Saturn F-Ring Mystery

Saturn F-Ring
Cassini Images an Object Puncturing the F-Ring of Saturn
Image Credit: NASA / JPL-Caltech / SSI / QMUL

Cassini has imaged small objects puncturing the F-ring of Saturn, leaving behind trails of debris that scientists have termed ‘mini-jets’.

Having chanced upon this phenomenon, Carl Murray, a Cassini imaging team member based at Queen Mary University of London, England and others searched through 20,000 images during the seven years Cassini has been at Saturn, and culled some 500 that show these wispy streaks.

Now the imaging team thinks they have the story. Prometheus is a large object in the dynamic F-ring, and its long axis is almost 150 kilometers. It is known to create channels, ripples and snowballs in the F ring, as shown in this video collage. Although a lot of the debris from these collisions dissipate, some of the 1 kilometer sized snowballs persist. They occupy orbits that take them above and below the F-ring, and collide with other particles in the ring at slow relative speeds, around 2 meters per second. These collisions drag glittering ice particles out of the ring, creating the 50 to 150 kilometer long ‘mini-jets’.