What would the impact on earth if Alpha Centauri became a supernova?
A near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth (roughly fewer than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth’s case, gamma rays induce a chemical reaction in the upper atmosphere…depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. The gamma ray burst from a nearby supernova explosion has been proposed as the cause of the end Ordovician extinction, which resulted in the death of nearly 60% of the oceanic life on Earth. Source: http://en.wikipedia.org/wiki/Supernova#Impact_on_Earth So at only 4.3 light-years, I’m guessing that an Alpha Centauri supernova would generate a gamma-ray burst that could wipe out all, or practically all, life on earth. (Apparently the planet itself would not be affected much.) Fortunately Alpha Centauri is not
