The branch of physics (specifically Astrophysics) that deals with major events that could cause devastation on a vast scale (usually known as catastrophes) and how to make sure they don't happen or at the very least try and find a way to reduce the impact of any given catastrophe.
News in Catastrophysics: A large Earth-killing asteroid is likely to hit us within the next century and there's nothing we can do about it!
by Will [Neffers] March 21, 2013