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature11216

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing