Extreme ultraviolet image of the Sun, showing an eruptive prominence (top). The photograph was taken from the Skylab 2 space station on 10 June, 1973. Prominences occur in the Sun's chromosphere & corona and are composed of glowing, incandescent gas in the form of loops, jets or arches. They are of two types: eruptive & quiescent. Eruptive prominences, such as this, are in violent motion & may extend outward for more than 700,000 km above the Sun's surface. Quiescent prominences are more stable & may hang around in the chromosphere for weeks before breaking up. They are best seen when jutting out from the Sun's limb.