A space radiation storm happens when an explosion on the sun accelerates solar protons toward Earth. These protons stream past our planet where they are (mostly) deflected by Earth's protected magnetic field. The NOAA Space Environment Center has defined five types of radiation storms, ranging from mild to extreme. Browse the table below to learn what effects these storms can have on Earth:
| Category | Effect | Physical measure |
Average Frequency (1 cycle = 11 years) |
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| Scale | Descriptor | Duration of event will influence severity of effects | ||
Solar Radiation Storms |
Flux level of >= 10 MeV particles (ions)* | Number of events when flux level was met (number of storm days**) | ||
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Biological: unavoidable high radiation hazard to astronauts on EVA (extra-vehicular activity); high radiation exposure to passengers and crew in commercial jets at high latitudes (approximately 100 chest x-rays) is possible. Satellite operations: satellites may be rendered useless, memory impacts can cause loss of control, may cause serious noise in image data, star-trackers may be unable to locate sources; permanent damage to solar panels possible. Other systems: complete blackout of HF (high frequency) communications possible through the polar regions, and position errors make navigation operations extremely difficult. |
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Biological: unavoidable radiation hazard to astronauts on EVA; elevated radiation exposure to passengers and crew in commercial jets at high latitudes (approximately 10 chest x-rays) is possible. Satellite operations: may experience memory device problems and noise on imaging systems; star-tracker problems may cause orientation problems, and solar panel efficiency can be degraded. Other systems: blackout of HF radio communications through the polar regions and increased navigation errors over several days are likely. |
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Biological: radiation hazard avoidance recommended for astronauts on EVA; passengers and crew in commercial jets at high latitudes may receive low-level radiation exposure (approximately 1 chest x-ray). Satellite operations: single-event upsets, noise in imaging systems, and slight reduction of efficiency in solar panel are likely. Other systems: degraded HF radio propagation through the polar regions and navigation position errors likely. |
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Biological: none. Satellite operations: infrequent single-event upsets possible. Other systems: small effects on HF propagation through the polar regions and navigation at polar cap locations possibly affected. |
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Biological: none. Satellite operations: none. Other systems: minor impacts on HF radio in the polar regions. |
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* Flux levels are 5 minute averages. Flux
in particles·s-1·ster-1·cm-2.
Based on this measure, but other physical measures are also considered.
** These events can last more than one day.