A giant explosion rocks the Sun in this animated view from the space-based Solar Dynamics Observatory. The outburst, on January 20, was a solar flare. Flares form when lines of magnetic force get tangled, snap, then reconnect. Especially powerful flares can disrupt satellites, knock out power grids, and cause other problems. This one wasn't that powerful, and it wasn't aimed at Earth. NOAA provides space weather predictions [2] to help operators of critical infrastructure prepare for possible problems. [NASA/SDO]