When Galaxies collide!!

Here’s an odd question… I remember from one of my astronomy classes back in college the Prof. telling us about the discovery of 2 galaxies that were evidentaly in a “state of collision” (his words) and him being terribly excited about it all. Well, me being in about the same mental state tonight as I was then (tired, slightly hung-over) got me thinking about this. If this were to happen to OUR galaxy, what changes in the local area of space (Solar system, etc.) could we reasonably expect?

Bad things. Very bad things.

NGC 6745, galaxies in collision.

IMDB galaxies in collision.

Galaxy collisions are reasonably common in the universe.

The usual two results are (1) the galaxies merge or (2) pass through one another. Other than their orbits changing (sometimes drastically) the existing stars are not generally affected. The gas and dust do collide, and this often results in a surge of star formation.

Pretty much all known collisions are between galaxies in the same cluster.

I took a college astronomy class a couple years ago and I remember the question coming up. As I remember it my prof’s explanation was that even though there were billions of stars involved, space is so vast that it would be extremely unlikely for collisions to happen. I seem to remember him suggesting that we had some small sister galaxy moving through ours currently, I might not remeber that part correctly though.