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The lakes of Titan
Lorenz, R. D.; Stiles, B.; Kelleher, K. +35 more
The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive…
Shear heating as the origin of the plumes and heat flux on Enceladus
Spencer, J. R.; Nimmo, F.; Pappalardo, R. T. +1 more
Enceladus, a small icy satellite of Saturn, has active plumes jetting from localized fractures (`tiger stripes') within an area of high heat flux near the south pole. The plume characteristics and local high heat flux have been ascribed either to the presence of liquid water within a few tens of metres of the surface, or the decomposition of clath…
Eruptions arising from tidally controlled periodic openings of rifts on Enceladus
Helfenstein, P.; Bills, B. G.; Hurford, T. A. +2 more
In 2005, plumes were detected near the south polar region of Enceladus, a small icy satellite of Saturn. Observations of the south pole revealed large rifts in the crust, informally called `tiger stripes', which exhibit higher temperatures than the surrounding terrain and are probably sources of the observed eruptions. Models of the ultimate inter…
Association of the jets of Enceladus with the warmest regions on its south-polar fractures
Porco, Carolyn C.; Spitale, Joseph N.
Jets of material have been seen emanating from the south-polar terrain of Saturn's satellite Enceladus. Observations have shown that this region is anomalously warm, with the hottest measured temperatures coinciding with the four `tiger stripe' fractures, named Alexandria, Cairo, Baghdad and Damascus, that straddle the region. Here we use Cassini …
A dynamic, rotating ring current around Saturn
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +2 more
The concept of an electrical current encircling the Earth at high altitudes was first proposed in 1917 to explain the depression of the horizontal component of the Earth's magnetic field during geomagnetic storms. In situ measurements of the extent and composition of this current were made some 50years later and an image was obtained in 2001 (ref.…
Hyperion's sponge-like appearance
Burns, J. A.; Denk, T.; Porco, C. +15 more
Hyperion is Saturn's largest known irregularly shaped satellite and the only moon observed to undergo chaotic rotation. Previous work has identified Hyperion's surface as distinct from other small icy objects but left the causes unsettled. Here we report high-resolution images that reveal a unique sponge-like appearance at scales of a few kilometr…
Modulation of Saturn's radio clock by solar wind speed
Lamy, Laurent; Prangé, Renée; Cecconi, Baptiste +2 more
The internal rotation rates of the giant planets can be estimated by cloud motions, but such an approach is not very precise because absolute wind speeds are not known a priori and depend on latitude: periodicities in the radio emissions, thought to be tied to the internal planetary magnetic field, are used instead. Saturn, despite an apparently a…
A belt of moonlets in Saturn's A ring
Schmidt, Jürgen; Sremčević, Miodrag; Albers, Nicole +3 more
The origin and evolution of planetary rings is one of the prominent unsolved problems of planetary sciences, with direct implications for planet-forming processes in pre-planetary disks. The recent detection of four propeller-shaped features in Saturn's A ring proved the presence of large boulder-sized moonlets in the rings. Their existence favour…
Surface composition of Hyperion
Sotin, C.; Brown, R. H.; Baines, K. H. +28 more
Hyperion, Saturn's eighth largest icy satellite, is a body of irregular shape in a state of chaotic rotation. The surface is segregated into two distinct units. A spatially dominant high-albedo unit having the strong signature of H2O ice contrasts with a unit that is about a factor of four lower in albedo and is found mostly in the bott…
An unexpected cooling effect in Saturn's upper atmosphere
Millward, G. H.; Miller, S.; Smith, C. G. A. +2 more
The upper atmospheres of the four Solar System giant planets exhibit high temperatures that cannot be explained by the absorption of sunlight. In the case of Saturn the temperatures predicted by models of solar heating are ~200K, compared to temperatures of ~400K observed independently in the polar regions and at 30° latitude. This unexplained `en…