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.

Spectral evidence for a carbonaceous chondrite surface composition on Deimos


The good match between the reflectance spectra of Phobos and Ceres, an asteroid inferred to have a composition analogous to carbonaceous chondrites because of its low density, 2.2g cm−3 (ref. 1), and spectral signatures that include a water of hydra-tion band centred at 3.0 µm (refs 2,3), has led to the conclusion4 that the surface composition of the inner martian satellite is similar to that of carbonaceous chondrites. Pollack et al.5 independently reached the same conclusion by comparing Phobos' spectral albedo with reflectance spectra of meteorites and basalts. Mass and density estimates (2g cm−3) for the satellite were made based on the perturbations on the orbit of Viking 1 by Phobos, during a series of close encounters6. The density of Phobos is consistent with the same composition as that inferred for its surface. Among materials expected to be common in the Solar System only ices or water-rich carbonaceous chondrites (20% H2O by weight in type C1) have densities as low as Ceres and Phobos7. The compositional results have forced a re-evaluation of hypotheses concerning Phobos' origin. Scientific opinion now seems to favour an origin by capture of a body that came too close to Mars8. The analysis of data on Deimos reported here reveals a spectral reflectance very similar to that of Phobos, indicating a surface composition analogous to that of carbonaceous chondrites.

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

Access options

Rent or buy this article

Prices vary by article type



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


  1. Chapman, C. R., Williams, J. G. & Hartmann, W. K. A. Rev. Astr. Astrophys. 16, 33 (1978).

    Article  ADS  Google Scholar 

  2. Lebofsky, L. Mon. Not. R. astr. Soc. 182, 17 (1978).

    Article  ADS  Google Scholar 

  3. Larson, H. P., Feierberg, M. A., Fink, U. & Smith, H. A. Icarus 39, 257 (1979).

    Article  ADS  CAS  Google Scholar 

  4. Pang, K. D., Pollack, J. B., Veverka, J., Lane, A. L. & Ajello, J. M. Science 199, 64 (1978).

    Article  ADS  CAS  Google Scholar 

  5. Pollack, J. B. et al. Science 199, 66 (1978).

    Article  ADS  CAS  Google Scholar 

  6. Tolson, R. H. et al. Science 199, 61 (1978).

    Article  ADS  CAS  Google Scholar 

  7. Mason, B. Handbook of Elemental Abundances in Meteorites (Gordon and Breach, New York, 1971).

    Google Scholar 

  8. Burns, J. A. Vistas Astr. 22, 193 (1978).

    Article  ADS  Google Scholar 

  9. Duxbury, T. C. & Veverka, J. Science 201, 812 (1978).

    Article  ADS  CAS  Google Scholar 

  10. Housen, K. & Davis, D. R. Bull. Am. astr. Soc. 10, 593 (1978).

    ADS  Google Scholar 

  11. Zellner, B. H. & Capen, R. C. Icarus 23, 437 (1974).

    Article  ADS  Google Scholar 

  12. Zellner, B. H., Leake, M. & Lebertre, T. Proc. Lunar Sci. Conf. 8, 1091 (1977).

    ADS  Google Scholar 

  13. Zellner, B. H., Lebertre, T. & Day, K. Proc. Lunar Sci. Conf. 8, 1111 (1977).

    ADS  CAS  Google Scholar 

  14. Goss, W. C. Appl. Opt. 9, 1056 (1970).

    Article  ADS  CAS  Google Scholar 

  15. Rhoads, J. W. TN-343–12 (Jet Propulsion Lab., Pasadena, 1971).

  16. Rhoads, J. W. TM-33-586 (Jet Propulsion Lab., Pasadena, 1972).

  17. Rhoads, J. W., Hanover, G. A. & Pang, K. D. Trans. Am. Geophys. Un. 60, 872 (1979).

    Google Scholar 

  18. Bowell, E. & Zellner, B. H. in Planets, Stars and Nebulae Studied With Photopolarimetry (ed. Gehrels, T.) 381–404 (University of Arizona Press, Tucson, 1974).

    Google Scholar 

  19. Pang, K. D., Rhoads, J. W., Lane, A. L. & Ajello, J. M. Bull. Am. astr. Soc. 9, 519 (1977).

    Google Scholar 

  20. Noland, M. & Veverka, J. Icarus 28, 405 (1976).

    Article  ADS  Google Scholar 

  21. Klassen, K. P., Duxbury, T. C. & Veverka, J. J. geophys. Res. (submitted).

  22. Lane, A. P. & Irvine, W. M. Astrophys. J. 78, 267 (1973).

    ADS  Google Scholar 

  23. Duxbury, T. C. & Born, G. H. Trans. Am. Geophys. Un. 59, 245 (1978).

    Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and permissions

About this article

Cite this article

Pang, K., Rhoads, J., Lane, A. et al. Spectral evidence for a carbonaceous chondrite surface composition on Deimos. Nature 283, 277–278 (1980).

Download citation

  • Received:

  • Accepted:

  • 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