News From Saturn
This week more news comes from Saturn's Rings. Perhaps humans are drawn to their beauty for a reason. They could hold secrets to how our planets formed, and may even point to future sources of energy. In the December issue of Nature scientists report discovery of an enormous ring current surrounding Saturn. Most of the plasma comes from the south pole of Enceladus. The clump of charged particles rotating in sync with Saturn is still considered a mystery. Charged particles circling the planet every 10 hours 47 minutes are like those that would be produced by an orbiting Black Hole.
Wednesday at AGU, Cassini scientists claimed that Saturn's Rings are nearly old as the Solar System. Previously it was thought that the Rings would decay within 100 million years. We would then face the anthropic question of why the Rings exist in just the right time for humans to enjoy them. Later I had the good fortune to talk with Larry Esposito, who wrote the book on Ring observations. He believes the Rings are continually replenished and recycled by icy moonlets orbiting within. These unseen bodies are held together in spite of Roche's Limit by colliding and melting into each other. Normally bodies colliding at orbital velocities should not stick together. Perhaps something else is needed to seed their formation.
Friday C.D. Murray talked about F Ring objects and embedded moonlets. The "fans" in this Ring are evidence of embedded objects. The shepherd moon Prometheus has been observed to interact with F Ring, sometimes leaving strands or jets of materiel. The "jets" are interpreted as resulting from collisions. A big question remains why F Ring precesses in the first place. The Rings would be another place to look for a Black Holes.
Afterward M. Sremcevic talked about Propellor features in the Rings. These are located in a narrow 3000 km belt at 130,000 km from Saturn. The objects that cause the propellors must be very small, for anything bigger than 1 km would open a gap in the Rings. Their behaviour is incompatible with an accretion origin, so they are considered as possible fragments of a shattered moon. I asked and Sremcevic confirmed that his computer models treated the objects as point masses (like Black Holes).
Many, many mysteries remain about the Rings. Some of these mysteries would be explained by very tiny but massive objects hidden within. Thes objects would also give off radiation, like the clump of charged particles. Saturn's rings show conditions similiar to those which formed our Solar System. Perhaps Black Holes are closer than we think.
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