Cassini Finds Expansive River System on Titan

This is an image of a small section of the much larger river system discovered on Saturn’s Moon Titan by the Cassini spacecraft. Image Credit: NASA/JPL-Caltech/ASI

Saturn’s moon Titan continues to amaze scientists and onlookers. Titan is the only planetary body, besides Earth, known to have a stable liquid environment on its surface. Unlike Earth, whose liquid is water, Titan’s liquid is a mixture of hydrocarbon molecules like ethane and methane.

Liquid was confirmed to exist on Titan since 2009, but scientists had identified several features thought to be seas or lakes much earlier. In 2007, Cassini discovered a vast sea, which is now named the Kraken Mare, near Titan’s north pole. The Kraken Mare is thought to be about the size of the Caspian Sea on Earth. Several other large seas and lakes cover the arctic region of Titan.

A Map of Titan's Seas
This is a map, produced from Cassini radar imaging data, of Titan’s features, including the Kraken Mare. Image Credit: NASA/JPL-Caltech/ASI

Cassini’s latest discovery flows into the Kraken Mare—an enormous river system stretching 400 km across Titan, emptying into the sea. Scientists looking over Cassini’s findings have compared its complexity to that of the Nile River on Earth.

A vast river system on Titan
This is a radar image of the newly discovered river on Saturn’s moon Titan. Image credit: NASA/JPL-Caltech/ASI

The river is thought to follow, for at least some of its path, a fault, a crack in Titan’s bedrock. Such faults are thought to be the cause of other, smaller rivers and perhaps the origin of the large seas as well.

Scientists justify their description of this formation as a river of liquid because radar images of its surface come back very dark, indicating an extremely smooth surface.

The full hydrologic cycle of Titan has not been completely studied yet, but its resemblance to Earth’s own cycle is stunning. Not only does the cold, distant moon have lakes and rivers, but it has active weather as well. Regions Cassini has examined on different passes sometimes look darker during a later pass. Scientists believe the change in albedo is due to rain having soaked the ground. Scientists have even detected entire lakes formed due to rainfall.

So, is rain the source of this extraterrestrial version of the Nile? No one yet knows, and there are many more questions to be answered about Titan.



  1. ” . . . there are many more questions to be answered about Titan” With the TiME mission to place a floating lander on an ethane/methane lake on Titan being relegated to the scrap heap of great ideas, such information about the newly discovered river system makes the TiME loss even more difficult to take. As stated by our new House SST committee chair Lamar Smith (R Tx.) “More importantly, NASA embodies the hopes and dreams of Americans for the new frontiers of space.” . . . Americans “have an innate sense that what NASA does is part of what makes our country great. At a fundamental level, NASA is in the inspiration business — a motivating example for young people to try what has never been done before. If we can go to the Moon, we can do almost anything” We CAN put TiME on Titan, but do we have the will?

  2. Here, here! With the new discoveries by Cassini, there is all the more reason to jump start TiME for missions to Titan AND Europa. The Cassini revelations are too imp;ortant to ignore and must be thoroughly examined. We have the technology. The possibility of life is in our backyard!

NASA Hosts Social Media Event at TDRS-K Launch in Florida

What Would a Mars Base Be Like?