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The Return of Saturn's Spokes

Posted by CowboyNeal on from the wheel-in-the-sky dept.

CheshireCatCO writes "After more than a year in orbit around Saturn, the Cassini spacecraft has finally spotted 'spokes' in the rings. Spokes, large radial structures in the rings, where seen by the Voyager spacecraft and have remained difficult to fully explain. The reappearce of the spokes comes about two years earlier than many models predicted."

2 of 125 comments (clear)

  1. See Cassini's path by latent_biologist · · Score: 5, Informative

    "Unlike Voyager or Hubble, Cassini is in a unique position to study ring spoke phenomena at Saturn."

    With Celestia, you can actually follow Cassini's path as it follows Saturn. It really puts the above statement in perspective (plus it makes u feel like an astronaut).

  2. Re:Cause of the spokes? by CheshireCatCO · · Score: 4, Informative

    In a word, no.
    The spokes must be tied to the magnetic field of Saturn. This explains why the stay at the same magnetic longitude of the planet and why they don't wind up as the inner parts of the rings orbit the planet faster. So they're not disturbances in the ring particles themselves, since the ring particles are too massive to really feel the magnetic field.

    However, if you levitated dust over the rings, that would do the trick. The problem is how to levitate the dust. It turns out that you can develop a negative potential on the rings (I think it's negative... I forget, to be honest) which can repel the dust and cause it to hover. So under the right conditions, if dust were kicked up by a small collision in ther rings (say a meteroid collision), it can float over the rings and spread radially, making a spoke.

    Or so we think...