An electrical current is flowing from Saturn鈥檚 moon Enceladus to the ringed planet, creating a glowing patch in the planet鈥檚 atmosphere.
Ultraviolet images taken by the Cassini spacecraft revealed the patch, which is distinct from the planet鈥檚 auroras. It lies near Saturn鈥檚 north pole 鈥� exactly where electrons emitted by Enceladus would hit after being chanelled along the planet鈥檚 magnetic field lines, report of Central Arizona College in Coolidge and colleagues.
Where do the electrons come from? The team believes that sunlight knocks them off water molecules spewed by geysers at Enceladus鈥檚 south pole.
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The brightness of the patch varies, which could be due to variations in the amount of water vapour released by Enceladus, says the team.
Journal reference: , DOI: 10.1038/nature09928
