xp65 writes: "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 with instruments aboard Japan's Hinode satellite reveal the culprit to be nanoflares. Nanoflares are small, sudden bursts of heat and energy. "They occur within tiny strands that are bundled together to form a magnetic tube called a coronal loop," says Klimchuk. Coronal loops are the fundamental building blocks of the thin, translucent gas known as the sun's corona. The discovery that nanoflares play an important and perhaps dominant role in coronal heating paves the way to understanding how the sun affects Earth, our place in the universe."