Eyes on the sun: Naked thallium-205 ion decay reveals history over millions of years

The sun, the essential engine that sustains life on Earth, generates its tremendous energy through the process of nuclear fusion. At the same time, it releases a continuous stream of neutrinos—particles that serve as messengers of its internal dynamics. Although modern neutrino detectors unveil the sun's present behavior, significant questions linger about its stability over periods of millions of years—a timeframe that spans human evolution and significant climate changes.