...a direct hit by an extremely bright [gamma-ray burst] generated by Eta Carinae could devastate our planet in a manner similar to but far worse than full-scale thermonuclear war. For several searing seconds, the planetary hemisphere facing the faraway star would be bathed in intense high-frequency radiation. The skies would fill with light much brighter than the sun, bright enough to ignite enormous continent-scouring wildfires on half the globe. The energetic burst of light would kick off atmospheric showers of highly penetrating radioactive subatomic particles called muons, which would stream down to poison life on the surface as well as that some distance underground and underwater. Even the far side of the planet facing away from Eta Carinae would not be spared, as the GRB’s intense energy would destroy the entire ozone layer while also sending superstorms rippling around the world. In the aftermath blackened, soot-filled skies would unleash torrents of acid rain, clearing only to soak the surface with damaging ultraviolet radiation. In a literal flash the Earth would become a planetary charnel house, and the shattered biosphere would require millions of years to piece itself back together.The magazine is citing the worst case scenario outlined in a scientific paper back in 2001. Of course, nothing at all could happen as well, though some have speculated that past gamma-ray bursts may have accounted for mass extinctions in the Earth's past, such as 450 million years ago. The article has a good discussion on the various theories surrounding the demise of Eta Carinae. Of course, the star may have already gone supernova and we have yet to see the results (and potentially feel the results).
We live in a fascinating and dangerous universe. Keep that in mind as you enjoy your Christmas meal.