In the search for life beyond Earth, scientists have justifiably focused on water because all biology as we know it requires this fluid. A wild card, however, is whether alternative liquids can also suffice as life-enablers. For example, Saturn's frigid moon Titan is awash in inky seas of the hydrocarbon methane. Here on warm, watery Earth, the molecules DNA and RNA serve as the blueprints of life, containing creatures' genetic instruction manuals. An immense family of proteins carries out these instructions. Yet in a hydrocarbon medium on Titan, these molecules could never perform their profound chemical duties. Other molecules must therefore step up to the plate if non-water-based alien life is to operate and evolve in a Darwinian sense, with genetic changes leading to diversity and complexity. A new study proposes that molecules called ethers, not used in any genetic molecules on Earth, could fulfill the role of DNA and RNA on worlds with hydrocarbon oceans. These worlds must be a good deal toastier though than Titan, the study found, for plausibly life-like chemistry to take place.
Kemo D. 7