5410 BCE 5259 BCE Found in beryllium-10 spike in ice cores and corroborated by tree rings. At least as strong as the 774–775 event. 660 BCE 774–775 CE This extreme solar proton event is known as the Miyake event. It caused the largest and most rapid rise in carbon-14 levels ever recorded. 993–994 CE It caused a carbon-14 spike visible in tree rings which was used to date Viking archaeological remains in L’Anse aux Meadows in Newfoundland to 1021. 1052 CE found in carbon-14 spike 1279 CE found in carbon-14 spike Direct measurements and/or visual observations Events not affecting Earth The above events affected Earth (and its vicinity, known as the magnetosphere), whereas the following events were directed elsewhere in the Solar System and were detected by monitoring spacecraft or other means. Soft X-ray solar flares Solar flares are intense localized eruptions of electromagnetic radiation in the Sun's atmosphere. They are often classified based on the peak flux of soft X-rays (SXR) measured by the GOES spacecraft in geosynchronous orbit (see ). The following table lists the largest flares in this respect since June 1996, the beginning of solar cycle 23. See also References Further reading External links The Most Powerful Solar Flares Ever Recorded (NASA's SpaceWeather.com) Solar Proton Events Affecting the Earth Environment (1976 - present) (SWPC) Archive of the most severe solar storms (Solarstorms.org) GOES X-ray Solar Imager Greatest Hits Solar storm Lists of natural disasters Solar System-related lists