Figure 16-12: The Solar Atmosphere This schematic diagram shows the three layers of the solar atmosphere. The lowest, the photosphere, is about 400 km thick. The chromosphere extends about 2000 km higher, with spicules jutting up to nearly 10,000 km above the photosphere. Above a transition region is the Sun’s outermost layer, the corona, which we discuss in Section 16-7. It extends many millions of kilometers out into space.
(Adapted from J. A. Eddy)