Scientists seem more firmly convinced alien life exists on Titan, Saturn's icy giant moon encrusted with methane ice and smothered by a methane atmosphere.
They feel this new life form will be, of course, methane-based considering the environment on Titan. They also believe these methane-based life forms can metabolize and reproduce just like carbon-based life on Earth.
Chemical engineers and astronomers from Cornell University developed a model that shows methane life can indeed thrive in alien worlds such Titan that's covered in vast seas of liquid methane. It's these methane seas that will be the birthplace of methane-based, oxygen-free living cells.
The team believes a unique cell membrane consisting of organic nitrogen compounds can thrive in liquid methane ocean whose temperatures plummet to 292 degrees below zero Fahrenheit.
They said that on Titan, oxygen won't be needed for metabolic processes in methane-based life forms. Nitrogen compounds will fulfill those needs within cells, said a story in Tech Times.
These nitrogen compounds, however, would need a special membrane to hold together organic material. On Earth, these membranes are called the phospholipid bilayer membranes. On Titan, the Cornell team gave this membrane the name, "azotosome".
The word "azotosome," comes from "azote", the French word for nitrogen, and "liposome", a familiar word that comes from the Greek "lipos" and "soma" to mean "lipid body." By analogy, azotosome means "nitrogen body", said the researchers in a story published by the Cornell Chronicle.
The azotosome is made from nitrogen, carbon and hydrogen molecules known to exist in the cryogenic seas of Titan, but which shows the same stability and flexibility that Earth's analogous liposome does. thought about the mechanics of cell stability before; they usually study semiconductors, not cells.
The engineers employed a molecular dynamics method that screened for candidate compounds from methane for self-assembly into membrane-like structures. The most promising compound they found is an acrylonitrile azotosome that showed good stability, a strong barrier to decomposition and a flexibility similar to that of phospholipid membranes on Earth.
Acrylonitrile - a colorless, poisonous, liquid organic compound used in the manufacture of acrylic fibers, resins and thermoplastics - is present in Titan's atmosphere.
The next step is to demonstrate how azotosomes behave in a methane environment and how they can produce methane-based cells capable of reproduction and metabolism like the ones here on Earth.
The research was led by chemical molecular dynamics expert Paulette Clancy, the Samuel W. and Diane M. Bodman Professor of Chemical and Biomolecular Engineering' with first author James Stevenson, a graduate student in chemical engineering. The paper's co-author is Jonathan Lunine, the David C. Duncan Professor in the Physical Sciences in the College of Arts and Sciences' Department of Astronomy.