Colliding Galaxies: Can the Milky Way Galaxy Collide with Andromeda?


ARP 87This is one of those things that’s hard to get your head around.  Imagine a collision between two objects whose size is measured in light years!  Despite the fact that the universe is vast – approximately 93 billion light years across, galaxies still manage to run into one another.

A galaxy is just about the largest object in the universe.  It is a collection of stars, planets, the remnants of exploded stars, interstellar dust and gas, and dark matter all bound together by a common gravitational influence. Our Milky Way is a great (and close by) example of a galaxy.  Galaxies come in all shapes from elliptical clusters to beautiful barred spiral galaxies with vast arms of stars and gas slowly revolving around a central gravitational mass.   It is estimated that galaxies can consist of anywhere between 10 million stars to as many as a trillion stars!ARP 194

It is likely that there are about 100 billion galaxies in the universe and galaxies move.  As an example, our Milky Way Galaxy moves about 18.9 billion kilometers per year.  Since the universe is between 13 and 20 billion years old, there is plenty of time for one galaxy crash into another one.  In fact, we are moving in the general direction of the Andromeda Galaxy and if we stay on course, we should reach it in about 3 billion years.

So what happens when galaxies do reach one another?  Since they generally don’t have enough momentum to separate after they meet, they will usually merge forming a new single galaxy.

If you thought that it would be nearly impossible for two galaxies to collide, check out Stephan’s Quintet sometime…

If you thought that it would be nearly impossible for two galaxies to collide, check out Stephan’s Quintet sometime…

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4 Responses to “Colliding Galaxies: Can the Milky Way Galaxy Collide with Andromeda?”

  • Nature Guy says:

    But, what is not answered above…..at least for me….is, when two galaxies do combine, do any suns and planets go crashing into other suns & planets at some point?? I find it difficult to imagine that kind of galactic catastrophe NOT happening when galaxies combine. YOUR THOUGHTS?? : )

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  • dan says:

    no they wont crash too much space in between stars

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  • Sam says:

    If Andromeda and Milky Way do clash, it would indeed be a catastrophe that only the people 3 billion years younger than us can answer..Wish to live to see that moment!

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  • Sultan says:

    i don’t really think that anyone of us or they one younger than us 3 billion years will live to see it …

    so 3 billion years is lot’s of time more than we can We can not imagine with these events, we try to approach the truth, of course, the sheer amount of information about the space does not narrate the thirst of knowledge, who was born with us since we were able to understand the world around us

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