How did the amino acids that make up the building blocks that generated life arrive? They could have formed in meteorites. And formed from internal reactions driven by gamma rays. Yes, life could have arrived in meteorites. Researchers at Yokohama National University in Japan say so.
Details are in the journal ‘ACS Central Science’. There is no agreement on how life began here on Earth. One of the hypotheses precisely is that meteorites brought amino acids to our planet. These are the building blocks of life.
Amino acids, the key
Since Earth was a newly formed barren planet, meteorites passed through its atmosphere. These early space debris could include carbonaceous chondrites. A class of meteorite whose members contain significant amounts of water and small molecules. For example, amino acids.
The origin of amino acids in meteorites has been difficult to pin down. Laboratory experiments were done. They showed that reactions between simple molecules, such as ammonia and formaldehyde, can synthesize amino acids and other macromolecules. But liquid water and heat are needed.
Radioactive elements, such as aluminum-26 release gamma rays, a form of high-energy radiation. It happens when they disintegrate. This process could have provided the heat needed to make biomolecules. Could radiation have contributed to the formation of amino acids in early meteorites?
Meteorites and life
The researchers dissolved formaldehyde and ammonia in water. They then sealed the solution in glass tubes. They then irradiated the tubes with high-energy gamma rays. They were produced from the decay of cobalt-60. It was observed that the production of alpha-amino acids increased in the irradiated solutions. It happened as the total dose of gamma rays increased.
Finally these results were measured. It was possible to confirm the gamma-ray dose expected from disintegration in meteorites. It would take between 1,000 and 100,000 years to produce the amount of alanine and beta-alanine found in the Murchison meteorite, which fell in Australia in 1969. This study provides evidence, there is no doubt. Gamma-ray catalyzed reactions can produce amino acids. So, yes, life could have arrived in meteorites.