Anniversary of the birth of Christiaan Huygens   ESA's probe on board the NASA/ESA/ASI spacecraft Cassini is named after the Dutch scientist Christiaan Huygens, who discovered Titan in 1655.   The ring swirling around Saturn consists of chunks of ice and dust. Saturn itself is made of ammonia ice and methane gas. The little dark spot on Saturn is the shadow from Saturn's moon Enceladus.   The Huygens probe is integrated with the Cassini Saturn orbiter in the Payload Hazardous Servicing Facility (PHSF) at NASA's Kennedy Space Center in Florida. The completed spacecraft left the PHSF on 28 August 1997 and was mated with its Titan 4B/Centaur launch vehicle on Cape Canaveral's pad 40. Release date: 13 May 2004