ClimateWire: A powerful blast of cosmic rayscarrying the energy of 167 megatons of TNTentered Earth from a star 1,200 years ago and filled the remote reaches of the Earth with beryllium, carbon isotopes and other elements. The cosmic event left its imprint in tree rings and ice cores, which are natural history books for times before the human era. And using it, scientists have resolved a long-standing argument on how the planet responds to volcanic eruptions. They have found that almost every major volcanic...