Skip to main content

Thank you for visiting 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:

Sublimation in bright spots on (1) Ceres


The dwarf planet (1) Ceres, the largest object in the main asteroid belt1 with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth–Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity2,3. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery4 of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5, 6, 7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager8. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles9,10 may explain this haze. We conclude that Ceres must have accreted material from beyond the ‘snow line’11, which is the distance from the Sun at which water molecules condense.

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: Enhanced colour mosaic of the surface of Ceres.
Figure 2: Perspective views of brightest spots on Ceres.
Figure 3: Ceres colour spectra.
Figure 4: Views of Occator crater at different times.

Similar content being viewed by others


  1. Russell, C. T. & Raymond, C. A. (eds) The Dawn Mission to Minor Planets 4 Vesta and 1 Ceres (Springer, 2012)

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

    Article  ADS  Google Scholar 

  3. Castillo-Rogez, J. C. & McCord, T. B. Ceres’ evolution and present state constrained by shape data. Icarus 205, 443–459 (2010)

    Article  CAS  ADS  Google Scholar 

  4. Küppers, M. et al. Localized sources of water vapour on the dwarf planet (1) Ceres. Nature 505, 525–527 (2014)

    Article  ADS  Google Scholar 

  5. Lebofsky, L. A., Feierberg, M. A., Tokunaga, A. T., Larson, H. P. & Johnson, J. R. The 1.7- to 4.2-micron spectrum of asteroid 1 Ceres: evidence for structural water in clay minerals. Icarus 48, 453–459 (1981)

    Article  CAS  ADS  Google Scholar 

  6. A’Hearn, M. F. & Feldman, P. D. Water vaporization on Ceres. Icarus 98, 54–60 (1992)

    Article  ADS  Google Scholar 

  7. Rivkin, A. S. et al. Hydrogen concentrations on C-class asteroids derived from remote sensing. Meteorit. Planet. Sci. 38, 1383–1398 (2003)

    Article  CAS  ADS  Google Scholar 

  8. Sierks, H. et al. in The Dawn Mission to Minor Planets 4 Vesta and 1 Ceres (eds Russell, C. T. & Raymond, C. A. ) 263–327 (Springer, 2012)

  9. Yamamoto, T. & Ashihara, O. Condensation of ice particles in the vicinity of a cometary nucleus. Astron. Astrophys. 152, L17–L20 (1985)

    CAS  ADS  Google Scholar 

  10. Schmidt, J., Brilliantov, N., Spahn, F. & Kempf, S. Slow dust in Enceladus’ plume from condensation and wall collision in tiger stripe fractures. Nature 451, 685–688 (2008)

    Article  CAS  ADS  Google Scholar 

  11. Martin, R. G. & Livio, M. On the evolution of the snow line in protoplanetary discs. Mon. Not. R. Astron. Soc. 425, L6–L9 (2012)

    Article  CAS  ADS  Google Scholar 

  12. Reddy, V. et al. Color and albedo heterogeneity of Vesta from Dawn. Science 336, 700–704 (2012)

    Article  CAS  ADS  Google Scholar 

  13. Nathues, A. et al. Detection of serpentine in exogenic carbonaceous chondrite material on Vesta from Dawn FC data. Icarus 239, 222–237 (2014)

    Article  ADS  Google Scholar 

  14. Vilas, F. & McFadden, L. A. CCD reflectance spectra of selected asteroids. Icarus 100, 85–94 (1992)

    Article  ADS  Google Scholar 

  15. De Sanctis, M. C. et al. Ammoniated phyllosilicates with a likely outer Solar System origin on (1) Ceres. Nature (this issue)

  16. Milliken, R. E. & Mustard, J. F. Estimating the water content of hydrated minerals using reflectance spectroscopy: I. Effects of darkening agents and low-albedo materials. Icarus 189, 550–573 (2007)

    Article  CAS  ADS  Google Scholar 

  17. Ehlmann, B. L. et al. Geochemical consequences of widespread clay mineral formation in Mars’ ancient crust. Space Sci. Rev. 174, 329–364 (2013)

    Article  CAS  ADS  Google Scholar 

  18. Blinn, J. F. Light reflection functions for simulation of clouds and dusty surfaces. Comput. Graph. 16, 21–29 (1982)

    Article  Google Scholar 

  19. Hansen, C. J. et al. Enceladus’ water vapor plume. Science 311, 1422–1425 (2006)

    Article  CAS  ADS  Google Scholar 

  20. Cintala, M. J., Head, J. W. & Parmentier, M. E. Impact heating of H2O ice targets: applications to outer planet satellites. Lunar Planet. Sci. XI, 140–142 (1980)

