You Wouldn't Hear Even the Biggest Explosion in Space

Sound is a mechanical wave — it needs particles that can vibrate and pass energy along. In the vacuum of space there are essentially no particles, so there's nothing to set vibrating.

The result: if you could stand (theoretically, since that would require a spacesuit and a miracle of survival) near an exploding star, a blast unlike anything on Earth would be completely silent.

That's why the famous "Alien" tagline, "in space no one can hear you scream," is scientifically accurate, even though sci-fi movies almost always add explosion sounds for dramatic effect.

A side note: in rare, denser pockets of space — inside planetary atmospheres or gas clouds, for example — sound could theoretically travel. Just not through the emptiness between stars.