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:

Detection of ice and organics on an asteroidal surface

Nature volume 464, pages 1322–1323 (2010)Cite this article

Subjects

Abstract

Recent observations, including the discovery1 in typical asteroidal orbits of objects with cometary characteristics (main-belt comets, or MBCs), have blurred the line between comets and asteroids, although so far neither ice nor organic material has been detected on the surface of an asteroid or directly proven to be an asteroidal constituent. Here we report the spectroscopic detection of water ice and organic material on the asteroid 24 Themis, a detection that has been independently confirmed2. 24 Themis belongs to the same dynamical family as three of the five known MBCs, and the presence of ice on 24 Themis is strong evidence that it also is present in the MBCs. We conclude that water ice is more common on asteroids than was previously thought and may be widespread in asteroidal interiors at much smaller heliocentric distances than was previously expected.

Access through your institution
Buy or subscribe

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

Access options

Access through your institution

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

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

Figure 1: The reflectance spectra of 24 Themis are well fitted by a mixture of ice-coated pyroxene grains and amorphous carbon.
Figure 2: Organic material is present on the surface of 24 Themis.

Similar content being viewed by others

References

  1. Hsieh, H. H. & Jewitt, D. A population of comets in the main asteroid belt. Science 312, 561–563 (2006)

    Article  ADS  CAS  Google Scholar 

  2. Campins, H. et al. Water ice and organics on the surface of the asteroid 24 Themis. Nature 10.1038/nature09029 (this issue)

  3. Rayner, J. T. et al. SpeX: a medium-resolution 0.8–5.5 micron spectrograph and imager for the NASA Infrared Telescope Facility. Publ. Astron. Soc. Pacif. 115, 362–382 (2003)

    Article  ADS  Google Scholar 

  4. Cushing, M. C., Vacca, W. D. & Rayner, J. T. Spextool: a spectral extraction package for SpeX, a 0.8–5.5 micron cross-dispersed spectrograph. Publ. Astron. Soc. Pacif. 116, 362–376 (2004)

    Article  ADS  Google Scholar 

  5. Lebofsky, L. A. et al. A refined ‘standard’ thermal model for asteroids based on observations of 1 Ceres and 2 Pallas. Icarus 68, 239–251 (1986)

    Article  ADS  CAS  Google Scholar 

  6. Mastrapa, R. M., Sandford, S. A., Roush, T. L., Cruikshank, D. P. & Dalle Ore, C. M. Optical constants of amorphous and crystalline H2O-ice: 2.5–22 μm (4000–455 cm-1). Astrophys. J. 701, 1347–1356 (2009)

    Article  ADS  CAS  Google Scholar 

  7. Emery, J. P., Cruikshank, D. P. & van Cleve, J. Thermal emission spectroscopy (5.2–38 μm) of three Trojan asteroids with the Spitzer Space Telescope: detection of fine-grained silicates. Icarus 182, 496–512 (2006)

    Article  ADS  Google Scholar 

  8. Shkuratov, Starukhina, L., Hoffmann, H. & Arnold, G. A model of spectral albedo of particulate surfaces: implications for optical properties of the Moon. Icarus 137, 235–246 (1999)

    Article  ADS  CAS  Google Scholar 

  9. Khare, B. N. et al. Production and optical constraints of ice tholin from charged particle irradiation of (1:6) C2H6/H2O at 77 K. Icarus 103, 290–300 (1993)

    Article  ADS  CAS  Google Scholar 

  10. Colangeli, L., Mennella, V., Baratt, G. A., Bussoletti, E. & Strazzulla, G. Raman and infrared spectra of polycyclic aromatic hydrocarbon molecules of possible astrophysical interest. Astrophys. J. 396, 369–377 (1992)

    Article  ADS  CAS  Google Scholar 

  11. Jones, T. D. An Infrared Reflectance Study of Water in Outer Belt Asteroids: Clues to Composition and Origin. Ph.D. thesis, Univ. Arizona (1988)

    Google Scholar 

  12. Schorghofer, N. The lifetime of ice on main belt asteroids. Astrophys. J. 682, 697–705 (2008)

    Article  ADS  Google Scholar 

  13. Cohen, B. A. & Coker, R. F. Modeling of liquid water on CM meteorite parent bodies and implications for amino acid racemization. Icarus 145, 369–381 (2000)

    Article  ADS  CAS  Google Scholar 

  14. Dorschner, J., Begemann, B., Henning, T., Jaeger, C. & Mutschke, H. Steps toward interstellar silicate mineralogy. II. Study of Mg-Fe-silicate glasses of variable composition. Astron. Astrophys. 300, 503–520 (1995)

    ADS  CAS  Google Scholar 

  15. Moroz, L. V., Arnold, G., Korochantsev, A. V. & Wasch, R. Natural solid bitumens as possible analogs for cometary and asteroid organics. Icarus 134, 253–268 (1998)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the NASA Planetary Astronomy programme. A.S.R. is a visiting astronomer at the IRTF, which is operated by the University of Hawaii under cooperative agreement no. NNX-08AE38A with NASA, Science Mission Directorate, Planetary Astronomy programme. All the observations used in this publication were obtained at the IRTF. We would like to thank the telescope operators of the IRTF for their efforts.

Author information

Authors and Affiliations

  1. Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723, USA ,

    Andrew S. Rivkin

  2. Earth and Planetary Science Department, University of Tennessee, Knoxville, Tennessee 37996, USA,

    Joshua P. Emery

Authors
  1. Andrew S. Rivkin
    View author publications

    You can also search for this author inPubMed Google Scholar

  2. Joshua P. Emery
    View author publications

    You can also search for this author inPubMed Google Scholar

Contributions

A.S.R. performed all of the telescopic observations and reduced all of the data, including the thermal flux removal. J.P.E. performed the spectral modelling of the ice and organics and performed spectral library searches. The authors contributed equally to interpretation and analysis.

Corresponding author

Correspondence to Andrew S. Rivkin.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Information and Data comprising: Consideration of alternate explanations for 3.1-µm absorption, Supplementary References, Supplementary Table S1 and Supplementary Figures S1-S4 with legends. (PDF 2547 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Rivkin, A., Emery, J. Detection of ice and organics on an asteroidal surface. Nature 464, 1322–1323 (2010). https://doi.org/10.1038/nature09028

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature09028

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