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This graphic shows how Saturn and its moon Enceladus are electrically linked. Magnetic field lines, invisible to the human eye but detectable by the fields and particles instruments on NASA's Cassini spacecraft, arc from Saturn's north polar region to south polar region. Enceladus resides in the arc of a set of the field lines and feeds charged particles into the Saturn atmosphere. As Enceladus orbits around Saturn, the "footprint" of its connection to Saturn's north polar region, visible in ultraviolet light, also rotates. A doughnut of plasma, or hot ionized gas, revolves around Saturn at t…
