Original: Huygens probe The Huygens probe, supplied by the European Space Agency (ESA) and named after the 17th century Dutch astronomer Christiaan Huygens, scrutinized the clouds, atmosphere, and surface of Saturn's moon Titan in its descent on January 15, 2005.
Simplified: The spacecraft has two main parts: the NASA Cassini orbiter, named after the Italian-French astronomer Giovanni Domenico Cassini, and the ESA Huygens probe, named after the Dutch astronomer, mathematician, and physicist Christiaan Huygens.