The origin of life is indeed one of the biggest mysteries of science, and it’s been the subject of intense research and speculation for many centuries. The abiotic synthesis of amino acids is widely believed to have been one of the critical steps in the formation of life, as these compounds serve as the building blocks for proteins, which are essential components of living cells.

There are several theories about how life might have originated on Earth, but the most widely accepted one is the so-called “RNA world” hypothesis. According to this theory, RNA (ribonucleic acid) was one of the first biological molecules to emerge, and it had the dual ability to store genetic information and catalyse chemical reactions. Over time, RNA molecules gave rise to more complex systems, including cells and eventually, the first living organisms.

In any case, the exact mechanisms and circumstances surrounding the origin of life are still unknown, and much work remains to be done to fully understand how life emerged from the non-living world. But the study of the origin of life is a fascinating and important area of research, as it holds the key to understanding the fundamental nature of life itself.

“Two scenarios are being discussed for the emergence of life on Earth: On the one hand, the first-time creation of such amino acid chains on Earth, and on the other hand, the influx from space,” explained Tilmann Märk of the University of Innsbruck. “For the latter, such amino acid chains would have to be generated in the very unfavourable and inhospitable conditions in space.”

A team of researchers led by Michel Farizon of the University of Lyon and Tilmann Märk of the University of Innsbruck has now made a significant discovery in the field of abiotic peptide chain formation from amino acids for the smallest occurring amino acid, glycine, a molecule that has been observed several times extraterrestrially in recent years.

A study published in the Journal of Physical Chemistry A, which also made the cover of the journal, shows that small clusters of glycine molecules exhibit polymerisation upon energy input. A reaction occurs within a cluster consisting of two glycine molecules. The two amino acids become a dipeptide and a water molecule. The reaction of a dipeptide to a tripeptide within a cluster was also demonstrated by the researchers.

“Our study sheds light on the less likely unimolecular scenario for the formation of such amino acid chains in the extreme conditions of space,” said Michel Farizon. “We were able to show that peptide chain growth occurs through unimolecular reactions in excited cluster ions, without the need for contact with an additional partner such as dust or ice.”

The current work provides evidence that the first step toward the origin of life can occur in the highly unlikely conditions of space. “The study is an important milestone on the route to understanding the origins of life. The results will serve as a basis for further research in this field,” Michel Farizon and Tilmann Märk are convinced.