In the last few seconds of a binary neutron star's life, the two stars spiral together and form a black hole surrounded by a hot, dense disk that blasts powerful jets. These cosmic rays may have changed life on Earth. At the same time, they argue in a report published in the June 29 issue of Physical Review Letters , the radiation would cause mutations, leading to the emergence of entirely new species on Earth. Such a violent collision blasts out jets of high-energy particles called cosmic rays. If Earth passed through one of these jets within about 3,000 years of the collision, the scientists theorize, the cosmic rays would be intense enough to destroy the ozone layer that protects Earth from harmful solar radiation, and make much of the planet highly radioactive.
Radioactive particles can destroy an organism's central nervous system and cause death within days.
Scientists have documented at least five major extinctions, in which many forms of life were eliminated, over the past 570 million years, as well as many lesser events in which only a few species died out. Cosmic rays could do that, the scientists argue, and much evidence should be awaiting discovery in the rocks and fossils of ancient Earth. A high-energy particle smashing through a rock leaves a track. Sensitive instruments should be able to find those tracks. The scientists are calling on their colleagues around the world to search for evidence of high energy particles in fossils and rocks that correspond in age to known periods of mass extinctions.