Scientists have uncovered a shocking surprise about Saturn’s ice-spewing satellite Enceladus: the little 318-mile-wide moon creates a loop of electrically-charged particles that run from its north and south poles all the way up and over to Saturn’s north and south poles, forming a giant electron beam connecting the gas planet and its icy moon. Where the electron particles connect with Saturn’s northern atmosphere astronomers have identified an ultraviolet “footprint”, about the size of the state of California. (A corresponding footprint near Saturn’s south pole has not yet been identified.)
Using Cassini data from 2008 this planet-moon connection has just recently been confirmed and published in the journals Nature and Geophysical Research Letters.
“The footprint discovery at Saturn is one of the most important fields and particle revelations from Cassini and ultimately may help us understand Saturn’s strange magnetic field. It gives us the first visual connection between Saturn and one of its moons.”
– Marcia Burton, a Cassini fields and particles scientist at NASA’s Jet Propulsion Laboratory
While bright in ultraviolet radiation, the footprint is invisible to our eyes. Were we able to see it, it would be similar in brightness to “normal” auroral lights in our own northern skies, whereas Saturn’s own actual aurorae are much, much brighter.
This electric connection may be caused by ionized water-ice particles sprayed into orbit by Enceladus, which then interact with Saturn’s powerful magnetic field lines.
The footprint signature on Saturn varies in size and brightness, leading scientists to believe that Enceladus’ rate of spray also varies…providing a roundabout way to answer that question!
“Scientists have been wondering whether the venting rate is variable, and these new data suggest that it is.”
– Abigail Rymer, Cassini team scientist, Johns Hopkins University Applied Physics Laboratory
Also, data collected in 2009 provided not only visible data on the electrical circuit but also audio information! The clip below presents enhanced audio signals created by the electrons moving along the beam from Enceladus to Saturn (if there’s no video below, click here):
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Creepy! But also very cool.
Now that’s what I call shock and awe! 🙂
Image credit: NASA/JPL/Space Science Institute