Originally published at: http://www.howtogeek.com/166187/no-gentle-galaxy-collision/
It is hard to imagine a more cataclysmic event than the collision of two galaxies and the effect such an event has on each one as they are ripped apart. See the destructive power of collision at work in this video showing the latest Hubble imagery of Arp 142, a.k.a. the collision of NGC 2936 and NGC 2937.
I read recently, and I can't remember where, that in such collisions nothing but gas collides. Collisions of massive bodies are exceedingly rare. Almost none. But, oh, how I'd love to see a couple of planets "merge" head on. More so a couple of stars.