Multiple exposure of the total solar eclipse which occurred on July 11th 1991. The image shows the beginning of the eclipse (left), the totality (centre) and the end. For a few minutes during totality the Moon completely covers the Sun making the solar corona visible as a shining white halo around the solar disc. The solar corona is a region of low density and high temperature (about 1 million Kelvin) and represents the upper part of the solar atmosphere. It is usually undetectable due to the overwhelming brightness of the inner region of the solar atmosphere, the photosphere. The image was taken in California, United States.