Cosmic rays could have caused one of the worst mass extinctions on Earth
450 million years ago , the Earth ’s tender oceans teemed with life-time we ’d recognize as seaweed , starfish , clams , and coral reefs . of a sudden , over half these specie croak . Now scientists say it was because of cosmic rays – and could encounter again . Image of a proton exhibitioner viaUniversity of Chicago . Usually call up the Ordovician Extinction , after the geologic era when it ended , this deep effect is well - documented in the fossil record but only hazily understood ....