Launched in October 1997, the American probe Cassini and the European lander Huygens reached Saturn in 2004 some 1.5 billion kilometres from Earth.
The mission had a twofold objective: study Saturn and land a capsule on Titan, the largest of its satellites. Cassini revealed the existence of a giant whirlwind in Saturn's atmosphere, and discovered new rings and unknown frozen satellites. Huygens landed on Titan on 14 January 2005 amid a desolate landscape of scattered ice blocks scoured by ancient methane flows.