Comet ISON passing round the Sun. These series of images were taken by the joint ESA/NASA Solar and Heliospheric Observatory, or SOHO, spacecraft, between 26th November and 1st December 2013. ISON is a sungrazing comet, and passed within 1.2 million kilometres of the surface of the Sun. The encounter left little visible of the comet, although a small fragment is thought to have survived.