Researchers in Japan used carbon 14 measurements from ancient buried trees and medieval diaries to identify a powerful solar proton event around 1200 CE. This study reveals that the Sun experienced shorter, more intense activity cycles during this period than the eleven year cycle seen today. Understanding these sub extreme solar events is vital for protecting modern electrical grids and future space missions. The findings highlight how historical data and dendroclimatology can help predict risks from space weather that could otherwise disrupt global energy infrastructure.
