Under the landscapes of mountains, rivers, and oceans that closely resemble Earth, Titan possesses a unique structure capable of maintaining warmth for oceanic life.
Scientists have recently discovered that the icy crust of Titan—the largest moon of Saturn—consists of a methane-rich insulating ice layer that is up to 9.7 kilometers thick. This increases the potential for extraterrestrial life.
Titan is famous for its landscape, which NASA has described as resembling a second Earth.
Titan, Saturn’s moon, may harbor life beneath its subsurface ocean – (Photo: NASA; Graphic: Robert Lea).
It is Saturn’s largest moon, with a size approximately 40% that of Earth, yet its surface landscape is remarkably similar, featuring mountains, river systems, lakes, and oceans…
The only notable difference on the surface is that “the ‘water’ within Titan’s river systems and oceans is liquid methane and other hydrocarbons like ethane.”
Nevertheless, NASA and various space agencies, along with other scientists, continue to believe that Titan has the potential for life.
This life is not on the surface but exists within a subsurface ocean beneath that Earth-like landscape.
Now, research from a group of planetary scientists at the University of Hawaii in Mānoa (USA) indicates that the barrier between that landscape and the subsurface ocean is a very thick ice shell, which includes the insulating methane ice layer mentioned earlier.
However, this is also the only potential solution regarding the existence of life on Titan.
Located far from the Sun, Titan is extremely cold. Yet, if there is a methane-rich insulating ice layer, the ocean beneath would be significantly warmed, not to mention the heat from hydrothermal systems similar to those on Earth at the bottom of this subsurface ocean.
And even though it makes direct access to the subsurface ocean more challenging for human spacecraft, this insulating layer facilitates our ability to find evidence of life right on the surface.
“If life exists in Titan’s ocean beneath the thick ice layer, any signs of life, biological signatures, would need to be transported up to Titan’s surface where we can easily access them,” said lead researcher Lauren Schurmeier.
Dr. Lauren also mentioned that if the ice shell surrounding the ocean is warm and interconnected, this transportation would likely occur easily.
The ice shell retains a significant amount of methane gas, which is precisely what they are hoping for.
The scientists identified this structure by observing the presence of shallow impact craters on Titan.
Impact craters on Titan suggest the presence of a methane-rich ice layer – (Photo: NASA).
Impact models indicate that these craters should be deeper and more numerous. Clearly, something special about this moon makes them shallower and disappear relatively quickly.
After testing various models, they concluded that the aforementioned craters could only form when Titan’s ice shell is made of methane clathrate, or “methane hydrate.”
This is a solid compound in which a large amount of methane is trapped within the crystalline structure of water, forming a solid similar to ice on Earth.
