OF ALL the threats to life on Earth, gamma-ray bursts are probably not uppermost on anyone’s mind. However, those of us who were worried can at last rest easy. It seems that the very nature of the Milky Way precludes these dangerous explosions from going off in our galaxy, let alone anywhere near enough to obliterate us.
A long gamma-ray burst within 6500 light years of Earth could produce enough radiation to strip away the ozone layer and cause a mass, or even total, extinction (New Scientist, 30 July 2005, p 13).
“A long gamma-ray burst within 6500 light years of Earth could produce…
