The Sun is Changing and We Don’t Know Why

The Sun has a heartbeat. Every eleven years it swells with magnetic fury, hurling solar flares and charged particles into space, sparking auroral displays and threatening power grids, all before quietening down again. We’ve tracked this rhythm for centuries. But now, scientists listening to sound waves deep inside our local star have found something deeply unexpected, that heartbeat is changing. And nobody yet knows what it means.