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Title: Tidal viscosity of Enceladus
Author: Michael Efroimsky

In the preceding paper (Efroimsky 2017), we demonstrated that under weak libration in longitude most dissipation is due to the gravitational tides (including the additional tides generated by libration). The other three sources of dissipation - which are the alternating parts of the centripetal, toroidal and purely radial deformations - are less important when libration is weak. Whether this is so for large-magnitude libration requires a separate study. In Ibid. it was also shown that in some situations the forced libration in longitude can provide a considerable and even leading input into the tidal heating: 52% in Phobos, 33% in Mimas, 12% in Enceladus, and 96% in Epimetheus. Equating our expression for the tidal dissipation rate (with the libration-generated input included) to the outgoing energy flux due to the vapour plumes, we estimate the mean tidal viscosity of Enceladus, under the assumption that the Enceladean mantle behaves as a Maxwell body. This method yields a value of 0.4 x 10^14 Pa s for the mean tidal viscosity, which is remarkably close to the viscosity of ice near the melting point. We then demonstrate that, with such a value of the tidal viscosity, the tidal dissipation in Enceladus is too low to influence its orbital evolution. Thus the orbital evolution of Enceladus is defined to a much greater extent by the tidal friction in Saturn.

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Cassini Finds Saturn Moon May Have Tipped Over

Saturn's icy, ocean-bearing moon Enceladus may have tipped over in the distant past, according to recent research from NASA's Cassini mission. Researchers with the mission found evidence that the moon's spin axis -- the line through the north and south poles -- has reoriented, possibly due to a collision with a smaller body, such as an asteroid.
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What ingredients are needed for life beyond Earth?

Nasa believes one of Saturn's moons, known as Enceladus, may now be the single best place to look for life beyond Earth.
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Saturn moon 'able to support life'

Saturn's ice-crusted moon Enceladus may now be the single best place to go to look for life beyond Earth.
The assessment comes on the heels of new observations at the 500km-wide world made by the Cassini probe.
It has flown through and sampled the waters from a subsurface ocean that is being jetted into space.
Cassini's chemistry analysis strongly suggests the Enceladean seafloor has hot fluid vents - places that on Earth are known to teem with life.

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NASA Missions Provide New Insights into 'Ocean Worlds' in Our Solar System

Two veteran NASA missions are providing new details about icy, ocean-bearing moons of Jupiter and Saturn, further heightening the scientific interest of these and other "ocean worlds" in our solar system and beyond. The findings are presented in papers published Thursday by researchers with NASA's Cassini mission to Saturn and Hubble Space Telescope.
In the papers, Cassini scientists announce that a form of chemical energy that life can feed on appears to exist on Saturn's moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter's moon Europa.

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For Saturn moon, possible 'restaurant' at bottom of the sea

Galactic hitchhikers take note: The restaurant at the end of the universe may be closer than we think.
After probing data from NASA spacecraft Cassini's flight through the watery plume of Saturn's icy moon Enceladus, scientists from the Southwest Research Institute, Johns Hopkins' Applied Physics Lab and Cornell confirm the presence of molecular hydrogen a potential microbial food source and an ingredient necessary for life. The new research is published April 14 in Science.

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Enigmatic plumes from Saturn's moon caused by cosmic collision

Enceladus' south pole is wounded, bleeding heat and water. Its injury may have come from a huge rock smashing into this frigid moon of Saturn less than 100 million years ago, leaving the area riddled with leaky cracks.
The region near Enceladus' south pole marks one of the solar system's most intriguing mysteries. It spews plumes of liquid from an interior ocean, plus an enormous amount of heat. The south pole's heat emission is about 10 gigawatts higher than expected - equivalent to the power of 4000 wind turbines running at full capacity. The rest of the moon, though, is cold and relatively homogeneous.

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Enceladus' south pole is warm under the frost

Over the past decade, the international Cassini mission has revealed intense activity at the southern pole of Saturn's icy moon, Enceladus, with warm fractures venting water-rich jets that hint at an underground sea. A new study, based on microwave observations of this region, shows that the moon is warmer than expected just a few metres below its icy surface. This suggests that heat is produced over a broad area in this polar region and transported under the crust, and that Enceladus' reservoir of liquid water might be lurking only a few kilometres beneath.
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Enceladus ocean 'must be global'

Scientists have determined that the sub-surface body of water on the Saturnian moon Enceladus must be far more extensive than first thought.
Using pictures from the Cassini probe, the researchers have detected and tracked a slight wobble in the moon.

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Under Saturnian moon's icy crust lies a 'global' ocean

By measuring with exquisite precision the tiny wobbles of Saturn's moon Enceladus - whose cosmic quavers are detectable only in high-resolution images taken by NASAs Cassini spacecraft - Cornell University researchers have learned that a global ocean lies beneath the moons thick icy crust.
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