Half-Mile Wide Snowballs Seen Punching Through Parts of Saturn's F Ring

Posted on April 29, 2012

Images from NASA's Cassini spacecraft have revealed half-mile-sized objects punching through parts of Saturn's outermost ring (F ring). These objects leave glittering trails behind them, called "mini-jets." The images above show some of these collisions and mini-jets.

More Cassini images here show Saturn's wavy, wiggly F ring. Scientists believe these objects are large iceballs or snowballs originally formed by the pull of the moon Prometheus, which averages about 53 miles or 86 kilometers across, on tiny F ring particles.

NASA says that as Prometheus works its way around Saturn, its gravitational attraction sometimes parts channels in the icy particles of Saturn's F ring and sometimes pushes together sticky snowballs. The moon's continued progress around Saturn pulls some of these giant snowballs apart while adding material to others. The trails are caused by surviving snowballs that strike through Saturn's F ring. The snowballs hit the F ring at slow speeds of 4 mph. Take a look:

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