""Most of us know about the sun's eleven-year activity cycle. However, relatively few other than scientists (and amateur radio operators) are aware that the current solar minimum has lasted much longer than expected. The last solar cycle, Cycle 24, bottomed out in 2008, and Cycle 25 should be well on its way towards maximum by now, but the sun has remained unusually quiescent with very few sunspots. While solar physicists agree that this is odd, the explanation remains elusive."" (Slashdot)

Original story here:

"MIAMIÑIn very rough terms, the sun's activity ebbs and flows in an 11-year cycle, with flares, coronal mass ejections and other energetic phenomena peaking at what is called solar maximum and bottoming out at solar minimum. Sunspots, markers of magnetic activity on the sun's surface, provide a visual proxy to mark the cycle's evolution, appearing in droves at maximum and all but disappearing at minimum. But the behavior of our host star is not as predictable as all thatÑthe most recent solar minimum was surprisingly deep and long, finally bottoming out around late 2008 or so.

Solar physicists here at the semiannual meeting of the American Astronomical Society this week offered a number of mechanisms to shed light on what has been happening on the sun of late, but conceded that the final answerÑor more likely answersÑremains opaque. Beyond scientific understanding, motivations for better solar weather forecasts include hopes to use them to safeguard against electrical grid disruptions, damage to Earth-orbiting satellites and threats to the health of space travelers posed by solar radiation flare-ups."