Natural disaster
A solar flare is a phenomenon where the Sun suddenly releases a great amount of solar radiation, much more than normal. Solar flares are unlikely to cause any direct injury, but can destroy electrical equipment. The potential of solar storms to cause disaster was seen during the 1859 Carrington event, which disrupted the telegraph network, and the March 1989 geomagnetic storm which blacked out Quebec. Some major known solar flares include the X20 event on August 16, 1989, and a similar flare on April 2, 2001. The most powerful flare ever recorded occurred on November 4, 2003 (estimated at between X40 and X45).
Solar storm of August 1972
Astronomers first reported unusual flares on August 2, later corroborated by orbiting spacecraft. On August 3, Pioneer 9 detected a shock wave and sudden increase in solar wind speed from approximately . A shockwave passed Pioneer 10, which was 2.2 AU from the Sun at the time. The greatly constricted magnetosphere caused many satellites to cross outside Earth's protective magnetic field, such boundary crossings into the magnetosheath lead to erratic space weather conditions and potentially destructive solar particle bombardment. The Intelsat IV F-2 communications satellite solar panel arrays power generation was degraded by 5%, about 2 years worth of wear. An on-orbit power failure ended the mission of a Defense Satellite Communications System (DSCS II) satellite. Disruptions of Defense Meteorological Satellite Program (DMSP) scanner electronics caused anomalous dots of light in the southern polar cap imagery.