Solar prominence. Ultraviolet SOHO (Solar and Heliospheric Observatory) satellite image of a solar prominence (bottom left). The prominence is erupting from the chromosphere (orange), which lies above the Suns visible surface. Prominences are dense clouds of plasma, or ionised gas, in the Suns outer layer, the corona. They are typically at temperatures of 60,000 Kelvin, much cooler than the several million Kelvin of the corona. Active regions (white) mark areas of high solar activity. The Suns activity peaks every 1011 years. Image produced by SOHOs Extreme Ultraviolet Imaging Telescope (EIT).
