The Big One The number of sunspots, along with other signs of solar magnetic activity, waxes and wanes on an 11-year cycle. The current cycle began this past January; over the coming half a decade, solar activity will ramp up from its current lull. During the previous 11 years, 21,000 flares and 13,000 clouds of ionized gas, or plasma, exploded from the sun’s surface.
