Enceladus: An Active Ice World in the Saturn System

Enceladus, one of the mid-sized icy moons of Saturn, has an importance to planetary science far greater than its modest 504-km diameter would suggest. Intensive exploration of Enceladus by the Cassini Saturn orbiter has revealed that it is the only known icy world in the solar system with ongoing deep-seated geological activity. Active tectonic fractures at Enceladus's south pole, dubbed “tiger stripes,” warmed by internal tidally generated heat, spew supersonic jets of water vapor, other gases, and ice particles into circum-Saturnian space. A subsurface saltwater sea probably exists under the south pole, between the ice shell and the silicate core. Because of evidence that liquid water is probably present at the jet sources, Enceladus is also of great astrobiological interest as a potential habitat for life.

[1]  P. Schenk,et al.  Enceladus' extreme heat flux as revealed by its relaxed craters , 2012 .

[2]  T. Johnson,et al.  Enceladus: A hypothesis for bringing both heat and chemicals to the surface , 2012 .

[3]  G. Tobie,et al.  Tidally-induced melting events as the origin of south-pole activity on Enceladus , 2012 .

[4]  S. Ida,et al.  N-BODY SIMULATIONS OF SATELLITE FORMATION AROUND GIANT PLANETS: ORIGIN OF ORBITAL CONFIGURATION OF THE GALILEAN MOONS , 2012, 1205.0301.

[5]  S. Charnoz,et al.  STRONG TIDAL DISSIPATION IN SATURN AND CONSTRAINTS ON ENCELADUS' THERMAL STATE FROM ASTROMETRY , 2012, 1204.0895.

[6]  F. Nimmo,et al.  Impact-driven ice loss in outer Solar System satellites: Consequences for the Late Heavy Bombardment , 2012 .

[7]  G. Tobie,et al.  The impact of a weak south pole on thermal convection in Enceladus’ ice shell , 2012 .

[8]  A. Ingersoll,et al.  Total particulate mass in Enceladus plumes and mass of Saturn’s E ring inferred from Cassini ISS images , 2011 .

[9]  J. Wahlund,et al.  Dusty plasma in the vicinity of Enceladus , 2011 .

[10]  P. Thomas,et al.  Geophysical implications of the long‐wavelength topography of the Saturnian satellites , 2011 .

[11]  W. McKinnon The Shape of Enceladus' Core: Predictions for Degree-2 Nonhydrostatic Gravity, and Role in Survival of the Subsurface Ocean , 2011 .

[12]  G. Neukum,et al.  Enceladus: Evidence for librations forced by Dione , 2011 .

[13]  J. Waite,et al.  Enceladus' Plume Composition , 2011 .

[14]  D. A. Patthoff,et al.  A fracture history on Enceladus provides evidence for a global ocean , 2011 .

[15]  S. Charnoz,et al.  Accretion of Saturn's mid-sized moons during the viscous spreading of young massive rings: Solving the paradox of silicate-poor rings versus silicate-rich moons , 2011, 1109.3360.

[16]  Paul D. Feldman,et al.  HUBBLE SPACE TELESCOPE/ADVANCED CAMERA FOR SURVEYS OBSERVATIONS OF EUROPA'S ATMOSPHERIC ULTRAVIOLET EMISSION AT EASTERN ELONGATION , 2011 .

[17]  F. Nimmo,et al.  Obliquity tides do not significantly heat Enceladus , 2011 .

[18]  P. Hartogh,et al.  Direct detection of the Enceladus water torus with Herschel , 2011 .

[19]  R. Srama,et al.  A salt-water reservoir as the source of a compositionally stratified plume on Enceladus , 2011, Nature.

[20]  Y. Sekine,et al.  Giant impacts in the Saturnian system: A possible origin of diversity in the inner mid-sized satellites , 2011, 1106.3827.

[21]  Robert A. West,et al.  The composition and structure of the Enceladus plume , 2011 .

[22]  Barry H. Mauk,et al.  The auroral footprint of Enceladus on Saturn , 2011, Nature.

[23]  J. Pearl,et al.  High heat flow from Enceladus' south polar region measured using 10–600 cm−1 Cassini/CIRS data , 2011 .

[24]  J. Pearl,et al.  High-Resolution Observations of Thermal Emission from the South Pole of Enceladus , 2011 .

[25]  Timothy A. Cassidy,et al.  Collisional spreading of Enceladus' neutral cloud , 2010 .

[26]  G. Tobie,et al.  Coupling mantle convection and tidal dissipation: Applications to Enceladus and Earth‐like planets , 2010 .

[27]  P. Thomas Sizes, shapes, and derived properties of the saturnian satellites after the Cassini nominal mission , 2010 .

[28]  A. Barr,et al.  On the origin of south polar folds on Enceladus , 2010 .

[29]  U. Beckmann,et al.  How the Enceladus dust plume feeds Saturn’s E ring , 2010 .

