The Sky at Night season 21 episode 5
The Solar Cycle
Sunspots are known to increase and decrease over an 11-year cycle. We have just passed through a period of minimum solar activity and the sun-spots should now be increasing, but are slow to do so. Patrick Moore and Dr Ron Maddi son discuss the possible causes of this apparent irregularity. in the solar cycle, and talk about some of the other interesting features of the sun's surface.