The Resilience of Life to Astrophysical Events
  Much attention has been given in the literature to the effects of
astrophysical events on human and land-based life. However, little has been
discussed on the resilience of life itself. Here we instead explore the
statistics of events that completely sterilise an Earth-like planet with planet
radii in the range $0.5-1.5 R_{Earth}$ and temperatures of $\sim 300 \;
\text{K}$, eradicating all forms of life. We consider the relative likelihood
of complete global sterilisation events from three astrophysical sources --
supernovae, gamma-ray bursts, large asteroid impacts, and passing-by stars. To
assess such probabilities we consider what cataclysmic event could lead to the
annihilation of not just human life, but also extremophiles, through the
boiling of all water in Earth's oceans. Surprisingly we find that although
human life is somewhat fragile to nearby events, the resilience of Ecdysozoa
such as \emph{Milnesium tardigradum} renders global sterilisation an unlikely
event.
