National Geographic : 2004 Jul
"Nobody dreamed there would be the possibility theory predicts should strike the Earth every day. Finally, three years ago, a remarkable inter national effort involving facilities in Japan and Canada solved the problem by demonstrating that the "missing" neutrinos had mutated into different types that had not been detectable until the latest instruments became available. Solar physicists are still rejoicing. Elation indeed is the feeling in the science community for what today's explorations are adding to our knowledge of the sun. Peter Gilman, a veteran sun researcher with NCAR's High Altitude Observatory, sums it up: "This is the golden age of solar science." As the neutrino resolution illustrates, it's an international affair. The workhorse of the solar space fleet, for instance, is the Solar and Helio spheric Observatory (SOHO), a satellite run 18 NATIONAL GEOGRAPHIC * JULY 2004 jointly by the European Space Agency and NASA. Launched in 1995, its arsenal of instru ments has contributed to the research of scien tists around the world. Breakthroughs have been made on all solar fronts. But nearly every hard-won answer has revealed new puzzles: The ceaseless dance between plasma and magnetic fields makes it madden ingly difficult to tease apart cause and effect. Each major level of solar phenomena is influenced by the others, each has a direct effect on Earth, and each is still not completely understood. The momentum toward solving what solar physi cists think of as the "big questions" isn't likely to slow, given our ever greater need to predict space weather. And because, as astronomer John Harvey of the National Solar Observatory puts it: "The sun is the only astronomical object that critically matters to humankind."