The finding represents the first direct evidence of the presence of liquid-filled channels on Titan.
The channels are named Vid Flumina, and are narrow canyons, generally less than half a mile wide and 90 to 1,870 feet (240 to 570 meters) deep.
The researchers used Cassini’s instruments to bounce radio signals off Titan’s surface. The returned signals defined the moon’s surface feature, allowing the researchers to discern rocky outcrops from smooth liquid.
The branching channels appear dark in radar image that Cassini captured, much like Titan’s methane-rich seas. This suggested to scientists that the channels might also be filled with liquid.
The channels flow directly into Titan’s second-largest sea, Ligeia Mare. The findings suggest the canyons were likely carved by liquid methane draining into Vid Flumina, a process similar to the carving of river gorges on Earth.
“These are processes we need to totally understand because they can shed deeper light on our own planet,” said Valerio Poggiali, lead author of the new study published in Geophysical Research Letters, a journal of the American Geophysical Union.