Unforeseen Danger: Nearby Supernovas Threaten Life.

X-rays produced by core-collapse supernovas can damage planets up to 160 light-years away, according to new evidence collected by NASA’s Chandra Observatory. Before Type II supernovas explode, the progenitor star throws off a lot of gas and dust. When the blast wave hits this material X-rays bathe everything around. These X-rays probably wouldn’t reach the lower stratosphere, let alone the surface, of a planet with an oxygen-rich atmosphere, but would produce chemicals that greatly damage the ozone layer. This in turn would let in ultraviolet light from the planet’s star. Earth-like life would be unlikely to survive, other than in the deep ocean or underground.