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.

  • Article
  • Published:

Composition and structure of the shallow subsurface of Ceres revealed by crater morphology

Nature Geoscience volume 9, pages 538–542 (2016)Cite this article

Subjects

Abstract

Before NASA’s Dawn mission, the dwarf planet Ceres was widely believed to contain a substantial ice-rich layer below its rocky surface. The existence of such a layer has significant implications for Ceres’s formation, evolution, and astrobiological potential. Ceres is warmer than icy worlds in the outer Solar System and, if its shallow subsurface is ice-rich, large impact craters are expected to be erased by viscous flow on short geologic timescales. Here we use digital terrain models derived from Dawn Framing Camera images to show that most of Ceres’s largest craters are several kilometres deep, and are therefore inconsistent with the existence of an ice-rich subsurface. We further show from numerical simulations that the absence of viscous relaxation over billion-year timescales implies a subsurface viscosity that is at least one thousand times greater than that of pure water ice. We conclude that Ceres’s shallow subsurface is no more than 30% to 40% ice by volume, with a mixture of rock, salts and/or clathrates accounting for the other 60% to 70%. However, several anomalously shallow craters are consistent with limited viscous relaxation and may indicate spatial variations in subsurface ice content.

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: The apparent depths of Ceres’ largest craters.
Figure 2: Comparison of the observed depths of Ceres’ largest craters with the depths expected for an ice-rich subsurface composition as a function of latitude.
Figure 3: The subsurface viscosity required to preserve crater topography on Ceres.
Figure 4: The topography of craters on Ceres that exhibit possible evidence for viscous relaxation.

Similar content being viewed by others

References

  1. Rivkin, A. S. et al. The surface composition of Ceres. Space Sci. Rev. 163, 95–116 (2011).

    Article  Google Scholar 

  2. De Sanctis, M. C. et al. Ammoniated phyllosilicates with a likely outer Solar System origin on (1) Ceres. Nature 528, 241–244 (2015).

    Article  Google Scholar 

  3. Ammannito, E. et al. The distribution of phyllosilicates on Ceres. Lunar Planet. Sci. Conf. 47, 3020 (2016).

    Google Scholar 

  4. Park, R. S. et al. Gravity science investigation of Ceres from Dawn. Lunar Planet. Sci. Conf. 47, 1781 (2016).

    Google Scholar 

  5. Russell, C. T. & Raymond, C. A. The dawn mission to Vesta and Ceres. Space Sci. Rev. 163, 3–23 (2011).

    Article  Google Scholar 

  6. Thomas, P. C. et al. Differentiation of the asteroid Ceres as revealed by its shape. Nature 437, 224–226 (2005).

    Article  Google Scholar 

  7. Castillo-Rogez, J. C. & McCord, T. B. Ceres evolution and present state constrained by shaped data. Icarus 205, 443–459 (2010).

    Article  Google Scholar 

  8. McCord, T. B. & Sotin, C. Ceres: evolution and current state. J. Geophys. Res. 110, E05009 (2005).

    Article  Google Scholar 

  9. Roberts, J. H. & Rivkin, A. S. The fate of Ceres’ original crust. AAS Div. Planet. Sci. Conf. 47, 212.07 (2015).

    Google Scholar 

  10. Zolotov, M. Y. On the composition and differentiation of Ceres. Icarus 204, 183–193 (2009).

    Article  Google Scholar 

  11. Castillo-Rogez, J. C. Ceres—Neither a porous nor salty ball. Icarus 215, 599–602 (2011).

    Article  Google Scholar 

  12. Hayne, P. O. & Aharonson, O. Thermal stability of ice on Ceres with rough topography. J. Geophys. Res. 120, 1567–1584 (2015).

    Article  Google Scholar 

  13. Bland, M. T. Predicted crater morphologies on Ceres: probing internal structure and evolution. Icarus 226, 510–521 (2013).

    Article  Google Scholar 

  14. Schenk, P. M. et al. Impact cratering on the small planets Ceres and Vesta: S-C transitions, central pits and the origin of the bright spots. Lunar Planet. Sci. Conf. 47, 2697 (2016).