[30]  J. Pearl,et al.  Thermal inertia and bolometric Bond albedo values for Mimas, Enceladus, Tethys, Dione, Rhea and Iapetus as derived from Cassini/CIRS measurements , 2010 .

[31]  A. Ingersoll,et al.  Subsurface heat transfer on Enceladus: Conditions under which melting occurs , 2010 .

[32]  F. Nimmo,et al.  The role of episodic overturn in generating the surface geology and heat flow on Enceladus , 2010 .

[33]  F. Nimmo,et al.  Recent orbital evolution and the internal structures of Enceladus and Dione , 2009 .

[34]  Larry W. Esposito,et al.  Saturn from Cassini-Huygens , 2009 .

[35]  P. Schenk,et al.  Crater modification and geologic activity in Enceladus' heavily cratered plains: Evidence from the impact crater distribution , 2009 .

[36]  P. Schenk,et al.  One‐hundred‐km‐scale basins on Enceladus: Evidence for an active ice shell , 2009 .

[37]  F. Postberg,et al.  Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus , 2009, Nature.

[38]  Michael E. Brown,et al.  No sodium in the vapour plumes of Enceladus , 2009, Nature.

[39]  A. Coradini,et al.  From Gas to Satellitesimals: Disk Formation and Evolution , 2009, 0906.3435.

[40]  D. Turrini,et al.  Planetesimals and Satellitesimals: Formation of the Satellite Systems , 2009, 0906.0353.

[41]  R. H. Brown,et al.  SPECTRAL OBSERVATIONS OF THE ENCELADUS PLUME WITH CASSINI-VIMS , 2009 .

[42]  C. McKay,et al.  The possible origin and persistence of life on Enceladus and detection of biomarkers in the plume. , 2008, Astrobiology.

[43]  Hauke Hussmann,et al.  Enceladus: An estimate of heat flux and lithospheric thickness from flexurally supported topography , 2008 .

[44]  A. McEwen,et al.  Enceladus' South Polar Terrain Geology: New Details from Cassini ISS High Resolution Imaging , 2008 .

[45]  J. Wisdom,et al.  Episodic volcanism on Enceladus: Application of the Ojakangas-Stevenson model , 2008 .

[46]  Gabriel Tobie,et al.  Solid tidal friction above a liquid water reservoir as the origin of the south pole hotspot on Enceladus , 2008 .

[47]  A. Barr LIMITS ON HEAT TRANSPORT AND RESURFACING RATES DUE TO MOBILE LID CONVECTION BENEATH ENCELADUS’ SOUTH POLAR TERRAIN , 2008 .

[48]  Y. Yung,et al.  Habitability of Enceladus: Planetary Conditions for Life , 2008, Origins of Life and Evolution of Biospheres.

[49]  A. Showman,et al.  A model for the temperature-dependence of tidal dissipation in convective plumes on icy satellites: Implications for Europa and Enceladus , 2008 .

[50]  I. Matsuyama,et al.  Tectonic patterns on reoriented and despun planetary bodies , 2008 .

[51]  J. H. Roberts,et al.  Near‐surface heating on Enceladus and the south polar thermal anomaly , 2008 .

[52]  N. Brilliantov,et al.  Slow dust in Enceladus' plume from condensation and wall collisions in tiger stripe fractures , 2008, Nature.

[53]  J. Bauer,et al.  Photometric and spectral analysis of the distribution of crystalline and amorphous ices on Enceladus as seen by Cassini , 2008 .

[54]  M. Zolotov An oceanic composition on early and today's Enceladus , 2007 .

[55]  R. Beyer,et al.  Unstable extension of Enceladus' lithosphere , 2007 .

[56]  J. Bauer,et al.  Hydrogen Peroxide on Enceladus , 2007 .

[57]  Carolyn C. Porco,et al.  Association of the jets of Enceladus with the warmest regions on its south-polar fractures , 2007, Nature.

[58]  J. Wisdom,et al.  Tidal evolution of Mimas, Enceladus, and Dione , 2007 .

[59]  S. Kieffer,et al.  Unified model of tectonics and heat transport in a frigid Enceladus , 2007, Proceedings of the National Academy of Sciences.

[60]  J. H. Roberts,et al.  Long-Term Stability of a Subsurface Ocean on Enceladus , 2007 .

[61]  G. Collins,et al.  Enceladus' south polar sea , 2007 .

[62]  J. Wisdom,et al.  Tidal heating in Enceladus , 2007 .

[63]  Bryan J. Travis,et al.  Enceladus: Present internal structure and differentiation by early and long-term radiogenic heating , 2007 .

[64]  R. T. Pappalardo,et al.  Shear heating as the origin of the plumes and heat flux on Enceladus , 2007, Nature.

[65]  R. Greenberg,et al.  Eruptions arising from tidally controlled periodic openings of rifts on Enceladus , 2007, Nature.

