In its 4.5 billion year history, Earth has had to run the gauntlet. Numerous catastrophes have imperilled the planet, from massive impacts, to volcanic conflagrations, to frigid episodes of snowball Earth. Yet life persists. Among all of the hazards that threaten a planet, the most potentially calamitous might be a nearby star exploding as a supernova. Whan a massive enough star reaches the end of its life, it explodes as a supernova. The hyper-energetic explosion can light up the sky for months, turning night into day for any planets close enough. If a planet is too close, it will be...