The Huygens probe lands on Saturn's moon Titan

On 14 January 2005, the European-built Huygens probe parachuted through the thick orange haze of Titan, Saturn’s largest moon, and settled gently onto its frozen surface. The descent lasted roughly two and a half hours, during which six instruments sampled an atmosphere richer in some ways than Earth’s own.

Huygens had hitched a ride aboard NASA’s Cassini orbiter, traveling more than a billion kilometers before separating in December 2004. Its landing remains the first—and so far only—touchdown on a body in the outer solar system, and the most distant landing humanity has ever achieved.

The surface had the consistency of damp sand, scattered with rounded pebbles of dirty water ice.

The images it returned showed an eerily familiar landscape: branching channels carved by flowing liquid, though here the rivers ran with methane, not water, at a bone-cracking minus 170 degrees Celsius. Huygens fell silent after about 90 minutes on the surface, but its brief postcard from Titan reshaped how scientists picture distant worlds.