The search for alien life has mainly been limited to planets that are in the “habitable zone” where oxygen-based lifeforms could develop — but what if life didn’t need oxygen?
In a new study, a team of scientists have proposed that methane-based lifeforms could have developed without oxygen, and they may exist on the surface of Titan, the largest moon of Saturn, which is covered in vast oceans of methane at very low temperatures that would be inhospitable to oxygen-based life, according to a Telegraph report.
Chemical engineers and astronomers from Cornell University teamed up to calculate how a form of life could thrive in the frigid world of Titan, and they came up with a model that suggests it is entirely possible the stable cells could develop based entirely on organic nitrogen compounds that could thrive in liquid methane, even in temperatures 292 degrees below zero.
Chemical molecular dynamics expert Professor Paulette Clancy and a graduate student in chemical engineering, James Stevenson, led the project. She said the fact that they weren’t biologists or astronomers meant they were able to approach it without preconceived notions of what life should look like, according to the report. They were assisted by Jonathan Lunine, a Cornell astronomer.
Life on earth are based on water-based membranes, which house the organic matter of cells necessary for life. Because of this, astronomers look for planets in habitable zones where liquid water can exist, but if life could exists in environments with liquid methane — which has a much lower freezing point — it would greatly increase the number of candidates for life-hosting planets.
The theorized membrane was named “azotosome” by the Cornell team, based on the French word for nitrogen, “azote.” The azotosome is based on nitrogen as well as carbon and hydrogen molecules, which can be found in Titan’s seas.
They found a compound called acrylonitrile azotosome, which showed promising stability and a resistance to decomposition that would have a flexibility similar to the water-based membranes here on Earth.
The next step for the team is to try to demonstrate how the cells would reproduce and behave in their environment.