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			from 
			
			Thuntherbolts Website 
			Dec 09, 2004 
  
			
			  
			
			Credit: 
			NASA/JPL/Space Science Institute  
  
			
			In Greek legend,
			Prometheus steals fire from the gods to give to man. 
			Unfortunately the story is misunderstood because the "fire of the 
			gods" was electrical. The similarity of an 
			electric discharge to fire lies in the fact that both are a 
			plasma. However, an electrical discharge in a plasma 
			may be invisible, unlike most flames. There is a plasma 
			discharge mode known as a "dark discharge". It may be 
			felt as a wind, or movement of particles in the direction of 
			the electric field. It will be familiar as the breeze from an air 
			ionizer. 
			 
			Pictured above is Saturn’s little moon 
			Prometheus, nestled inside the gas giant’s F ring. 
			The report accompanying the image says,  
			
				
				"In an image taken 
				on Oct. 29, Prometheus is seen stealing particles 
				from the F ring while connected to the ringlets by 
				a faint streak of material. 
				  
				
				" ... Scientists are 
				not sure exactly how Prometheus is interacting 
				with the F ring here, but they have speculated 
				that the moon might be gravitationally pulling material away 
				from the ring. Scientists speculate that the ring particles may 
				end up in a slightly different orbit from the one they were in 
				prior to getting a ’kick’ from the moon. These kicks occur at 
				specific locations in the rings and can actually cause large 
				waves or knots to form. In the still image, gaps in the diffuse 
				inner strands are seen. All these features appear to be due to 
				the influence of Prometheus in ways that are not 
				fully understood." 
			 
			
			It is unlikely that the 
			influence of tiny, potato-shaped Prometheus on 
			Saturn’s F ring can be understood in purely 
			gravitational terms. A giveaway to the electrical nature of the 
			interaction can be seen in the spiky projections, or "faint 
			streaks", projecting from the F ring toward 
			Prometheus. Faint streaks like that are seen in comet tails, 
			which are also an electrical discharge phenomenon. 
			 
			But is Prometheus stealing material from the rings or 
			is it losing material to the rings in a comet-like electrical 
			discharge? Is Prometheus undergoing electric discharge 
			machining (EDM) and providing fine dusty material for 
			the F Ring? The same process could account for the odd 
			discovery that Saturn’s A and B 
			rings are clean water ice while the Cassini division 
			between them is very dirty. There was probably a small moon orbiting 
			there which has recently been machined to dust. 
			 
			If this model is correct we should expect to see a freshly 
			cratered surface on Prometheus, rather like that of 
			Comet Wild 2, if the opportunity arises to see Prometheus 
			more closely. 
			
			  
			
			
			  
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