| Term: | Solar Cycle |
| Definition: |
The sun goes through 11-year variations or cycles of high and low activity - solar flares and coronal mass ejections, for example, based on the regular increase and decrease of sunspots. Cycles as short as 9 years and as long as 14 years have also been observed. The cycle is caused by the fact that the sun's magnetic north and south poles flip every 11 years. |