According to a study published in Scientific Reports, researchers suggest that iron-rich particles from meteors or volcanic eruptions on Earth about 4.4 billion years ago could have played a role in generating the precursors necessary for the origin of life.
Previous studies have proposed that the building blocks of organic molecules, such as hydrocarbons, aldehydes, and alcohols, might have been brought by asteroids and comets or formed through reactions in the early Earth’s atmosphere and oceans. These reactions could have been facilitated by lightning, volcanic activity, or impacts. However, due to limited data, the exact mechanism responsible for producing these precursors has remained unclear.
In this new research, led by Oliver Trapp and his colleagues, they investigated the potential of meteorite or ash particles deposited on volcanic islands to promote the conversion of atmospheric carbon dioxide into organic molecule precursors on the early Earth. To simulate the conditions that might have existed back then, they conducted experiments using a heated and pressurized system called an autoclave. They varied the pressure (ranging from nine to 45 bars) and temperature (ranging from 150 to 300 degrees Celsius) to represent different climate conditions. Additionally, they introduced either hydrogen gas or water to simulate wet and dry climates. To mimic the deposition of particles on volcanic islands, they added crushed samples of iron meteorites, stony meteorites, volcanic ash, and various minerals present in the early Earth’s crust, meteorites, or asteroids.
The findings revealed that the iron-rich particles from meteorites and volcanic ash facilitated the conversion of carbon dioxide into hydrocarbons, aldehydes, and alcohols under different atmospheric and climate conditions that might have existed on the early Earth. Interestingly, aldehydes and alcohols formed at lower temperatures, while hydrocarbons formed at higher temperatures around 300 degrees Celsius. As the early Earth’s atmosphere gradually cooled, the production of aldehydes and alcohols might have increased. These compounds could have then participated in subsequent reactions, potentially leading to the formation of essential building blocks like carbohydrates, lipids, sugars, amino acids, DNA, and RNA. Based on reaction rates and data from previous research on the early Earth’s conditions, the authors estimate that this proposed mechanism could have synthesized up to 600,000 tonnes of organic precursors annually across the early Earth.
The authors propose that their mechanism, combined with other reactions occurring in the early Earth’s atmosphere and oceans, might have contributed to the origins of life on our planet.
