'Death Star' Aimed at Earth 400
An anonymous reader writes "A spectacular, rotating binary star system is a ticking time bomb, ready to throw out a searing beam of high-energy gamma rays that could lead to a major extinction event — and Earth may be right in the line of fire. Australian science magazine Cosmos Magazine reports: 'Though the risk may be remote, there is evidence that gamma ray bursts have swept over the planet at various points in Earth's history with a devastating effect on life. A 2005 study showed that a gamma-ray burst originating within 6,500 light years of Earth could be enough to strip away the ozone layer and cause a mass extinction. Researchers led by Adrian Melott at the University of Kansas in Lawrence, U.S., suggest that such an event may have been responsible for a mass extinction 443 million years ago, in the late Ordovician period, which wiped out 60 per cent of life and cooled the planet.'"
