Abstract

The typically dark surface of the dwarf planet Ceres is punctuated by areas of much higher albedo, most prominently in the Occator crater1. These small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate1, in contrast to the average surface, which is a mixture of low-albedo materials and magnesium phyllosilicates, ammoniated phyllosilicates and carbonates2,3,4. Here we report high spatial and spectral resolution near-infrared observations of the bright areas in the Occator crater on Ceres. Spectra of these bright areas are consistent with a large amount of sodium carbonate, constituting the most concentrated known extraterrestrial occurrence of carbonate on kilometre-wide scales in the Solar System. The carbonates are mixed with a dark component and small amounts of phyllosilicates, as well as ammonium carbonate or ammonium chloride. Some of these compounds have also been detected in the plume of Saturn’s sixth-largest moon Enceladus5. The compounds are endogenous and we propose that they are the solid residue of crystallization of brines and entrained altered solids that reached the surface from below. The heat source may have been transient (triggered by impact heating). Alternatively, internal temperatures may be above the eutectic temperature of subsurface brines, in which case fluids may exist at depth on Ceres today.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

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

  2. 2.

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

  3. 3.

    , , , & Evidence for ammonium-bearing minerals on Ceres. Science 255, 1551–1553 (1992)

  4. 4.

    et al. Distribution of phyllosilicates on Ceres. Science (in the press)

  5. 5.

    , , , & A salt-water reservoir as the source of a compositionally stratified plume on Enceladus. Nature 474, 620–622 (2011)

  6. 6.

    et al. The geomorphology of Ceres. Science (in the press)

  7. 7.

    et al. The VIR spectrometer. Space Sci. Rev. 163, 329–369 (2011)

  8. 8.

    , & The surface composition of Ceres: discovery of carbonates and iron-rich clays. Icarus 185, 563–567 (2006)

  9. 9.

    in Micas: Crystal Chemistry and Metamorphic Petrology (eds , , & ). 351–370 (Mineralogical Society of America, 2002)

  10. 10.

    et al. Reflectance and emission spectroscopy study of four groups of phyllosilicates: smectites, kaolinite-serpentines, chlorites and micas. Clay Miner. 43, 35–54 (2008)

  11. 11.

    & Visible and near infrared spectra of minerals and rocks. II. Carbonates. Mod. Geol. 2, 23–30 (1971)

  12. 12.

    & Visible-near infrared spectra of hydrous carbonates, with implications for the detection of carbonates in hyperspectral data of Mars. Icarus 250, 204–214 (2015)

  13. 13.

    et al. Ammonia water ice laboratory studies relevant to outer Solar System surfaces. Icarus 190, 260–273 (2007)

  14. 14.

    , & Radiation products in processed ices relevant to Edgeworth-Kuiper-belt objects. Earth Moon Planets 92, 291–306 (2003)

  15. 15.

    et al. Reflectance spectroscopy (0.35–8 μm) of ammonium-bearing minerals and qualitative comparison to Ceres-like asteroid. Icarus 265, 218–237 (2016)

  16. 16.

    , & Carbonates in CM chondrites: complex formational histories and comparison to carbonates in CI chondrites. Meteorit. Planet. Sci. 45, 513–530 (2010)

  17. 17.

    & Carbonate compositions in CM and CI chondrites and implications for aqueous alteration. Geochim. Cosmochim. Acta 57, 2843–2852 (1993)

  18. 18.

    in Meteorites and the Early Solar System II 587–624 (Univ. Arizona Press, 2006)

  19. 19.

    . Aqueous fluid composition in CI chondritic materials: chemical equilibrium assessments in closed systems. Icarus 220, 713–729 (2012)

  20. 20.

    An oceanic composition on early and today’s Enceladus. Geophys. Res. Lett. 34, L23203 (2007)

  21. 21.

    & Ceres’ evolution and present state constrained by shape data. Icarus 205, 443–459 (2010)

  22. 22.

    et al. Impact induced heating of Occator crater on asteroid 1 Ceres. 47th Lunar Planetary Sci. Conf. abstr. 2268 (2016)

  23. 23.

    et al. Liquid water on Enceladus from observations of ammonia and 40Ar in the plume. Nature 460, 487–490 (2009)

  24. 24.

    et al. Sodium salts in E ring ice grains from an ocean below the surface of Enceladus. Nature 459, 1098–1101 (2009)

  25. 25.

    Theory of Reflectance and Emittance Spectroscopy (Cambridge Univ. Press, 2012)

  26. 26.

    , , , & Spectral variability of plagioclase-mafic mixtures (2): investigation of the optical constant and retrieved mineral abundance dependence on particle size distribution. Icarus 235, 207–219 (2014)

  27. 27.

    Spectrophotometric analysis of cometary nuclei from in situ observations. PhD thesis, Univ. degli studi di Roma Tor Vergata; preprint at (2015)

  28. 28.

    et al. The diurnal cycle of water ice on comet 67P/Churyumov–Gerasimenko. Nature 525, 500–503 (2015)

  29. 29.

    et al. Exposed water ice on the nucleus of comet 67P/Churyumov–Gerasimenko. Nature 529, 368–372 (2016)

  30. 30.

