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:

No evidence for thick deposits of ice at the lunar south pole

Nature volume 443, pages 835–837 (2006)Cite this article

Abstract

Shackleton crater at the Moon’s south pole has been suggested as a possible site of concentrated deposits of water ice, on the basis of modelling of bi-static radar polarization properties and interpretations of earlier Earth-based radar images1,2. This suggestion, and parallel assumptions about other topographic cold traps, is a significant element in planning for future lunar landings. Hydrogen enhancements have been identified in the polar regions3, but these data do not identify the host species or its local distribution. The earlier Earth-based radar data lack the resolution and coverage for detailed studies of the relationship between radar scattering properties, cold traps in permanently shadowed areas, and local terrain features such as the walls and ejecta of small craters. Here we present new 20-m resolution, 13-cm-wavelength radar images that show no evidence for concentrated deposits of water ice in Shackleton crater or elsewhere at the south pole. The polarization properties normally associated with reflections from icy surfaces in the Solar System4,5,6 were found at all the observed latitudes and are strongly correlated with the rock-strewn walls and ejecta of young craters, including the inner wall of Shackleton. There is no correlation between the polarization properties and the degree of solar illumination. If the hydrogen enhancement observed by the Lunar Prospector orbiter3 indicates the presence of water ice, then our data are consistent with the ice being present only as disseminated grains in the lunar regolith.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Radar image data from 24 October 2005, for a region covering the south pole and the nearside to latitude ∼68° S.
Figure 2: Comparison of the radar-scattering properties of Shackleton and Schomberger G craters from the 16 April 2005 data.

Similar content being viewed by others

References

  1. Nozette, S. et al. The Clementine bi-static radar experiment. Science 274, 1495–1498 (1996)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  3. Feldman, W. C. et al. Fluxes of fast and epithermal neutrons from Lunar Prospector: Evidence for water ice at the lunar poles. Science 281, 1496–1500 (1998)

    Article  ADS  CAS  Google Scholar 

  4. Campbell, D. B., Chandler, J. F., Ostro, S. J., Pettengill, G. H. & Shapiro, I. I. Galilean satellites—1976 radar results. Icarus 34, 254–267 (1978)

    Article  ADS  Google Scholar 

  5. Harmon, J. K., Arvidsen, R. E., Guinness, E. A., Campbell, B. A. & Slade, M. A. Mars mapping with delay-Doppler radar. J. Geophys. Res. 104, 14065–14090 (1999)

    Article  ADS  Google Scholar 

  6. Black, G. J. & Campbell, D. B. Rhea’s surface: Ice properties measured by radar. Bull. Am. Astron. Soc. 36, 1123 (2004)

    ADS  Google Scholar 

  7. 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 

  8. Arnold, J. R. Ice at the lunar poles. J. Geophys. Res. 84, 5659–5668 (1979)

    Article  ADS  Google Scholar 

  9. Slade, M. A., Butler, B. J. & Muhleman, D. O. Mercury radar imaging: Evidence for polar ice. Science 258, 635–640 (1992)

    Article  ADS  CAS  Google Scholar 

  10. Harmon, J. K. & Slade, M. A. Radar mapping of Mercury: Full disk images and polar anomalies. Science 258, 640–643 (1992)

    Article  ADS  CAS  Google Scholar 

  11. Campbell, B. A. Radar Remote Sensing of Planetary Surfaces (Cambridge Univ. Press, Cambridge, 2002)

  12. Hapke, B. Coherent backscatter and the radar characteristics of the outer planet satellites. Icarus 88, 407–417 (1990)

    Article  ADS  Google Scholar 

  13. Nelson, R. M., Hapke, B. W., Smythe, W. D. & Horn, L. J. Phase curves of selected particulate materials: The contribution of coherent backscattering to the opposition surge. Icarus 131, 223–230 (1998)

    Article  ADS  CAS  Google Scholar 

  14. Sprague, A. L., Hunten, D. M. & Lodders, K. Sulfur at Mercury, elemental at the poles and sulfides in the regolith. Icarus 118, 211–215 (1995)

