The mystery of the origin of hydrocarbons found in extraterrestrial environment may finally be resolved, thanks to a technique developed by researchers at Tokyo Tech based on a 13C-13C abundance analysis. By measuring the abundance of clumped 13C-13C isotope in the hydrocarbons, it can be inferred if a hydrocarbon was produced via biological processes. This could open doors to distinguishing such hydrocarbons from abiotic ones, aiding our search for extra-terrestrial life.
An important signature of life is the existence of organic molecules that have originated from biological processes. The most common organic molecule found in all life forms are hydrocarbons. However, they need not be of biotic origin, i.e., produced from thermal decomposition of sedimentary organic matter or microbes. So, while hydrocarbons have been found in several places outside Earth, they are not necessarily indicative of extra-terrestrial life. These hydrocarbons could well have formed from abiotic, or non-biological processes. Therefore, finding out whether a hydrocarbon is of biotic or abiotic origin is key to inferring the existence of life. Unfortunately, this has proved to be a tremendously challenging task so far.