Solar corona. Coloured image of the solar corona seen during a total eclipse. The Moon (dark blue/pink, at centre) is completely covering the Sun's disc. The corona (multicoloured) is the Sun's outer atmosphere and is a wide layer of very thin hydrogen gas, over a million degrees Celsius in temperature. The layers of the corona are colour-coded to show the diminishing brightness with increasing distance from the surface of the Sun. Streamers of gas held in place by the Sun's magnetic field are shown as blips in the corona layers. Photographed during the eclipse of 26 February 1998 over Aruba in the West Indies.