Titan: The Alien life we have been searching for might be here on our Solar System itself
We have always been searching for life beyond the confines of Earth. After all, given how vast our universe is, it is highly unlikely that Earth is the only planet that has had the gift of life.
The way we look for life is based on a planet’s ability to sustain water in its liquid form. For a planet to have liquid water, it has to be in the goldilocks zone of its star system just like how Earth is to our Sun.
This is so because life on our planet has been the result of the presence of liquid water. From the formation of the first molecules to the multicellular organism water played the pivotal role of being the medium for life to thrive and evolve. But what if we were to reframe the assumption that water is essential for life.
This is a serious and active area of scientific study among Astrobiologists (people who study potential alien biology). If we were to look past water, maybe the first alien life that we may discover will not be from a planet but a moon – Saturn’s Titan.
Titan is Saturn’s largest moon and it also adorns the title of being the second-largest moon in our entire Solar System. Titan, which is larger than Mercury, is famous for its golden hazy atmosphere. This haze is due to the thick hydrocarbon smog that is present in its Nitrogenous atmosphere.
Like Earth Titan too has rivers and lakes. Its icy surface has liquid methane instead of water. Some scientists speculate that life, at least in theory, could develop in liquid methane, taking a completely different trajectory from what we see on Earth. This is so because like in Earth, Titan’s unique condition makes it possible to have a Methane Cycle (like our water cycle).
These hypothetical organisms called Methogens might be consuming hydrogen, acetylene, and ethane to exhale methane. But this idea does come with other challenges. For example, single-celled organisms on Earth are held together by Lipids which act as regulators for water to flow in and out without losing the cell structure. Lipids cannot exist in a methane-rich environment.
Another study shows that under conditions similar to that of Titan the function of lipids could be replaced by a compound called acrylonitrile. Under specific conditions, life could develop based on this compound, forming a completely different cell shape. For this to work, acrylonitrile membranes should form spontaneously in liquid methane, similar to how lipids behave in water.
But with the kind of low temperatures that exist in Titan, methanogenic cells might end up being hard and crystalline with lower levels of mobility. In other words a sluggish existence. But this serves as a starting point for future missions as we know what might be the things we should look for when studying methane-rich environments like Titan.
Nevertheless without collecting more details about Titan’s surface and its atmosphere we cannot test out any of these wild theories. Unfortunately, it will take until 2035, for Nasa’s Titan mission to land there and give us some analysis data. It is not just the search for alien life that makes Titan interesting for scientists, as it also serves as an ideal place for studying the organic chemistry we had before life existed on Earth. There is also the possibility of finding amino acids – the building of life, whether or not they folded to create a lifeform there. We will have to wait more than a decade to have some answers to all these interesting questions and possibilities.