Considering that we would out of Milky Way, at what distance would a human will be able to see the collision with naked eye and and how fast would the galaxies appear to be approaching each other

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    $\begingroup$ You should define what you expect to see exactly and rigorously. The collision can be seen from inside the Mikly Way itself (even from our current position). $\endgroup$
    – Swike
    Sep 2, 2019 at 15:26
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    $\begingroup$ The collision would take place over many millions of years; in a human lifetime you would not detect a change with the unaided eye. $\endgroup$
    – antlersoft
    Sep 2, 2019 at 20:27
  • $\begingroup$ Astronomers have seen Andromeda moving toward us. We will eventually be right in the middle of the action. I suggest reading about it at en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision and then ask more detailed questions if you have some. At the moment, it is unclear exactly what you want to know. $\endgroup$
    – Bit Chaser
    Sep 6, 2019 at 0:03

1 Answer 1


The collision between the Milky Way and the Andromeda galaxy is not due to take place for another four billion years. The collision will take place so slowly that there would be no obvious change visible to whatever observer is present then. The night sky with Andromeda merging with our galaxy would seem quite normal, and only astronomers would detect any change from one decade to another.

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    $\begingroup$ The part of the answer which Mike G has removed as "irrelevant speculation" is that when this event happens there will be no human astronomers here to see it, they will all have become extinct billions of years earlier..That is fact, not speculation. The possibility that we may have been replaced by some other intelligent creature was admittedly speculation, but the trouble with people on this site is that with few exceptions they are good at mathematics but hopeless at general knowledge. One mandarin didn't even know that moulds were fungi, or that fungi are not plants! $\endgroup$ Sep 7, 2019 at 20:57
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    $\begingroup$ So you're saying you definitely know the future? Maybe you'd like to find citations for your facts. $\endgroup$
    – Ingolifs
    Sep 7, 2019 at 21:39
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    $\begingroup$ You are a typical example of users of this site with no general knowledge. Ask a biologist or palaeontologist whether there will be humans here in 4 billion years. You don't even seem to understand what a billion years is! $\endgroup$ Sep 7, 2019 at 21:54
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    $\begingroup$ Successful answers are focused, credible, and respectful to the reader. I think you can learn to do that if you pay attention. If you'd rather keep marching toward an answer ban, that's up to you. $\endgroup$
    – Mike G
    Sep 7, 2019 at 22:58

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