The images show what NASA is describing as "disturbances" on the edge of Saturn's outermost ring. The standout feature of these disturbances is an area significantly brighter than the surrounding ring. The bright spot is around 750 miles long. The findings were published today in the journal Icarus.
"We have not seen anything like this before," said Carl Murray, lead author of the report and an Astronomer at Queen Mary University of London. "We may be looking at the act of birth, where this object is just leaving the rings and heading off to be a moon in its own right."
Unfortunately, this disturbance is unlikely to become a new moon. Astronomers do not predict that it will grow larger. Instead, researchers are looking to the phenomena as a possible clue to how Saturn's current moons may have formed.
The object causing the large ring disturbance, nicknamed "Peggy" by astronomers, is estimated to be only half a mile in diameter - far to small to be seen using Cassini's cameras. Astronomers believe that Saturn's current rings, as spectacular as they are, do not have enough material to support the development of a new moon. Saturn's current moons are believed to have formed from even larger rings that existed in the planet's past.
"The theory holds that Saturn long ago had a much more massive ring system capable of giving birth to larger moons," said Murray. "As the moons formed near the edge, they depleted the rings and evolved, so the ones that formed earliest are the largest and the farthest out."
The Cassini probe is scheduled to make a close pass of Saturn's outermost ring in 2016. At that time astronomers will be able to study Peggy more closely, something that may not be possible at any point in the future.
Image via NASA/JPL-Caltech/Space Science Institute