On October 28, 2010, a twisted filament of magnetism on the sun suddenly untwisted, producing this spectacular eruption. At its peak, the twister--or rather, untwister--towered more than 350,000 km above the stellar surface. It appears to have hurled a fragment of itself into space, but not toward Earth; the blast was not geoeffective. Now that the filament has relaxed, it is unlikely to erupt again.