Thermal anomaly in Enceladus’ South Pole subsurface
نویسندگان
چکیده
On November 6, 2011, during the E16 flyby, the Cassini Radar had a unique opportunity to closely observe Enceladus in both its active and passive modes of operation. The E16 swath aimed at about 66°S, close to the active South polar rifted area. In this paper, we show that the radiometry data collected during this flyby revealed brightness temperatures much higher than expected, pointing to a geothermal anomaly in the subsurface. This anomaly could be indicative of a buried heat source, unless it is due to exotic thermal processes such as the solid-state greenhouse effect.
منابع مشابه
Interior thermal state of Enceladus inferred from the viscoelastic state of the ice shell
Recent geodetic measurements for Enceladus suggest a global subsurface ocean that is thicker beneath the south pole. In order to maintain such an ocean, viscous relaxation of topography at the base of the ice shell and melting of ice need to be balanced. In this study, we investigate the interior thermal state that can lead to the relaxation timescale being comparable to the melting timescale. ...
متن کاملDiapir-induced Reorientation of Enceladus
Introduction: The south polar region of Enceladus, a small icy satellite of Saturn, consists of young, tectonically deformed terrain and has an anomalously high heat flux [1,2]. We find that the pole-centered location of this region can be explained by reorientation of Enceladus induced by a large, low-density ice diapir within a relatively thick ice mantle. Poleward reorientation requires that...
متن کاملEstablishing a Long-term Fracture History of the South Polar Terrain on Enceladus
Introduction: Enceladus is the sixth-largest moon of Saturn and has a diameter of approximately 504 km. The icy moon synchronously orbits Saturn at a distance of approximately 238,000 km once every 33 hours between Mimas and Tethys [1] but is locked in a 1:2 resonance with Dione resulting in an orbital eccentricity of 0.0047 [2]. However, Enceladus is very different from other Saturnian moons, ...
متن کاملThe gravity field and interior structure of Enceladus.
The small and active Saturnian moon Enceladus is one of the primary targets of the Cassini mission. We determined the quadrupole gravity field of Enceladus and its hemispherical asymmetry using Doppler data from three spacecraft flybys. Our results indicate the presence of a negative mass anomaly in the south-polar region, largely compensated by a positive subsurface anomaly compatible with the...
متن کاملNear-surface heating on Enceladus and the south polar thermal anomaly
[1] Strike-slip motion is predicted to be a consequence of diurnal tidal stresses in most satellites of the outer solar system. Such motion can lead to near-surface heating through friction or viscous dissipation. Here we discuss the effect of near-surface shear heating on convection in the underlying ice shells of icy satellites. We present models of convection in spherical shells including ti...
متن کامل