While the possibility of alien life is still mostly speculative, a group of scientists working at Cornell University put together a scientifically sound idea of what alien life might actually look like. Far from little green men, or even the glowing octopus creatures of “Europa Report,” the alien being imagined by the team is a methane-based organism and lives in an oxygen free environment, but still metabolizes and reproduces like cell-life on Earth.
EurekAlert reported on Feb. 27, that the researchers behind the study decided that instead of hunting down alien life by looking for potential watery habitats, they would see if a different sort of environment could support life similar to that on Earth. The research team looked specifically at Titan, a moon of Jupiter, which is known to have large seas of liquid methane. The team, which consisted of an unusual grouping of both astronomers and chemical engineers, came of up with a theoretical cell membrane that is composed of small organic nitrogen compounds and could survive in a liquid methane environment with temperatures as low as 292 degrees below zero.
Jonathan Lunine, the paper’s co-author and the director for Cornell’s Center for Radiophysics and Space Research, is an expert on Saturn’s moons and took part in the mission that discovered methane-ethane seas on Titan. Hoping to probe the possibility of life existing in these methane oceans, Lunine enlisted the help of Paulette Clancy, chemical molecular dynamics expert and James Stevenson, a graduate student in chemical engineering.
“We’re not biologists, and we’re not astronomers, but we had the right tools,” said Clancy. But Clancy believes that her unfamiliarity with astronomy and biology might have been a boon for the team. “Perhaps it helped, because we didn’t come in with any preconceptions about what should be in a membrane and what shouldn’t. We just worked with the compounds that we knew were there and asked, ‘If this was your palette, what can you make out of that?’”
Most astronomers on the hunt for alien life focus their search on what is called the circumstellar habitable zone, which is the narrow band around a star in which an orbiting planet can have water that isn’t completely evaporated or frozen. Life, as we know it, is dependent upon water to develop what is called a phospholipid bilayer membrane, which is a strong but permeable membrane that houses the organic matter of a cell. When a vesicle is made from this kind of membrane it is called a liposome.
Instead of looking for life within the circumstellar habitable zone, the researchers at Cornell decided to draw inspiration for Isaac Asimov 1962 essay “Not as We Know It” (a quote often misattributed to the show ‘Star Trek’) and search for non-water based life. The researchers theorized a cell membrane composed of nitrogen, which they called an “azotesome,” “azote” being French for nitrogen.
The theoretical azotesome is composed only of molecules known to exist on Titan, such as nitrogen, carbon and hydrogen molecules. Remarkably, the nitrogen membrane showed resilience and stability that matched Earth’s equivalent liposome. With a very solid first step already taken, Clancy is hoping to show how this cell might function in a methane environment.
It might not be too long before we know for sure if there is life on Titan, as NASA is already looking into the possibility of sending an autonomous submarine to plumb the moons depths.
If the NASA mission is a go, then the Cornell study, which was published by “Science Advances” on Feb. 27, might prove invaluable as we would know what sort of life we should be looking for.