Comets have fascinated people for millennia and were believed in many ancient cultures to be a sign of impending war. Chinese records mention comets as far back as 240 BC; Halley’s Comet also makes a famous appearance in the Bayeux Tapestry before the Norman invasion in 1066.
Image taken of Halley's comet taken when it last returned in 1986 by the ESA Giotto probe which was sent out to study the comet.
Recently (January 2004) the NASA space probe STARDUST flew though the tail of the comet Wild 2 to collect dust which it will return to Earth in 2006 if all goes well.