    Google Scholar 

  15. Marchi, S. et al. Cratering on Ceres: the puzzle of the missing large craters. Lunar Planet Sci. Conf. 47, 1281 (2016).

    Google Scholar 

  16. Raymond, C. A. et al. The Dawn topography investigation. Space Sci. Rev. 163, 487–510 (2011).

    Article  Google Scholar 

  17. White, O. L. & Schenk, P. M. Crater shapes on the saturnian satellites: new measurements using Cassini stereo images. Lunar Planet Sci. Conf. 42, 2283 (2011).

    Google Scholar 

  18. Bray, V. J., Collins, G. S., Morgan, J. V. & Schenk, P. M. The effects of target properties on crater morphology: comparison of central peak craters on the Moon and Ganymede. Meteorit. Planet. Sci. 43, 1979–1992 (2008).

    Article  Google Scholar 

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

    Google Scholar 

  20. Barr, A. C. & McKinnon, W. B. Convection in ice I shells and mantles with self-consistent grain size. J. Geophys. Res. 112, E02012 (2007).

    Article  Google Scholar 

  21. Durham, W. B. & Stern, L. A. Rheological properties of water ice—Applications to satellites of the outer planets. Annu. Rev. Earth Planet. Sci. 29, 295–330 (2001).

    Article  Google Scholar 

  22. Ermakov, A. I. et al. Evaluation of Ceres’ compensation state. Lunar Planet. Sci. Conf. 47, 1708 (2016).

    Google Scholar 

  23. Roscoe, R. The viscosity of suspensions of rigid spheres. Br. J. Appl. Phys. 3, 267–269 (1952).

    Article  Google Scholar 

  24. Friedson, A. J. & Stevenson, D. J. Viscosity of rock-ice mixtures and applications to the evolution of the icy satellites. Icarus 56, 1–14 (1983).

    Article  Google Scholar 

  25. Durham, W. B., Kirby, S. H. & Stern, L. A. Effects of dispersed particulated on the rheology of water ice at planetary conditions. J. Geophys. Res. 97, 20883–20897 (1992).

    Article  Google Scholar 

  26. Durham, W. B., Pathare, A. V., Stern, L. A. & Lenferink, H. J. Mobility of icy sand packs, with application to Martian permafrost. Geophys. Res. Lett. 36, L23203 (2009).

    Article  Google Scholar 

  27. Mangold, N., Allemand, P., Duval, P., Geraud, Y. & Thomas, P. Experimental and theoretical deformation of ice-rock mixtures: implications on rheology and ice content of Martian permafrost. Planet. Space. Sci. 50, 385–401 (2002).

    Article  Google Scholar 

  28. McCarthy, C., Cooper, R. F., Goldsby, D. L., Durham, W. B. & Kirby, S. H. Transient and steady state creep response of ice I and magnesium sulfate hydrate eutectic aggregates. J. Geophys. Res. 116, E04007 (2011).

    Google Scholar 

  29. Durham, W. B., Prieto-Ballesteros, O., Goldsby, D. L. & Kargel, J. S. Rheology and thermal properties of icy material. Space Sci. Rev. 153, 273–298 (2010).

    Article  Google Scholar 

  30. De Sanctis, M. C. et al. Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres. Nature http://dx.doi.org/10.1038/nature18290 (2016).

  31. Nathues, A. et al. Sublimation in bright spots on (1) Ceres. Nature 528, 237–240 (2015).

    Article  Google Scholar 

  32. Melosh, H. J. Impact Cratering: A Geologic Process (Oxford Univ. Press, 1989).

    Google Scholar 

  33. Parmentier, E. M. & Head, J. W. Viscous relaxation of impact craters on icy planetary surfaces: determination of viscosity variation with depth. Icarus 47, 100–111 (1981).

    Article  Google Scholar 

  34. Melosh, H. J. & Raefsky, A. The dynamical origin of subduction zone topography. Geophys. J. R. Astron. Soc. 60, 333–334 (1980).

