Suppose 2 spaceships leave from the earth's north and South Pole going straight up which one will exit the galaxy first (assume they have the same speed and are going in a totally straight line) ? Edge of the galaxy means absence of stars, this question refers to the up-down edge of this spiral galaxy. The question is about the current distance from the earths poles to the edge (top/down) not to the galactic plane, as far as I understand after crossing the plane the nearest pole to the edge will be reversed.

  • $\begingroup$ Given the kind of distances involved, you can treat the Earth as a mathematical point without any loss of accuracy in the answer. Now, do you want "edges" in the spiral plane, or perpendicular to that? $\endgroup$ Mar 25 '19 at 17:31
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    $\begingroup$ You might like to edit your question to be a bit more precise. How do you define “edge”? Are you including the dark matter halo? Are you ignoring gravitational effects (both boosts and “drag”)? Ie is this about simple straight-line distance, or plotting an escape arc? $\endgroup$ Mar 25 '19 at 23:47
  • $\begingroup$ Edited to show the question requires a simple straight line, and edge means perpendicular $\endgroup$
    – user426132
    Mar 26 '19 at 8:08
  • $\begingroup$ and our solar system is at a large angle to the ecliptic plane (physicsforums.com/threads/…) so to get to the edge, you don't want to exit via the pole but at ~27deg from the equator. $\endgroup$
    – Hobbes
    Mar 26 '19 at 8:24
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    $\begingroup$ exiting from the pole gives a much longer trajectory than exiting perpendicular to the galactic plane. $\endgroup$
    – Hobbes
    Mar 26 '19 at 9:59

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