From a biological perspective, life on Earth since our planet had been created could have not begun out of thin air. Something must have brought the necessary elements for the biological reaction that produces life. A new study claims that resources used for the production of life may have been brought to our planet by meteorites that are thousands of light-years from their original departure.
The theory of life being brought to Earth by meteorites or cosmic objects isn’t new, as it has been argued for decades by various scientists, but there wasn’t much evidence to show this. Now an article that has been published in Nature Communications and written by experts from different parts of the argues that life was brought to Earth through meteorites.
In order for DNA (Deoxyribonucleic Acid) and RNA (Ribonucleic Acid) to be produced, two types of chemical building blocks or nucleobases are required. These are known as Pyrimidine nucleobases. The experiment was led by Yasuhiro Oba from Hokkaido University. The team of experts used state-of-the-art analytical techniques to identify these building blocks inside carbon-rich meteorites.
For this specific experiment, the research team has chosen to analyze three meteorites that are some of the richest in carbon on Earth. The first was the Murchison meteorite which crashed in Australia in 1969. The second was the Murray meteorite which crashed in Kentucky in 1950. Last but not least was the Tagish Lake meteorite which crashed in British Columbia in 2000.
The authors of the study mentioned that they identifies various pyrimidine nucleobases, such as cytosine and thymine for the first time. The compounds found in the study are similar to those predicted by experiments that looked at the existing compounds before the formation of the solar system. Despite how high-end the technology used in this study is, the researchers are not able to identify the original location of these compounds used to create DNA.
Compounds such as Cytosine, Guanine, Adenine, Uracil, and Thymine are all the building blocks of DNA, similar to a castle made out of lego bricks. Understanding the origin of these compounds or how they are formed will help humanity unlock more knowledge of how DNA defines our lives as humans and as organisms in this world.
Taking into account how important these compounds are for all types of biological organisms, the team says that these compounds are probably scattered all over space: “suggesting that these classes of organic compounds are ubiquitously present in extraterrestrial environments both inside and outside the Solar System” (Quote by Yasuhiro Oba)
Based on the knowledge of the research team and the existing literature, they suggest that these compounds that are needed to create life may have been generated by photochemical reactions in the interstellar media. Billion years ago when solar systems started forming, these compounds had been incorporated naturally into cosmic objects such as meteorites and asteroids.
Further analysis using the same technique on other cosmic objects that have landed on Earth will be done by the research team to reinforce their findings as well as their theory about life being formed outside of Earth.