[66]  W. McKinnon,et al.  Convection in Enceladus' ice shell: Conditions for initiation , 2007 .

[67]  C. Sotin,et al.  Distribution of icy particles across Enceladus' surface as derived from Cassini-VIMS measurements , 2007 .

[68]  M. Showalter,et al.  Enceladus: Cosmic Graffiti Artist Caught in the Act , 2007, Science.

[69]  Xinli Lu,et al.  A Clathrate Reservoir Hypothesis for Enceladus' South Polar Plume , 2006, Science.

[70]  Eoin L. Brodie,et al.  Long-Term Sustainability of a High-Energy, Low-Diversity Crustal Biome , 2006, Science.

[71]  William R. Ward,et al.  A common mass scaling for satellite systems of gaseous planets , 2006, Nature.

[72]  Robert L. Tokar,et al.  The Enceladus and OH Tori at Saturn , 2006 .

[73]  R. Pappalardo,et al.  Diapir-induced reorientation of Saturn's moon Enceladus , 2006, Nature.

[74]  Rosaly M. C. Lopes,et al.  Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot , 2006, Science.

[75]  G. Neukum,et al.  Cassini Observes the Active South Pole of Enceladus , 2006, Science.

[76]  R. Jaumann,et al.  Composition and Physical Properties of Enceladus' Surface , 2006, Science.

[77]  J. B. Dalton,et al.  Near-infrared (0.8-4.0 μm) spectroscopy of Mimas, Enceladus, Tethys, and Rhea , 2005 .

[78]  H. Keller,et al.  Ultraviolet Imaging Spectroscopy Shows an Active Saturnian System , 2005, Science.

[79]  T. Spohn,et al.  Thermal-orbital evolution of Io and Europa , 2004 .

[80]  J. Wisdom Spin-Orbit Secondary Resonance Dynamics of Enceladus , 2004 .

[81]  M. Horányi,et al.  Saturn's E ring: A dynamical approach , 2002 .

[82]  Gabriel Tobie,et al.  Europa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting , 2002 .

[83]  J. Moore,et al.  Flooding of Ganymede's bright terrains by low-viscosity water-ice lavas , 2001, Nature.

[84]  D. Stevenson Limits on the Variation of Thickness of Europa's Ice Shell , 2000 .

[85]  G. Consolmagno,et al.  THE AMMONIA-WATER SYSTEM AND THE CHEMICAL DIFFERENTIATION OF ICY SATELLITES , 1997 .

[86]  Todd O. Stevens,et al.  Lithoautotrophic Microbial Ecosystems in Deep Basalt Aquifers , 1995, Science.

[87]  David P. Hamilton,et al.  Origin of Saturn's E Ring: Self-Sustained, Naturally , 1994, Science.

[88]  D. Shemansky,et al.  Detection of the hydroxyl radical in the Saturn magnetosphere , 1993, Nature.

[89]  H. Melosh,et al.  Tectonics of planetary loading - A general model and results , 1990 .

[90]  R. Kirk,et al.  Subsurface Energy Storage and Transport for Solar-Powered Geysers on Triton , 1990, Science.

[91]  D. Stevenson,et al.  Episodic volcanism of tidally heated satellites with application to Io , 1986 .

[92]  D. Stevenson,et al.  Gas-driven water volcanism and the resurfacing of Europa , 1985 .

[93]  P. Haff,et al.  Ring and plasma - The enigmae of Enceladus , 1983 .

[94]  J. L. Mitchell,et al.  A New Look at the Saturn System: The Voyager 2 Images , 1982, Science.

[95]  J. Burns,et al.  Variability in the Particle Plume of Saturn’s Moon Enceladus , 2013 .

[96]  S. Asmar,et al.  The geodesy of the main Saturnian satellites from range rate measurements of the Cassini spacecraft , 2012 .

[97]  R. Tyler Tidal dynamical considerations constrain the state of an ocean on Enceladus , 2011 .

[98]  M. Showalter,et al.  Plasma, plumes and rings: Saturn system dynamics as recorded in global color patterns on its midsize icy satellites , 2011 .

[99]  Christopher P. McKay,et al.  Enceladus: An Active Cryovolcanic Satellite , 2009 .

[100]  W. Ip,et al.  Liquid water on Enceladus from observations of ammonia and 40Ar in the plume , 2009, Nature.

[101]  B. Buffington,et al.  The Cassini Extended Mission , 2009 .

[102]  J. Spencer,et al.  Endogenic heat from Enceladus' south polar fractures: New observations, and models of conductive surface heating , 2009 .

[103]  Barry H. Mauk,et al.  Fundamental Plasma Processes in Saturn's Magnetosphere , 2009 .

[104]  H. Melosh,et al.  Icy Satellites of Saturn: Impact Cratering and Age Determination , 2009 .

[105]  C. Murray,et al.  Solar System Dynamics: Expansion of the Disturbing Function , 1999 .