A massive explosion on the sun's surface has triggered the largest solar radiation storm since 2005, hurling charged particles at Earth. (NASA / May 4, 2012) A stream of highly charged particles from the sun is headed straight toward Earth, threatening to plunge cities around the world into darkness and bring the global economy screeching to a halt. This isn't the premise of the latest doomsday thriller. Massive solar storms have happened before — and another one is likely to occur soon, according to Mike Hapgood, a space weather scientist at the Rutherford Appleton Laboratory near Oxford, England. Much of...