Ancient polar ice shows that the famous 1859 solar storm was missing its expected blast of radioactive particles.
The Carrington Event is legendary for being the most powerful solar storm in history, once setting telegraph wires on fire. Scientists analyzed ice cores for Chlorine-36, which is a radioactive marker of massive solar particle hits. They found no significant spike during the 1859 event, meaning it was a magnetic storm rather than a particle storm. This challenges the long-held belief that all extreme solar flares come with a dangerous radiation bombardment. It forces us to redefine our benchmark for the risks a modern solar storm would pose to our satellites and power grids.
36Cl Concentrations from Polar Ice Cores Set New Constraints on the Carrington Event
arXiv · 2604.26608
The Carrington event of 1859 CE is considered as one of the largest geomagnetic storms of the observational era, and often used as a benchmark for a worst-case scenario. Yet, there exists no robust evidence of an associated solar energetic particle event of a significant magnitude, based on measurements of cosmogenic radionuclides 10Be and 14C from ice cores and tree rings, respectively. In this study, we present two 36Cl records from Greenland with 2-year and 4-year resolution from the EGRIP an