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Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures


One of the spectacular discoveries of the Cassini spacecraft was the plume of water vapour and icy particles (dust) originating near the south pole of Saturn’s moon Enceladus1,2,3,4,5. The data imply considerably smaller velocities for the grains2,5,6 than for the vapour4,7, which has been difficult to understand. The gas and dust are too dilute in the plume to interact, so the difference must arise below the surface. Here we report a model for grain condensation and growth in channels of variable width. We show that repeated wall collisions of grains, with re-acceleration by the gas, induce an effective friction, offering a natural explanation for the reduced grain velocity. We derive particle speed and size distributions that reproduce the observed and inferred properties of the dust plume. The gas seems to form near the triple point of water; gas densities corresponding to sublimation from ice at temperatures less than 260 K are generally too low to support the measured particle fluxes2. This in turn suggests liquid water below Enceladus’ south pole.

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Figure 1: Gas flow and condensation in cracks in Enceladus’ ice shell.
Figure 2: Temperature dependence of grain dynamics and homogeneous nucleation rate.
Figure 3: Comparison of model results with Cassini data.


  1. 1

    Dougherty, M. K. et al. Identification of a dynamic atmosphere at Enceladus with the Cassini magnetometer. Science 311, 1406–1409 (2006)

    CAS  Article  ADS  Google Scholar 

  2. 2

    Spahn, F. et al. Cassini dust measurements at Enceladus and implications for the origin of the E ring. Science 311, 1416–1418 (2006)

    CAS  Article  ADS  Google Scholar 

  3. 3

    Waite, J. H. et al. Cassini ion and neutral mass spectrometer: Enceladus plume composition and structure. Science 311, 1419–1422 (2006)

    CAS  Article  ADS  Google Scholar 

  4. 4

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

    CAS  Article  ADS  Google Scholar 

  5. 5

    Porco, C. C. et al. Cassini observes the active south pole of Enceladus. Science 311, 1393–1401 (2006)

    CAS  Article  ADS  Google Scholar 

  6. 6

    Ingersoll, A. P., Porco, C. C., Helfenstein, P. & West, R. A. the Cassini ISS Team. Models of the Enceladus plumes. Bull. Am. Astron. Soc. 38, 508 (2006)

    ADS  Google Scholar 

  7. 7

    Tian, F., Stewart, A. I. F., Toon, O. B., Larsen, K. W. & Esposito, L. W. Monte Carlo simulations of the water vapor plumes on Enceladus. Icarus 188, 154–161 (2007)

    CAS  Article  ADS  Google Scholar 

  8. 8

    Showalter, M., Cuzzi, J. & Larson, S. Structure and particle properties of Saturn's E ring. Icarus 94, 451–473 (1991)

    Article  ADS  Google Scholar 

  9. 9

    Nicholson, P. D. et al. Observations of Saturn's ring-plane crossing in August and November 1995. Science 272, 509–516 (1996)

    CAS  Article  ADS  Google Scholar 

  10. 10

    Haff, P. K., Eviatar, A. & Siscoe, G. Ring and plasma: the enigmae of Enceladus. Icarus 56, 426–438 (1983)

    Article  ADS  Google Scholar 

  11. 11

    Pang, K. D., Voge, C. C., Rhoads, J. W. & Ajello, J. M. The E ring of Saturn and satellite Enceladus. J. Geophys. Res. 89, 9459–9470 (1984)

    CAS  Article  ADS  Google Scholar 

  12. 12

    Kargel, J. S. & Pozio, S. The volcanic and tectonic history of Enceladus. Icarus 119, 385–404 (1996)

    Article  ADS  Google Scholar 

  13. 13

    Spencer, J. R. et al. Cassini encounters Enceladus: background and the discovery of a south polar hot spot. Science 311, 1401–1405 (2006)

    CAS  Article  ADS  Google Scholar 

  14. 14

    Brown, R. H. et al. Composition and physical properties of Enceladus. Surf. Sci. 311, 1425–1428 (2006)

