"This is the largest solar radiation storm in over 20 years," the Space Weather Prediction Center said on Monday.

Tree rings hold clues about ancient solar storms. New research shows tree growth and carbon storage can shift those signals across years.

A massive 2012 solar storm missed Earth by just over a week, which could have caused up to $3 trillion in damages.

Scientists have long relied on tree rings to learn about ancient solar storms—rare bursts of high-energy particles from the ...