March 31, 2021: What a difference 20 years makes. Today the sun is blank and featureless as Solar Cycle 25 struggles pull solar activity from the doldrums of a deep Solar Minimum. In March 2001, however, the solar disk was peppered with sunspots, including a monster named “AR9393.” The biggest sunspot of Solar Cycle 23, … Continue reading 20 Years Ago, An Extreme Geomagnetic Storm