Earth
A study suggests that the chemicals required for the creation of life on Earth roughly 4.4 billion years ago may have been produced by meteorites or volcanic eruptions on Earth.
Earlier studies have hypothesised that hydrocarbons, aldehydes, and alcohols, which are the building blocks of organic compounds, may have been carried by asteroids and comets or created by processes in the early Earth’s atmosphere and oceans.
These reactions may have been sped up by impact, volcanic activity, or lightning energy. It is unclear, however, what the main mechanism was that generated these precursors due to a lack of evidence.
The latest study, which was published in the journal Scientific Reports, examined whether meteorite or ash particles that were left behind on volcanic islands may have aided in the early Earth’s conversion of atmospheric carbon dioxide into the building blocks of organic molecules.
By adding carbon dioxide gas to a heated and pressurised apparatus (an autoclave) and varying the pressure and temperature, the researchers were able to mimic a variety of circumstances that prior research has revealed may have existed on the early Earth.
They also created dry and wet climate conditions by varying the system’s addition of water or hydrogen gas.
The team mimicked the depositing of meteorite or ash particles on volcanic islands by adding different combinations of crushed samples of iron meteorites, stony meteorites, or volcanic ash into the system, as well as minerals that may have been present in the early Earth and are found in either the planet’s crust, meteorites, or asteroids.
The scientists discovered that under a variety of atmospheric and climatic circumstances that may have existed in the early Earth, the iron-rich particles from meteorites and volcanic ash encouraged the conversion of carbon dioxide into hydrocarbons, aldehydes, and alcohols.
They noticed that whereas hydrocarbons formed at 300 degrees Celsius, aldehydes and alcohols developed at lower temperatures.
The researchers hypothesise that the generation of alcohols and aldehydes may have increased as the early Earth’s atmosphere cooled over time.
These compounds may then have participated in further reactions that could have led to the formation of carbohydrates, lipids, sugars, amino acids, DNA, and RNA, according to the researchers.
By calculating the rate of the reactions they observed and using data from previous research on the conditions of the early Earth, the researchers estimate that their proposed mechanism could have synthesised up to 600,000 tonnes of organic precursors per year across the early Earth.
