System can warn of dangerous solar storms

Solar radiation that could kill astronauts in space can be forecast nearly three hours in advance, giving them time to take protective action, researchers say. The radiation comes from massive explosions on the sun that send streams of charged particles toward earth. "Traveling nearly at the speed of light, it takes just 10 minutes for the first particles ejected from a solar storm to reach Earth," University of Delaware researcher John Bieber said. Beiber, along with colleagues from Chungnam National University in South Korea, said data collected by two neutron monitors installed years ago at the South Pole by the University of Delaware can determine the intensity of the high-energy, fast-moving particles that arrive to Earth first from solar storms. By examining the properties of these first-arriving particles, scientists can make useful predictions about the slower-moving, yet more dangerous particles to follow, Beiber said. "These slower-moving particles are more dangerous because there are so many more of them. That's where the danger lies," Bieber said. The system can provide a warning time up to 166 minutes about the arrival of the more dangerous particles, which would give astronauts time to seek out an armored area in their spacecraft, Bieber said. Most astronauts have flown in low Earth orbit in recent years, but if we go back to the moon or decide to send humans to Mars, Beiber said, the danger from radiation is significant. In fact, he said, he thinks some of the Apollo astronauts were just lucky. "Somehow they got these moon launches between big solar flares that would have killed them right then and there."