Prebiotic chemistry in planetary environments

Abstract

The formation of reactive organic compounds, such as HCN or HCHO, followed by their evolution in solution is one of the earliest steps in chemical evolution which might have led to the emergence of life on the Earth. Such organics are key ingredients of the prebiotic chemistry, since, in the presence of liquid water, they can give rise to the building blocks of living systems. Similar processes are going on in present planetary environments, especially on Titan, but in the absence of liquid water. With a dense reduced atmosphere mainly composed of N₂ and CH₄, rich in organic compounds in the gas and aerosol phases, and with the likely presence of an ocean of liquid methane and ethane, this moon appears as a natural laboratory for studying prebiotic organic chemistry at a planetary scale.