    Article  Google Scholar 

  35. Dombard, A. J. & McKinnon, W. B. Elastoviscoplastic relaxation of impact crater topography with application to Ganymede and Callisto. J. Geophys. Res. 111, E01001 (2006).

    Article  Google Scholar 

  36. Ranalli, G. The Rheology of the Earth 76–77 (Chapman and Hall, 1995).

    Google Scholar 

  37. Bland, M. T. & McKinnon, W. B. Forming Europa’s folds: strain requirements for the production of large-amplitude deformation. Icarus 221, 694–709 (2012).

    Article  Google Scholar 

  38. De La Chappelle, S., Castelnau, O., Lipenkov, V. & Duval, P. Dynamic recrystallization and texture development in ice as revealed by the study of the deep ice cores in Antarctica and Greenland. J. Geophys. Res. 103, 5091–5105 (1998).

    Article  Google Scholar 

  39. Souchez, R. A. & Lorrain, R. D. Ice Composition and Glacier Dynamics (Springer, 1991).

    Book  Google Scholar 

  40. Pathare, A. V., Paige, D. & Turtle, E. Viscous relaxation of craters within the Martian south polar layered deposits. Icarus 174, 396–418 (2005).

    Article  Google Scholar 

  41. Sori, M. M., Byrne, S., Hamilton, C. W. & Landis, M. E. Viscous flow rates of icy topography on the north polar layered deposits of Mars. Geophys. Res. Lett. 43, 3060–3068 (2016).

    Article  Google Scholar 

Download references

Acknowledgements

M.T.B. thanks Trent Hare for ArcGIS support. This work was supported by NASA’s Dawn Guest Investigator Program (NNH15AZ85I).

Author information

Authors and Affiliations

  1. US Geological Survey, Astrogeology Science Center, Flagstaff, Arizona 86001, USA

    Michael T. Bland

  2. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA

    Carol A. Raymond, Ryan S. Park & Julie C. Castillo-Rogez

  3. Lunar and Planetary Institute, Houston, Texas 77058, USA

    Paul M. Schenk

  4. Columbia University, New York, New York 10027, USA

    Roger R. Fu

  5. Institute of Geological Sciences, Freie Universität Berlin, Berlin 12249, Germany

    Thomas Kneissl

  6. Institut für Planetologie, Westfälische Wilhelms-Universität, Münster 48149, Germany

    Jan Hendrik Pasckert & Harry Hiesinger

  7. German Aerospace Center (DLR), Berlin 12489, Germany

    Frank Preusker

  8. Southwest Research Institute, Boulder, Colorado 80302, USA

    Simone Marchi

  9. Virginia Institute of Technology, Blacksburg, Virginia 24061, USA

    Scott D. King

  10. Department of Earth and Space Sciences, University of California, Los Angeles, California 90095, USA

    Christopher T. Russell

Authors
  1. Michael T. Bland
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Carol A. Raymond
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Paul M. Schenk
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Roger R. Fu
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Thomas Kneissl
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Jan Hendrik Pasckert
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Harry Hiesinger
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Frank Preusker
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Ryan S. Park
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Simone Marchi
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Scott D. King
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Julie C. Castillo-Rogez
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Christopher T. Russell
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

M.T.B. measured all craters, designed, performed and analysed all simulations, and wrote the manuscript. P.M.S. provided comparison data for crater depths on planetary bodies and discussed the results and implications of the observations and simulations. T.K., J.H.P. and H.H. provided crater counts for Coniraya and Vinotonus and discussed implications of the results. F.P. and R.S.P. created and provided the DTMs used to measure crater depths. C.A.R., R.R.F., J.C.C.-R., S.D.K. and S.M. provided substantive discussion of the observations, simulations and implications for Ceres’ near-surface composition, and provided critical comments on the manuscript at all stages of development. C.T.R. is responsible for the Dawn mission and all data acquisition.

Corresponding author

Correspondence to Michael T. Bland.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 5917 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bland, M., Raymond, C., Schenk, P. et al. Composition and structure of the shallow subsurface of Ceres revealed by crater morphology. Nature Geosci 9, 538–542 (2016). https://doi.org/10.1038/ngeo2743

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo2743

This article is cited by

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