    Article  ADS  CAS  Google Scholar 

  15. Harmon, J. K., Perillat, P. J. & Slade, M. A. High-resolution radar imaging of Mercury’s north pole. Icarus 149, 1–15 (2001)

    Article  ADS  CAS  Google Scholar 

  16. 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 

  17. Wilhelms, D. E., Howard, K. A. & Wilshire, H. G. USGS Map I-1162 (US Geological Survey, Washington DC, 1979)

  18. Campbell, B. A. & Campbell, D. B. Regolith properties in the south polar region of the Moon from 70-cm radar polarimetry. Icarus 180, 1–7 (2006)

    Article  ADS  Google Scholar 

  19. Campbell, B. A. & Hawke, B. R. Radar mapping of lunar cryptomaria east of Orientale basin. J. Geophys. Res. 110, (E9)E09002 (2005)

    Article  ADS  Google Scholar 

  20. Zuber, M. T. & Garrick-Bethell, I. What do we need to know to land on the Moon again? Perspective article. Science 310, 983–985 (2005)

    Article  CAS  Google Scholar 

  21. Benner, L. A. M. et al. Radar detection of near-Earth asteroids 2062 Aten, 2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN. Icarus 130, 296–312 (1997)

    Article  ADS  Google Scholar 

  22. Campbell, B. A., Campbell, D. B. & DeVries, C. Surface processes in the Venus highlands: Results from analysis of Magellan and Arecibo data. J. Geophys. Res. 104, 1897–1916 (1999)

    Article  ADS  Google Scholar 

  23. Campbell, B. A., Arvidson, R. E. & Shepard, M. K. Radar polarization properties of volcanic and playa surfaces: Applications to terrestrial remote sensing and Venus data interpretation. J. Geophys. Res. 98, 17099–17114 (1993)

    Article  ADS  Google Scholar 

  24. Margot, J. L., Campbell, D. B., Jurgens, R. F. & Slade, M. A. Topography of the lunar poles from radar interferometry: A survey of cold trap locations. Science 284, 1658–1660 (1999)

    Article  ADS  CAS  Google Scholar 

  25. Feldman, W. C. et al. Evidence for water ice near the lunar poles. J. Geophys. Res. 106, (E10)23231–23252 (2001)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We thank the staff of the Arecibo and Green Bank Observatories for their assistance with the observations, and J. Chandler for providing the lunar ephemeris observing files. This work was supported in part by grants from the NASA Planetary Astronomy and Planetary Geology and Geophysics Programs. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, which is operated by Cornell University under a cooperative agreement with the US National Science Foundation. The Green Bank Telescope is part of the National Radio Astronomy Observatory, a facility of the NSF operated under a cooperative agreement by Associated Universities, Inc. Author Contributions The work was initiated by D.B.C., who also wrote the initial draft of the paper. D.B.C., B.A.C., L.M.C. and J.-L.M. planned and made the observations. Software development and data reduction were done by B.A.C, L.M.C.and J.-L.M. All authors participated in the interpretation of the results.

Author information

Authors and Affiliations

  1. Department of Astronomy, Cornell University, Ithaca, New York, 14853, USA

    Donald B. Campbell & Jean-Luc Margot

  2. Center for Earth and Planetary Studies, Smithsonian Institution, Washington, Box 37012, DC 20013-7012, USA

    Bruce A. Campbell & Lynn M. Carter

  3. Defence Science and Technology Organization, Edinburgh, Box 1500, SA 5111, Australia

    Nicholas J. S. Stacy

Authors
  1. Donald B. Campbell
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Bruce A. Campbell
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Lynn M. Carter
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Jean-Luc Margot
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Nicholas J. S. Stacy
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Donald B. Campbell.

Ethics declarations

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Campbell, D., Campbell, B., Carter, L. et al. No evidence for thick deposits of ice at the lunar south pole. Nature 443, 835–837 (2006). https://doi.org/10.1038/nature05167

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature05167

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

Advanced 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