"The outer solar atmosphere is known as the solar corona. It is termed ‘quiet’ when there is little appreciable solar activity such as flares or coronal mass ej

"The outer solar atmosphere is known as the solar corona. It is termed ‘quiet’ when there is little appreciable solar activity such as flares or coronal mass ejections. How the quiet corona reaches a temperature of a million °C when the surface is just at ~6000 °C is a long-running mystery." I hadn't realised it was 6,000°C to 1,000,000 °C, that's just nuts! Edit0: corrected to a million, thank you kind stranger