A side-by-side comparison of the Sun from precisely two years ago (left, from SOHO) to the present (right, from Solar Dynamics Observatory) dramatically illustrates just how active the Sun has become (Mar. 27-28, 2011). Viewed in two similar wavelengths of extreme ultraviolet light, the Sun now sports numerous active regions that appear as lighter areas that are capable of producing solar storms. Two years ago the Sun was in a very quiet period (solar minimum). The Sun's maximum period of activity is predicted to be around 2013, so we still have quite a ways to go.
Search Tag(s): 171, active regions