New findings indicate that a massive solar storm, roughly 500 times more powerful than any previously recorded, left its mark on our planet near the end of the last Ice Age.
Approximately 14,000 years ago, the unprecedented solar event—now judged to be the most powerful known to have occurred—marked Earth’s transition into the Holocene epoch, according to the findings of an international team of scientists.
The team traces the event to around 12,350 BC using a new climate-chemistry model specifically designed to reconstruct ancient solar particle activity. This expands the known timeline for ancient solar storms and raises the bar on the upper boundaries of their intensity.
The findings also raise concerning questions about whether such an event could happen again and what the impact would be on Earth’s electrical infrastructure in today’s technologically dependent society.
The Most Powerful Solar Event on Record
Although the event in question was already known from past observations of radiocarbon spikes in ancient wood samples, its scale and magnitude remained unknown.
Now, thanks to a unique model employed by researchers at the University of Oulu in Finland led by postdoctoral researcher Kseniia Golubenko and Professor Ilya Usoskin, the ancient storm is recognized as being 18% more intense than the next strongest solar event of similar character, which occurred in AD 775 based on data from tree-ring data.
The discovery was made possible by the team’s specially designed SOCOL:14C-Ex model, which also showed the extremity of the event from 14,000 years ago compared with the most powerful solar storms of recent years.
“Compared to the largest event of the modern satellite era — the 2005 particle storm — the ancient 12,350 BC event was over 500 times more intense, according to our estimates,” Dr. Golubenko said.
Modeling the Ancient Sun
Although solar particle storms are relatively rare, energetic events in which radiation is expelled from the Sun do occur on occasion, flooding our planet’s atmosphere with highly charged particles.
When such events occur, they leave behind chemical “fingerprints” that include elevated radiocarbon. This is detectable in natural sources like tree rings and ice cores, which serve as nature’s own archives commemorating these events.
Designed specifically to simulate solar particle storm effects that were present long ago during glacial conditions in ancient times, the team’s SOCOL:14C-Ex model allowed them to test its prowess against long-established data from the AD 775 event as a test case. After successful modeling was achieved, the team turned their attention toward the anomalous Ice Age solar storm, drawing additional support from tree ring samples they recovered from the French Alps that preserved radiocarbon signatures from the 12,350 BC event.
The unprecedented data the team obtained has now identified the 12,350 BC event as the first known extreme solar particle event scientists have documented from before the onset of the Holocene epoch. According to Golubenko, the model “extends our ability to analyze radiocarbon data even for glacial climate conditions,” removing what had previously been a key limitation in solar and climate research.
Miyake Events and High-Energy Solar Event Impact
Another feature of particularly high-energy solar storms of this magnitude is that they trigger what are known as Miyake events. The radiocarbon spikes that coincide with such events can be viewed as timestamps in the geologic record and have been relied on in the past to help date Viking settlements unearthed by archaeologists in Newfoundland and several Neolithic communities in Greece.
“Miyake events allow us to pin down exact calendar years in floating archaeological chronologies,” explained Professor Usoskin, emphasizing that such dating methods allow scientists to enhance the accuracy of radiocarbon dating, while providing otherwise rare calibration points that researchers can use to reconstruct the ancient environment and its relationship to solar behavior.
A Warning from the Past?
Significantly, this record-breaking ancient solar event expanded scientists’ understanding of solar activity long ago and has potentially significant implications for our future.
Golubenko notes that the scale of such storms in the past reveals the potential that storms of similar magnitude could occur again. The impact such solar activity might have on modern infrastructure, including satellites, electrical grids, and communication systems, could be vastly underestimated.
“This event establishes a new worst-case scenario,” Golubenko said.
The team’s new paper, “New SOCOL:14C-Ex model reveals that the Late-Glacial radiocarbon spike in 12350 BC was caused by the record-strong extreme solar storm was published on April 28, 2025 in Earth and Planetary Science Letters.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.