Abstract
THE encounter of the Voyager 2 spacecraft with Neptune's satellite Triton revealed many 'dark' (about 10–20% darker than the adjacent frost) surface streaks in Triton's southern hemisphere1, resembling the streaks that are due to windblown dust on Mars2. It seems therefore that dust transport by winds in Triton's tenuous atmosphere is required, the main question being the mechanism for raising dust from the surface or sub-surface. The two obvious candidates are geyser-like eruptions and direct lofting by surface winds1. Here we show that, despite Triton's tenuous (16±3 µbar) atmosphere3, low-cohesion grains with diameters of ≲5 µm, may be carried into suspension by aeolian surface shear stress, given expected geostrophic wind speeds4 of ∼l0ms-1. (The wind velocities needed to lift grains as cohesive as those found on Earth, however, are implausibly high.) For erupting plumes, we show that dust-settling timescales and expected wind velocities yield streak length scales in good agreement with those observed. Both candidate mechanisms therefore seem to be consistent with present observations of Triton.
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References
Smith, B. A. et al. Science 246, 1422–1449 (1989).
Sagan, C. et al. Icarus 17, 346–372 (1972).
Tyler, G. L. et al. Science 246, 1466–1472 (1989).
Ingersoll, A. P. Nature 344, 315–317 (1990).
Sagan, C. & Pollack, J. B. Smithson. astrophys. Obs. Spec. Rep. 255 (1967).
Sagan, C. & Pollack, J. B. Nature 223, 791–794 (1969).
Bagnold, R. A. The Physics of Blown Sand and Desert Dunes (Chapman & Hall, London, 1954).
Sagan, C. et al. J. geophys. Res. 78, 4163–4196 (1973).
Thomas, P., Veverka, J., Lee, S. & Bloom, A. Icarus 45, 124–153 (1981).
Sagan, C. & Bagnold, R. A. Icarus 26, 209–218 (1975).
Iversen, J. D., Pollack, J. B., Greeley, R. & White, B. R. Icarus 29, 381–393 (1976).
Pollack, J. B., Haberle, R., Greeley, R. & Iversen, J. Icarus 29, 395–417 (1976).
Iversen, J. D. & White, B. R. Sedimentology 29, 111–119 (1982).
Greeley, R. & Iversen, J. D. Wind as a Geological Process (Cambridge University Press, 1985).
Thompson, W. R., Murray, B., Khare, B. N. & Sagan, C. J. geophys. Res. 92, 14933–14947 (1987).
Khare, B. N. et al. Icarus 79, 350–361 (1989).
Hansen, C. et al. Geophys. Res. Lett. (submitted).
Conrath, B. et al. Science 246, 1454–1458 (1989).
Carr, M. H. The Surface of Mars (Yale University Press, 1981).
Simonelli, D. P. et al. Icarus 82, 1–35 (1989).
Prokhavatilov, A. I. & Yantsevich, L. D. Soviet J. low-temp. Phys. 9, 94–97 (1983).
Sagan, C., Thompson, W. R. & Khare, B. N. in The Search for Extraterrestrial Life (ed. Papagiannis, M. D.) 107–121 (Reidel, Boston, 1985).
Gregg, S. J. The Surface Chemistry of Solids Ch. 3 (Chapman & Hall, London, 1961).
Pye, K. Aeolian Dust and Dust Deposits Ch. 3 (Academic, London, 1987).
Mitchell, J. et al. Proc. Third Lunar Sci. Conf. Vol. 3 (ed. Criswell, D. R.) 3235–3253 (MIT Press, Cambridge, 1972).
Lindsay, J. F. Lunar Stratigraphy and Sedimentology Ch. 6 (Elsevier Scientific, New York, 1976).
Cruikshank, D. P., Brown, R. H. & Clark, R. N. Icarus 58, 293–305 (1984).
Kitchener, J. A. in Powders in Industry 405–410 (Soc. chem. Ind., London, 1961).
Sagan, C. et al. Icarus 22, 24–47 (1974).
Lee, S. W. & Thomas, P. C. Icarus 44, 280–290 (1980).
Atkins, P. W. Physical Chemistry (Freeman, New York, 1986).
Epstein, P. S. Phys. Rev. 23, 710–733 (1924).
Kennard, E. H. Kinetic Theory of Gases (McGraw-Hill, New York, 1938).
Clark, R. Icarus 49, 244–257 (1982).
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Sagan, C., Chyba, C. Triton's streaks as windblown dust. Nature 346, 546–548 (1990). https://doi.org/10.1038/346546a0
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DOI: https://doi.org/10.1038/346546a0
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