    Optical constants of ice from the ultraviolet to the microwave. Appl. Opt. 23, 1206–1225 (1984)

  31. 31.

    et al. Optical constants of amorphous and crystalline H2O-ice in the near infrared from 1.1 to 2.6 μm. Icarus 197, 307–320 (2008)

  32. 32.

    et al. Optical constants of amorphous and crystalline H2O-ice: 2.5–22 μm (4000–455 cm-1) optical constants of H2O-ice. Astrophys. J. 701, 1347–1356 (2009)

  33. 33.

    et al. The surface composition of Iapetus: mapping results from Cassini VIMS. Icarus 218, 831–860 (2012)

  34. 34.

    Soda ash, Solvay style. Today's Chemist at Work 11 (2), 87–88, 90 (2002)

  35. 35.

    et al. Splib06a. US Geol. Surv. Data 231, (USGS Digital Spectral Library, 2007)

  36. 36.

    et al. Nature and degree of aqueous alteration in CM and CI carbonaceous chondrites. Meteorit. Planet. Sci. 48, 1618–1637 (2013)

  37. 37.

    & Quantifying absolute water content of minerals using near infrared reflectance spectroscopy. J. Geophys. Res. 110, E12001 (2005)

Download references

Acknowledgements

We thank the following institutions and agencies which supported this work: the Italian Space Agency, the National Aeronautics and Space Administration (NASA, USA) and the Deutsches Zentrum für Luft- und Raumfahrt (DLR, Germany). The VIR was funded and coordinated by the Italian Space Agency and built by SELEX ES, with the scientific leadership of the Institute for Space Astrophysics and Planetology and the Italian National Institute for Astrophysics, and is operated by the Institute for Space Astrophysics and Planetology, Italy. A portion of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, USA, under contract to NASA. We also thank the Dawn Mission Operations team and the Framing Camera team.

Author information

Affiliations

  1. Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Via del Fosso del Cavaliere 100, 00133 Rome, Italy

    • M. C. De Sanctis
    • , A. Raponi
    • , E. Ammannito
    • , M. Ciarniello
    • , F. G. Carrozzo
    • , S. Marchi
    • , F. Tosi
    • , F. Zambon
    • , F. Capaccioni
    • , M. T. Capria
    • , S. Fonte
    • , M. Formisano
    • , A. Frigeri
    • , M. Giardino
    • , A. Longobardo
    • , G. Magni
    •  & E. Palomba
  2. Earth Planetary and Space Sciences, University of California, Los Angeles, California, USA

    • E. Ammannito
    •  & C. T. Russell
  3. Institut de Recherche d’Astrophysique et Planétologie, Université de Toulouse, Centre National de la Recherche Scientifique (CNRS), Université Paul Sabatier (UPS), Toulouse, France

    • M. J. Toplis
  4. Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee 37996-1410, USA

    • H. Y. McSween
  5. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA

    • J. C. Castillo-Rogez
    • , B. L. Ehlmann
    •  & C. A. Raymond
  6. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA

    • B. L. Ehlmann
  7. Solar System Exploration Research Virtual Institute, Southwest Research Institute (SRI), 1050 Walnut Street, Boulder, Colorado 80302, USA

    • S. Marchi
  8. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA

    • L. A. McFadden
  9. Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA

    • C. M. Pieters
  10. Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstrasse 2, 12489 Berlin, Germany

    • R. Jaumann
  11. Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, Texas 77058, USA

    • P. Schenk
  12. Agenzia Spaziale Italiana, Via del Politecnico, 00133 Roma, Rome, Italy

    • R. Mugnuolo

Authors

  1. Search for M. C. De Sanctis in:

  2. Search for A. Raponi in:

  3. Search for E. Ammannito in:

  4. Search for M. Ciarniello in:

  5. Search for M. J. Toplis in:

  6. Search for H. Y. McSween in:

  7. Search for J. C. Castillo-Rogez in:

  8. Search for B. L. Ehlmann in:

  9. Search for F. G. Carrozzo in:

  10. Search for S. Marchi in:

  11. Search for F. Tosi in:

  12. Search for F. Zambon in:

  13. Search for F. Capaccioni in:

  14. Search for M. T. Capria in:

  15. Search for S. Fonte in:

  16. Search for M. Formisano in:

  17. Search for A. Frigeri in:

  18. Search for M. Giardino in:

  19. Search for A. Longobardo in:

  20. Search for G. Magni in:

  21. Search for E. Palomba in:

  22. Search for L. A. McFadden in:

  23. Search for C. M. Pieters in:

  24. Search for R. Jaumann in:

  25. Search for P. Schenk in:

  26. Search for R. Mugnuolo in:

  27. Search for C. A. Raymond in:

  28. Search for C. T. Russell in:

Contributions

M.C.D.S., A.R., E.A. and F.G.C. performed data analysis and calibration. M.C. provided optical constants from reflectance spectra. M.C.D.S., C.M.P. and B.L.E. contributed to the spectral interpretation of the data. All authors contributed to the discussion of the results and to writing the paper.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to M. C. De Sanctis.

The VIR calibrated data will be made available through the PDS Small Bodies Node website (http://sbn.pds.nasa.gov/).

Reviewer Information Nature thanks V. Reddy, A. S. Rivkin and M. M. Zolotov for their contribution to the peer review of this work.

Extended data

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature18290

Further reading

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.