The red supergiant star Betelgeuse is getting ready to go supernova, and when it does Earth will have a front-row seat. The explosion will be so bright that Earth will briefly seem to have two suns in the sky. There’s about sixteen known candidates in our galaxy for a future supernova explosion, and quite a few of them would have a dramatic effect on our skies. But Betelgeuse is by far one of the closest, and its huge size means its explosion will be particularly dramatic. This is one cosmic disaster that we actually want to see happen sooner than later, because there may never be a sight quite like this ever again.