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:

Infrared emission by organic grains in the coma of comet Halley

Abstract

Spacecraft1 and ground-based2–5 observations of comet Halley in the near-infrared reveal a triple-peaked emission feature near 3.4 µm, characteristic of C–H stretching in hydrocarbons (–CH3 and –CH2– alkanes). Here we discuss transmission spectra of organic residues produced by laboratory irradiation of candidate cometary ices, which serve as the basis for a model of emitting cometary dust. The laboratory synthesis of solid organic residue from irradiated low-occupancy methane ice clathrate simulates the radiation processing experienced by comet Halley. The transmission spectrum of this residue, convolved with a simple two-component thermal emission model based on the spacecraft-determined dust distribution in the Halley coma, fits the 3.4 µm feature, provides optical depths in excellent agreement with those observationally determined, and accounts for the absence of features at longer wavelengths (despite their presence in transmission spectra of typical ice irradiation residues).

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

Similar content being viewed by others

References

  1. 1. Combes, M. et al. Adv. Space Sci (in the press). 2. Wickramasinghe, D. T. and Alien, D. A. Nature 323, 44-46 (1986). 3. Danks, A. et al. in 20th Eslab Symposium on the Exploration of Halley's Comet 3 103-106 (ESA SP-250, 1986). 4. Baas, F., Geballe, T. R. & Walther, D. M. Astrophys. J. Lett. 311, L97-L101 (1986). 5. Knacke, R. F., Brooke, T. Y. & Joyce, R. R. Astrophys. J. Lett. 310, L49-L54 (1986). 6. Crovisier, J. & Encrenaz, Th. Astr. Astrophys. 126, 170-182 (1983). 7. Kissel, J. et al. Nature 321, 280-282 (1986). 8. Kissel, J. & Krueger, F. R. Nature 326, 755-760 (1987). 9. Sekanina, Z. in 20th Eslab Symposium on the Exploration of H alley's Comet 2, 131-143 (ESA SP-250, 1986). 10. Delsemme, A. H. & Swings, P. Ann. Astrophys. 15, 1-6 (1952). 11. Calcagno, L., Foti, G., Torrisi, L. & Strazzulla, G. Icarus 63, 31-38 (1985). 12. Davis, D. R., Libby, W. F. & Meinschein, W. G. J. Chem. Phys. 45, 4481-4492 (1966). 13. Khare, B. N., Murray, B., Sagan, C. & Arakawa, E. T. Icarus (in the press). 14. Thompson, W. R., Murray, B., Khare, B. N. & Sagan, C. J. geophys. Res. (in the press). 15. Khare, B. N., Sagan, C., Thompson, W. R., Arakawa, E. T. & Votaw, P. J. geophys. Res. in the press). 16. Sagan, C., Khare, B. N. & Lewis, J. S. in Saturn (eds Gehrels, T. & Matthews, M. S.), 788-807 (University of Arizona Press, 1984). 17. Chyba, C. & Sagan, C. in Proceedings of the International Workshop on Laboratory Simulation of Organic Cometary Material (eds Kissel, J. & Strazzulla, G.) 50-57 (University of Catania, 1987); Cornell CRSR Preprint No. 877 (1987). 18. Draganic, I. G., Draganic, Z. D. & Vujosevic, S. Icarus 60, 464-475 (1984). 19. Johnson, R. E., Cooper, J. F., Lanzerotti, L. J. & Strazzulla, G. Astr. Astrophys. (in the press). 20. Foti, G., Calcagno, L., Sheng, K. L. & Strazzulla, G. Nature 310, 126-128 (1984). 21. Moore, M. H., Donn, B., Khanna, R. & A'Hearn, M. F. Icarus 54, 388-405 (1983). 22. Biermann, L., Giguere, P. T. & Huebner, W. F. Astr. Astrophys. 108, 221-226 (1982). 23. Hanner, M. S. in Cometary Exploration II (ed. Gombosi, T. I.) 1-22 (Hungarian Academy of Science, Budapest, 1982). 24. Greenberg, J. M. in Cosmic Dust (ed. McDonnell, J. A.) 187-294 (Wiley, New York, 1978). 25. McDonnell, J. A. M. et al. 20th Eslab Symposium on the Exploration of Halley's Comet 2, 25-38 (ESA SP-250, 1986). 26. Divine, N. et al. The Comet Halley Dust and Gas Environment, JPL D-2823 (1985). 27. Gehrz, R. D. & Ney, E. P. 20th Eslab Symposium on the Exploration of Halley's Comet 2, 101-105 (ESA SP-250, 1986). 28. Bregman, J. D. et al. Astr. Astrophys. (in the press). 29. Khare, B. N. et al. Icarus 60, 127-137 (1984). 30. Hanner, M. S. Adv. Space Res. 5, 325-334 (1986). 31. Lamy, P. & Perrin, J. M. Icarus (in the press). 32. Herter, T., Gull, G. E. & Campins, H. 20th Eslab Symposium on the Exploration of Halley's Comet 2, 117-120 (ESA SP-250, 1986). 33. Alien, D. A. & Wickramasinghe, D. T. Nature 329, 615-616 (1987).

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chyba, C., Sagan, C. Infrared emission by organic grains in the coma of comet Halley. Nature 330, 350–353 (1987). https://doi.org/10.1038/330350a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/330350a0

This article is cited by

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.

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