Many writers of speculative fiction, and their readers, love catastrophes. No catastrophe is too great: spaceships breaking apart with human bodies and engine parts gyring away into the blackness of space, viruses let loose in a hospital, super-storms converging on a doomed city.

Perhaps the most succinct expression of catastrophe is an extinction event, the end of human life--or all life--on a planet. Here is a scholarly look at extinction events: Reducing the Risk of Human Extinction, Jason G. Matheny, Center for Biosecurity of UPMC (University of Pittsburgh Medical Center). Use this article to plan your next novel, or if a reader, to vet the science of a novel you're reading.