Moons of our Solar System
Moons of our Solar System

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Moons of our Solar System

1.6 How Enceladus works

This video explains how the eruption plumes of Enceladus might be generated as ‘cold geysers’. Remember that you saw a video that attempted to explain the general processes involved in tidal heating (‘Tidal heating explained’ [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] ) near the end of Week 1.

Download this video clip.Video player: moons_1_vid029.mp4
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The so-called ‘cold geyser’ process needs a source of heat to work. Varying tidal forces during Enceladus’s orbit around Saturn cause the moon to deform. Friction during deformation generates heat. This is what is known as tidal heating.
This frictional tidal heating causes temperatures to build up below the moon’s surface. The rising temperatures melt some of the ice, creating pockets of pressurised icy liquids trapped underground. These pockets are mainly composed of water, with ammonia and other impurities acting as antifreeze.
This pressurised liquid then escapes through cracks in the surface. As the liquid escapes, it expands and freezes into ice particles that are jetted into space as plumes that show up brightly when they’re sunlit. Plume material that falls back coats the surface in icy dust, which makes the surface bright.
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