The surface of Saturn's largest moon is etched with canyons that are flooded with liquid hydrocarbons, according to data from NASA's Cassini spacecraft.

Valerio Poggiali of the Sapienza University of Rome and his team used radar aboard Cassini to measure elevations on Titan and map out a network of steep-sided, narrow channels called Vid Flumina. Some of the canyons are up to 570 metres deep. Titan has low average temperatures of −179 °C, so it previously wasn't clear whether the dark material in these canyons was ice. However, the scientists found that liquid methane flows through the channels and into the northern sea, Ligeia Mare.

Other than Earth, Titan is the only planetary body in the Solar System that has active erosion caused by liquid on its surface.

Geophys. Res. Lett. http://doi.org/bn2p (2016)