A Jupiter Fragmented Comet: Cause of the K/T Boundary Record

  • N. C. Wickramasinghe
  • Max K. Wallis
Conference paper


The extended period of mass extinctions around the K/T boundary correlating with extraterrestrial amino acids in the sediment record constitutes strong evidence of a cometary cause. The input of extraterrestrial matter over 105 yr supports the hypothesis of a giant comet, fragmented into subcomets on close encounter with Jupiter, and subsequently perturbed into Earth-crossing orbits. Copious amounts of dust were emitted via this and possibly successive fragmenting encounters, and via normal cometary evaporation. The dynamics of dust from the disintegrating comet fragments favours retention in Earth-crossing orbits of the sub-micron fraction of organic composition. The shroud of dust accreted in the Earth’s upper atmosphere varied with time and imposed climatic stresses that caused species extinctions over 105 yr. While the iridium peak in the sediments coincides with the Chicxulub crater impactor, other iridium detail suggests that some of the impactor material was reinjected into space and in part re-accreted by Earth from the interplanetary orbits.


Mass Extinction Tsunami Deposit Close Encounter Cometary Dust Radiation Pressure Force 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alvarez, L.W., Alvarez, W. & Asaro, F 1980, Science 208, 1095–1108.ADSCrossRefGoogle Scholar
  2. Asphaug, E. & Benz, W. 1994, this conference; also Nature 370, 120.ADSCrossRefGoogle Scholar
  3. Bailey, M.E., Clube, S.V.M., Hahn, G., Napier, W.M & Valsecchi, G.B. 1994, in Hazards due to comets and asteroids, ed. Gehrels, T., U. Ariz. Press.Google Scholar
  4. Bada, J.L. & Zhao, M.1992, Symposium F3.1 World Space Congress, Washington, Adv. Space Res. in press, 1994.Google Scholar
  5. van den Bergh, S.1994, Pub. Astron. Soc. Pacific 106, 689–695ADSCrossRefGoogle Scholar
  6. Clube, S.V.M. & Napier, W.M. 1990, Cosmic Winter, Oxford Univ. Press.Google Scholar
  7. Dobrovolskis, A.R. 1990, Icarus, 88, 24–38ADSCrossRefGoogle Scholar
  8. Hoyle, F. & Wickramasinghe, C.1978, Astrophys. Space Sci. 53, 523–526.ADSCrossRefGoogle Scholar
  9. Hoyle, F. & Wickramasinghe, N.C. 1991, The Theory of Cosmic Grains, Kluwer.Google Scholar
  10. Hut, P., Alvarez, W., Elder, W.P., Hausen, T., KaufFman, E.G., Keller, G., Shoemaker,E.M. & Weissman, P.R. 1987, Nature 329, 118.ADSCrossRefGoogle Scholar
  11. Ishimoto, H. & Mukai, T.1991, Proc. 24th ISAS Lunar and Planetary Symp., eds. H. Mizutani, H. Oya and M. Shimizu, ISAS Tokyo, p. 148.Google Scholar
  12. Melosh, H.J. 1988, Nature 332, 687–688.ADSCrossRefGoogle Scholar
  13. Napier, W.M. & Clube, S.V.M. 1979, Nature 282, 455–459.ADSCrossRefGoogle Scholar
  14. Steel, D. 1992, Origins of Life and Evolution of the Biosphere, 21, 239–357.Google Scholar
  15. Steel, D. 1994, this conference.Google Scholar
  16. Wallis, M.K. & Wickramasinghe, N.C. 1994, Mon. Not. Roy. Astr. Soc. 270, 420–426.ADSGoogle Scholar
  17. Yabushita, S. 1994, Earth Moon Planets 64, 207–216.ADSCrossRefGoogle Scholar
  18. Zahnle, K. & Grinspoon, D. 1990, Nature 348, 157–160.ADSCrossRefGoogle Scholar
  19. Zhao, M. & Bada, J.L. 1989, Nature 339, 463–465.ADSCrossRefGoogle Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • N. C. Wickramasinghe
    • 1
  • Max K. Wallis
    • 1
  1. 1.School of MathematicsUniversity of Wales College of CardiffUK

Personalised recommendations