published on 17 April 2019 in space
Methane lakes found on Titan
Thanks to the data collected by the Cassini probe, a number of methane lakes have been discovered on Titan, Saturn’s largest satellite. The lakes are located in the northern hemisphere of the satellite and are surprisingly deep, perched on the top of hills and full of liquid methane. This is what has emerged from analysis of data collected by the Cassini probe during its last flyby around Titan, which took place in 2017.
This discovery, published in Nature Astronomy, is the first confirmation of how deep some of Titan’s lakes are (more than 100 metres) and of their composition. Additionally, the data collected by Cassini probe have made it possible for scientists to understand that the methane cycle on Titan works in a way very similar to Earth’s hydrogeological cycle: the methane evaporates, forms clouds and rain, flows and forms lakes on Titan, the only planetary body in the solar system, besides Earth, known to have a stable liquid on its surface. This may seem surprising, because we know methane as a gaseous substance, but on Titan it is so cold that methane behaves like a liquid. The sizes of the lakes studied – only a few dozen kilometres wide, but very deep – give us information on how they are formed: according to the scientists, the process whereby the lakes are formed on Titan is reminiscent of the formation of karstic lakes on Earth.