Saturn's rings may be giving birth to a brand new baby moon

Contributed by
Apr 15, 2014, 4:29 PM EDT (Updated)

Saturn may be adding another moon to its already impressive collection soon. 

The second-largest planet in our solar system already has 150 or so moons and "moonlets" orbiting it, though only a little more than 50 of them are named, and some of them are fewer than six miles in diameter. Now scientists have found what could be another baby moon getting ready to join the rest of Saturn's many natural satellites. 

In a new paper just published in the journal Icarus, a team of scientists revealed research centered in part around this image, taken by the Cassini spacecraft orbiting Saturn, which shows a 750-mile wide arc of icy material on the outer edge of Saturn's A-ring:

The researchers believe that arc, which has been visible in some form since 2012, is an indicator of "gravitational perturbation" inside the A ring, perturbation caused by an approximately half-mile-wide, still-unseen object inside, which could be a tiny new moon that's still coalescing from the particles that make up the rings. 

“We have not seen anything like this before,” said Carl Murray of Queen Mary University in London, lead author of the paper. “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.”

The researchers believe the object --unofficially named "Peggy," after Murray's mother-in-law -- could still grow into a slightly larger moonlet and eventually move out of the rings and into its own orbit around Saturn. Many of Saturn's natural satellites are thought to have formed this way earlier in the planet's history, but now the rings are largely depleted of the materials necessary to form a large moon, so small objects like Peggy are all they can muster. 

Of course, the researchers also acknowledge that the arc on the A ring could be an indicator of an object breaking up, not forming, but they'll continue to keep watch in hopes of catching a confirmed glimpse of Peggy. If they're right, we're witnessing the birth of a new moon, and even if it's a small one, that's worth letting out the space nerd in you.

(Universe Today via io9)

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