NASA's Cassini spacecraft has been studying Saturn for a long time. The spacecraft spied something interesting making its way through the rings of the giant planet. Cassini spied a disturbance in the A ring, which is the outer most ring of the planet's bright and large rings. Scientists have determined that the disturbance is an arc that is about 20% brighter than its surroundings.
This brighter arc is 750 miles long and 6 miles wide. Scientists looking at the image closely have also fond odd protuberances in the usually smooth profile of the edge of the ring. Looking at all the evidence, the researchers believe that the arc and protuberances are caused by the gravitational effects of a nearby object.
That nearby object could be a new moon for the planet. It’s not expected to grow any larger than it is now and there is a chance the new moon is already falling apart. The new object has been informally named Peggy and is too small to be seen in images right now.
The image that scientists are looking at was taken using the Cassini narrow angle camera on April 15, 2013. The results of the investigation of the image were published online this week; nearly a year to the day after the image was taken. Peggy is estimated to be about a half mile in diameter. Scientists believe that Peggy may be the last moon that Saturn can make. Saturn's ring system is believed to be too depleted to make more satellites. Cassini took a cool image of Saturn's rings and a distant Earth late last year.