Figure 9-21 RIVUXG A Solar Prominence A huge prominence arches above the solar surface in this ultraviolet image from the SOHO spacecraft. The image was recorded using light at a wavelength of 30.4 nm, emitted by singly ionized helium atoms at a temperature of about 100,000°F. By comparison, the material within the arches in Figure 9-20 reaches temperatures in excess of 3.5 × 106°F.