Scientists have found a sea full of liquid methane on Saturn’s moon, Titan, thanks to data collected from the Cassini Radar.

Titan is one of the few explored moons in the solar system that has similarities to Earth since it possesses a dense atmosphere and liquid reservoirs just like planet Earth. That’s why scientists have become so interested in the Saturn’s moon.

Data obtained by the Cassini Radar has shown a sea called Ligeia Mare, full of liquid methane instead of ethane like investigators had previously thought.

A sea full of liquid gas

Titan is one of Saturn’s largest moons and it is known as the only natural satellite that has a dense atmosphere as well as the Earth that shows surface liquids. The satellite is composed of water ice and rocky surfaces and it wasn’t until 2004 when the Cassini radar arrived on the planet and discovered hydrocarbon lakes on the polar section of Saturn’s moon.

Just like Earth, Titan’s atmosphere is primarily nitrogen (95 percent) but the natural satellite has low oxygen levels so the main gases are methane, ethane and other gases.

According to findings by the Cassini radar, Titan’s low temperatures (-292 degrees Fahrenheit/ -179.6 degrees Celsius) allow the satellite to transform gases like methane and ethane to a liquid form. Titan has over three large seas at its north pole area and smaller lakes are also found. In 2014, the Cassini radar showed investigators that Ligeia Mare- the large lake on the satellite- had methane on its composition.

A group of investigators led by Alice Le Gall from the University of Paris, have confirmed the methane-rich lake on Titan. The team published their findings in the Journal of Geophysical Research.

The team used data from a flyby of the Cassini Radar between 2007 and 2015 to have a better understanding of the composition of the Ligeia Mare lake.

“We expected to find that Ligeia Mare would be made up of ethane, which is produced in abundance in the atmosphere when sunlight breaks methane molecules apart. Instead the sea is made of pure methane,” said lead author Alice Le Gall from the French research laboratory.

Astonished by the findings, researchers are puzzling about the causes of the lake’s composition. Le Gall suspects that it could be methane rainfall or another composition is limiting the ethane on the surface.

Yet, further investigation on the matter needs to be made to understand the composition of Ligeia Mare in Titan.

The Cassini Radar

The Cassini is a collaborative mission between NASA, the European Space Agency and the Italian Space Agency.

It’s a spacecraft sent to Saturn to understand better its components, and it is the first spacecraft that was able to enter its orbit.

The spacecraft arrived on 2004 and since then it has been investigating the planet and its natural satellites.

Source: AGU Publications