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Andromeda and our galaxy

  1. Oct 8, 2008 #1
  2. jcsd
  3. Oct 8, 2008 #2

    George Jones

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    This not a particularly large speed. For example, the orbital speed of the Earth with respect to the Sun is 30 km/s, and the Sun's orbital speed about the centre of our galaxy is 220 km/s.
  4. Oct 9, 2008 #3
    Perhaps in earlier universe, the small cluster environment was very different; perhaps with many more closer galaxies and what we might call fragments of galaxies. http://en.wikipedia.org/wiki/Hubble_Deep_Field_North Then might one consider a scenario of a massive galaxy, and/or a succession of galaxies fragments, on a trajectory orthogonal to a line from our galaxy to Andromeda. Then when such 3rd galaxy intersected such line, then center of mass (CM) of such 3-system would markedly deform the manifold (i.e increased curvature), and hence lead to acceleration of outer 2 galaxies toward such CM; whereas the 3rd galaxy continues on it's way? Hence a scenario for current stage observed large closing velocity of the 2 galaxies? So might one model such a scenario, and adjust parameters in a simulation to see if one could obtain observed current stage findings? This would seem somewhat analogous to modeling the findings of our earth-moon system; wherein our early stellar system was quite different, since a Mars size planetesimal collided with proto-earth. http://en.wikipedia.org/wiki/Proto-earth#Moon
  5. Oct 9, 2008 #4
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