A1_1 Tick, tick, tick... GRBoom!

Abstract

This paper considers the possibility that a gamma ray burst (GRB) will cause a mass extinction on our planet. The distance over which a low energy GRB would expose a human to a lethal amount of radiation is calculated and found to be approximately 73 kiloparsecs. This indicates that we only need to consider GRBs occurring within the Milky Way galaxy. GRBs are also highly directional; the probability of a GRB striking the Earth is calculated to be 0.06%. From these calculations it is found that a lethal GRB is likely to impact on the Earth once every 328 million years.