Association of the jets of Enceladus with the warmest regions on its south-polar fractures (original) (raw)

Nature volume 449, pages 695–697 (2007)Cite this article

Abstract

Jets of material have been seen emanating from the south-polar terrain of Saturn’s satellite Enceladus1. Observations have shown that this region is anomalously warm2, with the hottest measured temperatures coinciding with the four ‘tiger stripe’ fractures, named Alexandria, Cairo, Baghdad and Damascus, that straddle the region1,2. Here we use Cassini images taken from a variety of viewing directions over two years to triangulate the source locations for the most prominent jets, and compare these with the infrared hotspot locations and the predictions from a recent model of tidally induced shear heating within the fractures3. We find that the jets emanate from the four tiger stripes, with the strongest sources on Baghdad and Damascus. All the jets from each fracture seem to lie in the same nearly vertical plane. There is a strong spatial coincidence between our geographical sources and the locations of increased temperature revealed by the infrared experiment. Comparison with the shear heating model shows broad agreement; the exception is the prediction that Baghdad is the least active lineament, whereas we find it to be the most active. We predict that several new hotspots remain to be discovered by future thermal observations.

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References

  1. Porco, C. C. et al. Cassini observes the active south pole of Enceladus. Science 311, 1393–1401 (2006)
    Article ADS CAS Google Scholar
  2. Spencer, J. R. et al. Cassini encounters Enceladus: background and the discovery of a south polar hot spot. Science 311, 1401–1405 (2006)
    Article ADS CAS Google Scholar
  3. Nimmo, F. et al. Shear heating as the origin of the plumes and heat flux on Enceladus. Nature 447, 289–291 (2007)
    Article ADS CAS Google Scholar
  4. Porco, C. C. et al. Cassini imaging science: instrument characteristics and anticipated scientific investigations at Saturn. Space Sci. Rev. 115, 363–497 (2004)
    Article ADS Google Scholar
  5. Hurford, T. A. et al. Eruptions arising from tidally controlled periodic openings of rifts on Enceladus. Nature 447, 292–294 (2007)
    Article ADS CAS Google Scholar
  6. Spencer, J. R. et al. The south polar hot spot on Enceladus. Lunar Planet. Sci. Conf. XXXVII, 2252 (2006)
    ADS Google Scholar
  7. Milazzo, M. P. et al. Observations and initial modeling of Lava-SO2 interactions at Prometheus, Io. J. Geophys. Res. 106 E12, 33121–33128 (2001)
    Article ADS Google Scholar

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Acknowledgements

We thank Paul and Pauline Helfenstein for the planning of the Enceladus plume observations and the staff members at the CICLOPS for technical support. D. Wilson at CICLOPS provided assistance with image processing. We thank H. J. Melosh, A. P. Ingersoll and P. Helfenstein for their comments. This work was funded by the Cassini project.

Author Contributions Both authors devised the approach and contributed equally to the discussion and conclusions. J.N.S. executed the work, produced the solutions and wrote most of the text. C.C.P. instigated the work and revised the text.

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Authors and Affiliations

  1. Cassini Imaging Central Laboratory for Operations (CICLOPS), Space Science Institute, 4750 Walnut Street, Boulder, Colorado 80301, USA ,
    Joseph N. Spitale & Carolyn C. Porco

Authors

  1. Joseph N. Spitale
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  2. Carolyn C. Porco
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Correspondence toJoseph N. Spitale.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains Supplementary Notes, Supplementary Tables 1-2 and Supplementary Figures 1-18 with Legends. The file is divided into following three sections: 1. Description of source identifications: This section describes the reasoning behind each source identification and gives a table (Supplementary Table 1) of observations comprising each source. 2. Data Table: This section contains a table of data (Supplementary Tables 2) used for our study. All image numbers are given, as well as relevant geometric information. 3. Figures showing plume measurements and labels: This section contains Supplementary Figures 1-18 showing all of the image measurements used in our study. (PDF 761 kb)

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Spitale, J., Porco, C. Association of the jets of Enceladus with the warmest regions on its south-polar fractures.Nature 449, 695–697 (2007). https://doi.org/10.1038/nature06217

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Editorial Summary

The road to Damascus

The Cassini flyby of 14 July 2005 revealed plumes of jets of water vapour and ice emanating from near the south pole of Saturn's icy moon Enceladus. This region is anomalously warm, with the highest temperatures associated with four 'tiger stripe' surface fractures on the moon's surface, colourfully named Alexandria, Cairo, Baghdad and Damascus. Joseph Spitale and Carolyn Porco have now applied triangulation techniques to Cassini images in order to obtain accurate bearings on the sources of the most prominent jets, and they find that they emanate from the tiger stripes, with the strongest sources situated on Baghdad and Damascus.