    ADS  Google Scholar 

  21. Bowling, T. J., Minton, D. A., Castillo-Rogez, J. C., Johnson, B. C. & Steckloff, J. K. Eroding the hydrosphere of 1 Ceres: water mass loss due to impact induced sublimation. In Proc. Astrobiology Science Conf. 2015 abstr. 7478, (2015)

  22. Williams, N. R., Bell, J. F. III, Christensen, P. R. & Farmer, J. D. Evidence for an explosive origin of central pit craters on Mars. Icarus 252, 175–185 (2015)

    Article  ADS  Google Scholar 

  23. Soderblom, L. A. et al. Triton’s geyser-like plumes: discovery and basic characterization. Science 250, 410–415 (1990)

    Article  CAS  ADS  Google Scholar 

  24. Roth, L. et al. Transient water vapor at Europa’s south pole. Science 343, 171–174 (2014)

    Article  CAS  ADS  Google Scholar 

  25. Schenk, P. et al. Impact craters on Ceres: evidence for water-ice mantle? In European Planetary Science Congress 2015 Vol. 10, (2015)

  26. Gounelle, M. The asteroid-comet continuum: in search of lost primitivity. Geosci. World 7, 29–34 (2014)

    Google Scholar 

  27. Platz, T., Michael, G. G., Tanaka, K. L., Skinner, J. A. Jr & Fortezzo, C. M. Crater-based dating of geological units on Mars: methods and application for the new global geological map. Icarus 225, 806–827 (2013)

    Article  ADS  Google Scholar 

  28. Kneissl, T., van Gasselt, S. & Neukum, G. Map-projection-independent crater size-frequency determination in GIS environments — new software tool for ArcGIS. Planet. Space Sci. 59, 1243–1254 (2011)

    Article  ADS  Google Scholar 

  29. Michael, G. G. & Neukum, G. Planetary surface dating from crater size–frequency distribution measurements: partial resurfacing events and statistical age uncertainty. Earth Planet. Sci. Lett. 294, 223–229 (2010)

    Article  CAS  ADS  Google Scholar 

  30. Michael, G. G., Platz, T., Kneissl, T. & Schmedemann, N. Planetary surface dating from crater size–frequency distribution measurements: spatial randomness and clustering. Icarus 218, 169–177 (2012)

    Article  ADS  Google Scholar 

  31. Schmedemann, N. et al. A preliminary chronology for Ceres. In Lunar Planet. Sci. Conf. 46 abstr. 1418, (2015)

  32. Schmedemann, N. et al. The cratering record, chronology and surface ages of (4) Vesta in comparison to smaller asteroids and the ages of HED meteorites. Planet. Space Sci. 103, 104–130 (2014)

    Article  ADS  Google Scholar 

  33. Bishop, J. L. et al. Spectral properties of Na, Ca-, Mg- and Fe-chlorides and analyses of hydrohalite-bearing samples from Axel Heiberg Island. In Lunar Planet. Sci. Conf. 45 abstr. 2145, (2014)

  34. Sierks, H. et al. The Dawn Framing Camera. Space Sci. Rev. 163, 263–327 (2011)

    Article  ADS  Google Scholar 

  35. Reddy, V. et al. Photometric properties of Ceres from telescopic observations using Dawn Framing Camera color filters. In Lunar Planet. Sci. Conf. 46 abstr. 1663, (2015)

Download references


We thank the Dawn operations team for the development, cruise, orbital insertion and operations of the Dawn spacecraft at Ceres. We also thank the FC operations team, especially P. G. Gutierrez-Marques, I. Hall and I. Büttner. The FC project is financially supported by the Max Planck Society and the German Space Agency, DLR.

Author information

Authors and Affiliations



The respective observations were planned by the Dawn science-operations team involving A.N., M.H., M.S., C.A.R., C.T.R. and J.R. A.N., M.H., L.L.C., V.R., T.P., E.A.C., M.R.M.I., D.M.A., N.S. and T.K. contributed to the data analysis. The manuscript was written by A.N., M.H., M.S., L.L.C., V.R., T.P., E.A.C., N.S. and T.K. with reviews and updates by all authors.

Corresponding author

Correspondence to A. Nathues.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Clear filter mosaic and locations of bright material (red) and global lineaments (blue).

Background map of Ceres is shown in equirectangular projection, combining FC clear filter mosaics from two different sequences of observations during the Rotational Characterization 3 phase at a distance of ~14,000 km (RC3). Several mosaics (all sequences from RC3 phase) with different stretches have been used for the mapping of the linear features. Both fractures and alignment of circular features have been mapped in blue. The former features could correspond to faults, and the latter could be pit crater chains or secondary crater chains. Bright material surfaces are those showing an absolute reflectance larger than 0.037 at 0.55 μm.

