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Earth's axis of spin w.r.t. galactic rotation axis

  1. Jan 25, 2010 #1
    Can anyone confirm the earth's spin axis direction with respect to the AXIS of rotation of the galactic center? (in this current epoch).

    I'm getting something like 84 degrees difference (6 degrees off perpendicular);
    Is that correct? If not tell me your method.

  2. jcsd
  3. Jan 26, 2010 #2


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    Irrelevant. Define the axis of rotation of the galaxy wrt the solar system. A lot of 2012 nonsence has originated from this mythology.
  4. Jan 26, 2010 #3
    Quite making assumptions Chronos. It has nothing to do with 2012 nonsense. If you don't know the answer just say so.

  5. Jan 26, 2010 #4


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    Would it not simply be a matter of the angle between Polaris and the Milky Way core, which is in Sagittarius?
  6. Jan 26, 2010 #5


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  7. Aug 7, 2010 #6
    As with anything galactic, catching the sense of the rotation of the Milky Way takes time and repeated observations, reinterpretation and so on. It takes over 600,000 years just to go around it one degree. Observe, and then a few months later, and so on for several years.

    A good way to understand galactic rotation is that the angle between the Galactic Center and the Andromeda Galaxy is slowly increasing. The angle now is about 121.17 degrees galactic longitude. Andromeda is something like 20 degrees off the galactic equator but that's okay.

    The rate of increase is about six thousandths of one arc-second each year. In 170 years that is one arc-second, enough to show up on an ordinary modern surveyor's transit.

    It IS significant in the human though because after all it always turns forward, and never backward

    Apparently the Sea of Galilee was named after it, or vice versa - both after the Galatian religious group. From the north end, the Milky Way rises above that Sea and must have inspired a good deal of love :smile:; galactic rotation is now figurative in both pregnancy and lactation. Common sense.
  8. Aug 8, 2010 #7



    The plane of the milky way is left-right across your screen in that picture, the axis of the Earth's rotation is slightly tilted relative to the center of the milky way (hence why it is hard to see Sag from the northern hemisphere, it's down near the horizon even during the summer night when it is visible), and the orbital plane of most of the solar system is skewed up a bit awkwardly such that the planets plow through the galactic medium.

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