NASA‘s Cassini Orbiter successfully concluded its mission by reaching Saturn‘s atmosphere on September 15th of 2017. Throughout the 13 years it spent analyzing the Saturn system, it unveiled a lot of information about the gas planet and its largest moon, Titan.
In the coming years, researchers are eager to send another spacecraft to Titan to further investigate the gas giant and get a better look at its surface features, methane lakes, and other interesting characteristics. These include the morphological features in the northern polar region that are incredibly similar to volcanic features on Earth.
Similarities to Earth’s Structures
As per a recent study conducted by the Planetary Science Institute (PSI), these properties could be evidence of cryovolcanism that continues to this day. These discoveries are the latest proof that Titan has an interior ocean and internal heating systems, which could mean the planet hosts life in its interior.
Their study, titled ‘Morphologic Evidence for Volcanic Craters near Titan’s North Polar Region,’ has recently been published in the Journal of Geophysical Research: Planets. It was conducted by Charles A. Wood, a data scientist with the PSI in Tucson, Arizona, and Jani Radebaugh, a Professor of planetary science at Brigham Young University who was also a member of the Cassini radar science team.
As they note in their research, the volcano-like features in Titan’s northern polar area are not like others discovered on the moon’s surface, such as dunes, rivers, or lakes, all of which are probably the outcome of atmospheric processes.
Moreover, the presence of morphological characteristics, such as collapse craters and small depressions, is further evidence of cryovolcanic activity. The closeness of these features to the moon’s famous northern lakes of methane is also rather telling.
Wood explained in the study: “The close association of the proposed volcanic craters with polar lakes is consistent with a volcanic origin through explosive eruptions followed by collapse, as either maars or calderas. The apparent freshness of some craters may mean that volcanism has been relatively recently active on Titan or even continues today.”
The team has also found some reasons for why these structures are found in the northern polar region, with some related depressions in the southern polar region. Basically, they theorize that it could be linked to how the ice crust around the low-elevation poles are warmer and thinner than in other regions.
Other signs that these characteristics are cryovolcanic at the base include the fact that they are nearly round, have raised edges, and sometimes overlap one another. This is what geologists and volcanologists have observed on Earth, on the Moon, and Mars. In all three cases, volcanic terrains are correlated to geological activity and were formed by explosions, excavations, and collapses.
As mentioned earlier, this is also evidence for an internal heating mechanism, similar to what has been found on Europa and Enceladus. In both cases, tidal stresses produced by engagement with their host planet – Jupiter and Saturn – causes heat to accumulate inside the moon’s cores.
This heat gets out to the surface as plumes of water that break through the icy crust, similar to the way lava breaks through the Earth’s crust. These features, finally, lend further weight to the concept that the interior of Titan could host life.
As Wood added: “That these features are at the polar regions, near the lakes of methane, may indicate methane, nitrogen or some other volatile may power them. The features appear relatively fresh, meaning they could still be forming today.”