© NASA
Illustration mapping the steady decline in sunspot activity over the last two solar cycles with predicted figures for the current cycle 24.
Illustration mapping the steady decline in sunspot activity over the last two solar cycles with predicted figures for the current cycle 24.
Three leading solar scientists presented the very latest data about the weakening solar activity at a teleconference yesterday in Boulder, Colorado, organised by the American Astronomical Society. It featured experts from Nasa, the High Altitude Observatory and the National Solar Observatory who described how solar activity, as measured by the formation of sunspots and by massive explosions on the sun's surface, has been falling steadily since the mid-1940s.
The sun goes through a regular 11-year cycle with a maximum, when sunspot activity is at its peak, followed by a minimum when sunspot numbers are reduced and are smaller and less energetic. We are supposed to be at a peak of activity, at solar maximum.
