Enceladus: An Active Ice World in the Saturn System

  title={Enceladus: An Active Ice World in the Saturn System},
  author={John R. Spencer and Francis Nimmo},
  journal={Annual Review of Earth and Planetary Sciences},
  • J. Spencer, F. Nimmo
  • Published 3 June 2013
  • Geology, Physics
  • Annual Review of Earth and Planetary Sciences
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… 
Geodynamic modeling of the ice-ocean system on Enceladus
The Saturnian moon Enceladus is one of the most geologically active bodies in the solar system. Ridged terrains dominated by intense tectonism are observed on both hemispheres while plume jets
The thermal and orbital evolution of Enceladus : observational constraints and models
Enceladus possesses a global subsurface ocean beneath an ice shell a few tens of km thick, and is observed to be losing heat at a rate of ∼10 GW from its south polar region. Two major puzzles are the
Solar system: Saturn's tides control Enceladus' plume
Data obtained by the Cassini spacecraft show that the plume of ice particles at the south pole of Saturn's moon Enceladus is four times brighter when the moon is farthest away from the planet than
The pH of Enceladus’ ocean
Spontaneous formation of geysers at only one pole on Enceladus’s ice shell
The ice shell on Enceladus, an icy moon of Saturn, exhibits strong asymmetry between the northern and southern hemispheres, with all known geysers concentrated over the south pole, even though the expected pattern of tidal forced deformation should be symmetric between the north and south poles.
Solving the puzzle of Enceladus’s active south pole
  • F. Nimmo
  • Physics, Geology
    Proceedings of the National Academy of Sciences
  • 2020
In PNAS, Kang and Flierl provide a possible answer: Localization of activity can arise spontaneously via a feedback process in the ice shell of Saturn’s moon Enceladus.


Cassini Observes the Active South Pole of Enceladus
The shape of Enceladus suggests a possible intense heating epoch in the past by capture into a 1:4 secondary spin/orbit resonance.
Enceladus' south polar sea
Convection in Enceladus' ice shell: Conditions for initiation
Observations of Enceladus by the Cassini spacecraft indicate that this tiny Saturnian moon is geologically active, with plumes of water vapor and ice particles erupting from its southern polar
Enceladus: An Active Cryovolcanic Satellite
Enceladus is one of the most remarkable satellites in the solar system, as revealed by Cassini's detection of active plumes erupting from warm fractures near its south pole. This discovery makes
Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot
Cassini's Composite Infrared Spectrometer (CIRS) detected 3 to 7 gigawatts of thermal emission from the south polar troughs at temperatures up to 145 kelvin or higher, making Enceladus only the third known solid planetary body—after Earth and Io—that is sufficiently geologically active for its internal heat to be detected by remote sensing.
A fracture history on Enceladus provides evidence for a global ocean
The region surrounding the south pole of Saturn's moon Enceladus shows a young, pervasively fractured surface that emanates enough heat to be detected by the Cassini spacecraft. To explain the
Unified model of tectonics and heat transport in a frigid Enceladus
A simple model is formulated that couples the mechanics and thermodynamics of Enceladus and gives a unified explanation of the salient tectonic features, the plumes, and the transport of heat from a source at a depth of tens of kilometers to the surface.
Habitability of Enceladus: Planetary Conditions for Life
It is hypothesized that Enceladus’ plume, tectonic processes, and possible liquid water ocean may create a complete and sustainable geochemical cycle that may allow it to support life.
Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus
The identification of a population of E-ring grains that are rich in sodium salts, which can arise only if the plumes originate from liquid water, and the abundance of various salt components in these particles exhibit a compelling similarity to the predicted composition of a subsurface Enceladus ocean in contact with its rock core.