NASA’s Cassini spacecraft has spotted evidence of a mysterious object measuring about half a mile wide at the edge of Saturn’s outermost ring, known as the A ring. NASA scientists believe this bright feature may be the gravitational disturbance caused by the birth of a new baby moon. Details of the observations were published online today in the journal Icarus.
Astronomer and lead author of the study, Carl Murray of Queen Mary University of London has named the moon “Peggy” after his mother-in-law who was celebrating her 80th birthday when he made the discovery, according to the Huffington Post. In a report from NASA Science News, Murray said,
“We have not seen anything like this before. 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.”
Peggy is too small to see in images so far, but Cassini will be moving closer to the outer edge of the A ring in 2016, giving researchers an opportunity to study the object in more detail. Peggy may be joining the already 60+ known moons of Saturn, from the colossal Titan (nearly 1.5 times wider than Earth’s moon) to tiny iceballs less than one mile across. Scientists believe these moons formed from ice particles within Saturn’s ring which later expanded outwarded and grew by merging with other satellites along the way. According to Murphy,
“The theory holds that Saturn long ago had a much more massive ring system capable of giving birth to larger moons. As the moons formed near the edge, they depleted the rings.”
Over time, Peggy might accumulate enough matter to become a larger moon and establish its own orbital path around the ringed planet. Conversely, the bright feature detected by the Cassini spacecraft may be caused by matter breaking apart instead of coming together. Further research is needed to come to a decisive conclusion. The process of moon formation may be ending with Peggy, so Murray and his colleagues are seizing this chance for all it’s worth.