Tiny Flares Responsible for Outsized Heat of Sun's Atmosphere

"Why is the sun's corona so darned hot?" asks James Klimchuk, an astrophysicist at the Goddard Space Flight Center's Solar Physics Laboratory in Greenbelt, Md.The mystery of why temperatures in the solar corona, the sun's outer atmosphere, soar to several million degrees Kelvin (K) —much hotter than temperatures nearer the sun's surface—has puzzled scientists for decades. New observations made