NASA’s Cassini spacecraft has sent back new images of Saturn’s moon Titan, revealing an amazing natural phenomenon. According to a statement from the Jet Propulsion Laboratory in Pasadena, CA, researchers have identified liquid methane running throughout a series of canyons carved into the surface of the moon. The study, published in the journal Geophysical Research Letters, confirms the first liquid-filled channels ever discovered on Titan.

The study refers to data gathered by Cassini during a close pass over Titan in May of 2013. The probe’s radar scanned the region of the moon branching out from the massive sea known as Ligeia Mare.

Previous images taken by Cassini suggested to scientists that the long channels covering Titan’s surface were filled with liquid, but this was not confirmed until researchers examined the most recent data. The radar instrument on Cassini is typically used as an imager, but was instead configured to act as an altimeter, measuring the height of the geologic features on the ground.

The radar instrument detected the smooth surface of the liquid methane channels, and was able to record their depths as it passed above Titan’s surface. The deep streams carved into the surface of the moon indicate that the process responsible for their creation was either active for a long time, or eroded the surface extremely quickly.

According to Valerio Poggiali, a Cassini radar team associate and the study’s lead author, “It’s likely that a combination of these forces contributed to the formation of the deep canyons, but at present it’s not clear to what degree each was involved. What is clear is that any description of Titan’s geological evolution needs to be able to explain how the canyons got there.”