B IS FOR “BOMB”: Big sunspot AR2738 is crackling with B-class solar flares. This morning in France, astrophotographer Philippe Tosi caught the sunspot in mid-flare, inserting an image of Earth for scale. On the “Richter Scale of Solar Flares,” B-class events are considered weak. In solar physics, however, such terms are relative. A typical B-class … Continue reading Big sunspot AR2738 is crackling with B-class solar flares.