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Cassini Observes the Active South Pole of Enceladus
C. C. Porco,1*P. Helfenstein,2P. C. Thomas,2A. P. Ingersoll,3J. Wisdom,4R. West,5G. Neukum,6T. Denk,6R. Wagner,7T. Roatsch,7S. Kieffer,8E. Turtle,9A. McEwen,9T. V. Johnson,5J. Rathbun,10J. Veverka,2D. Wilson,1J. Perry,9J. Spitale,1A. Brahic,11J. A. Burns,2A. D. DelGenio,12L. Dones,13C. D. Murray,14S. Squyres2
Cassini has identified a geologically active province at thesouth pole of Saturn's moon Enceladus. In images acquired bythe Imaging Science Subsystem (ISS), this region is circumscribedby a chain of folded ridges and troughs at 55°S latitude.The terrain southward of this boundary is distinguished by itsalbedo and color contrasts, elevated temperatures, extreme geologicyouth, and narrow tectonic rifts that exhibit coarse-grainedice and coincide with the hottest temperatures measured in theregion. Jets of fine icy particles that supply Saturn's E ringemanate from this province, carried aloft by water vapor probablyventing from subsurface reservoirs of liquid water. The shapeof Enceladus suggests a possible intense heating epoch in thepast by capture into a 1:4 secondary spin/orbit resonance.
1 Cassini Imaging Central Laboratory for Operations, Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301, USA. 2 Department of Astronomy, Cornell University, Ithaca, NY 14853, USA. 3 Division of Geological and Planetary Sciences, California Institute of Technology, 150-21, Pasadena, CA 91125, USA. 4 Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. 5 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA. 6 Institut für Geologische Wissenschaften, Freie Universität, 12249 Berlin, Germany. 7 Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489 Berlin, Germany. 8 Department of Geology, University of Illinois, Urbana, IL 61801, USA. 9 Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721, USA. 10 Department of Physics, University of Redlands, 1200 East Colton Avenue, Redlands, CA 92373, USA. 11 Centre d'Etudes de Saclay, Université Paris 7, L'Orme des Merisiers, 91191 Gif-sur-Yvette Cedex, France. 12 Goddard Institute for Space Studies, NASA, 2880 Broadway, New York, NY 10025, USA. 13 Department of Space Studies, Southwest Research Institute, 1050 Walnut Street, Suite 400, Boulder, CO 80302, USA. 14 Astronomy Unit, Queen Mary, University of London, London E1 4NS, UK.
* To whom correspondence should be addressed. E-mail: carolyn{at}ciclops.org
From the Cover: Unified model of tectonics and heat transport in a frigid Enceladus.
G. Gioia, P. Chakraborty, S. Marshak, and S. W. Kieffer (2007)
PNAS
104, 13578-13581
|Abstract »|Full Text »|PDF »
The Variable Rotation Period of the Inner Region of Saturn's Plasma Disk.
D. A. Gurnett, A. M. Persoon, W. S. Kurth, J. B. Groene, T. F. Averkamp, M. K. Dougherty, and D. J. Southwood (2007)
Science
316, 442-445
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Enceladus: Cosmic Graffiti Artist Caught in the Act.
A. Verbiscer, R. French, M. Showalter, and P. Helfenstein (2007)
Science
315, 815
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A Clathrate Reservoir Hypothesis for Enceladus' South Polar Plume.
S. W. Kieffer, X. Lu, C. M. Bethke, J. R. Spencer, S. Marshak, and A. Navrotsky (2006)
Science
314, 1764-1766
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Cassini encounters Enceladus: background and the discovery of a south polar hot spot..
J. R. Spencer, J. C. Pearl, M. Segura, F. M. Flasar, A. Mamoutkine, P. Romani, B. J. Buratti, A. R. Hendrix, L. J. Spilker, and R. M. C. Lopes (2006)
Science
311, 1401-1405
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Identification of a dynamic atmosphere at Enceladus with the Cassini magnetometer..
M. K. Dougherty, K. K. Khurana, F. M. Neubauer, C. T. Russell, J. Saur, J. S. Leisner, and M. E. Burton (2006)
Science
311, 1406-1409
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Cassini dust measurements at Enceladus and implications for the origin of the E ring..
F. Spahn, J. Schmidt, N. Albers, M. Horning, M. Makuch, M. Seiss, S. Kempf, R. Srama, V. Dikarev, S. Helfert, et al. (2006)
Science
311, 1416-1418
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Cassini ion and neutral mass spectrometer: Enceladus plume composition and structure..
J. H. Waite Jr., M. R. Combi, W.-H. Ip, T. E. Cravens, R. L. McNutt Jr., W. Kasprzak, R. Yelle, J. Luhmann, H. Niemann, D. Gell, et al. (2006)
Science
311, 1419-1422
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Composition and physical properties of Enceladus' surface..
R. H. Brown, R. N. Clark, B. J. Buratti, D. P. Cruikshank, J. W. Barnes, R. M. E. Mastrapa, J. Bauer, S. Newman, T. Momary, K. H. Baines, et al. (2006)
Science
311, 1425-1428
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55°S latitude. The terrain southward of this boundary is distinguished by its albedo and color contrasts, elevated temperatures, extreme geologic youth, and narrow tectonic rifts that exhibit coarse-grained ice and coincide with the hottest temperatures measured in the region. Jets of fine icy particles that supply Saturn's E ring emanate from this province, carried aloft by water vapor probably venting from subsurface reservoirs of liquid water. The shape of Enceladus suggests a possible intense heating epoch in the past by capture into a 1:4 secondary spin/orbit resonance. 
