THE IMPORTANCE OF DEATH RAYS FROM SPACE: “Although 30 light-years is small on a galactic scale, Fields thinks it likely that Earth has been caught in a supernova ‘kill radius’ as many as a dozen times over our 4.5-billion-year history.” I can live with those odds, I guess, but it would be better if we were widely dispersed throughout the galaxy.
Related (well, sort of): Make Plans Now: Earth to Be Destroyed in 2049.