The July 9 flare was considered fairly moderate. Twenty minutes after the flare, ripples appeared on the sun's surface, looking like ripples in a pool of water. In one hour, sound waves from the quake traveled 74,567 miles, a distance equivalent to 10 Earth diameters. Unlike watery ripples that move at a constant speed, the waves sped up, from 22,000 mph to 250,000 mph, before disappearing. The sound waves they detected were 10 times stronger than they predicted.
Solar flares create a massive electromagnetic explosion in the upper solar atmosphere.
The heat from the explosion generates a shock wave. When that shock wave hits the lower atmosphere or so-called surface of the sun 1,200 miles to 1,800 miles below, it creates the sound waves, Kosovichev said. Prediction is important because strong solar flares can disrupt radio and telephone communications on Earth, cause power surges and blackouts and damage satellites. The Associated Press contributed to this report. All Rights Reserved.