(CNN) - A gigantic gang of sunspots may unleash solar flares toward earth Wednesday. NASA is tracking a dark hole on the sun's surface. It's so big; it was visible with the naked eye at sunset Tuesday night in Los Angeles.
Experts say the sunspot is expected to launch a monster solar storm, which creates the flares. Sunspots are caused by extreme magnetic activity. The solar flares are not expected to cause any major damage, but could affect power grids, satellite signals and GPS devices.