Huygens' Titan Landing Still the Solar System's Farthest Reach

Only one spacecraft has ever landed in the outer solar system: the European Huygens probe touched Titan in January 2005 during the Cassini-Huygens mission, revealing a methane-driven hydrological cycle and ground of water-ice pebbles; it operated about 72 minutes after landing, but a missed command meant half of its wind data and some descent images were lost, leaving Titan the only outer-solar-system surface world visited—though NASA's Dragonfly aims to visit Titan in the 2030s.