Betelgeuse, the bright red star in Orion, is a ticking time bomb. It’s a red supergiant nearing the end of its life, and when it goes supernova, it will briefly outshine the full Moon. In late 2019, Betelgeuse dimmed unexpectedly, sparking speculation that it was about to explode. It turned out to be just a dust cloud, but the fact remains: it could go supernova tonight—or not for another 100,000 years.