Just because life on Earth requires water doesn't mean alien life does, too. That's the theory proffered by scientists at Cornell University, who say they've developed a theoretical framework for methane-based life forms that could exist on a super cold world like Titan, Saturn's largest moon.
In a paper published last week in the journal Science Advances, a team of chemists offer a theoretical proof for the possibility of methane-based, oxygen-free cells.
On Earth, cells are protected by a water-based lipid bilayer, a thin polar membrane surrounding the cellular goods. As such, life as we know it can't develop or exist in places where water can't exist in liquid form.
But researchers at Cornell suggest a membrane analogous to liposome could be derived from methane (one atom of carbon and four atoms of hydrogen). They designed a hypothetical membrane out of carbon, hydrogen and nitrogen, and called it "azotosome."
"We're not biologists, and we're not astronomers, but we had the right tools," study co-author Paulette Clancy, a chemical engineer, said in a press release. "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?'"
The theoretical azotosome is made up of stable chemicals that are readily available in Titan's seas. The scientists tested different combinations of the three chemicals to come up with the idea methane-derived compound for their hypothetical cell membrane.
They settled on acrylonitrile azotosome, which their chemical equations showed to be stable and strong yet flexible. On Earth, acrylonitrile -- a colorless liquid -- is used to make acrylic fibers, resins and thermoplastics. Acrylonitrile can be found in Titan's atmosphere.
Researchers say their next experiment will look to theorize how an azotosome-guarded cell might behave in a place like Titan.
Source: UPI