Supernova

How Close Would a Supernova Have to Be to Kill Us All?

New research suggests that exploding stars may still be deadly twice as far away as previously thought.

Getty Oliver Burston

By Avery Thompson

If you're looking for the deadliest explosion in the universe, a supernova is a good place to start. A supernova can form an incredibly beautiful nebula, but the intense radiation emitted by these stellar explosions can sterilize entire planets.

If a supernova were to occur near us, it could wipe out our entire civilization. But how far is "near?" New research suggests it's a lot farther than scientists previously believed.

A previous study found that any supernova that went off within about 25 light-years would be enough to wipe us out, but any farther than that and we'd be mostly safe. New research, however, increases that "kill zone" to 50 light-years.

"[The previous study] left some effects out or didn't have good numbers, so now we think it may be a bit larger distance," says Adrian Melott, a researcher from the University of Kansas and one of the authors of the study.

If you're feeling worried at this point, don't be: The closest star that could supernova is located more than 100 light-years away and probably won't explode for millions of years. This new study doesn't increase our chances of dying in a radiation-fueled apocalypse, but it does provide an interesting look at the complex dynamics of supernovae.

"Cosmic rays like to travel along magnetic field lines," says Melott. "If there's a magnetic field, it can either create a superhighway for cosmic rays, or it could block them." Depending on the orientation of the magnetic field around the supernova, it could either boost or block the radiation. A supernova combined with a boosting magnetic field could have a further reach than normal.

But even with an ideal magnetic field, there are no stars anywhere close to us that could pose a risk. You're safe from deadly supernova radiation. Just don't think about gamma ray bursts.