Extended Data Figure 2 Interior of Occator crater.

a, Image shows a scene of the centre of Occator crater from High Altitude Mapping Orbit (FC image 40752, resolution ~140 m per pixel) revealing curvilinear depressions and a smooth pond-like feature (arrow at upper centre) at one of its ends. A possible explanation of the last feature is former short-term liquid-flow material. b, Central and peripheral bright spots within Occator crater. A nonlinear stretch is applied to enhance the interior structure of the bright spot. c, 3D anaglyph (red–cyan glasses are required to see this scene in 3D) showing the northeastern portion of Occator crater. A flow lobe with well-defined margins at the image’s centre is clearly visible. Note that the extent of secondary bright spot occurrences is confined to the extent of the flow lobe. Extensive slumping of wall material is observed in the northern portion of the crater. The anaglyph (images 40736 and 40752) has a vertical exaggeration of 1.9 if viewed at a distance of 50 cm. Arrows above scale bars point towards north; scale bars are 7 km long.

Extended Data Figure 3 Crater counting area, superposed impact craters and model age.

The upper panel shows the crater counting area (blue outline) and measured impact craters (red outlines) on the ejecta blanket of Occator crater (FC images 40498, 40499, 40736, 40737, 40753, 40768, 40991 and 41006). On the basis of the mapped crater size–frequency distribution, we derived a model age of 78 ± 5 Ma for the formation of Occator crater (lower panels) shown in cumulative (left) and differential (right) plots. To model an absolute age we used the production function (PF) and chronology function (CF) of ref. 31 and fitted the isochron to the crater diameter range 0.5–1.7 km. Error bars are ± the square-root of the cumulative number of craters per bin divided by the counting area—the largest bins contain fewer craters and therefore have the largest error bars. The reference value N(1) denotes the cumulative number of craters larger than 1 km in diameter per square kilometre. Upper insets show results from a Monte-Carlo-based randomness analysis for the measured crater population using the mean second-closest neighbour distance (‘M2CND’) and the standard deviation of adjacent area (‘SDAA’) methods30. Standard deviations nσ are plotted above and below the Monte-Carlo-derived mean. Details about the methods are given in ref. 30. Here, the observed crater population plots within the 3σ range indicating a random distribution.

Extended Data Figure 4 3D anaglyph of Occator crater.

The interior of the 90.5-km-diameter crater is characterized by an abundance of terraces and a smooth inner floor surface. The inner crater rim appears scalloped in places. The central pit with the brightest spot on Ceres is partially rimmed. Occator ejecta extend up to one crater diameter outwards, partially or completely burying pre-existing terrain and impact craters. The anaglyph is composed of FC images 37674 and 37666. Vertical exaggeration is approximately 4.5 if viewed at a distance of 50 cm.

Extended Data Figure 5 3D anaglyph of an unnamed crater hosting feature A.

The large crater accommodating feature A is degraded and marked by a low-relief crater rim partially eroded by subsequent impact craters. Its interior exhibits a densely cratered floor and hosts an asymmetric dome. The bright material is exposed within a 10-km-diameter crater on the wall of the larger, degraded crater and its vicinity. 3D anaglyph is composed of FC images 38409 and 38407. Vertical exaggeration is approximately 3.0 if viewed at a distance of 50 cm.

Extended Data Figure 6 Average FC colour spectrum (‘FC RC1’) of Ceres and ground-based spectra.

Ground-based spectra (‘SMASS sp41’, ‘24COLOR’ and ‘FC Ground-based’) of Ceres are presented for comparison. Ceres spectra, obtained by ground-based telescopes, in general show a large variety. The ground-based average colour spectrum of Ceres using FC spare filters35 is, except for filter 0.44 μm, in good agreement with the in-flight spectrum. We note that the ground-based spectra are obtained under different viewing geometries and are not photometrically corrected compared to the in-flight data. Ground-based spectra ‘SMASS sp41’ and ‘24COLOR’ are available at Spectrum ‘FC Ground-based’ is presented in ref. 35.

Extended Data Figure 7 Haze cloud intensity profile.

Two flux profiles from FC clear filter images across the central part of Occator crater (indicated by the red line; see inset). Units of flux are counts per pixel (~1.5 km × 1.5 km). Each profile crosses the centres of the brightest and second brightest spots (see inset, noon image 37113). Two images were selected, the first (37113) showing the scene at low incidence and high emission angles, that is, an oblique view near local noon (‘Noon profile’). The second image (36681) was obtained at high angles in both emission and incidence, showing an oblique view near local sunset (‘Sunset profile’). While the ‘Noon profile’ shows a signal enhancement centred between the peaks, the ‘Sunset profile’ does not show this. The enhancement is best described by a parabolic fit of the background, ignoring the signal peaks (‘Parabolic fit of haze’). The shape of this fit is consistent with a diffuse light scattering component in Occator crater at maximum insolation, observable at very oblique views, which increase the length of the light path through the layer, resembling the phenomena associated with a haze layer.

Related audio

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

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

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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.


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