Huygens was an atmospheric entry probe that landed successfully on Saturn's moon Titan in 2005. Built and operated by the European Space Agency (ESA), it was part of the Cassini–Huygens mission and became the first spacecraft ever to land on Titan and the furthest landing from Earth a spacecraft has ever made. The probe was named after the Dutch 17th-century astronomer Christiaan Huygens, who discovered Titan in 1655.