According to the proposed model, such conditions could arise in aquifers surrounded by basaltic rocks, which can be found today, for example, in Iceland and Hawaii. Simple organic molecules formed in the atmosphere from carbon dioxide and formaldehyde, after which they entered aquatic environments and, under the influence of borates, were transformed into ribose—a component of RNA. Then, phosphorus compounds linked ribose with nitrogenous bases, forming nucleotides, which are the building blocks of RNA.
The study also highlights the impact of asteroid impacts. Scientists suggest that collisions with bodies about 500 kilometers in diameter temporarily enriched the atmosphere with iron, creating reducing conditions necessary for the synthesis of nitrogenous bases. At the same time, the impacts were not powerful enough to destroy already existing organic substances, which, according to the authors, created ideal conditions for the emergence of life.
Furthermore, the researchers point to the possibility of similar conditions existing on ancient Mars during a period known as Noah's, around 4 billion years ago. Significant deposits of borates have been found on the surface of the Red Planet, and its atmosphere and aquatic environment may have been more favorable for the synthesis of organic molecules than on early Earth. However, it remains unclear whether these processes led to the emergence of life on Mars and whether it exists today.
The paper emphasizes that the proposed period for RNA synthesis predates the data from molecular clocks indicating the divergence of the three kingdoms of terrestrial life (about 4.2 billion years ago), as well as the appearance of isotopically "light" carbon in zircons aged 4.1 billion years, which may be evidence of ancient life on Earth. Scientists also acknowledge that one of the main problems remains unresolved: how homochirality—the uniform "mirror image" of all RNA molecules necessary for Darwinian evolution—arose.
Previously, the Perseverance rover discovered rocks in the Jezero crater that may indicate the presence of ancient microbial life. A study describing unusual mineral formations in the Martian Bright Angel formation was published in the journal Nature.
