Two mounted photographs showing a series of sketches of solar prominences on the edge of the Sun. These are normally only visible at totality during a solar eclipse, but can seen using a spectroscope that is aimed at a tangent to the Sun with its split-jaws partly open. These observations were made on the 26 October 1869 by Professor Lorenzo Respighi (1824-1889) at the Observatory of the Collegio Romano, Rome in Italy. Prominences are massive eruptions of hydrogen gas, often larger than the Earth, which arch away from the surface of the Sun. Associated with its magnetic field, some violent flares called Coronal Mass Ejection can disrupt the Earth's radio communications and produce spectacular aurora displays.
© Science Museum / Science & Society Picture Library