Do things crash together or is it more serene?

Do things crash together or is it more serene?
What happens when an unstoppable force meets another unstoppable force…
Find out why manmade satellites don’t crash into each other all the time
These two interacting galaxies are providing us with a rare opportunity to observe a galactic collision.
Comet 2013 A1 (Siding Spring) is set for a close encounter with the Red Planet in late 2014.