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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."

5 of 125 comments (clear)

  1. Impact debris? by williwilli · · Score: 2, Interesting

    Isn't the most obvious reason that an asteroid or meteoroid or something similar simply hit the rings and broke apart? Is there some reason why this isn't likely?

    1. Re:Impact debris? by Malor · · Score: 4, Interesting

      The rings aren't very solid; most of the material is believed to be ice crystals that are, at most, a few meters in diameter. And despite their apparent solidity from here, they're an awful lot of empty space.

      Chances are pretty good that an asteroid would just sail right through the rings unimpeded. If it did hit something, it wouldn't be stopped. The inertia of the (small) body it hit would almost certainly be completely overcome by the incoming inertia of the asteroid. If it hit hard enough to break the asteroid apart, the result might look something like a shotgun blast, with a spray of asteroid chunks and a tiny bit of ring material continuing roughly along the same path the asteroid had been following. The 'hole' in the rings would almost certainly be filled within hours or days.

      If the asteroid happened to be slow enough to be captured into orbit, and happened to be on the same plane as the rings, it could potentially join the ring system. Over time, it might be torn apart by tidal forces into small chunks and blend in with the rest of the material.

      No matter what, it wouldn't just hit them and explode in place. The rings aren't nearly solid enough for that. It'd be like trying to stop a bullet with a sheet of Saran Wrap, perhaps with rice stuck to it.

  2. Re:Space.com lacking an editor? by VoidWraith · · Score: 2, Interesting
    The actual text is in a style I see very often in journalism, even when it is generally edited well. Personally, I think the best way to write it would be:

    Saturn's odd ring spokes were photographed during NASA's Voyager mission, which swung passed the planet in the 1980s, and were later observed by astronomers using the Hubble Space Telescope.
  3. magnetic fields by Kev_Stewart · · Score: 2, Interesting

    Could the magnetic fields be seasonal? I'm no expert but might that explain why they seem to appear and disappar periodically?

  4. Re:The Electric Universe theories predicted this by Markus+Registrada · · Score: 2, Interesting
    The "completely insane and already disproven multiple times" Electric Universe theory isn't one, and so can't have been. That is, "electric universe" is an amalgam of a lot of different theories, by a lot of different people, smushed together. Some are utterly compelling, and should make the jokers at NASA blush at their own poor educations. Others are frankly nuts. Most are in between, but testable.

    It's adolescent rubbish that (as far as I have been able to discern from their writings) Earth used to orbit Saturn, or that Venus was calved off of Saturn in immediate prehistory. It's almost certain that within that same period there were terrifying Aurorae Australis, bright enough to be seen by day. It's unlikely that there's no fusion going on within the sun, but very possible that the sun's chromosphere is a plasma "double layer" that accelerates into the corona those particles that overcome its activation threshold, producing the corona's astonishing temperature.

    It's likely that galaxies are not organized around "billion-solar-mass black holes," and that quasars are no more distant or energetic than the nearby Seyfert galaxies they cluster about. It's visibly true that currents in the interstellar plasma self-organize into intertwining filaments and extended membranes that sometimes fluoresce, exactly like neon lights, to produce stunningly beautiful nebular displays.

    It's an easy bet that cosmologists' notions of "dark matter" and "dark energy" adding up to over 99 times as much stuff as the visible universe are fantasies ginned up to rescue failed hypotheses. It's a matter of public record that astrophysicists, as a rule, have only rudimentary training in the dynamics of the plasma that they admit fills all of space, but insist on calling "ionized gas".

    Whatever their failings, the Electric Universe people have the best astronomical picture gallery on the web.