Data from NASA’s Cassini spacecraft have revealed that Enceladus, one of Saturn’s diminutive moons, is linked to Saturn by powerful electrical currents – beams of electrons that flow back and forth between the planet and moon. The finding is part of a paper published in Nature today.
CAPS, one of the instruments on board Cassini which made the electron beam discovery, includes a electron sensor called CAPS-ELS – led by UCL (University College London).
Since Cassini’s arrival at Saturn in 2004 it has passed 500km-wide Enceladus 14 times, gradually discovering more of its secrets on each visit. Research has found that jets of gas and icy grains emanate from the south pole of Enceladus, which become electrically charged and form an ionosphere. The motion of Enceladus and its ionosphere through the magnetic bubble that surrounds Saturn acts like a dynamo, setting up the newly-discovered current system.
Scientists already knew that the giant planet Jupiter is linked to three of its moons by charged current systems set up by the satellites orbiting inside its giant magnetic bubble, the magnetosphere, and that these current systems form glowing spots in the planet’s upper atmosphere. The latest discovery at Enceladus shows that similar processes take place at the Saturnian system too.