The Cassini orbiter has sent back images of a massive hydrocarbon river on the surface of Titan, Saturn’s largest moon, which resembles the valley of the river Nile in Egypt, reports Space.com
. The Mars Curiosity rover recently found a dried up river bed on Mars
but the Titan find shows evidence of a much larger river system. It is the first time a river quite so vast has been found anywhere other than on Earth.
The Titan river system is located in the Saturn moon’s north polar region. The image shown above was taken in late September 2012 and shows where the ‘Nile’ river valley flows into the sea called Ligeia Mare.
NASA has deduced
that the river is filled with liquid hydrocarbons since the river appears with dark hue along its entire course in the high resolution image meaning it has a smooth surface.
Jani Radebaugh, a Cassini radar team associate at Brigham Young University, Provo, Utah, said,
“Though there are some short, local meanders, the relative straightness of the river valley suggests it follows the trace of at least one fault, similar to other large rivers running into the southern margin of this same Titan sea. Such faults - fractures in Titan's bedrock -- may not imply plate tectonics, like on Earth, but still lead to the opening of basins and perhaps to the formation of the giant seas themselves."
According to NASA, Titan is the only world (apart from our own) so far discovered known to have liquid in a stable state on its surface. The difference is that whereas on Earth, water is the basis of a hydrologic cycle, Titan goes through the same cycle with hydrocarbons like ethane and methane.
Titan’s meteorological cycle was highlighted by Steve Wall, radar deputy team lead, based at NASA's Jet Propulsion Laboratory,
"Titan is the only place we've found besides Earth that has a liquid in continuous movement on its surface. This picture gives us a snapshot of a world in motion. Rain falls, and rivers move that rain to lakes and seas, where evaporation starts the cycle all over again. On Earth, the liquid is water; on Titan, it's methane; but on both it affects most everything that happens."
The Cassini-Huygens mission
is an international project bringing together NASA, the European Space Agency and the Italian Space Agency. Altogether, sixteen nations co-operated in formulating and bringing to fruition the Cassini-Huygens mission. Cassini was launched in 1997 after nearly two decades of planning and has also previously sent back remarkable images of Jupiter. Cassini has studied Saturn and its moons since its arrival in 2004. In 2005 the Huygens probe landed on the surface of Titan and sent back the first pictures from the surface.
Cassini’s mission remains ongoing.