A supernova is a star explosion – destructive on a scale almost beyond human imagining. If our sun exploded as a supernova, the resulting shock wave probably wouldn't destroy the whole Earth, but the side of Earth facing the sun would boil away.
What if a supernova explodes close to Earth?
The entire Earth could be vaporized in just a fraction of a second if the supernova was close enough. The shockwave would arrive with enough force to wipe out our entire atmosphere and even our oceans. The exploded star would grow brighter for about three weeks after the explosion, casting shadows even during the day.
Can Betelgeuse destroy Earth?
Will the Betelgeuse supernova destroy Earth? No. Whenever Betelgeuse does blow up, our planet Earth is too far away for this explosion to harm, much less destroy, life on Earth. Astrophysicists say we'd have to be within 50 light-years of a supernova for it to harm us.