The Sun in soft X-rays from the Yohkoh orbiting observatory.
Caption: This image of the Sun was taken on 24 January 1992 with the soft X-ray Telescope on the Japan/US/UK orbiting Yohkoh mission. It reveals the three-dimensional structure of the hot corona across the whole of the Sun's disk. The bright areas are regions where hot gas at temperatures of over a million degrees K are trapped by the Sun's magnetic field. The dark areas are coronal holes, which are the sources of the solar wind - streams of high speed particles - which flows past Earth and through the solar system at about 700 km per second.