How carbon atoms combine is a vital clue to origin of life

How carbon atoms come together

The origin of carbon atoms came to be due to nuclear fusion in stars. When these stars die, the explosion of the supernovae disperses the carbon atoms into interstellar space. To make organic molecules, however, these carbon atoms need to come together and make chemical bonds between them.

Previous research suggests that this process happens on the ice grains in interstellar space that offer extremely low temperatures for the reaction to take place. Moreover, these ice grains are present in abundance in interstellar space and make it possible.

What the researchers had not known was how the reaction occurred, and through experiments in the lab, the Japanese researchers attempted to solve this puzzle. They found that at extremely low temperatures, carbon atoms diffused and reacted to form diatomic carbon (C₂) molecules.

Where is diatomic carbon formed?

The researchers found that diffusion occurred at temperatures of 30 Kelvin (minus 243 °C/minus 405.4 °F) in the laboratory, while in space, the same reaction could happen at just 22 Kelvin (minus 251 °C/minus 419.8 °F).

Masashi Tsuge, a chemist at Hokkaido University, states their findings have brought to the fore a chemical process that has previously been overlooked. Tsuge suggests that complex organic molecules could be formed by the steady addition of carbon atoms instead of creating a complete molecule at once.

Such addition of carbon atoms could likely take place in the protoplanetary disks around stars, which is also the place where planets are formed. Alternatively, these conditions could be the result of translucent clouds, which later evolved into a star-forming region. These are likely explanations of how the many chemicals occurred on Earth and perhaps seeded life.

Apart from answering the important question of how life originated, the study also sheds light on how a large number of molecules were plausibly made and even continue to be made throughout the universe.

Just like how these molecules possibly led to the origin of life, it is also possible that the continuous formation of new molecules might lead to a change in the future.

The research findings were published in the journal Nature Astronomy.