Scientists have demonstrated that micrometeorites, tiny particles of space dust continuously falling on Earth, could have acted as "micro-laboratories" for the formation of the first protocells. These findings suggest a new mechanism for the origin of life on Earth, where micrometeorites not only transported organic materials but also provided the necessary physicochemical conditions for their assembly into prebiotic structures. This study adds to the growing evidence that outer space may have played a crucial role in abiogenesis.

The research team simulated the conditions experienced by micrometeorites upon entering Earth's atmosphere and interacting with aquatic environments. They found that the porous structure and mineral composition of micrometeorites, combined with the wetting and drying cycles that occur in shallow pools, facilitate the concentration and assembly of simple organic molecules into lipid vesicles. These vesicles, considered protocells, are membranous structures that can encapsulate genetic and metabolic material, a fundamental step towards life.

Experiments showed that micrometeorites can catalyze the polymerization of monomers into more complex polymers, and that these reactions are favored by the presence of certain minerals and alternating dry and wet conditions. The ability of micrometeorites to concentrate molecules and protect them within their pores, along with their abundance on early Earth, makes them plausible candidates for sites of life's origin. This work opens new avenues for understanding how the basic components of life could have organized into the first biological structures on a young planet.