Solar coronal loops Coloured ultraviolet TRACE image of coronal loops on the Sun The bases of the loops are the hottest areas white These heat the solar corona atmosphere to temperatures thousands of times that of the Suns surface dark lower frame The loops comprise electricallycharged gases plasma at millions of degrees Celsius Gas is heated as it is ejected from the surface and follows the arched paths of magnetic field lines before crashing back down to the surface at over kilometres per second TRACE Transition Region and Coronal Explorer is an observatory launched in to study the Sun at ultraviolet wavelengths