A cosmic ray attack on the Earth

Leading on from the previous posting this story comes from www.dailygalaxy.com/my_weblog/2012/12/-december-27-2004-the-day-planet-e… … which sounds a bit over the top – and probably is. You may not have realised that on December 27th 2004 something so dire occurred but apparently a burst of energy equivalent of half a million years of sunlight was directed at the Earth, a gamma ray burst that ionised Earth's upper atmosphere. The source was in the region of the sky occupied by the constellation of Sagittaurus. It was detected by NASAs Swift satellite and it has now all been written up in a paper in Nature – but under a pay wall.