New research reveals the strongest solar event ever detected, in 12350 BC

Summary

Credit: Earth and Planetary Science Letters (2025). DOI: 10.1016/j.epsl.2025.119383 An international team of scientists has discovered an extreme spike in radiocarbon corresponding to the year 12350 BC during the dusk of the last Ice Age. However, the strength of the event could not be assessed earlier because of the lack of an appropriate model. It has now been identified as the most powerful solar particle storm known to date—a colossal space weather storm that struck Earth 14,300 years ago. This recent finding expands the timeline and intensity of known solar activity and sets a new upper boundary for such solar phenomena. In the study, postdoctoral researcher Kseniia Golubenko and Professor Ilya Usoskin at the University of Oulu, Finland, used their newly developed chemistry–climate model called SOCOL:14C-Ex, specifically designed to reconstruct solar particle storms under ancient glacial climate conditions. The model confirmed that the detected solar event was approximately 18% stronger than the notorious AD 775 event—until now the strongest solar storm ever recorded in tree-ring archives. The work is published in the journal Earth and Planetary Science Letters. "Compared to the largest event of the modern satellite era—the 2005 particle storm—the ancient 12350 BC event was over 500 times more intense, according to our estimates," says Dr. Golubenko. Other large known solar particle storms have occurred around 994 AD, 663 BC, 5259 BC and 7176 BC, and a few other candidates are under investigation. The new model was also verified using wood samples recently found in the French Alps, dating back some 14,300 years. Solar particle storms are rare, but when they occur, they bombard Earth with an enormous amount of high-energy particles. In comparison, the famous Carrington event in 1859 was a different kind of event and not accompanied by a solar particle storm. "The ancient event in 12350 BC is the only known extreme solar particle event outside of the Holocene epo...