The sun reverses its magnetic field about every 11 years, producing a cycle marked by solar flares, sunspots, and magnetic storms that can disrupt satellite orbits and telecommunications, bring down electric power grids, and increase the radiation exposure of astronauts in space. Scientists are predicting that the next cycle will start a year late, in late 2007 or early 2008, and will be 30 percent to 50 percent stronger than the previous one.

This is the first time that scientists have been able to predict solar cycles by using a computer model based on mathematical equations using known solar physics, instead of using historical records. Using data collected by NASA and the European Space Agency, the computer model tracks sound waves reverberating inside the sun and plasma flows which affect solar activity.

Several National Research Council reports deal with the sun and solar physics. The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics offers an overview of the field of solar and space physics, summarizes key problems that research should target during the next decade, and recommends research initiatives. Understanding the Sun and Solar System Plasmas: Future Directions in Solar and Space Physics is a popularization of the decadal survey that is available upon request to the Space Studies Board. Ground-Based Solar Research: An Assessment and Strategy for the Future makes recommendations concerning U.S. investments in the ground-based research programs that are directed at understanding the fundamental processes that are responsible for solar variability.

• Understanding the Sun and Solar System Plasmas: Future Directions in Solar and Space Physics (2004)
• The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics (2002)
• Ground-Based Solar Research: An Assessment and Strategy for the Future (1998)

Other Resources:

• National Science Foundation Press Release
• NASA Inside Our Sun Feature
• European Space Agency