Huygens probe mounted on heat shield. The 1.3-metre-wide probe is at centre, with struts attaching it to a supportive framework (upper left). The larger circular structure partially seen behind the probe is the 2.7-metre-wide heat shield (aeroshell) that protected the probe as it entered the atmosphere of Titan, the largest moon of Saturn. Huygens was brought to Titan by the Cassini spacecraft (launched in 1997). Huygens entered Titan's atmosphere on 14 January 2005. After the heat shield had successfully slowed the probe, a parachute was used to bring it safely to the surface. The gold-coloured material is thermal insulation and foil to protect the spacecraft during its journey to Saturn.