  High energy cosmic ray jets from nearby mergers or accretion induced collapse
(AIC) of neutron stars (NS) that hit the atmosphere can produce lethal fluxes
of atmospheric muons at ground level, underground and underwater, destroy the
ozone layer and radioactivate the environment. They could have caused most of
the massive life extinctions on planet Earth in the past 600 My. Biological
mutations due to ionizing radiations could have caused the fast appearance of
new species after the massive extinctions. An early warning of future
extinctions due to NS mergers may be obtained by identifying, mapping and
timing all the nearby binary neutron stars systems. A warning of an approaching
cosmic ray burst from a nearby NS merger/AIC may be provided by a very intense
gamma ray burst which preceeds it.
