The constellation of Orion, along with the great molecular cloud complex and including its brightest stars. Betelgeuse, the nearby, bright red supergiant (and supernova candidate), is at the lower left. Image credit: Rogelio Bernal Andreo.

What will happen when Betelgeuse explodes?

It might be the nearest supernova humanity will ever see. What will happen when it goes off?

“Without these supernova explosions, there are no mist-covered swamps, computer chips, trilobites, Mozart or the tears of a little girl. Without exploding stars, perhaps there could be a heaven, but there is certainly no Earth.” -Clifford A. Pickover

Every star will someday run out of fuel in its core, bringing an end to its run as natural source of nuclear fusion in the Universe. While stars like our Sun will fuse hydrogen into helium and then — swelling into a red giant — helium into carbon, there are other, more massive stars which can achieve hot enough temperatures to further fuse carbon into even heavier elements. Under those intense conditions, the star will swell into a red supergiant, destined for an eventual supernova after around 100,000 years or so. And the brightest red supergiant in our entire night sky? That’s Betelgeuse, which could go supernova at any time.

The color-magnitude diagram of notable stars. The brightest red supergiant, Betelgeuse, is shown at the upper right. Image credit: European Southern Observatory.

Honestly, at its distance of 640 light years from us, it could have gone supernova at any time from the 14th century onwards, and…