Astrophysicists from Solar Physics Research Corp. in Tucson, Ariz., and NorthWest Research Associates in Boulder, Colo., have developed a technique that may enable scientists to forecast solar storms more than a week in advance. Reporting in the March 10 issue of Science, Charles Lindsey and Douglas Braun described how they used the Michelson Doppler Imager on NASA's Solar and Heliospheric Observatory to detect sunspots on the far side of the sun, 10 days before they rotated into view.

The researchers' technique monitors the transmission of sound waves through the sun with computer simulations of the star. Active regions on the sun's surface give rise to solar flares that can disrupt satellites, power grids and radio communications.