Drainage, flow and erosion on the Huygens landing site

Close - by are stubby canyons with only a few branches. They have probably been formed by ‘spring sapping’, whereby methane flows through the subsurface before emerging as a spring near the base of a hill. The spring erodes the hillside, causing it to collapse and form a cliff face.

The third area is the flat dark plain. This is mostly water ice mixed with tholin grit. “Titan’s river channels, canyons, and flood plains rival the variety seen on Earth,” says Soderblom. The dark plains show markings that suggest the region occasionally experiences flash flooding, but not from the highland drainage channels. Instead large quantities of liquid methane appear to flow from east to west.

Planetary scientists can now begin to piece together the sequence of events that led to the formation of this exotic landscape. “Huygens and Cassini have taken giant steps forward in our understanding of Titan,” says Soderblom.