Quanta Magazine
September 7, 2023
The sun looks immutable, a boring celestial lightbulb that’s always turned on. But this fusion-powered ball of plasma is in constant flux. Every 11 years or so, it swings between slumber and an active, unruly epoch marked by sunspots and solar eruptions, such as flares and plasma outbursts.
The sun is now approaching its maximum level of activity in the current cycle, and it’s not exactly behaving according to plan. Scientists had predicted that this cycle would be weak, like the previous one, but the sun is exhibiting a level of activity unseen in more than 20 years. In June and July of this year, according to data from the National Oceanic and Atmospheric Administration (NOAA), it averaged roughly 160 sunspots daily, more than twice as many as predicted. Solar flares are also increasing.