Solar corona. Ultraviolet SOHO (Solar and Heliospheric Observatory) satellite image of the corona (hazy) around the Sun. The corona, the Sun's outer atmosphere, is seen at three ultraviolet wavelengths, showing areas at: 1 million (blue), 1.5 million (green) and 2 million degrees Celsius (red). Details of the Sun's magnetic field are seen because it affects the charged atoms (ions) in the corona, forming the patterns seen here. Active areas of the Sun's surface are white. The activity of the Sun peaks every 10-11 years. This image is from SOHO's Extreme Ultraviolet Imaging Telescope (EIT) in May 1998, as the Sun neared the solar maximum in 2000.