FIGURE 5.5 October 28, 2003, evolution of a solar storm. A large sunspot (brownish black spot seen in the lower half of the solar disk in the upper-left-hand image) erupted with a strong x-ray flare (bright white spot in lower half of the false-green color EIT image of the Sun, upper-right-hand image). Within minutes, LASCO detected a halo coronal mass ejection (CME) emerging from the Sun (which is blocked by the central occulting disks in the lower-left-hand image). An hour and a half after the flare, a shower of energetic protons and ions reached the SOHO spacecraft, creating the “snow” in the lower right LASCO image, confirming that the CME was headed toward Earth. When it impacted Earth’s magnetic field, this CME triggered powerful geomagnetic storms that caused problems for the electric grid in Northern Europe, polar cap absorption events, and in-orbit satellite anomalies and failures. SOURCE: NASA; see http://sohowww.nascom.nasa.gov/hotshots/2003_10_28/.