    CAS  Google Scholar 

  15. 15

    Spitale, J. N. & Porco, C. C. Association of the jets of Enceladus with the warmest regions on its south-polar fractures. Nature 449, 695–697 (2007)

    CAS  Article  ADS  Google Scholar 

  16. 16

    Kieffer, S. W. et al. A clathrate reservoir hypothesis for Enceladus' south polar plume. Science 314, 1764–1766 (2006)

    CAS  Article  ADS  Google Scholar 

  17. 17

    Gioia, G., Chakraborty, P., Marshak, S. & Kieffer, S. W. Unified model of tectonics and heat transport in a frigid Enceladus. Proc. Natl Acad. Sci. USA 104, 13578–13591 (2007)

    CAS  Article  ADS  Google Scholar 

  18. 18

    Shaw, R. A. & Lamb, D. Experimental determination of the thermal accommodation and condensation coefficients of water. J. Chem. Phys. 111, 10659–10663 (1999)

    CAS  Article  ADS  Google Scholar 

  19. 19

    Batista, E. R., Ayotte, P., Bilic, A., Kay, B. D. & Jonsson, H. What determines the sticking probability of water molecules on ice? Phys. Rev. Lett. 95, 223201 (2005)

    Article  ADS  Google Scholar 

  20. 20

    Matson, D. L., Castillo, J. C., Lunine, J. & Johnson, T. V. Enceladus' plume: compositional evidence for a hot interior. Icarus 187, 569–573 (2007)

    CAS  Article  ADS  Google Scholar 

  21. 21

    Collins, G. C. & Goodman, J. C. Enceladus' south polar sea. Icarus 189, 72–82 (2007)

    Article  ADS  Google Scholar 

  22. 22

    Nimmo, F., Spencer, J. R., Pappalardo, R. T. & Mullen, M. E. Shear heating as the origin of the plumes and heat flux on Enceladus. Nature 447, 289–291 (2007)

    CAS  Article  ADS  Google Scholar 

  23. 23

    Viisanen, Y., Strey, R. & Reiss, H. Homogeneous nucleation rates for water. J. Chem. Phys. 99, 4680–4692 (1993)

    CAS  Article  ADS  Google Scholar 

  24. 24

    Juhász, A. & Horányi, M. Saturn's E ring: a dynamical approach. J. Geophys. Res. 107, 1–10 (2002)

    Article  Google Scholar 

  25. 25

    Horányi, M., Burns, J. A. & Hamilton, D. P. The dynamics of Saturn's E ring particles. Icarus 97, 248–259 (1992)

    Article  ADS  Google Scholar 

  26. 26

    Hamilton, D. & Burns, J. Origin of Saturn’s E ring: selfsustained—naturally. Science 264, 550–553 (1994)

    CAS  Article  ADS  Google Scholar 

  27. 27

    Hurford, T. A., Helfenstein, P., Hoppa, G. V., Greenberg, R. & Bills, B. G. Eruptions arising from tidally controlled periodic openings of rifts on Enceladus. Nature 447, 292–294 (2007)

    CAS  Article  ADS  Google Scholar 

  28. 28

    Kempf, S. et al. The E ring in the vicinity of Enceladus I: spatial distribution and properties of the ring particles. Icarus (in the press)

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We thank M. Burton, P. Krapivsky, H. Salo, T. Spilker, M. Sremčević and F. Tian for discussions. We acknowledge the efforts of the Cassini ISS team in the design and operation of the ISS instrument. This work was supported by Deutsches Zentrum für Luft und Raumfahrt and Deutsche Forschungsgemeinschaft.

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Correspondence to Jürgen Schmidt.

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Supplementary Information

This file contains Supplementary Notes with additional references and Supplementary Figures S1-S8 with Legends. (PDF 1970 kb)

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Schmidt, J., Brilliantov, N., Spahn, F. et al. Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures. Nature 451, 685–688 (2008).

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