Saturn may be birthing a brand-new baby moon

An icy object causing a commotion in Saturn's rings may give astronomers insight into how Saturn's moons form.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

Disturbance on Saturn's rings
The red circle marks the area of disturbance in Saturn's outer ring. NASA/JPL-Caltech/Space Science Institute

Congratulations, Saturn. It's a brand-new bouncing baby icy object.

NASA's Cassini spacecraft has witnessed some hijinks going on within Saturn's rings. There's a disturbance at the edge of the planet's outermost bright ring, creating an obvious visual bump along the normally smooth arc. Astronomers attribute the anomaly to a nearby object that isn't yet visible.

Scientists conjecture the object may be a small icy moon, which could give us a peek into the process of how Saturn's moons form. One theory is that the moons form from icy particles in the rings and eventually work their way outward from the rings to either orbit on their own or merge with other moons. The odd formation was captured by Cassini a year ago, but the results of the study were only recently published in the journal Icarus.

"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," says the study's lead author, Carl Murray of Queen Mary University of London.

Saturn already has over 60 confirmed moons, so it's been busy in the moon-making process before. The new object has already been given the informal name "Peggy." Peggy is estimated to be about a half-mile in width.

Astronomers suspect that Saturn may have had a much larger ring system in its past that helped with the creation of so many moons. "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," says Murray.

If Peggy turns out to be a new moon, it could potentially be one of the last, making it the littlest sister in a very large family.