Yohkoh Solar Observatory

This animation shows the multi-layered nature of the solar atmosphere. It was built from three images, a white-light image of the photosphere, a red-light image of the chromosphere, and an X-Ray image of the corona, the outermost layer. These images were captured on the same day by the telescope aboard the Yohkoh Solar Observatory satellite. The satellite was launched from Japan in August of 1991 and is used to investigate X-Rays and Gamma rays from the Sun. Yohkoh is Japanese for sunbeam.

Layers of the Solar Atmosphere

The Sun is a giant ball of gas; there is no hard surface on the Sun to stand on. However, there is a surface through which we cannot see called the photosphere. The location of the photosphere is defined to be where the gas is so dense that it becomes opaque. The photosphere is about 330 kilometers thick and lies 696,000 kilometers from the center of the Sun. Above the photosphere is the chromosphere, about 2,000 kilometers thick, where the temperature rises from the 5,800-Kelvin-photosphere to tens of thousands of Kelvin. Beyond the chromosphere is the corona, where the density of the gas is very low and tenuous. The corona is difficult to observe and is only seen on Earth during a total solar eclipse.

Ellen Cohen